Chain “bunching” when back pedalling

[Fifelad]

As the title says, but only when in the small chainring. Could it be due to the chain being stretched ? I am going to
renew the chain and cassette anyway as they are getting to that stage. Before anyone says you pedal forward anyway, you often have to back pedal when adjusting pedal position after stopping.

 

[ColinJ]

If it isn't due to stiff links in the chain, then it might be due to a sticky freehub?

What happens if you push the bike forwards?

 

[slowmotion]

If it isn't due to stiff links in the chain, then it might be due to a sticky freehub?

What happens if you push the bike forwards?

Yep. I was told it might be a freehub not running freely too. It's really annoying because it often makes the chain fall off the chainrings.

 

[Fifelad]

If it isn't due to stiff links in the chain, then it might be due to a sticky freehub?

What happens if you push the bike forwards?

No problem when pedalling forward

 

[ColinJ]

Yep. I was told it might be a freehub not running freely too.

I had one try to drive the chain round as I was freewheeling on a fast descent. It was a bit scary because I wasn't sure if the chain could end up getting tangled up somehow and jamming the wheel!

 

[ColinJ]

No problem when pedalling forward

PUSHING - not pedalling!

Standing on the ground and making the bike move with your hand on the saddle.

 

[Rusty Nails]

That's happened to me twice. Each time it's been fixed by cleaning and oiling the chain.

The stiff chain turned OK when pedalling as it was under pressure, but when backpedalling the pressure was not there to overcome the stiffness of the chainlinks, hence the bunching.

 

[Fifelad]

PUSHING - not pedalling!

Standing on the ground and making the bike move with your hand on the saddle.

No problem either

 

[Fifelad]

Perhaps a stiff link, never crossed my mind as I clean and lube the chain regularly, but having said that not a great deal of use lately...🤔

 

[ColinJ]

No problem either

It sounds like the freehub is okay then. Have you got any stiff links in the chain?

PS Cross-posted! Yes, just go round the chain and check if any are not properly floppy.

 

[Big John]

Fancy admitting on Cyclechat to being on the small ring! 😉

Either measure or use a guage to see if the chain is worn. Take a look at the teeth and shape of the curve between the teeth to see if the most commonly used sprockets are worn. Likewise take a look at the inner chain ring to check for wear (mine never gets used, of course 🤥). All looks good? Colin's suggestion is favourite. Sticky freehub or stiff link(s).

 

[Fifelad]

The chain is nearing 100% wear as per chain wear guage. Sounds like it might be a stiff link.

 

[ColinJ]

The chain is nearing 100% wear as per chain wear guage. Sounds like it might be a stiff link.

I was going to say that freeing a stiff link isn't difficult, but it sounds like you need a new chain anyway.

It is possible that your cassette and/or chainrings might also be severely worn. Sometimes a new chain will slip and the other parts will need to be changed too.

 

[Tigerbiten]

Check the alignment of the rear derailleur and for wear.
I've had that type of problem with a slightly bent mech hanger, the chain ran free in the normal direction but was slightly sticky in reverse.
Also a draggy jockey wheel can be same as a draggy freewheel when you backpedal.

Luck .........

 

[Cycleops]

Could be any of the foregoing. Flush the freehub out with some WD40 too.
New chain and cassette might not be a bad idea.