Bicycle Mechanics - tooth worn on STI shifters?

When shifting to the 5th cog it always jumps down to the 4th cog within 1-5 seconds. It is the only gear that this happens. It definitely is skipping on the ratchet in the lever as after if jumps it is perfectly alligned over the 4th cog .

It is a road bike with all mirage components, STI shifters

I had just changed the hub from 8 to 9 but replaced with the conversion spacers so i have 8 pseeds only. It shifts to all gears fine.

Like two years ago i recall someone complaining about this problem on the forum. The replies were that it must be something else as the ratchets never wear out. Could it be something else? I cleaned the cable guide under the bottom bracket.



Erik

Originally posted by Mzungu
It is a road bike with all mirage components, STI shifters

I'm a bit confused. Is it all Campy Mirage components with Shimano STI shifters or are using the term STI generically and it actually has Campy Ergo shifters?

STI ratchets do wear out or break. I have two of them that did, both in the 8-10kmi range. On one the shifter did not cover the last two ratchets and on the other the bad one was the 5th.
Both were 8spds. I have three 9spd ratchets, one of which is in that 8-10kmi range, so far so good but the oldest is finicky about getting into the 12t cog. It is always the R side shifter. There is no practical way to rebuild/repair Shimano, Campy reportedly can be rebuilt/repaired, but finding the parts may be a challenge.
Steve

And just to echo sch, I too had a shimano STI shifter wear out at 10k. However it just felt dead sloppy at the lever but the shifting was OK. Have you checked that the cable tension at the derailleur is OK?

Originally posted by khuon
I'm a bit confused. Is it all Campy Mirage components with Shimano STI shifters or are using the term STI generically and it actually has Campy Ergo shifters?

I should of checked that. I was using it generically. They are Campy Ergo shifters. Sorry i wasn't sure if STI was a brand or not.

Will try to "sharpen " the one tooth in the ratchet.

I bought my bike second hand but 10kmi is probably what i have done too.

If i have to replace the shifter what options do i have? I have to do it mail order , just any 9 speed Campy?

More likely are the "G" springs in the ergo shifter. They are replaceable. I have done it myself. They will wear out in about 10,000 miles causing sloppy shifting. Check out www.branfordbike.com, they stock and sell all the bits for Ergopower controls.

Yeah when i think about it it is pretty hard to imagine the gear would get wear. Hadn't thought of springs. thanks

Cogs do in fact wear out, and the chain will skip on them. Typically your larger cogs are the first to go. Always replace the chain when replacing cogs.

Campy only has a short article on rebuilding the Ergo levers, and a blow up picture of the inside of the levers.
http://www.campyonly.com/howto/ergo_rebuild.html

STI = Shimano Total Integration