Squeal

I have a fairly old (8 years or so) specialized Allez with a Shimano 105
drivetrain which I now use exclusively on my trainer. The drivetrain has
about 10,000 miles of use on it. Lately I have been getting a squeal (high
pitched screech) when I use the bike on the trainer, particularly when I am
using certain cogs. Any views on how to fix the problem? Replace cogs
(entire freewheel at this point I guess)? Do I need to also replace the
chain and the chainrings? Or could the squeal be coming from the rear hub?
It's hard to isolate the sound?

If the squeal does not happen when the bike is off the trainer, maybe
the trainer itself is making the noise, or the rubber of the tire is
squealing at the point of contact. When you change gears, you change
the torque at the contact point and that could increase or decrease
the noise.
If the gear sprockets are badly scalloped you should probablyb change
out the drivetrain anyway.

r.b.

"j morelstein" wrote in message . ..
I have a fairly old (8 years or so) specialized Allez with a Shimano 105
drivetrain which I now use exclusively on my trainer. The drivetrain has
about 10,000 miles of use on it. Lately I have been getting a squeal (high
pitched screech) when I use the bike on the trainer, particularly when I am
using certain cogs. Any views on how to fix the problem? Replace cogs
(entire freewheel at this point I guess)? Do I need to also replace the
chain and the chainrings? Or could the squeal be coming from the rear hub?
It's hard to isolate the sound?

"j morelstein" wrote
I have a fairly old (8 years or so) specialized Allez with a Shimano 105
drivetrain which I now use exclusively on my trainer. The drivetrain has
about 10,000 miles of use on it. Lately I have been getting a squeal (high
pitched screech) when I use the bike on the trainer, particularly when I am
using certain cogs. Any views on how to fix the problem? Replace cogs
(entire freewheel at this point I guess)? Do I need to also replace the
chain and the chainrings? Or could the squeal be coming from the rear hub?
It's hard to isolate the sound?

Are you sure it's not the trainer squealing? Or the tire slipping on
the trainer's drum? Maybe the rear hub? I can't see how worn cogs
would cause a squeal.

If you have 10,000 miles on the chain it probably is "stretched."
Measure 12 full links, and replace the chain if the measurement is
more than 12-1/16". Then, if you get skipping, replace the cassette.

Art Harris