darwin-t
10-18-2009, 03:20 PM
When one adjusts the BB, what happens to the varying length of the chain? Does the chain tube take care of it with the extra slack in front of it? It seems like it would change the tension of the rear derailer.....
PeterT
10-18-2009, 03:51 PM
Having a sliding BB, (total of 8" travel or less) the Der can usually take up most of the slop in the chain, ... set it up at the further most point away from the Der for chain length, and when you move it back to the closest position, the Der should have taken up the slack.
My F-RQ has a sliding seat, as well as the sliding BB, so i have to build all the cables and things going to the rear, at the furtherest point forward, and all of the cables and things going forward of the handle bars with the seat fully back, so that everything works without stretching!
If you find the Der cant take up the slack adequately, just install a second Der so that the chain is tight in any position.
PeterT
fultondp
10-18-2009, 06:09 PM
A number of years ago I made a 1/2 scale tadpole for my daughter. Knowing she would be growing and every kid on the playground would want to try it, I made the whole frame telescope. It could fit a 5 year old kid up to about an 11 year old. But I had the same issue, how to make it grow or shrink without constantly adding chain. Like PeterT, I found that simply adding another rear derailleur (with tension spring intact) in the middle of the return side chain line solved the problem nicely, and gave good chain management as a bonus. I'll see if i can dig up any pictures.
Darren
darwin-t
10-18-2009, 06:36 PM
I think I'll use that idea for my return chain.
THANKS.