Problem with rear derailleur and cassette
 

This is my very first post to these boards…

First, a little bit of history. I bought a Fisher Marlin about 4? years ago and rode it very hard for at least two seasons. Being a middle of the road kind of bike, the components weren’t that great and they took a pretty good beating. I rode in some pretty harsh conditions. By the end of the second season some real maintenance was definitely in order. The biggest problem was that, as I rotated the pedals with a bit of force, every few revolutions would cause some sort of skip on the rear cassette. I’m not sure if it was shifting half way through gears or what.

So this year I took every moving part off the bike except for the crank case, and cleaned it. I put everything back together along with a new chain, cables, and housings. My first ride was a 40 mile trip on a rails-to-trails and the bike performed flawlessly. It shifted well and everything was very smooth and clean. A couple days after that ride I decided to get out and hit some singletrack and everything went to pieces. The problem began again where every few revolutions of the pedals results in a skipping on the rear cassette. It’s incredibly annoying and makes the bike pretty much impossible to ride. I took it home and went to work adjusting the rear derailleur. I’m certainly not a bike mechanic, I just kind of figured things out as I went. I also downloaded the manual for the rear derailleur so I could figure out what each screw did. I thought I had it fixed so last night I brought it out to another local rails-to-trails to test it and it was still skipping every few revolutions of the pedals. :( It’s almost like the chain advances one slot on the cassette or if it’s trying to shift but doesn’t. It’s not every single revolution of the pedals, just like every fourth or fifth time around.

Anyone have any advice? Should I just bring it to the LBS for a tune-up or is there a trick to adjusting the rear derailleur? It seems like if I go too far with the cable, the derailleur doesn’t want to shift right, and if I don’t go far enough with the cable, the derailleur is in the spokes.

Any help or advice would certainly be appreciated. Thanks in advance…

After 2 years of hard trail riding, your chain DEFINITELY needs replacing, and I suspect your cassette is past its prime as well. Dirty chains wear faster, and as they wear, they damage the shape of the teeth on the cassette, causing the whole shebang to skip.

As long as everything's adjusted right and the chain is sized properly, it sounds as though your cassette wore out with the old chain and doesn't mesh well with the new one.

-Moab

How many miles are on the bike?

Also, as a quick palliative, check for a sticky link on the chain; the frequency of the skip suggests this, and it may well have happened when you reinstalled the chain.

I'd say that I put a couple thousand miles on the bike the first couple years. I don't believe it's the cassette, it's probably the third cassette I've put on the bike, it's not that old.

I'll take a close look at the chain, see if I can find a sticky link.

I'd love to get one more season out of this bike and then buy a new one during the winter. I've ridden for a few years now so I know what I want. I'll never buy a low to middle end bike again. My next bike will cost at least a grand.

Thanks for the advice, back to the garage with me!

You've changed out cassettes twice?!? Are you still on the original chain? Here's a very general rule: If you don't change out anything over several thousand miles (say, 3,000), you'll pretty-much have to replace all the driveline components (chain, cassette, rings, pulleys) at the same time, as the worn chain has worn the other components to match it. If, however, you change out the chain every 1,000 miles or so, the components thru which it passes will all last much longer, as they won't match the wear on a progressively-worn chain. Or did you know all that already?

Actually, I changed cassettes because my LBS sold me new rims with the cassettes already on it. I know now that probably wasn't the best deal but... Live and learn no?

BTW, I installed a new chain before my first ride this year.

Is it possible that my rear derailleur not being adjusted correctly would cause this problem?