chain catching when reverse pedalling

ryanincontrol

Hi!
Need some advice on my friends bike.

I noticed when the chain is in the smallest cog and pedal in reverse it seems to be slightly touching the second cog and if you reverse rotate it really fast the chain comes off the guide pulley on the deailleur. No problems when pedalling forward or freewheeling. His bike is a Felt Q720 only a month old and must've done around 50 miles. I tried removing the casette and it didn't seem to have any problems. Removed the hanger and doesn't appear to be bent. Degreased and greased the chain. Adjusted the B tension and the gears. Still to no avail.

nicklouse

so dont pedal backwards fast. it is not meant to go that way.

ryanincontrol

I know it's not meant to but compairing it to my old bikes, they're smooth rotating forwards or reverse. Even the wife's low end Giant bike dont have this problem.

I just find it annoying when relubing the chain.
Im guessing the spacing on the crankset might have something to do with it

The Rookie

9/10 speed will flex more and cause more issues than stiffer 7/8 speed chains.......

Simon

bails87

Just put the chain on a middle-ish cog when lubing it.

ryanincontrol

Just an update, I brought the bike to my trusted mechanic and he said exactly what the chaps above said. The chain is not meant to go backwards and it's not unusual for a 10 speed to catch the second cog when reverse rotating. He also said to lube it on the 4th or 5th cog.
My wife's bike is 8 speed and my old one is 9 speed so don't flex as much as a 10 speed so don't have this problem.

So that's explains it.

Many thanks for all the input guys!

DickBarton

A 10-spd block takes up the same space as a 9-spd - but things are thinner to take that into account...sounds as though the gear you are using to spin it isn't keeping a straight chain and as it is needing to bend to sit on each cog (front and back) that it is making it easier for the chain to drop off...

Try to put the chain in the middle cog at front and middle of the block at the rear and try again...it should be much better as the chain is less 'bent'...

cloudynights

your chain should be able to go round in reverse and not jump off, if not then either rear mech is ever slightly out or its slightly twisted or a slight burr on a tooth, had this problem with a sram mech once and no matter what i did couldnt fix it any ways big do's little do's it got changed for a shimno one, problem was solved , i suggest the bike shop who told you its not ment to go backwards so dont worry about it are not very good, chain should run freely running backward or foward regardless of cassette speed my lbs would never fob any one off with such a lame reason , your drivetrain should run perfectly if not its got a fault

bails87

cloudynights
It does run "perfectly good", because it shouldn't be run backwards. If the chain is on the big rings front and rear and you back pedal, there's nothing keeping the chain on the big cog, so it may well shift up to a smaller cog. The rear mech has nothing to do with it because the chain will derail before it gets to the rear mech. Obviously when you pedal forward the chain goes through the mech before it gets to the cassette, so skipping when forward pedalling could be blamed on the mech.

DickBarton

Not strictly true cloudynights...the chain should be able to go in both directions and do so smoothly but it won't go backwards smoothly in every gear option due to the chain bend to get it sitting on the cogs...big/big will put a large bend in the chain and it can be enough to not allow it to turn smoothly...it works fine going forward as the rear mech helps the chain stay on the cog it is intended for...

If you use a gear where there is little bend in the chain then it should go smoothly...this issue has been made worse since we went 9-spd and 10-spd...the width of the cassette has meant the chain needs to bend (flex) enough to accommodate the extra width and as such won't always run smooth depending on which gear you are in...

cloudynights

All i will say is i can run my chain forward or backward any any gear front or rear mech and the chain will not jump snag come off at all,l like i said before, your drive train has to be set up spot which if you're a compitent bike mechanic is simple, its not witchcraft

cloudynights

rear mech size is important lots of riders will run too small a cage which alters chain tension and position, only offering a little advice can take it or leave it but its not a problem my drivetrain has

cooldad

@ cloudynights. Balls.

getonyourbike

cooldad wrote:

@ cloudynights. Balls.

agreed, absolute bollox. So I'm with nicklouse, Bails, 'cool'dad :P and DickBarton

cloudynights

like i said take it or leave it, i come across many blokes who say they know this or can do that but when it comes to it they can do very little but talk bout it

cooldad

cooldad wrote:

@ cloudynights. Balls.

supersonic

Chainline. End of.