Framebuilders - Seat stay/chain stay?

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View Full Version : Seat stay/chain stay?


meech151
09-03-09, 02:31 PM
Being a new frame builder I am constantly running into situations that are new to me but some of you have already encountered. My question is, I have an old pair of S-bend seat stays, I believe 17mm, that i cut too short a while back and I saving them for that frame that eventually comes along so that I can use them. Today I was looking at them thinking they could make a sweet pair of chain stays, is this a good or bad idea? They seem fairly beefy, I don't think any lighter than the OX Platinum chain stays I have been using. Give me some opinions.

thanks

Dimitri


Nessism
09-03-09, 08:09 PM
17mm is way too small for chain stays. Old school std diameter tube frames used 22.2 mm chain stays and newer frames use ovalized 24mm stays.

sannerbikes700
09-03-09, 08:57 PM
Also depends who is going to ride the frame. If it is for a 100 lb lady to ride to church once a week it is probably not a problem.


NoReg
09-03-09, 11:35 PM
There are a lot of bikes that do use pretty thin chainstays. Examples are the straight 4130 stays or bontrager type deals that use 5/8" joined to 1/2" tubing, but the wall is about 1/16". Normally the fatter tubing in STs is pretty thin wall. It could be interesting as an experimental you want to try out on yourself, when you just have to know.

meech151
09-04-09, 07:12 AM
That was more or less my thinking, mainly experimental. I can't think of any frame in particular but I know I have seen some really small chain stays, maybe on old bikes or something and I don't know how thick they were. If I were to use them and put a large fillet around the base of the BB shell and then equally strong seat stays I don't see why it wouldn't work. Where would the problem be mainly, in side to side flex from torque on the crank. Also, are S-bend style stays stronger than straight or is it just for looks? Thanks for the feedback.

NoReg
09-04-09, 09:44 AM
Stronger in what aspect. The longer a stay is for a given stay length, the more flexible it will be, all else equal. The bends are to blend spacing for the hub and the brakes, or tire clearance.