Mountain Biking - GRRRR! My chain keeps skipping!

Over the past couple months I have switched out every part of my drive train except for the front derailler to try and get rid of my chain skipping. I have a new rear derailler, cassette, chain, crankset and bb, but when I pedal through someting rough, my chain will still fall off or skip on the second chain ring. I've tried adjusting everything I can think of, but it doesn't seem to do anyting. Could my chain be too long/too short? Is that just something that bikes do and I'd have to get a chain guide to remedy it? I'm pretty sure all my parts are compatible, but here's a list just in case:

Chain-SRAM PC68
Cassette-Sram 5.0
Deraillure-Shimano Deore
Crankset/bb-Race Face Evolve XC + SRX bb

I don't remember the chain skipping or falling off like that, but then again, I didn't use to ride as hard as I do now. The only other possibility I can think of is that I shortened the chain too much or something.

test

I know yoy shouldn't make a practice of this but with the bike upside down or on a stand make sure you can go large chain ring to large gear on the cassette. If you can the chain is not too short. Make sure nothing is bent. I had thiis happen in one gear when the RDR was at the wrong angle.

Joe

Is this on a full suspension bike?????

I had this happen to me as well. I finally tracked it down to the length of derailleur cable housing around the bottom of the bottom bracket. It was too short, thus, when the suspension cycled through it's movement, it would cause the derailleur cable to tighten and shift my rear derailleur.

If it's a hardtail, it could be a stiff link!

L8R

Sounds like it could also be . . .

Limit screw in too much
Cable tension too tight (more likely limit screw)

Sounds like it could also be . . .
Limit screw in too much
Cable tension too tight (more likely limit screw)
If I am thinking right, limit screws only change how far the derailleur goes over when you shift it, right? I honestly don't know how long a chain should be so I can't really help you in that department. Here is a link that I go to whenever I have to do drivetrain adjustments though... CLICK HERE (http://www.parktool.com/repair_help/FAQindex.shtml#drivetrain)

hope this helps

It could be a stiff link. I just got one of those. Just identified the link. Took it apart and used the chain lube on the inside of the link. Like where the two parts meet. Fixed it right up.

If nothing from the above helps maybe you should invest in a chainguide. There are several triple chainring guides.

I had thiis happen in one gear when the RDR was at the wrong angle.

Joe

What's the RDR? My bike is a hardtail.
Thanks for the help! I'll check my chain and stuff. Hopefully I can find the problem and fix it myself.

If I am thinking right, limit screws only change how far the derailleur goes over when you shift it, right? I honestly don't know how long a chain should be so I can't really help you in that department. Here is a link that I go to whenever I have to do drivetrain adjustments though... CLICK HERE (http://www.parktool.com/repair_help/FAQindex.shtml#drivetrain)

hope this helps

Yes but if you are having the problem of skipping only in the outter or inner most gears the screw could be jsut enough to cause issues while the chain will sometimes make it into that gear. usually at this piint a 1/4-1/2 turn of the screw will fix the issue.

Yes but if you are having the problem of skipping only in the outter or inner most gears the screw could be jsut enough to cause issues while the chain will sometimes make it into that gear. usually at this piint a 1/4-1/2 turn of the screw will fix the issue.

Ahhh, okay. Thanks for clearing that up for me.

EDIT: and Chambo, I think that by RDR he meant rear derailleur.

Bent derailleur hanger? Even if its not visibly bent its still enough to mess with shifting pretty badly.

is the chain and front der. completely Parralel to each other? to remedy mine I finally put the der. so its touching the inside of the chain just barely. I broke 2 teeth on my middle gear from cranking on a chain that kept moving like that. A2 gave me a good piece of advice on how to check correctness of the der. it was something to do with a penny height below the chain( der. guide) and centered up over gear. I do not remember specifically but it worked after removing a couple of links like you said you already did

Bent derailleur hanger? Even if its not visibly bent its still enough to mess with shifting pretty badly.

I don't think that my derailleur hanger is bent. My old one got bent, and I bought a new one a couple of months ago. I'm afraid that my dropout might be bent. I think that I'll just bring it to a bike shop and have them look at it. I'm really tired of trying to get my stupid bike to work.

I tested my chain for stiffness in a link, and it was just fine.

I don't know if my front der. in parrallel to the chain. I'll have to check it when I get home from school.

I think my chain was the right leangth, but I screwed up. My bike is an 8-speed, my cassette is 11/32. The "chain too long" test told me that my chain was a little too long, so I shortened it. But then when I tried the "chain too short" test my chain was too short. crap. What can I do now? I'm getting sick and tired of working on this stupid bike all of the time! It never seems to work right!

This only happens on the largest cog down to the second cog? Or did you really mean chainring as in front der?

The chain comes off the second chainring, but that doesn't really seem to be what is making the chain jolt like that. It only comes off a little bit and puts itself back on. If I go through something really rough, it'll come all the way off.
It seems to skip only when I'm on the 5-7 cogs on the cassette and the second chainring.

I found my chain coming off the front problem was that the my front Derailleur was mounted too high and not adjusted to the outside enough. Might check those. I only mount the front der about 1-2mm above the 3rd rings teeth.