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

New: Take part in the February Giveaway for Villy Custom Elvis beach cruiser valued at $590 💙


Chain bounces off drivetrain on hard bumps
#1
I have a GT ZuM with a 38T single chainring front w/ a bashguard, a Shimano CS-HG30-8I 8-speed cassette and what I assume is an 8-speed chain. I have an issue with the the chain bouncing around (both up/down and some side-to-side swing) when I am in the highest gears (11T and 13T). Under some conditions, the chain disengages from the drivetrain near the crankset and falls on the bottom bracket area of the frame. The two most common conditions for this are very bumpy riding surfaces (ex: grass) and when I stop pedaling abruptly after vigorous accelerating (sometimes backpedaling a slight bit).

I considered the problem being too long of a chain, but it came with the bike, I assume the previous owner did not modify the drivetrain, and I also doubt I would be able to return to first gear (32T) if it were any shorter.

Is this common? Does anyone have any idea as to how I can prevent this from happening? I am wondering if there are any sort of "inner bash guards" sold out there that I could mount to the frame side of the chainring so that the chain would have a "side wall" stopping it from sliding out and keep it in track with the help of the real bash guard.
  Reply
#2
There are two simple things you can try before going to the chain..
http://bikeride.com/adjust-front-derailer/ then
http://bikeride.com/adjust-rear-derailleur/ .
If those two things do not help try to take a picture or short video and post it.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
  Reply
#3
I don't have any experience with them myself, but downhill riders with a single chainring up front, often use a chain guide/device to prevent the chain bouncing off.

Take a look at these for some ideas: http://www.bikeradar.com/gear/category/components/chain-guide
  Reply
#4
(07-17-2010, 12:34 PM)xerxes Wrote:  I don't have any experience with them myself, but downhill riders with a single chainring up front, often use a chain guide/device to prevent the chain bouncing off.

Take a look at these for some ideas: http://www.bikeradar.com/gear/category/components/chain-guide

That seems like what I want, thanks!
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Identify and Appraise Vintage Torelli Ro...
Yesterday 05:21 PM
Vintage bike stuff
Yesterday 11:26 AM
Hello from Oregon!
Yesterday 04:07 AM
Cracked shimano DI2 front derailleur
02-07-2023 10:51 AM
Bikepacking/gravel bikes
02-07-2023 03:45 AM
Help riding this tricycle
02-05-2023 01:00 PM
What was your first bicycle?
02-05-2023 10:02 AM
Riding in a foreign country?
02-04-2023 02:02 PM
Club Rides
02-04-2023 10:08 AM
ONLINE BIKE PURCHASING & SHIPPING
02-03-2023 07:48 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. Sybian
15 posts
no avatar 2. enkei
14 posts
no avatar 3. Jason in Ecuador
11 posts
no avatar 4. Lss555
11 posts
no avatar 5. Talha
11 posts