[Fot] checking bearing clearances

[Bill Babcock]

I'd say you did the right thing but came to the wrong conclusion.  
First, you can and should use plastiguage across the bearing parting  
lines, I generally put it there and in the middle of the top bearing.  
Second--most folks wouldn't have found the problem any quicker with an  
inside mike--everyone checks the middle anyway. It's not the right  
thing to do, but I've seen even good machinists measure only there.  
Third, all measurements can lie--if your crank doesn't turn completely  
freely there is something wrong that WON'T GET BETTER by itself.

On Feb 1, 2008, at 12:15 PM, riverside wrote:

> Once upon a time,  I laid -check that- installed a
> reground crank with nice new  standard bearings that checked
> out fine with plastigauge if a bit on the loose side.
> you could barely turn the crank by hand.
> bought a set of bearings from another manufacturer (.001 undersize)
> and installed same.  plastigauged snugger as one would expect,
> but crank turned freely now.
> i bought a set of modestly priced micrometers and bore gauges from
> Enco and measured everything.  The first set of bearings were
> junk across the parting lines where the plastic could not go.
> Haven't used the stuff since and don't plan on it.
>
> art de armond
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Bill Babcock
Babcock & Jenkins
Billb at bnj.com
503.936.7660
www.bnj.com