Wrench help please

Triathlon Forum
1

So I just finished changing my drop handlebars to a base bar and clip-ons. At the same time I went ahead and replaced the shifter cables and housings (Kestrel Talon). Now that the bike is built back up, I am having a problem with the 11t cog that I have not had before.

Symptom: When the chain is on the 11t cog, the chain feels like it is trying to shift up. This only happens when I pedel with force. So turing the pedels while the bike is on the bike stand, or just spinning in that gear, nothing happens. What ever is happening is very quick, like it is catching on a single tooth of the 12t cog, then falling back down, and does NOT happen on every turn of the cog.

I am pretty sure it is a derailluer problem. I have switched the cassette to a newer 11-23 set, as well as replaced the chain with no luck. It is also not the limit screw because I can turn it so that the pully is outside of the 11t cog, and it still happens.

My best guess was to adjust the B-screw to get the pully right over the 11t cog, but the derailleur has been neglected a bit. So when I turn the B-screw, the pulley really does not move much. Is there something that I can do, or do I need to have a shop rebuild the derailleur?

Thanks in advance,

Jeromy

2

try tightening the barrel adjustment a few clicks.

3

It could be a cable friction problem- the talons have a god-awful amount of internal routing. I would slack the cable totally by unclamping it at the R derailleur (so the chain is in the 11T cog). take it out and ride it trying to duplicate whatever you do when it skips. If there’s no problem there is probably some friction in the cable that isn’t allowing it to go all the way to the end of its travel. If there still is a problem it’s got to be some alignment issue with the 11 tooth cog.

If it is a cable friction problem, make sure there are no tight bends in the cable, and lube the hell out of everything.

this is assuming that you’ve got the limit screw adjustment set properly like you said you have. Another thing to check- is it possible that your 12t cog is installed inside out? For the single shimano cogs it is possible to put them on so you have the incorrect side facing out (the writing on the cog should be facing out). If this is the case there might be some interaction with the shifting ramps that is causing the chain to jump.

good luck.

J

4

Thanks, I will try this when I get home.

Jeromy