On 2018-11-24 15:53, Sir Ridesalot wrote:
On Thursday, November 22, 2018 at 7:05:29 PM UTC-5, Joerg wrote:
After installing a new Sunrace 40-11T cassette (minus one cog), a
new chain and a new rear derailer the road bike can now climb hills
much better. 40T as biggest cog versus 32T before. Woohoo!

However, on the middle and three larger cogs (it's now a 7-speed)
there is a distinct vrrrt .. vrrrt sound when under heavy load.
Maybe from the chain because with a derailer setup it'll never run
100% straight. Hard to say. The noise appears briefly twice per
pedal crank rotation and always on the power strokes.

The chain is a KMC Z50 that should be suited for 7-speed and I
looked, it doesn't rub against a neighbor cog. Maybe a "teeth exit
grinding"? On the 3rd cog from the largest it's really weird
because that has an almost perfect chain line when on the small
chain ring up front.

Anyone heard that before? Can it simply be ignored? Or maybe it'll
go away over time?

-- Regards, Joerg

http://www.analogconsultants.com/

When you installed your hacked cassette you didn't put the individual
cogs on backwards did you?


No but I might do that with some once they are worn. Done it before and
it has never caused growling noises. I don't care much about losing the
HG advantage and milliseconds during shifts.


Still thinking about whet might be causing that noise.


After church I'll do a ride with a buddy who is a machinist. Hopefully
we'll find out what the noise is because next week there'd be a longer
ride with a few guys where I don't want to become the one whose bike croaks.

BTW, the machinist rides a beautifully restored (but modified) Peugeot
PX-10 from 1972.

--
Regards, Joerg

http://www.analogconsultants.com/