[jacksonpt]

I read through a bunch of old posts about adjusting my rear der. I tinkered around with it for about 30 minutes the other day and made some very noticable headway. I've got so that everythign is basically lined up over the smallest cog when in the highest gear, and lined up over the largest cog when in the lowest gear. My my stand, the bike shifts smoothly and quickly, just like it should. When I ride it, it shifts fine to and from the largest/smallest cogs, but seems to jump back and forth between mid-range cogs. It won't shift and stay in gear... instead the chain jumps between the cog I shifted to and the one I just came from.

Any tips on how I can fix this? Is it a cable tension thing? If I understand correctly, the limiting screws stop the der. from pusing the chain too far (off the cassette in either direction), and the barrel adjuster (the thing under the small rubber boot) lines up the pulleys/chain with the appropriate cog, correct?

Any tips would be helpful.

 

[mrbigisbudgood]

Originally posted by jacksonpt


Any tips would be helpful.

I'm going to guess and say 75% of shifting problems are unlubed, sticky cables. Pull all your cables, lube, then start your adjusting.

 

[Tweek]

Jackson - You're right about the limiter screws, but the barrel adjuster fine-tunes the cable tension. Screw/unscrew it to help the chain drop down/move up the cassette to get your shifting perfect. Get it good in the stand, and if it's problematic when you're riding, try readjusting the same way with the barrel adjuster at the shifter.

 

[sub6]

Originally posted by Tweek
You're right about the limiter screws, but the barrel adjuster fine-tunes the cable tension

true, but he's right in that the cable tension is used to line up the pulleys with the appropriate cog.



Jackson - check to make sure your derailleur hanger isn't bent. That would cause the problems you're referring to. You might want to have a shop throw an alignment guage on it to check, it's a quick, easy procedure.

 

[Repack]

Is it a full suspension bike? If it is, where the housing goes from the main frame to the swing arm, you might have the length wrong. When the suspension moves and bends the housing, this can distort the cable tension. Had this problem on my fsr. I found that running the housing as short as possible over the section made everything work well.

 

[jacksonpt]

Originally posted by mrbigisbudgood
I'm going to guess and say 75% of shifting problems are unlubed, sticky cables. Pull all your cables, lube, then start your adjusting.

How often should cables be replaced/cleaned/lubed? I had my bike in to the LBS for a professional tuneup, which includes cable inspection/replacement/lubing. That was about 4 weeks ago, but only 3 rides ago. None of those rides were at all wet.

 

[jacksonpt]

Originally posted by sub6
Jackson - check to make sure your derailleur hanger isn't bent. That would cause the problems you're referring to. You might want to have a shop throw an alignment guage on it to check, it's a quick, easy procedure.

I'll take a look... I just had the hanger straightened by my LBS 3 rides ago. I don't remember crashing or hitting anything with the bike since then, but I'll take a look just to be sure.

 

[jacksonpt]

Originally posted by Repack
Is it a full suspension bike? If it is, where the housing goes from the main frame to the swing arm, you might have the length wrong. When the suspension moves and bends the housing, this can distort the cable tension. Had this problem on my fsr. I found that running the housing as short as possible over the section made everything work well.

Do you mean here?

Maybe I don't really understand what you're saying, but doesn't the housing have to be the same length as the cable is through that section? Are you saying to tighten up the cable too?

 

[Repack]

Originally posted by jacksonpt
How often should cables be replaced/cleaned/lubed? I had my bike in to the LBS for a professional tuneup, which includes cable inspection/replacement/lubing. That was about 4 weeks ago, but only 3 rides ago. None of those rides were at all wet.

Every so often, with bike in stand, shift in to the big-big. Then click the shifters so there is enough slack to slide the housing out of the guides. (Sorry if that was redundent. No insult/assumption of mechanical ineptitude intended.) Remove the end-caps of the derr housing. I replace cables whenever the strands are sticking out much more than 3mm, or when they rust. I lube cables every time I wash my bike. Before I lube them, I always wipe the exposed cable down with a rag. I use Extra Dry bc it doesn't attract much dirt. It also breaks down quicker than other lubes, but its not like its a tough job. After a while you may find that lubing has little or no effect. Replace the cables then.
I stay away from coated cables. Never lube them. My issue with them is that they shift great for a while, but then the coating breaks down inside the housing creating more friction.