• Frequently Asked Questions

      March 13, 2019


      Consumer Product Safety Bulletin

      (technical clarification, following ENVE’s Consumer Safety Bulletin of March 6th, 2019)



      This bulletin is to reconfirm that Challenge Tires should not be used with any rims or wheels that do not comply with either the current 2019 ETRTO, past ETRTO or soon to be released ISO 5775 global standards for tire and wheel fit.


      Challenge specifically clarifies herewith, that both old and new ETRTO and future ISO standards require a minimum 0.7mm rounded radius on all hooked rims.


      It has come to Challenge’s attention that ENVE SES model carbon wheels do not comply with the above standards on the design of the rounded hooked rim radius. In fact, ENVE’s SES have two sharp (<0.2mm) radii in their hooks, that leave two parallel cuts about 0.5mm apart, around the entire radius of our (and other company’s) tires, at around 3-4mm above the bead.


      Challenge has noted failures of its clincher tires, communicated by consumers and athletes, caused by the sharp edges on the ENVE SES hooks. This international design standard violation has been communicated back to the affected consumers, shops, endorsed teams, ENVE and their parent company, as Challenge has been made aware of problems. ENVE, however, continues to produce and promote usage of the said SES models, as part of their line.


      Challenge has consequently been forced to list the specific ENVE SES rims as not compatible with any Challenge clincher tire models, on the website. Challenge asks that consumers do not mount ENVE SES wheels with any model of Challenge clincher tire whatsoever.


      Failure to follow this warning could cause the ENVE SES wheel to cut Challenge’s quality casings resulting in explosive air loss from the tire and/or inner tube, potentially causing a crash and injury to the rider.


      This bulletin also aims at providing the technical clarification, that only a precisely defined 622.0mm+-0.5mm bead seat diameter, specifically defined wall height and center channel, as described in the new above standards, will safely and easily allow proper tire and rim fit and function. Challenge has regularly been attending standards meetings and being involved for the past three years in confronting the market’s accelerated changes, such as the implementation of progressively wider rims, carbon fiber clinchers rims and tubeless and tubeless ready tire technologies. Challenge has invested time, knowledge and energy together with other elite bicycle industry companies to address and update tire & wheel fit issues with the ETRTO and ISO.




      Challenge handmade tires have been produced for close to 20 years using the same handmade processes that have been proven over the past 50 years at the highest levels of racing without significant failures - if the rims and wheels comply with internationally accepted design standards. And this applies for both aluminum and carbon fiber rims.


      Regarding carbon fiber rims, there had also been other periodic problems in the past with some carbon rims that had cut our (and other tire manufacturers’) tire casings just above the beads. These tire cuts were however normally caused by less than optimal QC at the factory, resulting in quality issues of improper finishing at the tire hook during production. Normally roughness at the hook was due to failure to completely remove resin flashings created while molding the rim. Proper finishing leaves the required 0.7mm min. radiused rim hook smooth, without roughness, thus eliminating a potential tire failure.


      In the above cases, Challenge has routinely and successfully worked with the wheel suppliers (including ENVE) to fix the problems or replace these wheels to the consumer. However, specifically with ENVE’s SES model wheels, it is the first time that Challenge has known of a rim hook design that does not meet the above recognized design criteria, reason for which Challenge feels compelled to follow up with the release of this informative bulletin to protect its customers.


      For further questions please contact local distributors or Challenge at info@challengetech.it.


      First of all, make sure your tire is paired with an appropriately-sized rim. Our tires follow ETRTO standards for rim compatibility (see chart below):




      The first installation may still be quite tight, even with the correct rim, but the tire will stretch once you begin riding and subsequent installations will be easier. The best way to mount an Open Tubular tire is:

      1. Center  the rim inside the flat carcass (or casing) of the Open Tubular tire



       2. Pull the tire around the rim so that the tire lies flat over the whole rim and a bead hangs over each side



      3. Install one side of the tire, beginning opposite the valve hole



      4. Install the tube. Note: If you plan on using latex tubes, ride the new OT tire with a butyl tube for a short while until the Open Tubular tire stretches to shape in order to avoid pinching the latex tube

      5. Install also the second side of the tire, beginning opposite the valve hole.

      6. Push the casing in all along both sides of the tire to make sure that the tube isn't pinched under the bead anywhere!

      7. Deflate and inflate again, checking again that the tube isn't pinched! If the tube should be folded anywhere it will get back to round with a second inflation.






      A mounting aid tool used for any standard or tubeless clincher.

      Stronger levarage can be applied than with a standard plastic tire lever without risking it to break.

      Standard tire levers are more brittle, risk not doing the job, you still somewhat hurt your fingers and can risk pinching the tube if not carefull, none of which will happen with this tool!

      It is s a lightweight but strong, heavy duty nylon tool that helps to pull a tight tire bead over and seat it into the other edge of the rim.

      It works by pushing against the rim wall on one side used as a fulcrum, while the other side will lift and pull the bead up and over the opposite edge of the rim.

      Great for many consumers and shops to have around as an aid for more difficult tire mounts.  


      Yes, you need to be careful of how you pair tires and rims! As wider rims gain popularity, the industry is forgetting the compatibility standards and education is lacking about pairing rims and tires. We suggest following ETRTO guidelines:



      Challenge tires are handmade, providing incomparable performance. They are very special  but can be somewhat delicate at the same time.


      Warranty procedure:

      If you think your tire has a defect that would fall under a warranty replacement, please follow these steps for approval.

      If your tire was purchased in a shop, bring in (or send) a photo of the problem and the tire itself back to the shop with a proof of purchase. All returns should be sent postage prepaid.

      Explain if brand new and unused or how long you have had the tire for, the approximate number of miles you have ridden and the conditions in which you have been riding on the tire.

      The shop will send all information back to the Challenge distributor, who will recognize if it is an accepted  warranty  case or not. As soon as the distributor acknowledges it as a warranty case, the shop may proceed to grant you a replacement tire, for which they will in turn receive replacement.

      In rare cases, you may also be asked to look for a production run number on the product. The open tubular clincher has a manufacturing number (or date) stamped on the inside of the product. A tubular will have to be cut open to read this number inside. But this is only when unexplainable situations occur, that require further investigation by the factory.

      If you purchased the tire from an online retailer, mail order, Amazon, E-Bay or other please forward them all the above information and photo. They should be able to process it the same way. However, if they can’t or will not handle the case, that will unfortunately be a risk you are taking when ordering cheaply online or from an unreliable source.

      In most cases factory defect tires are replaced immediately, but it may take a few days determining whether it is a factory defect or the person mishandling the tire.


      Factory warranted defects:

      Challenge is one of very few factories mastering an artisan handmade manufacturing process. Because we consider of primary importance maintaining the rubber’s natural properties intact, we produce via this handmade process, rather than an industrial one, so avoiding extreme high heat treatments.

      The majority of other tires are industrially produced using a prolonged high heat treatment called vulcanization which bonds the materials together. While on the one hand vulcanization produces a sturdy tire, on the other hand the consequence of this process dries and hardens the rubber, eliminating most of the rubber’s natural properties. It reduces the rubber’s grip, its shock-absorption, its ride quality and safety while cornering, all of which are of particular importance for a high performance tire.

      Making handmade tires is a difficult process and we pay constant attention to each step and detail along the way. Nevertheless, rare situations may occur that are imperceptible during production and that may also pass the QC (quality control) inspection.

      The tread is applied manually and as with any manual operation slight, involuntary human error may at times occur. These are rare cases that occur less than 1% of the time and we are constantly striving to bring that number to zero.

      The most common case is when the side of the tread isn't properly adhered to the casing. This is a rare case of human error during the production process. If a worker touches the side of the tread improperly when applying it to the casing, his fingers may have taken off a spot of glue, causing adherence problems. In this event, the glue may appear well adhered in the QC check , but the problem becomes more perceptible later during use, because of that ‘weak’ spot.

      Another rare possibility is that the inside of the tread may at times come improperly  in contact with chemical agents, such as solvents, when cleaning the base tape and applying the glue to the cotton tape, or afterwards when cleaning the tread area after gluing it to the casing.


      Proper tire care and handling:

      Problems may however also occur when a user mishandles a totally perfect product. These high-end, special handmade products are somewhat delicate and require proper care more so than others.

      High-pressure bike washes pointed for long directly at the side casing damage the delicate tire and must be avoided. Never point it directly at one spot for long, especially on the sides. Also avoid scrubbing sidewalls with stiff brushes. These improper actions may sooner or later cause delamination problems.

      Bike cleaning agents that contain degreasers also damage handmade tires. Remove the wheels before using harsh cleaning and degreasing products on your frame. These products contain solvents which may weaken the glue on the hand glued parts of the tubular or tire.

      To avoid potential damage, instruct your staff, dealers, media editors and teams about handmade products and their care, in order to get better longevity and the most out of top performance tires.



      Why is the way they are made (the materials used and their construction) so important ?

      The only touch point that a bicycle has with the road is with its tires. So why compromise the feel of your wonderfully put together expensive bike, by using cheap quality, non-performing tyres?!?

      Challenge tires can help reduce shock and reduce rolling resistance, leading to an overall more comfortable, faster and longer ride!

      Some of this is achieved by using a certain type of rubber or rubber compound. Challenge is lucky enough to produce there where the natural rubber drips from the trees rather than use artificially produced petroleum based rubber, which obviously doesn’t have the same properties as natural rubber.

      But of great importance is also the type casing used in combination with the quality rubber tread:-

      A high-end, flexible casing provides more grip as it allows more tread adherence with the ground.

      A high-end, flexible casing provides more comfort due to greater shock absorption.

      A high-end flexible casing provides more speed, as its greater adherence provides lower rolling resistance

      Better grip and handling, more speed and comfort also allow for a longer lasting ride.

      The density of the weave of the casing is expressed in TPI (Threads per Inch of material), the greater the TPI count, the finer the thread and denser the weave.

      A greater TPI count casing is actually the more supple and flexible but also stronger at the same time. Throughout  time suppliers have been able to deliver higher and higher grade thinner threads which have made it possible for manufacturers using these improved threads, to go from a maximum weave of 260/300TPI to nowadays 320TPI and up. Challenge ranges from a ‘low’ of 220TPI to the higher 320TPI.

      The more supple & flexible the casing, the more comfort and most of all the more adherence and grip to the road, therefore achieving the most speed.

      Challenge has maintained natural properties of the rubber and suppleness of the casing by opting for the so called “Handmade manufacturing process”. This process avoids vulcanization (very high heat treatments) which would otherwise dry up, harden and mostly eliminate the fine properties of the natural rubber and would also stiffen the casings. The ‘Handmade’ Process preserves the properties of natural rubber intact as well as the suppleness of the casings, allowing for unsurpassed adherence of the tyre, guaranteeing an optimal and confident bike handling for enhanced safety especially when cornering.

      A PPS (a Puncture Protection Strip) is added for puncture resistance. Some models now have two (PPS2).

      The Tubular or ‘Open Tubular’ clincher tire becomes even more puncture proof when paired with our seamless latex inner tubes. The great elasticity of latex tends to stretch and go around an object long before it puctures through, unlike butyl which punctures through very easily, releasing the air quickly to rapidly flatten the tire. Latex will be much more difficult to puncture, but even then,  it will release the air very slowly allowing you to ride comfortably back, or to a point you choose, without stranding you.

      The great elasticity and easy flex of the latex tube also further enhances the comfort of the ride, adherence to the road, contributing to an even lower rolling resistance = speed.

      The ‘Open Tubular’ tires,which Challenge produces, begin with being constructed with the same technology used to produce a tubular (it is the same production process of tread glued to a supple casing). They are then made into a clincher tire by folding the sides of the casing around aramid or Kevlar beads instead of sewing the sides together into a tubular with an inner tube inside. This type of beaded casing can therefore be mounted as a convenient clincher tire but, having at the same time the ride and almost the feel of a high performing tubular. This high quality performance in a conveniently mounted clincher tire, really makes the ‘Open Tubular’ tire the best of both worlds!

      The main feature of "handmade" tubulars is that no vulcanisation treatment is done, except for the one done separately to the tread before it is applied to the finished casing.

      First the single ply is made on the loom, using only the warp held together by a latex coating which replaces the conventional weft.

      Subsequently two single plies are attached together in a round shape and the threads of each ply are placed to form a herringbone pattern.

      This new coupled ply is then pressed with hot cylinders, cut to the desired size and the edges folded for subsequent sewing.
      The finished casing is obtained by sewing the two edges of the ply together, inserting the inner tube at the same time.

      The ribbon is manually applied to cover the stitching, and to serve in the future to glue the tubular to the rim.

      The finished casing is mounted on a rim and then inflated. The tread, separately prepared, is manually applied and the tubular is now ready!


      An open tubular is constructed using the same casing and tread materials and process as a tubular, but instead of sewing the casing together (closed), the sides of the tubular casing are folded around aramid fiber cords to produce beads. This ‘open’ design performs like a tubular, yet conveniently mounts like a standard clincher tire.

      If combined with a Latex inner tube the ride becomes even closer to that of a tubular, offering excellent traction and cornering, low rolling resistance and shock absorption.


      Threads Per Inch (TPI) measures the number of threads in a casing, which translates to how thin and supple the tire is, and its overall quality. The higher the thread count, the better the quality of the tire.

      Corespun is a technical, high-performance fiber. It's made with a polyester inner core and a cotton outer layer. A Corespun casing is more supple than Poly or SuperPoly and more puncture resistant and lighter, as well.

      The tubular with a softer corespun casing can be inflated to higher pressure without loosing grip and confort.

      Suppleness is key for a performance tire, allowing for increased cotact of a better contact patch and lower rolling resistance. 

      The TPI is important but it's not the only one feature when we look at the quality of a tire. The Compound used for the tread is important as well. A new Carbon High Tech compound has been developed to perfectly fit the new corespun casing and give the best of the performance. With this new super soft compound the tubular has a perfect grip doesn't matter if you are riding on wet or dry ground, and a very low rolling resistance is granted at the same time.

      The traditional tread design, which has made our Criterium Challenge famous over the years, remains unchanged.


      Silk is unfortunately expensive.

      BUT it is natural and has many “Top-Class” properties:

      - Much finer but stronger weave than cotton or polyester

      - Impossible to count TPI as threads are so much thinner/finer than cotton or poly and count is extremely higher!

      - At the same time softer and more supple even to cotton or poly

      - A maximum level of comfort reached with a very strong holding product !

      - A demanding and technical rider will also feel it rides smoother and faster.

      An 8-Bar inflated Tubular is quite comfortable, while a Silk Tubular with the same pressure seems almost not inflated enough.

      The feel is slightly different with Silk. In fact on the Track where they want higher inflating pressures and the fastest performance, this is where they will often prefer Silk.


      OT vs CL


      We don't recommend attempting to run our Open Tubular tires in a tubeless format. As of this time the bicycle industry does not have an agreed-upon standard for road Tubeless which has resulted in numerous tubeless rim shapes. Our Open Tubular tires are designed to work with ETRTO standards for rim bead shape and rim bead width. We can't guarantee they will be compatible with non-ETRTO standard rims.

      If you are considering tubeless as you seek better performance and a more comfortable ride than your current vulcanized clincher, please consider the use of a handmade Open Tubular tire, which has a higher ride quality and shares many of the same benefits. Higher thread counts and flexible, natural rubber provide a tire that hugs the road, inspires cornering confidence and reduces the amount of road vibration that reaches your body. Tubeless tires typically take a traditional, bouncy, vulcanized clincher tire with less grip and reduced comfort.



      Latex inner tubes are more supple than normal butyl tubes. They adapt quickly to the tire changing shape while cornering and rolling. This is because latex extends and expands 7 to 8 times its original size, butyl only about 1.5, which means latex is much, much more flexible, guaranteeing more speed, improving rolling resistance and comfort than a standard butyl tube.

      Latex inner tubes also weigh less than standard butyl tubes so can help save weight.

      They also increase puncture protection; the latex stretches and deforms around the body which is trying to penetrate the tube instead of it trying to resist the body and shortly after being punctured through. The highly elastic latex material is much more difficult to puncture.


      The disadvantage of latex lies in poor air retention. Latex is more porous and gas permeable. A tire with a latex tube should be checked for inflation pressure before every ride!

      Installation of a latex tube is also not so easy for the inexperienced hand. It can be much more prone to pinch flats if not installed properly. The suppleness of latex means it can find its way into the smallest of cracks and holes and push itself in between and pinch.

      On the other hand, if seated correctly in its cone, it can be extremely strong, reliable and a great added benefit.



      - it could be best to use a butyl tube with your brand new Open Tubular tires for a short while until your tires have stretched to shape, when installation will then be easier


      -slightly inflate before mounting (but less than you would a butyl tube before mounting)

      -see that it has (otherwise you can add) a little coating of talcum powder to eliminate the stickiness of the latex, which otherwise would not make it as easy to slide and seat smoothly in its cone

      - Inflate and deflate a couple times, checking that the tire is free of the bead each time !

      Finally, a latex tube is known to be somewhat delicate. It is susceptible to greasers and degreasers, ammonia and solvents, direct prolonged sunshine and high heat, all which may contribute to damaging its properties, so must be avoided as much as possible.

      It is advisable to change the tube every time a tire is changed.

      The above warnings explain why latex tubes are not often suggested for quick everyday rides.

      But if the additional precautions and care are taken, you’ll feel the difference and certainly enjoy your ride!


      • made of superior Latex unique formula
      • the only Seamless ‘one-piece’ latex inner tube on the market
      • extremely elastic and strong, thus very reliable
      • seamless & smooth, no bumps at the valve, no “out of round, unbalanced” wheel
      • improves rolling resistance
      • improves resistance to punctures
      • is lighter weight than standard butyl
      • has two-piece removable valve core for valve extender use


      Here are a few tips to help you summer-ize your cyclocross tubulars.

      Wash your wheelset using water with dish soap or diluted Simple Green. Avoid harsh scrubbing of the delicate sidewalls with a stiff-bristled brush. Instead, use a sponge or softer brush. Stiff bristles are OK for the treads.

      Thoroughly dry the wheels by hand with a clean towel and let air dry completely. Tip the wheel on its side and tilt slightly one way then the other to let any water trapped in the rim drain.


      Inspect the tread of the tires for cuts, glass, little bits of stone, and abrasion. Check if any lugs are loose or missing. Small cuts can be repaired and filled with Super Glue. Check out the valve cores. Are they bent, loose, dirty? Unscrew and dry them before tightening.

      Look at the sidewalls. If your tires have cotton casings (Dugast, Challenge and others) they should be sealed to protect them from and moisture. An unprotected cotton sidewall will rot if wet and dry out if stored unsealed. If they are already sealed, inspect the sealant for peeling or bubbles. Dark or black spots indicate moisture and rot. If you need to re-seal, I recommend removing the old before applying a new coat of Aquaseal. Make sure the sidewalls are completely dry before sealing, otherwise you are just sealing in the moisture. If you do re-seal, wait until the sealant is dry before proceeding to the next step.

      Inflate the tires to 30-40 psi and check the glue job by trying to roll the tire off the rim. Don't check just one spot, go all the way around the rim. If you have to re-glue, I suggest waiting until late summer or whenever you are a few weeks out from your first race.


      Store the wheels either in wheelbags or on your bike. In either case hang them - bike on a hook or wheel bags from a hook. Leave some air in the tires and check them every month or so. This will help the sidewall hold its shape and avoid pinching or folding. Latex tubes will lose some air over time. Lastly, whether the wheels are in bags or on your bike, put them in a temperature controlled, dry environment out of direct sunlight like a basement (or garage if you live somewhere where it does not drop below 45°).

      Follow these steps and your tubulars will be ready to go when September comes.


      Tubulars require a little attention prior to gluing and mounting.

      It is important to mount and inflate the tubular to 8 bars for a minimum of 12 hours.

      This process allows the tire to stretch and regain its shape before gluing (after it has hung in a shop and priorly been shipped and/or packaged).

      In this phase you must make sure the tubular is centered on the rim and confirm the round shape before deflating.

      Where the tubular were not aligned properly, deflate the tubular and align it, balancing the view of the slight exposure of the base tape on both sides of the rim.

      Re-inflate the tire and leave for 12 hours before gluing the tubular.

      This operation will help you mount the tubular more easily during final gluing and assure proper alignment and roundness of the tubular during the life of the tire.


      Many cyclocross treads are directional. Note: “Forward” refers to the direction of the tread when looking at the top of the tire, and will be the same as how it touches the ground.



      The Grifo can be used in different directions to achieve different results.

      If you point the arrow < < < of the tread forward the tire rolls faster.

      If you turn the tire around with the arrow pointing backwards > > > the tire has more grip but added rolling resistance. 

      The rear tire is usually more suited to switching directions. Have fun trying different orientations for different conditions.



      For these tires it is advised to have the long arm of the "Y" pointing forward and the open V shape of the Y pointing back “ ˂ “ on both the front and rear tire.

      The tire in this direction has less drag or rolling resistance. Additionally it also sheds dirt and mud better on the road, so that maximum grip is once again obtained. Using the tires in this direction on both wheels also ensures optimal grip.



      The Fango will get more bite with the slightly taller end of the scoops that run down the center facing forward and will roll faster with the shorter end in front.


      The Limus, Baby Limus, Chicane and Gravel Grinder tires all share the same aggressive "Y"-shaped outer knobs. Most of our athletes prefer to mount the tires with the leg (bottom) of the "Y" pointing forward so that this portion hits the ground before the open portion of the "Y".
      You can run these the other way around with the open end of the "Y" hitting ground first if you desire more traction. However, it will be slower when cornering. 


      CONDITION: Predominantly hard-packed ground


      Dry first option: Grifo XS - Provided it was dry, I would start my pre-ride on the Grifo XS.  These tires are fast and you can be confident in the corners. If you find you slide beyond what you feel comfortable with in the corners, try to lower the pressure, in very small amounts.


      Wet first option: Chicane - Hard-packed ground when wet will usually only give you a problem in the corners and transition areas.  I would first try the Chicane as these give you all of the confidence in the corners.  You might even be able to run these at a slightly higher pressure, as you'll naturally have the grip in the corner.


      Other options and scenarios: Grifo - If the course has muddy sections due to the wet (maybe you are in a late race and the course is already cut up), then go with the Grifo.  This is a great option providing you with the best of both worlds above.  You can be confident with a Grifo and they give you amazing variability when you alter the pressure.


      REMEMBER:  You don't need to run the same tread front and back.  Also don't assume the same pressure front and back is the right option for you.



      CONDITION: Dusty hard-packed ground


      First option: Grifo - There is lots of time to be made in the approach and exit of a corner.  Having the confidence to carry race pace through a corner can be the difference between winning and loosing.  The Grifo provides excellent corner grip and gives you a great feeling of security when the bike isn't totally leaned over. 


      Second option: Fango - These are a commonly-chosen option for people that like a fast-rolling tire with a little extra corner grip.  Varying your pressure between the front and back can transform the way these treads perform.


      Other options and scenarios:


      The Grifo XS could be great.  If the dusty areas of the course are straight, or if there are slow corners that take the skill element way, you might find you can excel with the Grifo XS.  These are fast tires and are more versatile than you might first expect.


      REMEMBER: Always ride whats best for you. Don't be influenced by those around you.  Riding with confidence in your equipment makes you fast. Approaching a corner slowly because you've risked a more aggressive tire choice could slow your lap time down.



      CONDITION: Loose over hard packed ground


      First option: Grifo - When the ground is loose, you need to feel at one with your bike.  You need to put your focus in pre-ride to find the best lines. The Grifo gives you the ability to move around on your bike and give you the right balance between grip and speed on the straights.


      Second option: Chicane - If the course is loose, but you fancy riding in a “foot out, flat out” style, try the Chicane. Maybe you'll slide a few more inches but you can be sure the side-knob grip is going to kick in and you'll be fast on the exit as soon as you hit the straight.


      Other options and scenarios: Loose ground can cover many things. If the loose sections are on uphills, you need to consider a Limus rear so you can really get the power down and keep traction.


      REMEMBER: Always consider the type of loose ground you are on.  You might want to run slightly higher pressure to avoid a flat if there are largish stones on the course.  Ride with finesse and you'll be fine.  My tip would be have a slightly higher pressure on your pit bike to avoid a second issue.





      CONDITION: Dry course with short sand sections


      First option: Whatever you would use for the course should the sand not be there.  Don't change your race for one short section of sand. Consider the remainder of the course first and put your energy into being first into the sand pit.


      Second option: Grifo XS - If there are multiple sand sections, try the Grifo XS on a low pressure.  This is the natural choice for loose sand, but if its going to neutralize the way you ride the remainder of the course then its potentially not worth it.


      REMEMBER: You can ride sand on any of the Challenge tire options. Dry sand is loose, and best ridden on a very low-pressure Grifo XS.  Ride the ruts, and look forward to the exit of the sand pit. 



      CONDITION: Sandy course


      Dry first Option: Grifo XS - This is the natural tire choice for these conditions. Think of the Koksijde World Cup course as a pure-sand course. You are aiming to float over the sand and keep as little sand flicking all over your drivetrain from the tire treads as possible.  Run them low.


      Wet second option: Grifo - The Grifo might allow you to run a slightly more balanced race.  If there is a little moisture in the ground, a fraction of the skill of sand riding has been taken away, and the sand will lean towards speed more than balance.  Having the ability to corner fast in the wetter corners could mean faster entrance to sand sections.


      Other options and scenarios: If you have sand on one side of course and not on the other, you could consider 2 set ups if there are going to be a large number of pit changes.  If you can change fast you won't lose time and could have the best options for both sides of the course. 


      REMEMBER: When riding sand, steer with your eyes by being focused on the exits to the sand zones.  You can ride sand on any of the tire options available from Challenge.  Start aggressive and move up the grip options as you feel necessary.




      CONDITION: Dry grass


      First option: Grifo XS - There is more side grip on these than you might think at first. I tend to run slightly lower pressure in the front for my first lap of pre-ride and see how that rolls.  Dry grass and fast transitions make for quick races.


      Second option: Fango - The choice of many for grass is the Fango.  Fast in a straight line and great on off-camber, the Fango can give a great second option for grass races.  Even with higher pressure, these are option well worth trying.


      Other options and scenarios: Chicane - The Chicane might give you that little more security in the corner, particularly where the grass is a little longer and you get some great bite in the large side knobs.


      REMEMBER: If you are pushing things with your first option, put a more grippy option onto your 2nd bike. A fast dry course should mean no changes. A change in these conditions means potential disaster recovery, so plan for it in advance.




      CONDITION: Wet grass


      First option: The Grifo is going to be a great option to try first off.  With wet conditions, be prepared to slip and slide and maybe keep the pressures towards your personal lower limits.  This will give you maximum contact in the corners and allow you to power away in the straights. 


      Second Option: Limus - If you think the course could really get cut up, then consider the Limus. You'll have lots of grip and it will clear very quickly on any asphalt sections.


      Other options and scenarios: If you feel the course will dry up very quickly, you could try the Chicane.  You'll still have all the corner grip and it could save you a bike change.


      REMEMBER: Find the limits of the tires.  Don't change for a tread with more grip before you have experimented with your pressures.



      CONDITION: Wet dirt


      First option: Limus - It will give you a consistent performance all the way around the course. They are faster than you think and shed well enough you might be able to get away with no pit changes.


      Second option: Chicane - The Chicane could come into its own if you are still able to get the power down on the straights.  Lower pressure will help with somewhat slippy conditions and you have grip close to a Limus in the corners.


      Other options and scenarios: Grifo - The Grifo is a very happy tire in the dirt, wet or dry.  Try it if you don't quite feel you are getting what you need out of the Limus or Chicane.


      REMEMBER: Try to read the conditions. If you think it's going to dry up quickly, plan in advance.



      CONDITION: Sticky mud


      First option: Limus - The Limus is your best friend in these conditions.  All you need to focus on is finding the right pressure for you, then you can be confident you can ride where others can't.


      Second option: If you don't have a Limus in your armory, then consider the Grifo, nice and low.  Get that tread flat across the mud and you will be amazed at the grip.


      Other options and scenarios: You might be able to get away with a Grifo on the front and Limus on the rear.  If the course has multiple long straights, you might be fine with this as it allows you to get the power down and maybe keep the speed up on the asphalt.


      REMEMBER: Ride the ruts. They are faster and you can see what's in them rather than hit hidden obstacles.



      CONDITION: Snowy mud


      First option: Chicane will come into its own in these conditions showing its versatility if the mud is light. Snow means cold, so the grip will be needed in the corners.  You might have hidden frozen ruts so plan for slightly higher pressures when first checking out a course.


      Second option: Limus could be your best option especially if the day is warm enough for the course to defrost mid-race. 


      Other options and scenarios: You might find a Limus on the rear and a Chicane on the front could be the fastest option. 


      REMEMBER: Frozen courses have a lot of hidden problems.  Its worth an extra warm up lap to try to get the course very dialed in. 



      CONDITION: Snow and ice


      First option: Grifo XS - This would be the first option for me in pre-ride. I want as much rubber on the floor when I hit ice.  Snow itself can give lots of grip in a corner so give the Grifo XS a try before scaling up your grip.


      Second option: Chicane - This will give you a little more grip in the corner, helping you flow in the technical sections.  These are really good when the course has more protected areas like in woods where less snow has reached the ground.


      Other options and scenarios: Fango - Fangos are good in the ice.  How much of the course has exposed ice is something you need to consider.  You might find the Fango is a great option for you.


      REMEMBER: Riding in ice is a confidence thing. The more you can ride a course like you would in the dry, the better you are going to be.  Try to adjust your tread choice, not your riding style.



      CONDITION: Ice


      First option: Grifo XS - With all icy conditions I try to ride the Grifo XS. They grip by giving me a lot of surface area on the floor, plus they keep me quick in the straights.


      Second option: Fango - This is a good option on the ice. Running low pressures they give exceptional grip and seem to be very at home in the ice.


      Other options and scenarios: If you suspect the course will warm up and might get more slick in the corners, start with the Chicane and certainly consider this on the front.


      REMEMBER: As with other conditions, set your second bike up to try to predict for course changes and certainly give yourself a more secure option for a last-minute change before you can get your pit crew to change your option for you.




      The short answer is probably yes. The longer answer is more interesting and here you will learn from the experts how to prevent a majority of these cuts from becoming a problem.

      The natural latex and rubbers that handmade tires use in their casings and tread rubber are softer and stickier than synthetic rubbers and vulcanized processes used for normal clincher tires. Therefore a Challenge tire may be more likely to pick-up a small sharp stone or piece of glass in the tread and hold it there for multiple tire revolutions, allowing the stone or glass to progressively cut the tread and eventually the casing. Essentially the same special soft, sticky materials that give the casings and treads incredibly low rolling resistance, cornering and traction also make them more susceptible to cuts if certain precautions are not applied.

      In January 2013, the Belgian woman’s team Challenge sponsors reported multiple cuts on many Challenge training and racing tires. They had some similar problems with other tires and with Challenge in the past but now it seemed much worse. We felt this was strange because our second, larger (meaning both more and bigger riders), men’s Belgian team was riding the same tires and were not reporting any problems. We went to the men’s team training camp in Calpe, Spain to investigate this problem (along with having other technical discussions).

      Immediately when I brought up the problem in front of team management they looked at me incredulously and said, ”What? You do not know that you need to apply vinegar to the tires before riding in this “season of the little stones”?” I could not have been more stunned.

      They then patiently described (like to a child) that “everyone in Belgium” knows that in the “winter” (which in Belgium is the standard three months plus two months on either side when you can get “winter” for two hours on any give day) you need to take special precautions against tire cuts.

      The state trucks that sand or grit the roads plus heavy rains that wash dirt from the fields combine to dump many small, sharp stones and pieces of glass into the roads. Cars then spray the stuff to the sides of the roads where cyclists are forced to ride through it. Average people know you need thick, heavy, hard tires on your commuting bike to keep from getting flats. Riders and mechanics for professional teams are all taught at a young age that you must treat racing tires with vinegar every two to three days during “winter” (or when “winter” suddenly reappears).

      Vinegar.” I said again, patiently, “Vinegar.” I thought they are pulling some old Belgian joke, which would be fine, but I did not want to pass along the joke before I understood I alone bore the brunt of the joke. “Yes,” they said, “You must wipe the tires with vinegar, any cheap vinegar, to clean the sticky oils from the tread and “dry out” the surface of the natural rubbers.” I know that vinegar is an astringent that will dry oils from your skin so I let them continue.

      The small sharp stone or glass may still stick in the soft rubber but after using vinegar the centrifugal force of the spinning tire will be sufficient (with the less sticky tread) to throw the sharp object out of the tire. The problem only comes when the sharp object stays in the tread and continues to cut, deeper and deeper.”

      Hmmm… fortunately a mechanic walked into our meeting at that moment so I told my manager friends to stay quiet and I asked the mechanic how he kept the sharp stones or glass from cutting racing tires. He said, “Well, of course, I must apply vinegar to all of the tires every day or two before riding in the “winter” season.” Normally in Spain or Italy or southern France it is not a problem but he heard from other mechanics that this year, with winter snows heavier and further south, they needed to use the same process in these areas.

      OK, the mechanics and managers were all in on the joke but I needed one more check. That night at dinner I chose one of the younger Belgian riders who came from a cycling family and asked him the same questions. He said his father taught him the same story when he was 12. Vinegar.

      Long story short, if you want to have all the incredible performance - low rolling resistance, cornering and traction – that the Pros enjoy with Challenge Handmade tubulars but do not want to get a bunch of cuts or punctures, simply keep a rag handy and wipe your tires with vinegar every couple rides in that “season of the small stones”.

      Go for it. Just be careful putting them on the rims! We would recommend using a rim strip. That will protect your tubular base tape from the rough edges of the spoke nipple holes in the rim bed.
      If you're using bare rims and not a complete wheel, also be careful when stretching the tubular not to break the rim. Rims without a hub and spokes don't have much radial strength.

      Handmade tires have separate pieces of tread and casing, which are glued together. The bond of the glue improves for 6-8 months, so pro teams buy tubulars at the end of the previous season and keep them in storage to get the best longevity, and ideally you should, too.


      Store them in a dry, dark, room-temperature place lightly inflated and without any folds that could weaken the casing.


      Read more >> http://www.cxmagazine.com/buying-tubulars-tires-early-aging-process-explained


      When trying to determine the optimal tire performance characteristics for wet weather riding, it is best to study the riders who spend the most time and ride the most aggressively in wet conditions — professional riders who are paid to suffer in these conditions. Pros do not like to crash any more than the rest of us, but two things they have that most of us don’t are the choice of the best tires — regardless of cost — and the most experienced mechanics in the world who are experts at fine-tuning the tires for the riders and conditions.

      It is critical to fine-tune every component of the tire before riding aggressively in wet conditions to maximize the surface area gripping the road surface while squeezing water out from under the tires wherever possible. This is why all top level road teams and even experienced pro triathletes will ride tubular tires with soft, supple casing materials, natural rubber tread compounds, and supple latex inner tubes, sized to the rider weight and road condition and adjusted to a minimum pressure to keep the rims from bottoming out on the bumps. If you must ride a clincher, then a use a clincher made with the same materials as our tubulars (we call them Open Tubulars) that when matched with a latex inner tube are the next best option.

      Pro Tour team mechanics will carry small charts listing tire size and pressure for each road type — “Grand Tour Perfect” (paved yesterday), “Normal,” “Poor,” “Tour of Flanders Bad,” and “Paris-Roubaix Worst” — and rider (due to weight), for front and rear wheels. Unfortunately, this information is rarely shared due to the strategic advantage it gains the team with the most technical savvy.

      The most important issue is to have a soft tire — casing, tread rubber and inner tube — as described above, adjusted to the proper pressure to maximize tire patch size, grab every road imperfection and to deform and absorb bumps. The casing is the primary factor in this fast and grippy tire system. The casing must be able to deform as much as possible to adapt to the surface of the road, having always the maximum contact patch. If the casing is stiff due to material or pressure, then cornering traction will be compromised. This is true in wet and dry conditions.

      A hard (due to materials or pressure), bouncing tire will lose contact, allow water to penetrate under the tread and lose traction quickly and without warning. This is why current tubeless technology that requires a stiff sidewall to keep from burping runs counter to optimal road performance.

      In the wet, lowering the pressure will give the casing even more flexibility so the tire will be able to deform and adapt to terrain and weight transfers — to lean, brake, climb, and descend comfortably. The tire is the only suspension on the bike and suspension on a bike is critical! Frames must be stiff for the reasons we all know, but tires have to compromise stiffness with suppleness. The result should be a less nervous bike, smooth rolling to avoid any loss of contact. The tire will also give you constant info on what is going on and where the limit is. It will allow you to adapt, correct lines, and resolve most situations, while hard, stiff tires will go from grip to no grip with no notice and no time to react. Again, casing and pressure are fundamental.

      In theory, every riding condition requires a specific tread compound, but this is not possible, at least in bike racing. Car and motorcycle racers have test days to choose the right tire, and if conditions change during a race they change the tires. In bike racing this does not work, so the compound has to be a compromise between good traction in wet, and durability, puncture protection, and strength. A soft compound increases grip in wet but lowers wear and puncture resistance. It must be able to keep its properties during all riding conditions. This is the difficult part.

      Tread design on a road tire is like the cherry on the icing on the cake. A slick tread will function on any dry road surface, but once it gets wet, a herringbone tread pattern like on our Forte, Strada, or Paris-Roubaix tires will help channel water outward while slightly deforming and again, maximizing tread contact. Traditional patterns like the herringbone are the most effective and do help in most conditions. The small grooves of a herringbone help the compound to drain the water, and the small rubber wings that come up can flex and deform to optimize grip. A Forte pattern with the deep fine “S” on the side has proven to be a very good tire in wet dirty conditions when used by Bretagne-Séché and Team3M.

      In summary, in wet weather a soft, supple tire and inner tube at a moderate pressure is most critical. Reducing the tire pressure does help further increase the contact patch and maintain traction if you have that soft, supple tire and tube. The right tread pattern is the final element to help ride safe at speed in wet conditions.

      The additional weight is due to the additional latex coating. The Corespun Cotton used in the Team Edition casing absorbs more latex than our polyester casings. We opted to include the latex coating as our process provides a thin and consistent waterproof coating allowing you to ride the tires as soon as they are installed, saving you the time normally required to seal a cotton tire. Though this may add a few grams to the tire, the combination still provides a more supple ride and higher performance than our SuperPoly tires.
      Side note: All CX tires should be gently washed with mild soapy water and a soft brush, then thoroughly dried before storing. If and when the outer threads start to show through the casing the sidewall should be sealed again after it is cleaned and dried.