wallymann

when i set the chain-length to *just* fit on big-big combo, when i shift to small-small the chain is like 3 links too long.

i ran a c-record back in the late '80s, but that was my young years and i rolled 53/42 rings and 13-21 cogset...nowhere near as much range of gearing.

looks like the c-record rear mech just doesnt have alot of range of motion to account for this gearing range *or* i'm missing some arcane bit of knowledge on how to config a c-record rear mech.

i'd appreciate any help getting this to work! as an fyi, my c-record rear mech is one of the latest ones made, in the early '90s.

edit: the c-record rear mech supposedly has a 30t capacity, and my combo only requires 25 (14 for rings, 11 for cogs). i must be doing something wrong.

repechage

You did not state HOW many cogs in the rear, if 8 then it may not work, the swing is not helping as it swings in it goes up fast and you lose what you need distance from the cogs.

Beyond that the jockey cage has I think two or more stops, reset it to catch the spring that provides the most wrap.

wallymann

yep - 8spd. although i dont see how that matters.

with 8 cogs covering the equivalent gearing range, the % from lowest to highest is the same and the average % change for each shift will be smaller (same diff broken up into smaller slices) -- "as it swings in it goes up fast" -- that shouldnt matter whether 8spd or 7spd, the "going up" is a function of the cog SIZES not the total number of cogs.

you mentioned "two or more stops"...i'll take a closer looksee at the stop for the lower pivot. i glanced at it and didnt notice any obvious way to re-position the stop. maybe i'll just back it out and see what i see...

thx for the info.

wallymann

i completely *removed* the travel-stop for the lower pivot, to allow maximal cage swing forward. that additional range allowed me to add in 1 more link, that along with some tweaks to the b-screw adjustment i can comfortably shift thru the entire big-big to small-small range w/o problems.

actually, i can only go small-ring with next-to-smallest-cog. i'm going to replace that 39 with a 42 so i'll be able to shift thru the entire range.

ps. i know doing big-big and small-small are ill-advised cross-chain combos, but i have always strongly believed that quality components should be able to cover that range w/o damage to anything!