[CR]Re: Blue Cotterpins, was Cotterpin Blues

(Example: Production Builders:Cinelli:Laser)

From: "Aldo Ross" <aldoross4@siscom.net>
To: <classicrendezvous@bikelist.org>
References: <BAY115-F32C05E768ED34EF0724FB4BFA00@phx.gbl>
Date: Sun, 28 Jan 2007 14:38:16 -0500
reply-type=response
Subject: [CR]Re: Blue Cotterpins, was Cotterpin Blues

Neil Foddering wrote: "I know a couple of guys who use engineers blue (I think it's called) to show up high spots for more accurate filing."

Another product machinist's use is "High Spot Blue Marking Paste", aka "Prussian Blue". Here's a sample of a UK source for this type of product:

http://www.maintechmro.com/product.php?productid=294&cat=0&page=1

It's also available in the USA:

http://www.mcmaster.com/

(Enter item number 6165K11 in the search window.)

Some guys use actual Prussian Blue artist's oil paint. Cheaper, easier to find in craft or art stores, and supposedly the identical product.

I've run into lots of different problems with the cotter bolts on some of my older Italian bikes, up to and including flats on the bb axle that are not machined parallel. The hard part is getting everything to fit AND make sure the left and right crank arms are parallel. You'll know it the arms aren't parallel, because the bike will feel like it's handling funny, and when you stand on the pedals to climb, the bike will lurch to one side or the other.

Aldo Ross
Middletown, OH