Cyclocross - Cross bike geometry...

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View Full Version : Cross bike geometry...


Timo
05-31-03, 01:57 PM
Some questions for the experts. I hope you all understand my questions (some technical words are hard to find a translation for):

1.) I just bought a cheap Kinesis alu frame and fork, originally designed for a randonneur bike. I want to build a cyclocross bike with it but noticed that, compared to my roadbike, the wheelbase is much longer, including a more "lazy" Kinesis alu front fork (the "angle" of the headset tube, don't know the english word, and the fork stays).

Is this normal for a cross bike, or should it have angles and a wheelbase comparable to a roadbike?

2.) In the rear I have a short cage Shimano Ultegra and a 12-25t. cassette, but what to do in front? A single blade setup (Holland is flat enough) and I'm considering two options:

A.) Shimano Ultegra cranks with 42t chainring, Spooky chainguards and an Ultegra 118.5mm bottom bracket

B.) Shimano XT cranks with 44t chainring and a Roox Chaindog (or alternative a Rohlof CC8290 Kettenführung)

Which opinion would be best? It appears to me that I save weight with option B but does is work as good as option A? Also, does anyone know which bottom bracket length I should use for option B in order to get a good working chainline?

3.) I've got my old set of Spinergy Rev-X roadwheels. Can I use them for cyclocross?

Thanks in advance,
Timo


Kev
05-31-03, 03:11 PM
I"m not sure on the geometry so can't answer that one.

2 Since mostly flat should work fine, you can always swap the cassette later if you need to. The wait you save with a single would be offset with the chainguards or chain dog.. And it is minimal weight savings, if I remember correctly the 118 BB goes with a tripple and 109 goes with the double crankset, I could be wrong though.

3. Any wheelset will actualy work, but they take quite a beating if you are riding them off-road. Alot more so then riding on the roads so is up to you :)

Timo
06-01-03, 12:35 PM
Thanks Kev :)

I just checked. My Kinesis cyclocross/trekking frame has a wheelbase (axle to axle) of 109cm (frame heigth is 60cm) Is this a common wheelbase for a cross bike?