Peddling backwards upsets the derailler

[Mike123456]

Hello all,

I searched the forum but could not find this specific topic. When peddling backward (when lubing the chain etc.), the chain seems to "jump" and the rear derailler seems to get pulled back and then releases hard. I have no issues when peddling forward and riding, but have not seen any other bikes that do this so figure something is amiss.

Did any of the above make sense? :-)

Mike

[NYrr496]

Has it always done this?
Has it been a while since you lubed the chain?

Sounds like possibly the chain may be "stiff".

[shwinn8]

flip bike upside down. rotate drive train in the correct direction. while rotating, lube chain and cycle through the gears. finish with a rag on the chain which will absorb excess lube

[Mike123456]

Has it always done this?
Has it been a while since you lubed the chain?

Sounds like possibly the chain may be "stiff".

Not certain if always (bike only 4 months old)
I'm pretty sure it's lubed ok BUT will re lube to be certain.

Thanks

M

[Mike123456]

flip bike upside down. rotate drive train in the correct direction. while rotating, lube chain and cycle through the gears. finish with a rag on the chain which will absorb excess lube

Will do, thanks!

M

[NYrr496]

Has it done it for the entire four months you've owned it??

[scatterbrained]

Perfectly normal BTW. If you don't have a cog selected in the rear that is aligned with the chainring in the front the chain will want to fall (or rise) to align itself when pedaled backwards.

[dru]

Pedaling backwards can cause problems if you are cross chaining. My bike jumps the cassette if I'm in granny up front and either of the smallest 2 cogs on the back.

I store the bike in this combo so that's why I notice it. I generally don't pedal backwards ever when riding.

Drew

[Saul Lumikko]

Could be caused by a dragging freewheel or slight misalignment of the rear derailleur. While you don't need to pedal backwards, you should be able to do it without issues. To me it's an indicator.

Put the bike in a bench or have a helper hold the rear tire off the ground and pedal while you look at the cassette and shift through gears. On any given gear the chain should be in the middle of the cog. If the shifter cable is too tight it rubs on the larger cog next to it and is sluggish to change to a smaller cog. If the cable is too loose, shifting up requires pushing the lever further than just the click, and the chain can occasionally jump to the smaller cog. Look at the relationship of the top sprocket of the rear derailleur and the cog: the chain should go straight to the cog.

[scatterbrained]

Could be caused by a dragging freewheel or slight misalignment of the rear derailleur. While you don't need to pedal backwards, you should be able to do it without issues. To me it's an indicator.

Put the bike in a bench or have a helper hold the rear tire off the ground and pedal while you look at the cassette and shift through gears. On any given gear the chain should be in the middle of the cog. If the shifter cable is too tight it rubs on the larger cog next to it and is sluggish to change to a smaller cog. If the cable is too loose, shifting up requires pushing the lever further than just the click, and the chain can occasionally jump to the smaller cog. Look at the relationship of the top sprocket of the rear derailleur and the cog: the chain should go straight to the cog.

Why do you think you should be able to pedal backwards without issue? Tell you what, put your bike in it's largest cog in the rear and largest in the front and pedal backwards. . . . . . . .

The derailleur guides the slack side of the chain onto the correct cog...you don't need anything on the top because the tension from pedaling keeps the chain from lifting off of the cogs. When you pedal backward however there is nothing on the top to guide the now slack chain onto the correct cog.

[knoob]

Works just fine on my bike. That is where I put it to clean & lube my chain.
Granted it only takes the slightest side pressure to make it jump.

[Saul Lumikko]

Scatterbrained, I specifically said you don't need to pedal backwards, but a drivetrain that works correctly allows you to do that. Of course not if you're cross-chaining the thing, but you shouldn't do that anyway backwards or forwards.

The derailleur guides the slack side of the chain onto the correct cog - when the derailleur is adjusted properly. That's why I advised the OP to take a look to make sure it is.

[J.B. Weld]

Pedaling backwards will magnify any flaws in derailleur alignment and adjustment, so gears that are adjusted marginally OK will jump around when pedaling backwards but still stay on the sprockets when pedaling forward. If everything is dead on and tuned well you should be able to pedal backwards and have everything run smoothly even when cross chained pretty bad. My 1x10 set up has no problems when pedaling backwards in any gear.

Pedaling backwards will expose bad and tight chain links too.

[shwinn8]

you can't go forward if you are pedaling backwards...

[AZ]

Back pedaling contributes nothing to forward propulsion.

[Max24]

Hello all,

I searched the forum but could not find this specific topic. When peddling backward (when lubing the chain etc.), the chain seems to "jump" and the rear derailler seems to get pulled back and then releases hard. I have no issues when peddling forward and riding, but have not seen any other bikes that do this so figure something is amiss.

Did any of the above make sense? :-)

Mike

Sounds more like a stiff chain to me...

[J.B. Weld]

Back pedaling contributes nothing to forward propulsion.

It does if you find yourself in a position where you can't turn the crank forward and need to ratchet them to clear said obstruction.

[Stripes]

It does if you find yourself in a position where you can't turn the crank forward and need to ratchet them to clear said obstruction.

This, especially with newer bikes having lower bb heights, people are going to have to learn to ratchet again.

With the new Shimano 2x setup, I've found I can pedal backwards, BUT the front gears need to go through one or two rotations before I can ratchet without the chain falling off.

[scatterbrained]

Scatterbrained, I specifically said you don't need to pedal backwards, but a drivetrain that works correctly allows you to do that. Of course not if you're cross-chaining the thing, but you shouldn't do that anyway backwards or forwards.

The derailleur guides the slack side of the chain onto the correct cog - when the derailleur is adjusted properly. That's why I advised the OP to take a look to make sure it is.

My point is that we don't even know if he's crossing up the chain or not. I've spent my entire life turning wrenches and even did a stint as tech support, it's been my experience that the issue is usually user error or misunderstanding. The amount of times I've seen people trying to get warranty repairs on heated seats and mirrors because they didn't know that they circuits only worked when the ambient temp. was below a certain point; or the times I've seen techs brick cars because they tried to reflash the CEM while using a trickle charger instead of a proper charger. People bringing their cars in thinking they have a brake light out, when they never realized they turned the rain light on. . . .etc. etc.
My default when diagnosing is to ensure the user knows exactly how the system is supposed to function, and that they are testing it correctly before moving on to actually testing for a fault in the system. In this case you have a new bike, and a new rider, which has me leaning towards a case of possible user error/misunderstanding, which was the point of my post. Sure it can be a mechanical issue, but personal experience tells me that the likelihood for that is the lower of the two options.

[MSU Alum]

Damned double posts!!

[MSU Alum]

Saul Lumikko and J.B. Weld have it right. With a straight derailleur hanger and a properly adjusted rear D, you shouldn't be getting this problem as long as you're not completely cross chained.

[Saul Lumikko]

My point is that we don't even know if he's crossing up the chain or not.

It has very little to do with your attack on my claim that a properly functioning drivetrain should revolve backwards with ease. And it does so even if the selected cog isn't precisely in line with the chainring.

You and Drew had already said that cross-chaining could cause problems the OP described. I'm sure it's come to his attention already.

[rangeriderdave]

A few have mentioned a stiff chain ,more that likely it would be a stiff link. To check for a stiff link pedal backwards watching the chain move though the deraileur jockey wheels. You will notice a jump or hop ,you can fix by grabbing the chain where the stiff link is and flexing it sideways.

[spirit4earth]

Pedaling backwards can cause problems if you are cross chaining. My bike jumps the cassette if I'm in granny up front and either of the smallest 2 cogs on the back.

I store the bike in this combo so that's why I notice it. I generally don't pedal backwards ever when riding.

Drew

Curious----why do you store your bike in this combo?

[faceplant72]

Not certain if always (bike only 4 months old)
I'm pretty sure it's lubed ok BUT will re lube to be certain.

Thanks

M

In the 4 months have you adjusted the cable tension. It might take a 1/4 turn of the barrel to get the derailleur perfectly aligned so you can back peddle ( alignment is slightly less critical when peddling). The cable housings will have bedding in over the past 4 months.