[ramjm_2000]

Ok so I'm at my wits end with my newly acquired HT. I picked up a NOS 06 Cannondale F400 that I immediately stripped down and upgraded with a mix of higher end parts from my back up bike. The only original drive train part I decided to use was the SRAM chain and x.7 RD. As she sits I've got some older ESP 9.0 SL twist shifters mated to Stylo team cranks and an XT rear cassette with some miles on it. After a few uneventful shake down rides everything went to pot. I started getting some horrific skipping in the to the point it was unridable. I checked the RD hanger alignment and afterwards immediately suspected the cassette had reached the end of it's lifespan. I then decided to put the stock PG-950 cassette back on to match the new chain. I also shortened the way too long factory housing running to the RD. After a blissful 45 minutes into today's ride the damn skipping is back, not as bad as before but getting progressively worse. The odd thing is it was fine for the first 45 minutes (maybe a small hiccup every so often) but then all of the sudden skipping. Could it be a faulty powerlink? Could it be that my shifter is the culprit? Did the chain wear out in 2 short 1 hourish rides with the older cassette? I've been wrenching for a while and this is the first time I've ever suspected the shifter. Anyone ever wore one out? The shifting detents are still sharp and crisp. Any ideas would be helpful thanks!

JR

 

[jodysbike]

OK. The usual list:
Parts are new or relatively new? YES
Hanger is aligned? YES
Chain has no tight links/twist/pins coming apart? Shouldn't NEW
Cassette is on tight?
Rear derailleur cage is tight with no binding of the guide pulleys?
Rear axle in wheel is not bent or broken?
Bottom Bracket spacing is correct/chain line (Cranks don't sit to far outboard)?
No bent teeth on cassette or chain rings?
Correct adjustment of B tension screw? Sram doesn't have one.

Does it only do it in certain gears or all over the cassette?
Let me think a bit more while you think on these possibles.

 

[ramjm_2000]

After disassembling everything I've come to the conclusion that it's a combination of things. First since it's a new chain it still has some of that waxy resin type coating on it, second I noticed the "hiccup" was isolated to one area on the chain (no stiff links and not the powerlink) and third I discovered a frayed cable inside the housing that hugs the TT/ST junction. After getting a new RD cable to replace the new teflon coated cable that frayed, I reinstalled everything lubbed the housings and gripshift internals, plus scrubbed off all the wax coating on the chain. So far so good. The "bad" spot seems to be much minimized and shifting is smooth. If it comes back I suspect it has to be a bad chain. Thanks for the input.

 

[lugnuts]

my troubleshooting would be....
- cable tension, limit screws, B tension, etc.?
- poor chainline or pilot error?
- new chain w/old cassette?
- no bad links in chain, no bent teeth on cassette?
- der hanger straightness?
- der drops easily on its own?
- cables move easily and allow der to drop is if it was on its own?
- cassette on tight, freehub doesn't have too much play?
- d-train components compatible with each other? i.e.- 8spd shifter w/9 spd cassette by accident? cable pull on shifter matches that needed by derailleur? etc.