Archive for May, 2007

Before I jump into the one bike or two discussion, I’ll talk a little about whether to get a bike at all. Let’s say you’re interested in racing cross and it looks like the bee’s knees. You should give it a try on your mountain bike (if you have one) or borrow your friend’s pit bike. Do a couple races and see what you think. If you get bitten by the bug, buy a bike.

I encourage racers to purchase an inexpensive race worthy bike for their first bike. if you’re patient, you can get a lot of bang for your buck by buying used. Race this “starter” bike for the season and see if you are still gung ho about cross after some cold and muddy races. If it isn’t for you, you haven’t invested a butt load of money on a bike that will sell for half of what you paid for it.

Still crazy about cross? Then it’s time to buy your race machine. That way you end up with two bikes.

What’s this about two bikes, you might ask? A cyclocross will have one or two pit areas. The best configuration is a common pit with two entrances. Many racers stick a spare set of wheels in the pit in case of a flat. However, it’s much better to have a spare bike because; 1) grabbing a spare bike is faster than a wheel change, and 2) you are insured against any mechanical, not just flats. In a muddy race, it’s a real asset to have a pit person who can clean your bikes after exchanges so you can always be on a lighter (not mud caked) and better shifting (not clogged by mud) bike.

Some of you will want to drop some ungodly sum of money on your first cross bike. While that’s fine and good, I would counsel spending a little less on the dream bike and use some of the left over scratch for that pit bike.

Here’s what I did. While I would prefer to buy new, I’m on a limited budget so I bought both of my bikes used from Ebay. One was an okay deal and the other was a great deal.

Bike 1: I purchased a Redline Conquest Pro with lots of non-stock bits from Ebay. It had been raced pretty hard. I bought it having never raced a cross race. I’d watched a race and thought it looked pretty fun so I bought the Redline. It turned out to be a size too small. Over the course of three seasons, I replaced the frame with a size larger, wheels (with some tubies), bar, stem, brakes, seat, shifters, and rear dérailleur. The specs:

’03 Redline Conquest Pro size 54cm
Alpha Q CX fork
Wheels: DA hubs laced x3 to 32 hole Reflex tubular rims
Ultegra crank 46/38
Ultegra brifters
Ultegra rear dérailleur
Ultegra front dérailleur
Ultegra cassette 12/27
SRAM chain
Avid Tri-Align II cantis (they were the shit in the mid 90’s)
Ritchey BioMax bar
Some stem
King headset
Terry Fly seat
Crank Bros Eggbeater pedals
No-name seat post

Bike 2: The next season, I purchased a Merckx Alu-cross from Ebay. The frame was damaged during shipping and the guy I bought it from worked with UPS to get the money for a new frame. I replaced the brakes and the wheels.

’03 Merckx Alu-cross with tribal paint 54cm
Wound-up CX fork
Wheels: DA hubs laced x3 to 32 hole Reflex tubular rims
Ultegra crank 46/38
Ultegra brifters
Ultegra rear dérailleur
Ultegra front dérailleur
Ultegra cassette 12/27
SRAM chain
Avid Tri-Align II cantis (they were the shit in the mid 90’s)
Deda bar
Deda stem
Ritchey headset
Terry Fly seat
Crank Bros Eggbeaters pedals
No-name seat post

FWIW, the Merckx is faster.

If you’ve raced ‘cross for a season or so, you will have come to appreciate racers’ obsession with tires. Crossers will try different combinations of rubber — and interrogate one another — in an attempt to figure out what tires are going to deliver the performance they are looking for for specific conditions. First we’ll take a look at the reasons for this obsession with rubber compounds and tread patterns and then we’ll look at why tubular tires are usually the best choice for cyclocross.

The primary surfaces traversed in cyclocross races are grass, dirt and pavement. When you mix in some rain, the grass and dirt turn into mud. A crosser wants her tires to perform well on uneven surfaces, grip well in all conditions, and not be a liability on the pavement. A racer may also elect to use different tread pattern and tire widths for different conditions. For example, the best tire for a dry course with lots of grass (file tread for low rolling resistance) will be different than the optimum tire for a muddy course (open pattern knobs to provide grip and shed mud). Since most racers have limited budgets, they will often select an all-around tire tread pattern. All-around treads should perform well in mud.

A softer rubber compound will provide better traction. The downside is that the tire will wear faster than a harder rubber. A good solution is to reserve soft compound tires for race day and train on a longer wearing tire.

Apart from tread pattern, a racer cares about tire pressure. Grass is bumpy. Transitions from one surface to another can be sharp. So what do you do? Run a low pressure to smooth out the bumps or keep the pressure a little higher to resist pinch flat over the sharp transitions? First, let’s take a look at the notion that low pressure assists performance over uneven surfaces. Other than a rider’s arms and legs, tires provide the only suspension for a cyclocross bike. Suspension is important because it increases efficiency by allowing the rider’s mass to move over the ground in a flatter trajectory. Tires offer better suspension when they have large volume and low pressure.

To run really low pressure, tubulars are almost the only choice. A Stan’s tubeless setup is another option and Erik V. does has an excellent analysis on his blog. The integrated tube and tubular rim configuration prevent virtually all pinch flats (NB: sidewall cuts are still possible when traversing objects such as pointy stick and sharp rocks). Without the risk of pinch flats, a cross racer can run absurdly low pressure (25-35 psi) and get better traction and suspension than can be had with higher pressure. Additionally, tubular tires are generally more supple than a clincher and tube configuration which results in less rolling resistance.

So that’s pretty much it. Tubulars definitely increase performance. They provide better traction, lower rolling resistance, smooth out the bumps, and resist pinch flats. Gluing isn’t painless but it isn’t as scary as some might make it out to be. I’ve had good luck picking up good quality tubular wheelsets at very reasonable prices (~$200) on Ebay. Pick up a set and give it a whirl.