Re: [CR] Measuring bike frame angles

(Example: Racing:Jacques Boyer)

From: "David Snyder" <dddd@pacbell.net>
To: <classicrendezvous@bikelist.org>
Date: Tue, 6 Oct 2009 14:15:55 -0700
Subject: Re: [CR] Measuring bike frame angles


I'm surprised that no one has suggested the "regular" mechanical hanging-weight dial angle finder, such as the $10, ~4X4" Craftsman.

It's easily good to a half degree I'd say, enough to get in the ballpark with stem length or a prospective frame/bike purchase. I carry one to every bike swap.

One drawback can be fitting it along the head tube, as it's more bulky than these tiny digital units. (and with center pulls, I have to turn the bars 90-degr.)

I always measure with the bike on the ground, on it's wheels or inflated tires. I then turn the bike 180-degr and check again, correcting for non-level ground. One should also verify an on-center instrument by checking seat angle from the right, then left side of the bike. The 2 readings should be identical, or the indicator line is likely not quite square with the magnetic side of the angle finder (I checked the whole rack of instruments in the store, doing left/right comparisons against a shelving strut. Many were not centered too well).

No batteries to replace, cheap, fast and durable. Mine's going on 10 years plus now.

David Snyder
Auburn, CA usa