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

maddmaxx 

It's virtually never the shifter. Try to keep an eye on the chain/cassette while riding to determine if its "skipping" (rare) or "ghost shifting". If it's the latter, you will see the chain start to hop to the next cog and then come back. Could be as easy as an adjustment or as hard as a stickey cable. In addition, check the "b" screw adjustment.....is the jockey wheel too close to any of the cogs. Is the chain short enough so that the RD maintains tension?

mparker326

I had similar problems on an older road bike that was caused by a faulty derailleur tension spring. Do you have another derailleur you can switch onto the bike to rule that out?

filtersweep

normally when I have had skipping, it was from a stuck link.

Retro Grouch 

Check your shift cable housing ends.

I've encountered housing end failures a couple of times. When that happens you can tune up the derailleur and it will shift fine for a while but then, as the housing shortens itself, the crisp shifting will gradually worsen.

Look for 1 or 2 tiny wires sticking from any of your frame's cable stops.

sam83

I once had a ghost shifting problem that seemed to happen only when I stood to pedal. A little grease on the cable guides under the bottom bracket solved it.