Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the November Giveaway for the Fiido D11 folding sport e-bike


Gears shift and chain jumps while coasting
#1
Hi, I bought a barely used mountain bike from a friend. It rode great with no problems for a while, then I started noticing the rear derailleur loosening - like I was changing gears and making a clicking noise - whenever I was coasting and not pedaling. When I did begin pedaling again, the chain was sometimes still slack but would catch after a second. It got progressively worse and now whenever I stop pedaling or brake, the chain gets slack and jumps off onto the axle - (almost killed myself at a busy intersection). I did some research and watched a couple of videos on adjusting tension, etc. and think that is probably the problem, but wanted to get some "expert" advice from ya'll before I started tinkering on my own. Any ideas? Thanks!
  Reply
#2
I'm not sure if I understand you right but-
Does the chain go slack on the top run when you stop pedaling?
If you manually push the bike forward does the chainset also turn because the chain is going round?
If so then it sounds like your freewheel is jamming up. Turn the pedals backwards and watch the dérailleur. It should stay hanging down but if it screws upwards then take out the back wheel and try turning the freewheel by hand. It should spin backwards with ease. Make sure nothing has got between the freewheel and the hub spokes (string or rag).
If not like the above then ignore my theory. ಠ_ಠ
Ride hard or ride home alone!
  Reply
#3
Thanks Cycler. Yes, the chain goes slack on top. Yes, I think the chainset turns too - but I'll have to check for sure when I get home. The derailleur pulls upward whenever I stop pedaling and I'm sure it does when I pedal backward too. I took the back wheel off and cleaned everything and I'm pretty sure the freewheel could spin, but I don't remember it being with ease - by any stretch. Thanks for the tips!
  Reply
#4
Hello Souza,

The problem is not your derailleur but your freewheel/freehub body.

There is too much gunk inside and it just makes it stick. When you stop pedaling to just coast, your rear wheel is still rotating obviously and the stickiness inside your freewheel makes it want to go forward anyway. This causes your untensioned chain (the bottom part) to be pulled upward over the freewheel and as it does, it ends up tensioning your derailleur at its maximum.

You can try and remedy the situation by using some sort of degreaser that you would shoot through the back of a freewheel or of a freehub body. Which means you need to disassemble your hub in order to do so. And then you need to relube once the degreaser has completely been drained from the system.

If you are using a freewheel, a replacement can be had for as low as $10 nowadays so maybe go this way instead of degreasing. It will save you time and you will be sure that it will not happen again.

I hope this helps.

Have a great day!
  Reply
#5
Thanks! That makes perfect sense and your description is exactly what seems to be happening. I'm all about spending $10 rather than playing grease monkey. Thanks again!
Souza
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Seeking recommendations
Yesterday 06:18 PM
Please help me identify this old bicycle...
Yesterday 02:46 AM
What is your dream cycling destination?
Yesterday 02:33 AM
LYGIE AND ATALA WINTER PROJECTS
11-30-2021 10:34 AM
Yet another bike ID thread (Pseudo-Batta...
11-30-2021 06:18 AM
Schwinn meridian fork replacement
11-30-2021 12:41 AM
Help! Trying to identify this bike
11-29-2021 07:20 PM
New Memeber
11-27-2021 06:51 PM
Budget Carbon Frames! ...who has bought...
11-26-2021 12:45 AM
Cycling motivation through the dark mont...
11-25-2021 06:28 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. ReapThaWhirlwind
27 posts
no avatar 2. Jesper
17 posts
no avatar 3. jeffg
10 posts
no avatar 4. steven chen
6 posts
no avatar 5. Zviedrs
5 posts