[CR]Re: measuring built bikes

(Example: History:Ted Ernst)

Date: Thu, 27 Jan 2005 14:58:26 -0800
From: "John Jorgensen" <designzero@earthlink.net>
To: classicrendezvous@bikelist.org
References: <MONKEYFOODoe2U8QVjp00001ba4@monkeyfood.nt.phred.org>
x-mac-creator="4D4F5353"
Subject: [CR]Re: measuring built bikes

> Chuck Schmidt wrote on Measuring:
>
> For fork rake I have a plexiglas gage called a "Gabe Meter" made in
> Germany in the early 1980s that has a v-block (with magnets) on the back
> that attaches at the top of the fork leg that has a scale you read at
> the pointed end of the QR.
>
> For head angle and seat angle I use a 4' long metal straight edge along
> top tube and a draftsman's 14" adjustable triangle that has a degree
> scale on it to measure the angle.
>
> I think this is much more accurate than one of those angle finders that
> relies on leveling the top tube first (fluid filled, with floating pointer?).
>
> I also use the 4' metal straight edge and a vernier caliper to measure
> the BB drop.
>
> Anyone have a better method to measure fork rake, head and seat angle?

Other than wishing I had that Gabe meter, a good methodology, the Primary thing I do that is differently from the start is use a true set of wheels without tires.

I learned long ago that all top tubes are not level, tires have diameter variation, so a level base plane with a bare set of wheels shows not the intended but the actual.

For my subjective comparisons, front center distance and trail make the handling differences that I can feel.

I like large drop BB's for downhill stability but always want a higher one going into a corner on a level turn.

A good excuse to have more than one bike.

John Jorgensen
Palos Verdes Ca