Buying that Cross Bike!

BY KENNETH LUNDGREN

Some athletes may not want to add a new bike to their already enormous collection, so converting an old road bike into a cyclo-cross rig is an option… Issues to consider are using strong enough wheels (Mavic Ksyriums) and making sure you have enough clearance in the rear wheel… The wheel and the frame must have enough clearance to accomodate the fatter tires used for cross racing… Not only this, but you need the extra room to allow mud to fly through… Most racing frames today are on the tight side, so you have to make sure this is not a problem…

The other thing to consider is brakes. The cantilever brakes used on cross brakes allow much more mud clearance. Years ago, cantilever brakes used to be more powerful than road caliper brakes, but this is not the case anymore (go Dura-Ace!). However, these horseshoe road brakes will allow minimal mud clearance and if you’re on a messy course, it will make for a frustrating day…

As mentioned, the wheels are the same size — it’s the tires that are bigger, usually higher in height and fatter in width. These two clearance issues must be realistically addressed before you take that rig out there…

Gearing is also something to be considered. Cross bikes have lower gears to accomodate for the lower speeds. The standard 53/39 crank is going to be too big — you’ll be grinding too much… Compact gearing is actually a great fit for cross, the 48/34t set-up… Regarding the cassette, go bigger. With Shimano, you should look for the 25 or 27t cassette, and with SRAM utilize the 26 or 28t… I would recommend buying an entirely new drivetrain set-up — crank, chain, cassette — to ensure successful shifting…

It’s better to have that gear and not need it than to need that gear and not have it…

Pedals are also a huge decision. Look, Crank Brothers, Shimano, Time all make mountain bike pedals, but from what I’ve read the Egg Beaters (or Candy SLs) from Crank seem to be the best. Nothing worse than having clipping-in issues (or clipping-out issues, for that matter) when you need to dismount and mount at top speed, lap after lap after lap…

If you’re taking out that old road bike, you’ll have to alter the position a bit… I fit Rich Hofbauer, who took 4th in the NJ State CycloCross Championships last year, on his cross bike, and we lowered his seat significantly from his road position and raised his handlebar height, even raked the drops up more… It’s almost the opposite of time trialing, where you take the road position and pivot everything forward and down — for aerodynamics. For cross, you take that road position and pivot everything up and back… Cross is about power — in those woods, you need to be as efficient and powerful as possible… I would recommend lowering the saddle, moving it back a hair (for traction issues), and raising the height of the handlebars (getting a shorter stem is necessary).

In the end, your old race bike won’t make a GREAT cross bike, but it can make for an excellent training tool or back-up bike… You can set up this bike EXACTLY as your cross bike and do longer rides, road rides on it and such, get the body acclimated to the position…

If you have an old road bike, why not use an old mountain bike? It CAN be done… In my opinion, the biggest problem is the position — you just can’t get as aero or as aggressive on that mountain bike frame. Most frames and forks have lock-out options, so getting rigid is not a problem. And mountain bikes either have disk or V-brakes, which are VERY mud-clearance friendly… Finding narrow tires should not be a problem. You can find 1″ tires, or go as wide as 1.5″… You can also swap out the cassette, so with a bigger 12-28 and set up the front derailleur to not go into the granny ring… These are all options, but in the end you just will not go FAST enough… Seat back too far, handlebars too high, too close… Setting this bike would be fun, fun to ride, but if you want to be competitive, you’ll be disappointed…

In a perfect world, we would all buy new cyclocross bikes. It’s the most cost-efficent option, actually, and you get the most bang for your buck… Fit is crucial. I tell guys all the time: your TT bike is 3 cm smaller than your road bike — for most, this holds true. For the cross bike, you want to go a hair smaller than your road frame. I ride a 58 road bike. I rode a 57 cross bike and it felt PERFECT. I would recommend looking to get a slightly more compact position on that cross bike — will be more comfortable during those strenuous DEATH MODES in the race and will also be easier to manuever on the more technical, tighter sections of the course…

If you’re seriously looking to get a new cross rig, shop around. Obviously. Look for the differences. All cross bikes are not created equal. As mentioned earlier, one of the most critical parts of the frame is the clearance with the rear wheel. Some frames have more space that others. The drawback is a longer frame is harder to accelerate on, harder to turn with, so you should ride each bike. Key is to find a bike that handles like a sports car but also has great clearance in the rear… Nothing more frustrating than racing at a sub par level when the body is performing at an optimal level…

Another issue is bottom bracket height. Again, not all bike created equal. You would like to get a BB that’s a little higher. Most are 280. If you look, some are higher. On some courses, that extra clearance will make a HUGE difference…

Seat tube angles are also different with each company. This is personal for most. I actually prefer a steeper head tube (the time trialist in me talking). Further forward, you’ll feel more aggressive and possibly more powerful, but you can lose traction and will have trouble recruiting power from your lower back later in the race…

I see guys going out and getting uber light cross bikes. In my opinion, not necessary. You take one hit on that rail-thin aluminum frame and you’re left with a tin can. Trick is to go in the middle. Carbon not a bad option, very stiff, very forgiving… Cheaper frames are heavier because they have thicker frame tubes, but they’re also more durable.

With the drivetrain, you WILL need bigger gears… 46 or 48t and a 36t… OR compact, which actually works well on these slower cross courses… SRAM makes cassettes with 26 or 28t, and Shimano has the 25 or 27t. Either way, you don’t ever want to go bigger than a 28. For one, if you’re in that 28, you should be running!!! And, to my knowledge, none of the available derailleurs will work with a 30+t if it’s road-compatible — the derailleur cage is not long enough. If it were long enough, say goodbye to it — you’d be getting that thing caught up on cross road “furniture” rocks and roots!!!

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Kenneth Lundgren's Diary | Thursday, October 29th, 2009 | | |