Why does...
Author
Discussion

anonymous-user

Original Poster:

83 months

Tuesday 24th January 2017
quotequote all
[redacted]

RCBRG

603 posts

170 months

Tuesday 24th January 2017
quotequote all
sounds like your gears are in need of adjustment to me

Benmac

1,697 posts

245 months

Tuesday 24th January 2017
quotequote all
Also worth checking your freehub is spinning, erm, freely. If it is sticking a bit then it'll slacken the chain a touch as you start to pedal backwards which would help it drop off.

Big Rod

6,264 posts

245 months

Tuesday 24th January 2017
quotequote all
I had something similar to this and found there was excessive play in my bottom bracket.

New bracket = no more problem.

It only lasted 700 miles too but I'm advised it's a consumable item. :-/

louiebaby

10,942 posts

220 months

Tuesday 24th January 2017
quotequote all
Benmac said:
Also worth checking your freehub is spinning, erm, freely. If it is sticking a bit then it'll slacken the chain a touch as you start to pedal backwards which would help it drop off.
Also worth making sure the jockey wheels aren't gunked up, especially at this time of the year...

okgo

42,085 posts

227 months

Tuesday 24th January 2017
quotequote all
Poor indexing more than likely, and/or possible limit screw adjustment needed.

E65Ross

36,729 posts

241 months

Tuesday 24th January 2017
quotequote all
Big Rod said:
I had something similar to this and found there was excessive play in my bottom bracket.

New bracket = no more problem.

It only lasted 700 miles too but I'm advised it's a consumable item. :-/
Consumable, yes....but I reckon I got well over 10x that out of my last BB.

WestyCarl

4,057 posts

154 months

Tuesday 24th January 2017
quotequote all
If it only happens when pedaling backwards, check the read mech isn't bent inwards towards the wheel

okgo

42,085 posts

227 months

Tuesday 24th January 2017
quotequote all
E65Ross said:
Consumable, yes....but I reckon I got well over 10x that out of my last BB.
Mine has done nearly 20,000 miles. Still fine.

toast boy

1,242 posts

255 months

Tuesday 24th January 2017
quotequote all
Sounds like your gears need adjustment... although this also happened to me a while ago and I found that I had one slightly bent link in my chain. It was fine going forwards but going backwards it would throw the chain off.

Eddh

4,656 posts

221 months

Tuesday 24th January 2017
quotequote all
Big Rod said:
I had something similar to this and found there was excessive play in my bottom bracket.

New bracket = no more problem.

It only lasted 700 miles too but I'm advised it's a consumable item. :-/
If it is a SRAM one you'd do well to get 70 miles out of it...

Big Rod

6,264 posts

245 months

Wednesday 25th January 2017
quotequote all
Eddh said:
Big Rod said:
I had something similar to this and found there was excessive play in my bottom bracket.

New bracket = no more problem.

It only lasted 700 miles too but I'm advised it's a consumable item. :-/
If it is a SRAM one you'd do well to get 70 miles out of it...
It was on an inexpensive Cross bike and it cost something like £35 to have a decent one installed so I'm not losing sleep over it.

Stiggolas

361 posts

176 months

Wednesday 25th January 2017
quotequote all
If the chain otherwise moves freely backwards, it points to a chain line problem. If the BB is too wide, the chain will do this (unlikely if its too narrow) so that's where I'd start. I once had a spare BB lying around and fitted it to a mountain bike. It was 3mm too wide and gave exactly the symptoms you describe.

gazza285

11,113 posts

237 months

Wednesday 25th January 2017
quotequote all
Try pedalling forwards, it's like magic...

Daveyraveygravey

2,106 posts

213 months

Wednesday 25th January 2017
quotequote all
gazza285 said:
Try pedalling forwards, it's like magic...
I was thinking that!

citizenmtb

1,495 posts

207 months

Wednesday 25th January 2017
quotequote all
I've been curious, is this the same for rolling a bike backwards?

I always thought it was cheap gear, but even my DI2 Ultegra does it.

anonymous-user

Original Poster:

83 months

Wednesday 25th January 2017
quotequote all
Sounds like your mech isn't aligned and the tail is pushing the chain onto the inner ring when you pedal backwards

SoliD

1,507 posts

246 months

Wednesday 25th January 2017
quotequote all
Benmac said:
Also worth checking your freehub is spinning, erm, freely. If it is sticking a bit then it'll slacken the chain a touch as you start to pedal backwards which would help it drop off.
This, noticed my single chainring CX bike wasn't spinning well backwards the other day, just a loose freehub, quick grease and tighten and all sorted.

Herman Toothrot

6,702 posts

227 months

Wednesday 25th January 2017
quotequote all
Poor chainline. Lots of people who swap mountain bikes to single ring setups complain about this, it's not an issue if the right parts with correct offsets are used.

Kell

1,708 posts

237 months

Thursday 26th January 2017
quotequote all
Stiggolas said:
If the chain otherwise moves freely backwards, it points to a chain line problem. If the BB is too wide, the chain will do this (unlikely if its too narrow) so that's where I'd start. I once had a spare BB lying around and fitted it to a mountain bike. It was 3mm too wide and gave exactly the symptoms you describe.
Genuine question...

If the BB is too wide, wouldn't the chain be pushed off the big ring to the outside rather than off the little one on the inside.