Re: [CR]Thoughts on drilling track forks

(Example: Books:Ron Kitching)

Date: Sat, 16 Dec 2006 21:06:39 -0600
From: "John Thompson" <JohnThompson@new.rr.com>
To: Ben Sanford <B.Sanford@cox.net>
Subject: Re: [CR]Thoughts on drilling track forks
References: <004201c72153$2e0944b0$6400a8c0@BSSatellite>
In-Reply-To: <004201c72153$2e0944b0$6400a8c0@BSSatellite>
cc: classicrendezvous@bikelist.org

Ben Sanford wrote:
> The fork bent in the area of the crown itself \u2013 between the section
> where the steerer tube is brazed into the top of the crown and the
> section where the fork blades come up into the crown. The fork
> blades are not bent, and the hole for the brake wasn\u2019t near where the
> fork crown bent, so it wasn\u2019t weakened by the drilling \u2013 although
> this one was factory drilled.

What type of crown was this? We had some trouble like this on the early Trek 170 frames (Reynolds 753) that used a modified Ishiwata SCM crown:

http://www.os2.dhs.org/~john/ishiwata-1.jpg

The stock crown came with a flat front and rear; at Trek this was milled away between the steer tube and blades to produce the effect in the picture above. A pretty crown, but we took to calling it the "frame-saver" crown since it could be counted on to bend on frontal impact long before the frame would. :-)

--
John Thompson (john@os2.dhs.org)
Appleton WI USA