Ultegra Cassette on SRAM Force - skipping cogs

bsharp77

Hi guys,

I have a focus izalco ergoride 3.0 with SRAM Force (great bike), and I've swapped over my ksrium elite wheels from another bike - they have an ultegra 6700 cassette on it which I thought would be fine.....

The problem is when you shift gears, it misses a cog every time, so in effect you only have 5 shifts before it reaches the opposite end of the cassette (and when it reaches the smallest gear, the chain actually just runs loose).
Ive been riding properly for a year, but have always left servicing to my LBS - so im scratching my head wondering what to do!
Sorry if this is a real noob question, but im just panicking in case the bike shop wont be able to have a look tomorrow evening, and im due for a 80 mile ride on saturday morning!!

Any help or advice much appreciated!

MisterMuncher

At first guess, the chain is a bit long. Did your force cassette have a larger "bottom" gear?

freezing77

Gears may need re-indexing. All wheels axle spacings are not identical. Your cassette may be in a slightly different position relative to your derailleur from the original wheels and cassette.

Bar Shaker

Totally agree. The chain is slipping because it is too long and the rear derailleur will have reach full stretch before you reach your smallest rear cassette cog. - Just a thought, are you trying to do this on your small front chainring?

The skipping cogs sounds like just an indexing problem. Index the derailluer on your biggest rear cog, so the alignment and stops are perfect, then see if it clicks down the cogs ok.