Gears skipping at random

[Super Sywurm]

When I ride off road over rocks or corrugation, my mtb keeps skipping and shifting gears at random (when I go over bumps in the road). I have a brand new chain on and had the bike at my lbs and they did some adjustments on my rear derailleur, but they did not fix the problem.

 

What to do???

[Old school]

Is it a dual suspension bike?

[Super Sywurm]

Is it a dual suspension bike?

 

Yes.

[Old school]

Best way to solve this problem is run a uninterrupted gear cable housing from your shifters to the dérailleurs, this would mean opening frame ferules with a drill to fit the housing through. The problem on many dual suspensions that was clearly not thought through. As your suspension moves the places where gear cable runs open (without housing) is where the problem lies as it adjusts with your suspension movement. Just let the distributor know of your intention to do this as it may void the warranty but it is the only real solution.

[gummibear]

Get a rear derailleur with a clutch system.

 

http://merlincycles-img.s3-eu-west-1.amazonaws.com/productImage_1280_1024_ffffff_image-jpeg/8578_shimano_xt_m786_10_speed_shadow_rear_mech.jpg

[Cassie]

yes, a agree with the solution to the problem.

 

Lately i had some random skip (mostly on front ring, under some torgue) and found it to be my quicklink that was starting to show wear...replaced it and problem went away!

[Old school]

I don't see a clutch derailleur solving the problem it only controls your chain slack better. This is cable tension related.

[Cassie]

wow! how much will one of these babies set you back?? Mega dollars, i supose?

Edited April 9, 2014 by Cassie

[ichops]

Get a rear derailleur with a clutch system.

 

http://merlincycles-img.s3-eu-west-1.amazonaws.com/productImage_1280_1024_ffffff_image-jpeg/8578_shimano_xt_m786_10_speed_shadow_rear_mech.jpg

Just fitted one to my KTM 26er - works like a charm for chain suck - nothing - nada - not even an attempt at chain suck - even in the roughest of single track

[North Shore]

Try replacing your cassette before you try anything else, you say you replaced the chain but not the cassette? I'm willing to bet it's that.

[Super Sywurm]

I don't see a clutch derailleur solving the problem it only controls your chain slack better. This is cable tension related.

 

I also don't think it would, because my derailleur was tightened to the max. It only started skipping gears about a month ago.

[Old school]

A worn cassette will only make the chain slip over one gear not change to another.

[Super Sywurm]

Try replacing your cassette before you try anything else, you say you replaced the chain but not the cassette? I'm willing to bet it's that.

 

That was my best guess as well after I googled the problem.

[Super Sywurm]

Bent hanger!!

 

I don't think that is the problem, but I will check it when I get home.

[Super Sywurm]

When I ride off road over rocks or corrugation, my mtb keeps skipping and shifting gears at random (when I go over bumps in the road). I have a brand new chain on and had the bike at my lbs and they did some adjustments on my rear derailleur, but they did not fix the problem.

 

What to do???

 

And this problem might cause a crash in a race...

[NotSoBigBen]

Try replacing your cassette before you try anything else, you say you replaced the chain but not the cassette? I'm willing to bet it's that.

 

I understand the logic to this but it's an expensive way to possibly find out that it's something else?