Cyclocross - What makes a cross bike a cross bike?

I've read a lot about cyclocross bikes but I'm still not certain what actually makes a cross-bike. The one thing I've seen a lot is the ability to accept wider tires. But at what point does a road bike become a cross bike?

I've also seen a lot of people use them as commuters. I'm assuming this is because they can handle dirt and pavement equally well?

aside from cantilever brake mounts and the ability to accept wider tires, 'cross bikes have higher bottom brackets than a traditional road bike. like a criterium or track bike, a 'cross bike will have a taller standover clearance than a road bike of the same size... the geometry is more aggressive than a touring bike, which looks similar in the respect of tire clearance and brakes... i'm sure i'm probably leaving something out, but i'm pretty new to 'cross bikes.

also, the cross bike's steering is a bit more relaxed and less twitchy than a road bike (typical head tube angles : road 73.5, cross 72, mtb 71 degrees), and the rider position is a bit more upright than a road bike, but lower and more aero than a hybrid.

Sometimes, the gear cables will route along the top tube, like a mountain bike to keep them from getting muddied and bashed up along the bottom bracket.

As far as bottom bracket height is concerned, there is very little difference from my Bianchi Axis and my Eros frames (both lugged "Superset II" steel, same size).

I was curious about this so I one day I measured the BB height while using the same wheelset (700 x 20 road) and the difference is only a quarter of an inch. Of course I would use tires larger than 20mm for cross so that will make the BB height substantially higher.

What is interesting is the wheelbase of my Axis is 2 1/2 inches longer than my lugged steel Colnago road bike despite the Axis's much smaller frame.

I read an interesting note in 'Cyclo-Cross Training & Technique' by Simon Burney , the bible of cyclocross apparently, that the BB height idea came in the old days when they still used clips and straps. The BB was higher so that the cage would not get caught up in the dirt to make mounting faster. I don't know if it is a coincidence that it also is an advantage or that the tradition just stuck with modern designs.

In short, the cyclocross bike is to the cycling world what the rally car is the the automobile world. To understand exactly what a 'cross bike is is to understand cyclocross itself.

Check out cyclocrossworld.com to check it out

The Brake Levers are inverted. I hope I do not offend the non-racer crowd; but racing bikes also have the brake cables inverted. In other words, road bikes usually have the back brakes connected to the right front brake lever. Most cross racers set up the rear brake on the left side of the handle bars. When dismounting for an obstacle with only one foot on the pedals as the leg comes to the insde ---- The dismount is usually on the left. Therefore the right hand is usually on the top tube and the left hand is on the bars. This is why the rear brake cable is directed to the left brake lever.

Also - Cross bikes do not usually have chain rings as large as road bikes. Some guys even use single front chain rings. Even if people have doubles, the larger one is only about a 46 or something like that.

In short, the cyclocross bike is to the cycling world what the rally car is the the automobile world.....

I thought that I was the only one to notice the similarities.

I thought that I was the only one to notice the similarities.

That's one of the many things that makes 'cross bikes so damn sexy!

When I finally upgrade my current commuter to a cross bike, it's getting painted world rally blue.

- cross bikes have road bars, NOT flat bars!

:-)

Not always, there's no requirement for drop bars in any level of racing I believe. I've been told it was more common in the past for high level dudes to rock a flat bar, but not so much anymore.

Not always, there's no requirement for drop bars in any level of racing I believe. I've been told it was more common in the past for high level dudes to rock a flat bar, but not so much anymore.

- i reviewed the app forms at:

http://www.usacycling.org/news/user/story.php?id=775

and did not see any criteria regarding equipment!!!! i guess i could use a gas-powered vehicle?

- can *anyone* post a link to required equipment and/or restrictions for U.S. Cyclocross events?

- tia!

(and tks to endform for pointing out my possible misperception [i'm in training for next year])...

:-)

The thing to remember is that there is no *pure* bike anymore. Road bikes, MTBs, cross bikes, touring bikes.... all barrow from eachother. The MTB craze of the 80's completely changed road bikes....

Cross bikes are hybrid between MTBs and road bikes-- whatever that means

I read an interesting note in 'Cyclo-Cross Training & Technique' by Simon Burney , the bible of cyclocross apparently, that the BB height idea came in the old days when they still used clips and straps. The BB was higher so that the cage would not get caught up in the dirt to make mounting faster. I don't know if it is a coincidence that it also is an advantage or that the tradition just stuck with modern designs.

Depending on the course that higher BB is still important. It helps keep your pedals out of the deep mud and gives clearance over some of the nastier, rideable obstacles on a course. True it isn't as big a deal as in the clips and straps days, especially on those mostly smooth European courses I see on video, but for the MTB influenced courses that we see it sure makes a difference. Besides, it's good for guys like me who use their cross bike for playing on the single track.

Ron