How to Convert a Road or Mountain Bike into a 'Cross Bike

Written by

Two Mountain Bikers Talking


Previously, I presented cyclocross as an excellent off-season alternative to mountain bike racing, and gave you guidelines to use it as such.

Here, I will give you advice on setting up your equipment to train and race.

Specific cyclocross bikes are available, both as framesets and complete bikes, in a broad range of prices from a wide variety of manufacturers. But if you've already got a garage full of bikes, you might consider modifying one of them instead of adding yet another.

"Many cyclists have raced cyclocross on doctored road bikes, mountain bikes and 'cross bikes," says Patrick O'Grady, a cyclocross racer and race promotor from Colorado.

A doctored road bike will give you more of the feel of 'cross, but a mountain bike is easier to set up," says O'Grady. "However, since 'cross, for most of us, is a sideline--a way to stay fit and build strength for road or mountain biking--consider using whichever bike is your primary racing machine."

Converting a Road Bike

Your road frame will probably have more aggressive angles, less tire clearance and a lower bottom bracket than a 'cross frame, but it'll serve for starters.

Get rid of the bottle cages--you're going to be shoving your shoulder through that main triangle for run-ups. Lose the frame pump and saddle bag, too.

Remove the pedals and replace them with whatever you're using on your mountain bike. Don't forget your off-road shoes. Raise your stem a centimeter, lower your saddle by the same amount, and move your brake levers a tad farther up the bars for a more upright riding position. If your bar tape is one of those slippery brands, consider something with a little more grip to it.

At the other end of the bike, swap your straight-block for a 13, 26 or 28 and your slicks for knobbies. Sewups are best, but clinchers will do, if you don't mind the occasional pinch flat (a spare wheelset for the pit is an excellent idea for such occasions).

Vittoria Mastercross and Normal Cross are excellent all-conditions fronts, with a file tread pattern. Wolber 28 Cross Extra or Clement Grifo Neve are all-purpose rears, with an arrow-and-block tread. If you're going with clinchers, the Vredestein Campo (700 x 28 and 32) is the best around, while the Hutchinson Cross mimics the Wolber nicely. Ritchey's SpeedMax Cross is supposed to be an excellent tire, too.

Your 53/39 crankset will do as is; snug your front derailleur up to the big ring to keep your chain from bouncing off as you jounce across hill and dale. If you've got $25 to spend on a 48-tooth outer ring, and time to rearrange your front derailleur, replace that 53.

Shimano STI brake levers are the coming thing in 'cross, so if you're using either on the road, keep it for the dirt. Still shifting from the downtube, or worried about foul weather or crash damage? Invest $100 or so in the aero brake levers and bar-end shifters of your choice. You'll save weight, and bar ends are nearly indestructible.

However you decide to shift, consider rearranging your brake cables so that your rear brake is on the left; it's nice to be able to modulate your speed when you're rumbling up to a barrier in a half-dismount, with your left hand on the bars and your right on the top tube.

Your road pads will probably suffice for dry conditions. And when the going gets gooey, the minimal tire clearance of a road frame is going to set you afoot in short order anyway.

Converting a Mountain Bike

Mountain bikes are indeed legal in American cyclocross, and this may be the best way to get your feet muddy. A few aficionados may turn up their noses when they see you with your straight bars and fat tires, but you'll spend less time and money getting a mountain bike cyclocross-ready, which should lessen the sting somewhat.

Pull off your bottle cages, saddle bag and pump. Do the same with the bar ends, banned by U.S. Cycling Federation. Finally, swap the fat rubber for something a little skinnier (26" x l.5"), which will lower your rolling resistance while increasing your tire clearance.

There you have it!