hedgehog9

Hi all. ~Noob here.

So I've got this problem: there's some kind of noise (perhaps it's called clunking?) coming from the rear wheel at least once every rotation. It's most pronounced when freewheeling and the sound does remind that of lose bearings or something like that, however if I take the chain off and just spin the wheel, the sound disappears completely! Then if I place some chain on the cassette while the wheel still spinning freely, the sound immediately comes back and the cassette starts vibrating somewhat. So this must have something to do with the chain or derailleur, especially given that before the last ride (when the noise appeared – right from the first metres) I had been adjusting the derailleur.

Thanks for any advice.

cny-bikeman

If merely putting the chain on the cassette creates the sound, then the cause has to be the cassette/freewheel. The chain is putting tension on the cassette, which is probably rocking back and forth or similar to make the noise. As the chain is not moving neither the chain nor the derailleur can be the cause. This is something best diagnosed in person, so take to a bike shop or bike co-op, or perhaps a friend who works a lot on his bike or others.

Andrew R Stewart 

Agreed! I'll add that at times the best repair is to just replace the wheel. It all depends on the wheel's condition. budget and expectation. If bearings are worn/damaged are they replaceable? How are the spokes (tension level and evenness), nipples rounded yet, any chain damage from over shifting and is the rim basically straight with no bumps/dings/dents/cracks? Next up is the hub. We already believe the freehub body bearings are the source of the noise. Can this part be had? How much$? Check out the hub shell/axle bearings also as they have seen the same use as the FH ones.


Only if all of the above are not hindering the repair and only if the customer was Ok with the cost would I (as the shop wrench) do the repair, replacing the FH body (which at Full Moon Vista would cost from $65 P&L for basic Shimano to a few times that for fancy stuff). If the rest of the wheel showed any concerns (rim, spokes, nipples) I would look at the then higher repairs (and their rough future reliability) and compare to a replacement wheel who's grade could also be discussed. When the repairs approach 1/2 of a new and acceptable wheel I start to suggest the new wheel path as it will likely out last the repaired old one (which then can still be dealt with later if a back up wheel is a good thing to have on hand).


Last is what the rider expects. Does he rely on the bike for a paycheck? As in ride to work/school? If it breaks down does he have easy commuting options? Is he Training (note the capital "T" )? As in can't get through a day without his endorphins or ego lift. Maybe the rider only rides the bike when at the vacation spot. Or with the local club on weekends. The greater the rider's need to stay on their bike the more the replacement wheel path makes sense. There is what I call "the death spiral". The wheel went 1500 miles before the first spoke broke or the rim was wobbled. It gets fixed and only lasts another 900 miles before problem 2 comes about. Another repair and 250 miles... The period between problems gets smaller and less as the number of repairs add up. At some point the down time (and "while riding" reliability) become the issue.


Do know that if one is doing this themselves then add the cost of tools specific to the job. Having a bench vice makes working on a wheel easier sometimes. Don't worry about a truing stand, just use your frame with a brake pad or a tiny hex wrench rubber banded onto your blade/stay as an indicator. Andy