Yeah, bikes are not made to pedal backwards. I know that. But still, sometimes when I pedalback, even a half - circle, my chain gets stuck because it automatically shifts in easier gears. I don't remember having this problem before. It gets annoying after a while.

Since there is only a jockey pulley on the bottom side of the rear derailluer, pedaling backwards will rarely work perfectly. Just pretty much just the way it is.

I had a problem similar a while back. It was because my chain was too long, I removed one link and it fixed it. Another cause can be a dirty drivetrain or even something as simple as a sticky pulley on the rear derailleur.

That will fix the issue, thanks!

before you shorten the chain, try cleaning and oiling it, as well as the RD bearings...the reason it sticks is beacuse the links and RD are binding because of dirt and friction

Actually you should be able pedal the drivetrain backwards. If you can't then something needs adjusting or fixing:

It could be:
- Dirt on parts/chains like mentioned above
- Bent hanger, incorrect alignment.
- Out of place cable tension (try pedaling backwards while adjusting the tension)
- Out of place limit screws

Bet these are just off the top of my head.

Oh yeh, it could be a tight link. The joining link is usually the cuplrit for a tight link that dosn't go back into place after comeing out of the jockey wheels. This can catch up sometiems.

Make sure you don't have any bent teeth on your chainring.

Yeah, I made a mistake actually. While backward pedaling, chain doesn't go to the easiest gears, it goes to the harder ones. And this happens only when I'm in easy gears, like 8-7-6. Chain never skips when I'm in harder gears like 4-3-2-1.

I still think that chain is a bit too long, so that might fix the issue. I will see my friend at the lbs today, see if I can use his tools

Thanks for replies

Good post. I'll also mention B-screw adjustment. If the top pulley and rear cog come into contact this can also cause skipping while pedaling backwards, while it may not be immediately apparent pedaling forward.

Had same problem. It was the chain; it was made of a very weak metal and was too flexible sideways.
Was able to pedal forward. The derailleurs were keeping the chain in place, but when tried to pedal backward the chain slipped from both chain-ring and freewheel. It didn't happen on all speeds. Just for the sprockets that were not aligned with the chain-ring. Out of 7 speeds/sprockets, I was able to pedal backwards on only 3 of them (on speeds 3-4-5).
Tried to get used to it and use the bike as is, but the chain broke in about 100m; at the first stop (I suppose the chain is most stressed when you stop) Changed with another identical chain and it also broke in 100m. Those bad chains costed me less than 1€ each. Changed with a better chain made of strong steel and less flexible sideways that costed 3€ and I no longer have any problem pedaling backward.

Could be extreme gear combo's too.

I have the same problem, though also happens when I coast at high speed. I will start with a clean of chain and gears and report how that turns out. If that fails I will move on to the chain. Unless anyone else has a better idea?

Sometimes you have to file down nubs on the chainring teeth.

If/When I have this problem, it's usually the result of the rear derailleur not being aligned properly, due to being bumped or other randomness.

Probably a waste of time but in case this guy has notification turned on:

If you can't coast at high speeds then you most likely have an issues with your pawls - contamination or lack of lube. Basic hub maintenance will solve those problem.

"Doc, it hurts when I do 'this'!"
"Then don't do 'this'"
Same principle!

FYI Cracked bearing rear hub. Thanks.