Cyclocross - cannondale cyclocross sizing

hey-

i've read some stuff here and there online regarding cannondale's sizing on their cyclocross bikes. one guy recommended downsizing by 4 cm (i.e. if you ride a 54cm road frame, buy a 50cm cdale cross frame). cdale's cross geometry page states that you should downsize by one size to retain the same top tube length as your standard size but get more standover height.

i'm eyeing a used 54cm 2005 cannondale xr1000 disc cross bike. i ride a 54cm felt f55. felt specs are very near in top tube length etc., but the standover height is what concerns me...giving credence to cdale's statement. the 2006 version of their cross bike lists a standover height of 82.3cm. my felt has a standover of 77.6cm. that's a big difference, esp during a cross race when you are jumping over the top tube all the time...

thoughts/experience with the cdale sizing? thanks!!!

I have a 52cm Cannondale road bike, and a 50cm Cannondale cross bike. The cross bike is a tiny bit shorter in the top tube, but the road bike has gobs more standover. Go figure.

-James

I ride a 58cm C'dale CAAD7 roadie, but my C'dale CX is a 56cm. As previously mentioned, the TT is a little shorter on the CX, but like that on a CX race bike. As for the stand over height, between the higher BB clearance and the fat tires, the TT noticeably closer to the boys then on the road bike. I'm generally not fan of compact frames, but I'm actually glad that this has a sloping TT!

I ride a 2005 C'dale CX (canti's, no disk). I bought it new, and had it sized same as any road bike. If the bike is too small, then that top tube is definately gonna be way too short. I stepped onto the C'dale at the next size down (going from a 52 cm to a 50cm) and the difference was night and day.

This is a bike where you want to get the sizing absolutely right, and I would skip the used bike if you're unsure of the sizing. It's not worth saving money on a used bike that simply might not fit.

At what point in a cross race are you jumping over the top tube?

When in a race are you standing astride the bike with both feet on the ground?

None of this ever happens.

Standover is a nonissue and is only important for convenient administrative handling of the bike. At most, after the race you can stand there leaning over with your forearms on the bars talking to your new buds. THat's the only time I've ever found standover important.

Ron

Well I suppose the SO is an issue if you happen to miss or slip off the saddle...you know, if you're really fatigued during the final laps or something like that.

Hmm...and while not directly related to how close your boys are to the TT, wouldn't the height of the TT relative to your elbow and shoulder height from the ground, affect how high you can lift your bike during one on those suit-case pick ups? And since this height is basically the SO height, it could factor in...

Yeah, I know, it's a stretch...

Sure, you miss a pedal or something and end up with a foot on the ground. Still never hit my nads. I wouldn't want a bike with negative clearance, but I really don't feel the need for a lot of space.

You're right the higher SO isn't going to come up as far off the ground with a suitcase carry.

Ron