Carbon Wheels for Cyclocross? The Pros Do It, So Why Not?
In part one of this little Q&A session, we asked several manufacturers about running carbon handlebars on your cyclocross bike.
Now, having seen all manner of carbon rims and wheels being raced from the local level on up to the recent nationals in Bend, OR, we thought we’d see what the wheel manufacturers had to say about this trend. Are they approved for this use? Warrantied for this use? Heck, are they even made strong enough to handle the bumps, jumps and crashes of cyclocross? After all, a carbon handlebar pales in comparison to replacing a set of carbon hoops or putting a second set on your “B” bike!
On the surface, it seems that the mud, dirt, grit and abuse would quickly wear through a carbon brake track, gouge the rim edge or otherwise torture them…but as with many things, it goes deeper than that. See what Mercury, Zipp, Ritchey and Reynolds have to say on the matter after the break…
UPDATED 12/23 – New answers from American Classic, plus new questions and answers about maintaining a carbon brake track and how disc brakes will change things up.
BIKERUMOR: Which of your CARBON wheels/rims does your company recommend for cyclocross?
REYNOLDS: All are good for ‘Cross. The most popular is the 46 (above, left) or the Assault.
ZIPP: We recommend the Zipp 303 Cyclocross. We also have a Zipp 404 Cyclocross that offers most of the same benefits as the 303. Both are full-carbon tubulars. We’ve also seen the Zipp 202 under smaller riders in ‘cross (U23 National Champion Kaitie Antonneau) on occasion.
MERCURY: We recommend the tubular M/S-3′s or the M/S-5′s which are full carbon rim. The 3 series have a 39mm depth where the 5 series have a 59mm depth. If the course is muddy or wide open, we have heard the 5′s are the way to go. This will give you a bit of aero and you will find it easier to roll through the softer sections. The tubular’s will allow you to dial in the tire pressure du jour without having to worry about pinch flatting or damaging your clincher’s if you hit a rock or any other obstacle going at speed. Although, we aren’t too worried with our carbon clincher rims breaking as we have demonstrated that you can bounce them off concrete without a scratch.
RITCHEY: All carbon wheels in the Ritchey line are Cyclocross approved. The top sellers are The WCS Apex tubulars since they’re nearly as light as our top end Superlogic wheels but more affordable.
AMERICAN CLASSIC: We recommend the carbon 58 tubulars or 420 aero 3 (alloy) for ‘cross.
BIKERUMOR: Do those models’ warranties cover cyclocross or off-road use?
ZIPP: Yes. Warranty covers 2-year manufacturer’s defect. We also have a crash replacement program that allows the rider to replace a wheel for non-warranty issues (see local bicycle shop for price).
MERCURY: The Mercury warranty covers both road and cross riding. We are confident with the rims, hubs and spokes, but we are also 100% confident with the build. They are handbuilt for us at Handspun (QBP).
RITCHEY: Yes, the standard warranty still applies. Our wheels are plenty strong and have benefitted from what we’ve learned on the World Cup Mountain Bike circuit, both carbon clincher and tubular. Most carbon CX rim manufacturers don’t have that experience to draw upon.
AMERICAN CLASSIC: Yes if it is within reason. If carbon tubulars are being used for DH, no, for cross yes.
BIKERUMOR: Do you recommend the use of carbon rims/wheels for cyclocross? What are the pros / cons of doing so?
REYNOLDS: We sponsor Geoff Kabush and his Maxxis/Rocky Mountain team for cyclocross and he was racing our full carbon RZR wheels this season!! (Editor’s Note: full carbon = carbon hub, spokes and rims! We posted on these wheels at Interbike.) We design our rims to withstand the rigors of the pro peloton and we are supremely confident in our engineering so we have no qualms whatsoever with racing ‘Cross on any of our carbon wheels. You get a much stiffer more responsive wheel with carbon.
ZIPP: The 303 rim was designed specifically for the Spring Classics and for Cyclocross. Lightweight (1206 grams), aerodynamic (faster than most deeper V section rims), 45mm depth helps with mud (and sand) shedding, has a rounded radius on the outside diameter of the rim that helps prevent pinch flatting when the rim bottoms out on a rock or root, reinforced with a Kevlar stitching under the outside diameter for greater impact resistance, outside diameter that is designed for gluing 27mm-32mm tires (using laser scans of actual tires), the wheel is very comfortable yet laterally very stiff, 88/188 hubsets with labyrinth seals to keep out mud, sand, water.
One consideration when using carbon tubulars is that the conditions of cyclocross vary so much. That said, it’s best to select a versatile tire or have multiple wheelsets with various tread patterns.
MERCURY: The carbon rim adds a certain stiffness to the wheel that some riders prefer. Luca Damiani, who rode for the Italian National team last year, prefers the M-5′s. He claims they allow him to carry a higher amount of speed into corners. The down side is the price of carbon vs. alloy as the carbon tends to be a bit more expensive.
RITCHEY: Absolutely, most of the U.S. Ritchey employees race CX at a high level and use our carbon wheels exclusively. Our carbon wheels offer increased lateral stiffness and big weight savings over an alloy wheel. The downsides to any carbon wheel for CX is obviously the higher cost vs. aluminum, and also the slightly reduced braking quality of a carbon sidewall. This can be improved with pad selection and brake adjustment, but even some of the recent wheels with Teflon sidewall treatments still don’t stop as well as an aluminum rim.
AMERICAN CLASSIC: The pros are the carbon 58 tubulars are light, deep and stiff. Light means less rolling resistance. Cross is a long, hard time trial effort for the rider. Dragging a wagon wheel on grass and through mud is no fun. Light wheels allow you to sustain the effort longer. Deep rims sheds mud and lends to lateral stiffness.
The cons are if you hit carbon hard enough on rocks, they can crack (not a warranty!) so potential repairs can be expensive.
BIKERUMOR: Are your carbon rims / wheels better suited for cyclocross than alloy ones? Not as well suited? Equally suited?
REYNOLDS: Without a doubt our carbon wheels are a better option. The carbon rims we produce are much stronger than an alloy rim and given the demands of cyclocross you want that strength obviously. With carbon it’s really the best of all worlds- strength, stiffness and lightweight.
ZIPP: Elite racers and most category racers prefer the Zipp 303 carbon rim, as they are better suited for ‘cross (see benefits above). However, many category racers are also arming themselves with a set of Zipp 101s (aluminum clincher) for their durability, light weight and ability to change out tires for the varying conditions of ‘cross. Our sponsored pro ‘crossers use the 101 as their training wheels (on and off road).
MERCURY: The Mercury carbon rims are equally suited to the road or cross. We run a higher spoke count and double cross our spokes in the rear to add strength and stiffness to the wheels without adding a ton of weight.
RITCHEY: Equally suited if you’re talking tubular. Our carbon clinchers can be used for CX but the low tire pressures may result in rim impacts. The rims are plenty strong but any lightweight rim will have a breaking point. Tubulars are stronger due to the shape of a tubular rim. Ritchey rims are monocoque constructions, so they’re created as one piece—other rims are made as 2 or 3-pieces bonded together—so there are no bond points or seams that can bring stress risers and failure points into the rim. Also we employ a patented bladderless construction method (vs foamcore or plastic bladders used by other manufacturers) process that yields a totally smooth inner rim surface, no wrinkles, no excess resin, optimum fiber-to-resin ratio and even compression throughout the structure. All this brings an incredibly high level of toughness and durability to our carbon rims, perfect for the abusive world of Cyclocross.
AMERICAN CLASSIC: Both are suited for cross. Some people do not want to deal with tubulars and prefer clinchers for the ease of changing flats or changing tires out based on terrain conditions. Also alloy rims are less costly than tubulars in case of mishaps.
The 420 aero 3 wheels have the same great properties as the carbon 58 tubular, light, deep and stiff.
BIKERUMOR: Many of the carbon wheels seen on cyclocross bikes, particularly at the pro level, seem to have a relatively deep dish. What’s the benefit if any?
REYNOLDS: The main reason our athletes ask for deeper rims is for stability on unstable ground. Additionally when you have a deeper wheel it will have a little more mass at the rim than a shallower rim. That added Rotational Mass Inertia is always trying to keep you upright and given the unpredictable nature of courses this is an added benefit. With carbon you can have that RMI benefit without sacrificing the quick acceleration/deceleration that is required in cyclocross and only carbon inherently brings this to the table.
ZIPP: Aerodynamics (yes it matters in ‘cross), mud and sand shedding, flat protection (especially pinch flatting), damping – the Zipp 303 Carbon Clincher can take big hits and the 45mm deep toroidal shape absorbs the impact, handling – wider carbon rim seems to provide a better footprint for increased traction.
MERCURY: We have provided Luca Damiani and Johnny “El Gato” Sundt with a few sets of wheels this past year. Johnny prefers the Mercury S series alloy. He likes the weight of the alloys coming in at 1250 grams for the set. He claims he can float through the turns without compromising any speed and sling-shot’s out of the corners giving him a gap on his competitors in each and every corner. He recently was recently crowned the Texas cross champion and won it on the S-alloys (MSRP-$649)!
Luca prefers a slightly deeper dish wheel. He likes the M-5′s which boast a 59mm depth in carbon with a White Industries hub. Luca really likes the M-5′s for the light weight with still a bit of aero for the races where he needs every bit of aero advantage over some of the bigger more powerful pro’s. Look out for him over barriers as he is usually the one bunny hopping them!
RITCHEY: A deeper wheel serves a slightly different purpose for Cyclocross than it does for the road. While aerodynamics could still factor to a degree, the real advantage of a deep wheel for CX is how they ride through deep mud, sand and snow. A shallow rim will dig into a soft surface, so as it rolls it’s taking energy to ‘pull out’ of the trail. A deeper rim will not get buried in mud, sand, etc., and therefore tends to roll faster and also be a little easier to handle. Another advantage of deeper wheels is that they use shorter spokes at a steeper bracing angle. When combined with our very stiff rims, you get excellent lateral stiffness, which is great for hard cornering and accelerating out of hairpins.
AMERICAN CLASSIC: The deep section sheds mud. Deep rims mean shorter spokes, shorter spokes are stronger than long skinny ones. Barb Howe and Amanda Carey were 8th and 9th in the elite nationals at Bend and both won silver in age group nats on Carbon 58 tubulars. YAY!
BIKERUMOR: Anything else you’d like to share about using carbon rims/wheels for cyclocross?
REYNOLDS: The chasm between carbon and aluminum will only get bigger as disc specific rims are developed for cyclocross. Without having to worry about heat dissipation from rim braking the shackles are off for carbon and the development doors are wide open.
ZIPP: We’ve had a lot of success with the Zipp 303 CX since introducing it to ‘cross two seasons ago. We’ve won countless UCI races, National Championships and Cyclocross World Cups under Katie Compton, Cannondale prepared by Cyclocrossworld.com team of Tim Johnson, Jeremy Powers, Jamey Driscoll and Kaitie Antonneau, Specialized’s Todd Wells and Danish National Champion Joachim Parbo.
RITCHEY: Carbon tubulars require a little more care when gluing, specifically you don’t want to use anything sharp or abrasive when cleaning old glue off the rims. It’s also known among our team mechanics that all carbon tubular rims require more diligent gluing, especially first time around, you want to get 1-2 more base layers of glue built up (with adequate drying time between) onto the rim to ensure a proper bond.
BIKERUMOR: How do your brake tracks stand up to the typically dirty, wet and gritty conditions of cyclocross? What specific measures should consumers take to prolong the life of the brake track?
ZIPP: (We’d) recommend using our Tangente High Performance Cork brake pad for dry conditions. It provides the best in heat dissipation and brake modulation. Our black pad is the choice for more varied conditions. The yellow Swiss Stop pad is also good for wet and muddy conditions. With any of these three pad choices the brake track will stand up well to the conditions of ‘cross. We have pros and amateurs that have been riding the same rims for over 2 seasons now with no problems.
MERCURY: Of course dirt, grime or mud is the enemy to any braking surface. We recommend using carbon specific brake pads, but we also recommend riders to clean out any debris that might be lodged in their brake pads after each use. We also recommend cleaning the wheels(especially the brake tracks) after any use off road, which will ensure a longer lasting wheel, but will also keep the wheels looking good.
RITCHEY: The best thing you can do is run good pads (SwissStop Yellow’s for Ritchey wheels, or Reynolds Cryo Blue for our Superlogic wheels) and pay close attention to pad condition. Frequently filing the pad surface clean to remove little bits of embedded debris will improve braking performance and rim wear.
BIKERUMOR: How will the presumably inevitable use of disc brakes in cyclocross change a carbon rim or wheel?
ZIPP: So many unknows with disc but obviously the prospects of it are exciting. Frame spacing is a key variable that is driven by the frame manufacturers and will have an impact on wheel development. We are testing the concept and have already built a couple of prototypes that have been tested by the pros using our existing rim models. It is certainly something that we can do and may do depending on the acceptance by the frame makers, pro athletes, and consumers. In speaking with our pro athletes, the responses were mixed in if they would use disc and beyond that if they would use them in every situation or in on special situations.
MERCURY: really like the idea of disc brakes into the cross scene. It will allow us to reduce the weight of our rims in the brake track area. This is significant as the outermost part of the wheel has the furthest to go around. It compares to someone holding out their arms straight away from their body with their palms upward holding a pound weight. It gets heavy quick! Now move the weights closer to your body, it seems lighter even though the weight is the same. It is the same with revolving weight.
RITCHEY: It certainly seems inevitable, but it’s interesting that none of the pro’s are racing disc brakes currently, even though there are options currently available. But discs will eventually be the way to go, since it’ll not only offer better braking, but also lighter, stronger rims since brake tracks and related heat/pressures won’t be a factor. Spoke count and/or type may also be affected, as 20 metal spokes may not be enough to handle disc brake forces up front.
NOTE #1: It’s worth mentioning that we reached out to Mavic, too, but since they don’t technically make a carbon cyclocross wheelset (rumor: yet…), they declined to comment. Easton may or may not be sending us a response, I’ll add it if we get it.
NOTE #2: We’ll be updating this post shortly with comments about brake tracks in these conditions and more about what will happen when disc brakes become prevalent, so check back.
NOTE #3: It’s also very interesting to note that the two wheels that Reynolds points out as their top sellers for ‘cross are available as both tubulars and clinchers, which makes them a more versatile choice…letting you use them year ’round much more easily than tubulars. They use their new CTg brake track, which we covered here in great detail (along with the rest of their 2011 wheels).
Mercury Bikes’ wheels are also available in both clincher and tubular, and they come with some wicked light Ti skewers.
The Zipp 303 is available in a clincher, too, but the cyclocross-specific model is a tubular. The Clincher has an aluminum brake track and 6 fewer spokes on the front wheel and makes no mention of cyclocross on its web page.
I spoke with Bill from American Classic and they won’t be offering a full carbon clincher rim anytime soon, citing safety concerns over heat built up causing the tire bead to potentially disengage from the rim, which isn’t an issue with tubulars.
NOTE #4: Overall, the clincher models run about 300g to 400g heavier than tubulars.
So, some of the things to consider if you’re contemplating upgrading to a carbon wheel for cyclocross include:
- Picking one tire for all conditions if you’re going with tubulars. Unless, of course, you’re printing money and can have a couple wheelsets laying around.
- Cost, and specifically tying up that money in a wheelset that you may only use a few months out of the year.
- Keep your brake pads cleaned out. Check them after every ride and race to remove any debris that may gouge a carbon rim’s brake track. And make sure you’re using the manufacturer’s recommended brake pads when specified to a) prolong the life of the rim and b) maintain the warranty.
- When disc brakes inevitably take over, can your wheel be rebuilt with disc hubs?
Leave a comment!
What are you running? If you’ve got carbon rims or wheels, how have they held up for cyclocross? If you’re running tubulars, what tires did you commit to? Any other questions you have for the manufacturers?