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How much difference?(7 posts)

How much difference?collinsc
Aug 2, 2003 10:26 AM
Take two bikes, made of the same stuff, nearly identical geometries, but one has a 74 STA and 40cm CS, the other, 73.5 STA and 40.3 CS
The TTs are 56 and 56.5 respectively, so I imagine the common theory about 1 degree of STA being ~ 1.2 cm applies to fit here. I guess that would mean that weight distribution would remain nearly the same on each bike.

If that is right, how much difference in ride can a third of a centimeter make on the chainstays?
You have just made my headache come back...nmthatsmybush
Aug 2, 2003 1:19 PM
Aug 2, 2003 1:58 PM
Man, you're overthinking. Ride is determined by many other things than chainstay length and a fraction of a centimeter is negligible.

The headtube angle and fork rake both have an effect on wheelbase.
guys, guys...collinsc
Aug 2, 2003 4:13 PM
I was looking at the angles with as much skepticism as anything else.

I know, too, how much the front end effects things. It just so happens that both these frames choose to keep those values a secret. I was simply curious, seeing all these geometry charts, and their tiny differences. I know just how small half a centimeter is.
OK, breath slowly into the paper bag!Kerry Irons
Aug 2, 2003 4:05 PM
Your saddle adjustment will overwhelm the STA, unless the saddle was already all the way forward or back. 3mm (look at a ruler!) will not affect handling at all. Front center distance, stem length, HTA, and fork offset will have affects that can swamp these differences. As noted by another poster, you're thinking too hard!
Front centercollinsc
Aug 2, 2003 4:14 PM
This is one I havent figured out, I know what it is, but not what it really means, or why it matters. Could you explain?
valuable info...C-40
Aug 2, 2003 8:00 PM
Front center can tell you if the frame is likely to produce toe overlap.

For instance, my 54cm Colnago has a front-center dimension of nearly 59cm, while my Fondriest has a much shorter 57cm dimension, (although the geometry chart claimed it was 58cm). I only checked the front-center on the Fondriest after I lightly grazed the tip of my shoe with the front wheel, during a start from a stop light. A little toe overlap is no big deal, but major overlap requires a little more attention during slow speed maneuvers.