How to Dial in Your CycloCross Ride
Cyclocross season is just around the corner and the time has come to dust off last year’s mud from your trusty ‘cross bike that’s been itching to be ridden. Let’s not waste time here; this article is about the bike — how to choose a new one or get the most out of your current set up.
I’ll say a word about frame materials. If you want a cyclocross bike to race on, that will last season after season, choose either steel or titanium because they are light and absorb some of the harshness of riding off road. Bump absorption will save your body from undue fatigue allowing you to put more energy into the course to hurt the competition. If necessary these frames can be repaired, which adds to their longevity.
If you want a bike that is light and you don’t plan to race on it season after season, choose aluminum or carbon fiber. Carbon fiber frames will have a nicer feel — comfortable yet stiff — but the potential for chipping or cracking from small rocks or crashes on ‘cross courses can shorten the frame’s lifespan. Aluminum bikes often will come with carbon fiber forks and/or seat stays to help with shock absorption. Fully aluminum bikes can feel harsh, but are generally the least expensive option and very light.
Your frame should be the same size as your road bike, but the saddle position, bars, and brake hoods will be different. Consider lowering your saddle as much as 1 cm from your road bike’s height assuming that your road bike saddle is correctly set up. Ask your coach if you’re not sure if your road bike saddle height is correct. A lower saddle height allows for more clearance for the bike to bounce underneath you while pedaling as well as the ability to absorb more bumps even when your leg is at the very bottom of your pedal stroke. You’ll want wider bars or some that get wider from tops to drops. Brake hoods are better positioned higher up on the bar for an easier reach. Instead of simply using them as a place to rest your hands, you’ll need the control on the uneven terrain of cyclocross courses.
Your wheel choice will make a big impact on how your bike handles. Tubular wheels are lighter, more robust, and more expensive than clinchers. For professionals who are not concerned about cost, tubular wheels are better because they are lightweight and tubular tires are suppler and have a lower risk of pinch flatting at low tire pressures. However, it is much easier to change tires for different courses and conditions with clinchers. The lower price and high quality tire options are closing the performance gap.
Whether you choose tubular or clinchers, choose a rim with a deep aero cross section. The deep rims slice their way out of standing mud and resist becoming dented out of true better than low profile rims. Lower spoke count wheels can be built on deep rims, countering the slightly higher weight of the bigger rim and thus keeping the wheel’s weight low.
Tire choices are largely personal and the subject of many debates. In general the harder the surface you’ll be racing on, the smaller the knobs you’ll need on your tires for adequate traction. Soft mud and sand will require larger broader knobs to get traction. Because no course is only one type of terrain, choosing the right tread becomes a fine balancing act. Aim to play to your personal strengths. A mountain bike racer may choose a less aggressive tread to take advantage of his experience in limited traction riding, and benefit from a tire that is a little faster on the smooth sections. For road racers who can power through smooth sections with a knobbier tire may want a more aggressive tread for help in the mud and sand not typically encountered in road racing. Also consider the course. It may be worth slipping through the mud if the muddy section is straight and short while the rest of the course is fast and dry.
During a warm up lap at a race as I rode past a group of spectators, they asked me how much tire pressure I was running. I jokingly replied, “Negative five!” because in general, the lower the tire pressure the better the traction. Realistically, for a 150 lb rider this might be 50lbs +/- 10. Start here and on your warm up lap pay extra attention to how close to bottoming out your rims you come, and then adjust your pressure accordingly. You can typically run 2-5 pounds less pressure in your front tire depending exactly how your weight is distributed on your bike.
As always, it will take some trial and error to get your rig fully dialed in. Use these suggestions as a guide to speed the process along. Good luck and keep the rubber side down.
Coach Aaron Oakes specializes in cyclocross, mountain bike and road racing and is available to take on athletes of all levels.