[Closed] gears shift when backpedaling!!

Running big-big? You shouldn't pedal in that gear and it WILL give you this problem.

THREAD CLOSED>

Indeed, the bike is punishing you for the crass crime of cross-chaining.

And you may have a stiff link in the chain or maybe a stiff jockey wheel.

Dont pedal backwards?

If you got clearance for the chainrings to the frame and chainstay and your running a HT2 type BB you could swap the spacer over to the non drive side to improve the chainline from the middle ring (assuming that what you mean by biggest of the 2) to the largest cog on the back... However that will possibly give you headaches getting the front mech to drop you into granny gear...

I think at least 2 of you just fell for the old not reading the post correctly, he is running 2 front rings, so I have assumed its a granny and a middle.

ps have you got quite a new chain on? Old knackered chains do/will pedal backwards better.

If it's shifting fine when pedalling normally, then leave it alone, don't use that gear (Big - Big gives a poor chainline and is bad) and don't pedal backwards! 🙂

3 of you now..

No harm in checking the alignment of your rear mech hanger. If it's a wee bit off it might be causing the smaller cassette cogs to snatch at the loose chain as it's backpedalled. I've got one of [url= http://www.wiggle.co.uk/p/cycle/7/Cyclus_Gear_Hanger_Alignment_Tool/5300003490/ ]these[/url] and it does the trick nicely. 🙂

yes it is a double front with bashguard so i would have thought big 2 big should be ok?

It is ok.

It's meant to work pedalling forwards, not backwards.

Just been telling my youngest grandson (4 years old) not to pedal backwards as we're trying to get him to ride properly, and here's Markyboy nearing 30 and he's still doing it 😉

Any bike will do this. My Norco with a single 32T front ring and chain device, XT rear mech and a new Hope hub does it some of the time just back pedalling it in the workstand.

You shouldn't be backpedalling anyway though, not more than half a crank or so anyway, in a real world situation, surely?

People ride Big/Big because they don't want the embarrasment of the granny ring lol

If it's a 32/34 front chainring, and the chainline is not all to cock for some reason, I can't see why running from that to big at the back would be a bad idea at all... after all, you should be able to use the entire block while sat in middle at the front, and that is all this is...

As for peddling backwards and it changing gear... I'd expect it to be a sticking link in the chain as it shouldn't change gear if everything else is spot on. I can quite happily do it on all my bikes, including the 1x10 setup on my crosser. Does it tend to pull on the rear mech a lot when you do it?

Also, when it changes gear, does it stay in 3rd? Or does it then try and change back into 1st again? If it stays in 3rd I'd have a look at your mech and see if anything funny is going on there, and see how angled the chain is going into the top jockey wheel.

reason i ask is
1-it didnt used to happen
2-i have another bike with double/bash and it doesnt do it

so i presume something has bent,worn but cant see anything

and pepper is nearley 40 😀

I guess it's something most folk don't worry about cos there's no need for it.

Worry about your drivetrain when something useful is impaired.

the chain bends, as it's being pushed instead of pulled, and gets picked up by the next cog. maybe your freewheel isn't as smooth as it used to be. not a problem as long as it works when you pedal the right way.

Chain is being pulled. It sags at the top though and falls off the bigger cogs.

cynic al...your not getting it!
half a turn back and its down 3 gears! pedal forward and its back on.sometimes causes chainsuck.it is a recent problem didnt used to happen.was looking for some ideas on fixing problem not tips on how to change gears 😕

thanks funkynick that was the kind of answer i was looking for 🙂

I often pedal backwards more than forwards.
the chainline from the ring is derailling the chain in the same way the mech does when pedalling forwards, perfectly normal.
if it really bothers you set-up the chainline as close to the frame as feasable.

If the hanger or mech isn't bent, unscrew the lower limit adjust half a turn or so?

markyboy.. if it's doing it that quickly have a look at the rear mech, see if any of the jockey wheels are fouled up and not turning easily... if the cage is straight.. if the mech hanger is straight.. that sort of thing.

By the sounds of it the chain is binding with the mech and pulling the cage forward which is moving the body of the mech down...

It certainly shouldn't be doing what you describe.

Peppers over 40 now 🙁

I'd look very carefully at the state of the chain. A stiff or bent link or a sideplate popped out, maybe signs of impending chain break.

funkynick has it.. check the jocky wheels spin.

It should work fine and does on my 2x9. It's no worse than middle and biggest sprocket on a triple setup.

Likely causes are:

- a slightly stiff link or two in the chain which work ok when pedalling as there's tension on the chain to straighten them out

- your freehub isn't as free as it should be so when you back pedal, the chain from the top of the chainring to the top of the cassette goes slack and then jumps.

- Something (mech, mech hanger, jockey wheels) is twisted/bent/out of line.