Bicycle Mechanics - New chain, freewheel- now new vibration

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johnnygofaster
05-04-06, 09:20 PM
I was so proud of myself. Took my junky steel commuter and replaced the 16 year old chain and freewheel assembly as well as the derailleur (a $4.00 Shimano SIS job).

Now when I am "under load" I get the slightest vibration/buzz through the crank. Happens at the same place relative to the crank arm travel (right side, about 5 to 8 o'clock). Seems to happen in the smaller/outer/higher/however you say it gears. It's not bad per se, just curious why it's doing it.

So I think...
1: I never noticed it before, but now that I'm a "mechanic"... ;)
2: The old stuff was so old and loose and this is new and tight and it's just happening
3: The chainring is bent (it looks true when spinning)
4: Satan posessed my bike.

Any insight would be helpful. Trying to learn this stuff on my own (with some books).

Cheers,
Brian

PS: Any ideas why the next to smallest rear sprocket won't index with all the others would be good too. I'm thinking a bind in the cable.

nodnerb
05-04-06, 10:39 PM
Rubbing against the front deraileur would be my first guess.
_dhan_
05-04-06, 11:13 PM
I'm assuming you replaced the rear derailleur? You might want to check to see if there's enough space between the derailleur sprockets and the cog when in the highest gears. You might be getting some rubbing there. That would also provide a plausible explanation for the shifting problems. You can fix that by adjusting the b-limit screw.

how's the chain length? possibly too long? just throwing that out there.

johnnygofaster
05-05-06, 10:30 AM
Chain length matches the old chain. used Sheldon Brown's method and got the exact same length.

I am familiar with the FD rubbing sound but I won't say it's not that.

No b-limit screw (REALLY crappy RD) but the distance between the cog and the sprockets.

Really perplexed by the vibration aspect. Glad to see it's not something supremely obvious.