Sorry If this is a dumb question but I am trying to learn more about bike maintenance and just swapped my chain for the first time. Tested it out and it seems to work fine, but I noticed that when at my lowest gear with no force on the pedals the chain makes slight contact with the frame of the bike. As soon as I apply force to the pedals and reduce the slack on the chain it comes back off of the frame but I was wondering if this is something I should be worried about? Should I go ahead and remove a link with a tool? Thank you in advance!
by saxmanserg
10 Comments
Its too long, there should be a name on your shifter if you look it up you should find a guide to determine the correct chain lenght for that shifter. Make sure the chain is routed correctly too.
Did you take any links out of the replacement chain? Could be too long.
Did you size the chain or just install the way it came? It needs to be adjusted to the proper length.
Did you cut the chain to the correct length? Measure the new chain to the same length as the old chain.
Take a link or two out. Or just match the length to the length of the old chain. Assuming it fit before and you didn’t change anything else on the bike.
It’s too long, the derailleur can’t pull any more slack out cause the cage is fully rotated.
>Should I go ahead and remove a link with a tool?
Not just “a link.” You must size the chain to the correct length for your specific drivetrain setup. Lots of instructions online if you google it.
here’s the simplest and most reliable way to size a chain:
1. take the quick link out and remove the chain from the derailleur completely.
2. wrap the chain around the biggest chainring in front and the biggest cog in back (don’t run it through the derailleur).
3. pull the chain tight and see where the ends meet.
4. from that point, add two full links (one inner + one outer).
5. break the chain there, then route it back through the derailleur correctly and reinstall the quick link.
after that, shift through all the gears and make sure the derailleur still has tension in the smallest gear and isn’t over-stretched in the biggest gear. if the chain was rubbing the frame in low gear, it was likely too long.
also double-check the chain is routed through the derailleur cage correctly. it’s really easy to miss a guide tab and that can cause weird slack and rubbing.
Make sure and check that the new chain is the same length and then make sure you routed the chain thru the rear derailleur the proper way. Plentt of pic on the web and youtube. If those two are good then come back here and post again. It could be your derailleur clutch is worn out or it slipped (the spiring inside) and your not getting tension like as before.
show us how the derailleur looks when you go big chainring + big cassete
same for small-small show us the chain tension
you definitely need to take out at least one link because it shouldn’t be slacking like that in any combination
Here is the how to video for sizing your chain:
https://www.parktool.com/en-us/blog/repair-help/chain-length-sizing
If you are new then here is some advice… anytime you are doing something new, always check the “help me fix it” section of the Park Tool website first. This is the most concise collection of professionally produced how to videos and articles anywhere on the internet.
https://www.parktool.com/en-us/