Bicycle Mechanics - chain length
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
i used the trick where you wrap the largest chainring and largest cog then add 2 links, and my chain ended up being too long (problems with chain wrapping running granny front and 3rd inner cog (1-3)). took out 2 links was a little better but still had problems running a 1-3. took out 2 more links and all 8 cogs worked well for granny ring, but when i use my largest ring it couldn't get into the 3 or 4 largest cogs in the back. put one link back on and still had the problem.
my question is, is this normal? it's been a while and i never use a 1-8 or 3-1 combo but shouldn't i be able to? if it helps i'm running 22-32-44 and 12-28 cassette with SRAM 9.0SL short cage rear derailleur (rant: it's a 2000 gen derailleur with plastic parts god i hate that POS and the return spring popped out of it's seating today but it seems to still be functional? would love to get new drivetrain either newer alloy SRAM stuff or shimano okay rant over).
i used the big ring, big cog plus 2 trick too.. But it has never failed me, since..
But maybe its the fact that I am riding a roadbike..
Is your bike a full suspension bike?
07-11-03, 12:44 PM
Add 2 entire links??? That's waaaaay to many. The old rule we used was thus; using the big ring, big cog, pull the chain (inside the derailleur cage, btw) as tight as possible, then back off to the nearest possible connection. If it's less than a half link (don't forget, a link is both the inner and the outer bit), then go to the next one.
07-11-03, 01:23 PM
I do a number of things to check. I do the big-big bypassing the derailleur and add two links. I then take some white out or my wife's nail polish and mark that point.
I then go through the derailleur and go to the next connection pin, mark that!
I then go to small-small through the derailleur and set length to where the jockey pulleys are nearly vertical.
If the three are the same, I'm happy. If different, I split the difference, but err on the side of too long vs. too short.
thanks guys... i've never had this problem before, but i suspect it's the POS sram composite derailleur that's giving me the headache. i think the old shimanos i used to run allowed for more movement of the derailleur. plus the cage is made of plastic and is pretty short. i will try the largest/largest through derailleur and pulling it tight, then backing off to nearest position. btw i can't do half-links adjustment because i run a sram powerlink, so there's no way i can be that exact.
Could the short cage be causing problems, I've always seen long cages with tripple front. Since the chain requires so much more chain to run a tripple up front vs. a double.
07-12-03, 12:03 PM
move the derraileur to the smallest cog, then put the chain through all the parts (rear der,front der,chain tensioner,etc) hold both ends of the chain and pull. yu must keep pulling until the bottom pulley wheel is just below the first pulley wheel. put chain together removing as many links as is needed to achieve this. voila perfect chain length. if this is too confusing tell me and i will TRY and psot pics.
07-12-03, 12:05 PM
oh sorry ive just realised. im used to my single chainring at the front. i dont about a tripple chainring at the front. sorry
07-13-03, 02:40 AM
Get a long arm Derrailleur
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.