[I Are Baboon]

My chain is skipping and I can't figure out the problem. It's skipping real bad too, not just an occasional skip. My last ride, I had to keep my rear cassette in the biggest ring to keep it from skipping. I recently installed an entirely new drivetrain (cassette, front rings, chain, and rear derailleur). All this new gear and I am skipping. WTF? Any ideas what might be the problem? Is it possible I need to just take a link out of the chain to shorten it and increase the tension? My derailleur hanger looks straight, so I don't think it's that. I figure if this was just a matter of adjusting the derailleur settings, it would not skip in every single gear.

AHHHH!

 

[disasterarea]

could it be a wonky bb to freewheel alignment? I had that once and took me forever to discover it as it was only slightly out.

 

[I Are Baboon]

Originally posted by disasterarea
could it be a wonky bb to freewheel alignment? I had that once and took me forever to discover it as it was only slightly out.

This skipping problem has only been recent. If it was a bb/wheel alighnment issue, I'd think it would have been happening longer. The wheels do appear to be dished and trued. It is certainly something for me to look at though.

 

[ET_SoCal]

Have you got Shimano components w/ mixed HG & IG ???

I've seen that cause skipping before...

Also one time it was a 9sp chain on 8sp drivetrain...
Or was it the other way around ?

 

[I Are Baboon]

Originally posted by ET_SoCal
Have you got Shimano components w/ mixed HG & IG ???

I've seen that cause skipping before...

Also one time it was a 9sp chain on 8sp drivetrain...
Or was it the other way around ?

I have XT front rings and derailleur, with Sram chain and cassette. That could cause problems? Hmmm.......

I never had a problem running a PC69 chain with XT rings and cassette before, but the Sram cassette is new.

 

[Tenchiro]

Originally posted by I Are Baboon
I have XT front rings and derailleur, with Sram chain and cassette. That could cause problems? Hmmm.......

I never had a problem running a PC69 chain with XT rings and cassette before, but the Sram cassette is new.

If you have an old chain on a new cassette, it can cause skipping if the chain is stretched.

 

[Tweek]

SRAM cassette may be suspect if you were running a Shimano before, but running a SRAM chain with Shimano rings and derailleur shouldn't be a problem.
If you're running the chain the same length as the one you replaced, check your rear der. cable and/or it's tension.

 

[I Are Baboon]

Originally posted by Tenchiro
If you have an old chain on a new cassette, it can cause skipping if the chain is stretched.

The chain is new.

Originally posted by Tweek
SRAM cassette may be suspect if you were running a Shimano before, but running a SRAM chain with Shimano rings and derailleur shouldn't be a problem.
If you're running the chain the same length as the one you replaced, check your rear der. cable and/or it's tension.

Are you saying the Sram cassette could be part of the problem?
I'll check that der. cable.

 

[ET_SoCal]

I've had no problems mixing Sram & Shimano drivetrain components (8-speed only, don't have 9sp on my Mtb, so I dont have experiece mixing them)

As I remember (8 speed only); Sram cassette teeth widths are in between IG & HG, the chain plates are very close to Shimano (width). ('course length is the same or we'd get a lot of skipping)

You said in large gear (Cassette) no skipping...
I has a a skipping problem like that before and it was my rear derailer pivot was stiff, I had to RR the main pivot and that cleared up the skipping.

 

[Tenchiro]

I run a Shimano cassette, SRAM chain and Race Face rings with no problems, it is even 9 speed, so mixing shouldn't be an issue.

Is the chain skipping across the top of a single cog or is it skipping cogs?

 

[I Are Baboon]

Originally posted by Tenchiro


Is the chain skipping across the top of a single cog or is it skipping cogs?

It's skipping across the top of every cog I shift to. It is not skipping gears. Once I get into a gear it stays there, but it skips like a mofo.

 

[Tenchiro]

If it is tensioned properly it sounds like a bunk chain to me.

 

[I Are Baboon]

Originally posted by Tenchiro
If it is tensioned properly it sounds like a bunk chain to me.

Perhaps. I'm getting frustrated and may just melt the whole friggin bike down into a lump of aluminum.

 

[Joe33]

I've had this happen before, you hay have smacked your chain on something or possibly got a defective one with a stiff link. You can either find the stiff link and replace it or even better just buy a new chain. I tried to fix the stiff link on mine by takin it apart and filling the bur off but it did not work. The link loosened up a little bit but still skipped and I continued hitting my knees on the stem. If I had the money at the time I would of saved myself a lot of trouble and just replaced it.

There is also a small chance adjusting the b screw could help.

Whatever it is dont let it go to long or it will wreck you cogs and the chain links will start develping cracks.

 

[ET_SoCal]

Originally posted by Joe33
... stiff link...

Oh ya, why didn't I think of that?

Run the cranks backwards looking at the rear derailer pulley's for skip/hopping to find the bad one. Remove the bad section & use a power link.

 

[Tweek]

Originally posted by Tenchiro
I run a Shimano cassette, SRAM chain and Race Face rings with no problems, it is even 9 speed, so mixing shouldn't be an issue.
...

Right. That's what I was referring to also in my post. (I run SRAM chain/Shim cassette and der/Truvativ rings no problem)

If it skips in the same place on the chain, (e.g., every rev) it's obviously the chain. If it skips constantly (like every 10,12 links) it still sounds like a rear derailleur adjustment problem to me.

 

[oldfart]

If it works in one gear, the lowest cog, the chain is fine. Its all new so should work fine. There are no compatibility issues between SRAM and Shimano cassettes and chains. It sounds to me like the cable and housing have simply settled in and you need to adjust the cable tension a bit.

 

[deroyo]

Originally posted by I Are Baboon
Perhaps. I'm getting frustrated and may just melt the whole friggin bike down into a lump of aluminum.

Melt your Titus??????
You are a frustrated :nuts:


Hiya Andy!!!Yes you,Oldfart!!!

 

[ghostrider]

I dunno if anybody has posted this yet, but take a minute to figure out if it is skipping on the front rings or rear cogs. Be sure you have it right, or you will waste a bunch of time and money. I once replaced a bunch of stuff in the back, when it turned out to be a worn middle chainring. At least I got a bunch of new stuff outta the deal.

 

[Echo]

Originally posted by I Are Baboon
My derailleur hanger looks straight, so I don't think it's that.

It is impossible to tell if your derailleur hanger is straight by looking at it...

 

[oldfart]

Derailleur hangers aren't that finicky. If it looks straight, its straight enough to work. Mine are little off most of the time because I ride into stuff. You should use a tool which is designed to measure and straighten the dropout, but I have used a big adjustable wrench lots of times at home, then when I go to the shop to get it right with the proper tool, its already there.

The original posting said ALL NEW PARTS. Cogs rings chain and rear derailleur. It also said it was working but now its not. Something has happened in the meantime. The most likely and simplest explanation is thet the cable housings have settled in a bit and the tension needs to be tweeked.

It is possible its something else though. But he said it worked OK if he shifted to his largest sized cog. That would suggest the chain is fine, the cogs are fine and the rings are fine. If they weren't, they should skip. The only exceptin could be if an 7 or 8 spd chain was being used on a 9 spd cassette. The chain might be trying to shift to a lower gear as it catches the next lower gear, which it can't do in the lowest gear.

 

[johnbryanpeters]

OK, IRB,

Is it fixed? What did the trick?

J

 

[I Are Baboon]

Originally posted by johnbryanpeters
OK, IRB,

Is it fixed? What did the trick?

J

I have not touched my bike in about three weeks, JBP. It sits here in my spare bedroom covered in mud. Rest assured, when I get off my ass and work on it, I will be referencing this thread.

 

[I Are Baboon]

ok, turns out it was a simple matter of adjusting the rear derailleur cable. I had my shop look at it, since I was heading there anyway (and I knew they wouldn't charge me). I took my bike out yesterday for a brief ride and it didn't skip once.

The important thing is that I learned something, so next time this happens I'll know what to do.

 

[narlus]

IRB, i got on this thread late, and glad you got it sorted.

one other thing to keep in the mental checklist is to check to see if the cassette is properly tightened. i had the lockring loosen and give enough wiggle that the chain skipped during pedaling, and that was a b!tch to troubleshoot.

 

[Wumpus]

Reason it wasn't skipping on the big cog was that that position is set by the limiting screw unless the cable is too tight. Same would apply for the littlest cog.

After you get the initial setup, it will probably need some minor adjusting for the first few rides.

 

[oldfart]

Woo Hoo! I win. Actually we all do as the problem is solved.

 

[rockracing]

I've decided to hikack this thread cos I'm having smething similar going on, here's the scenario:

new Sram chain and cassette (pc59 and 9.0) with XT crank and derailleurs, everything is fine except when riding middle baled at 34t at back (I had a 34 on my previous shimano cassette no problems) the chain line looks awfull and when climbing in the combo it feels not solid at all like theres a "skip" on each revolution. I can't remeber what the chain line looked previously as it orked fine so never looked.

I fiddled with the limit screws and got the derailleur settled down, no jumping around, but I see there is one spot on the front chainring that has a little "click" when the chain makes contact, cuold it be one or two teeth that are more worn so when the chain conncects at the funky angle it doesn't seat so well at first.

brw, if I shift down one cog at the back, perfect, but lets face it I need the 34.......

thanks

 

[Wumpus]

Check the chain for tight links. Maybe a bent tooth up front.

My shimano chain was derailing the other day and I didn't have one of the pins pushed in good enough and one link started coming apart....So make sure that your powerlink is not loose.