Re: [CR] French-to-English Pedal Tapping - Drill or No?

(Example: Framebuilding:Brazing Technique)

Date: Mon, 14 Feb 2011 18:29:46 -0800
From: "verktyg" <verktyg@aol.com>
To: Classicrendezvous@bikelist.org
References: <686980.44463.qm@web31808.mail.mud.yahoo.com> <4ECD6A7017B31A4297D2B431006E5DF903296547A2@EXMBX13.mmeprod.cbeyond> <01ac01cbcca6$2c8d5b50$85a811f0$@com>
In-Reply-To: <01ac01cbcca6$2c8d5b50$85a811f0$@com>
Subject: Re: [CR] French-to-English Pedal Tapping - Drill or No?


Scott,

A 9/16-20 thread could be rolled into pre-threaded aluminum crank arm if it were reamed out about .010" to .011", maybe less, trial and error. You will probably get about 50% threads. Drilling isn't that accurate so reaming would work better.

9/16-12 and 9/16-18 while not common threads sizes are the US standards. One each of a special RH and LH 9/16-20 Form Tap is going to cost somewhere between $60 and $100 each. How many do you want?

Chas. Colerich Oakland, CA USA


> I wonder what a threadforming tap (as opposed to a threadcutting tap) would
> do in this application? Not that anybody probably makes them in this
> oddball size (especially the left-handed one).
>
> Scott Minneman
> San Francisco, CA USA