In a world full of absurdist concepts, I’ve got one that won’t make you blink: Your bicycle is on your shoulder and you don’t live on a second story walk-up. You are running through a farm pasture, have not committed a crime and your bicycle works perfectly well.
Sounds like a great time, huh? Such is our love of cyclocross. There’s something in this equation that doesn’t quite add up, and it’s not that we carry our bicycles. It comes when we put that bike back down and willingly lob our asses skyward. Whether we have dreams of procreation or not, the delicate business means landing sidesaddle in proximity to a collection of biology known to us primarily for its ability to remind us of what NOT to do, the event is meant only to speed our return to the pedals. Click, click—and we’re off again.
Years ago the process was a little more involved. You had to hit each pedal with your foot, flip it over and jam your foot back in. Because races took place on grass, the bicycle’s bottom bracket had to be much higher than that of a traditional road bike so the toe clips wouldn’t drag in the grass—this is a detail the Frogs figured out in the 1950s.
Fast forward to, oh say, now. Swing the right knee skyward and once safely aboard, the feet go straight into the pedal stroke, no flipping over of the pedals.
So why are bottom bracket heights on cyclocross bikes still on average 2cm higher than those on road bikes?
It wouldn’t be a cause for concern were it not for this little detail. Name another cycling event where the rider makes tighter turns? Add to that the fact that these oh-so-tight turns are conducted aboard bikes with 700C wheels and it’s fair to ask the question: What can we do to make this bike easier to turn?
The answer is simple: Make it easier to lean the bike over to carve a tight turn. Okay, so how do you do that? Simple. Lower the bottom bracket. Drop the center of gravity of the bicycle and leaning the bicycle into a turn becomes a good bit easier.
How much could it be dropped? It’s hard to say; there hasn’t been much experimentation with this. Pedaling through corners doesn’t happen to the same degree it does in crits, so dragging a pedal through the dirt isn’t a big concern.
To illustrate the point, let’s consider an example in extreme. Say you’re driving down a twisty road. Would you rather take the twists and turns in a Ford Expedition or a Mini Cooper? My preference would be for the Mini Cooper, with a center of gravity lower than most Congressional standards, it can turn circles around the SUV. Put another way, I’d rather run a steeplechase barefoot than on stilts.
I went to the trouble to build, with the help of Toby Stanton of Hot Tubes, a ‘cross bike with a low bottom bracket. In Part II I’ll describe the process of building the bike and racing it at ‘Cross Nat’s and since.
Photos courtesy Chris Milliman