One trick that we used to use was to clamp, face-to-face, an old crankarm to to the one being threaded to pilot the tap into the crank being rethreaded. Later, we scored a set of pedal taps that had a reamer/pilot built into them, so that wasn't such a big issue. The trick about starting from the back is primarily for straightening out threads when some shmuck has forced the pedals in crooked--a common problem with over-the-counter sales (that, and putting the wrong pedal in a crank). Typically, only the threads in the face side are buggered. You can get the tap started straight on the good threads in the back side of the arm, and the tap will often restore the threads on the other side well enough to hold the pedal. Sometimes a little thread reapir epoxy is necessary as well. When that failed, we reamed them out and put in an insert, as long as it was an aluminum crank. Steel cranks went in the junk. Obviously, one would go to greater lengths to repair a rare crank. Almost anything can be fixed, if you have the time and money.
--Steve Barner, who hasn't used a pedal tap in years, Bolton, Vermont
Date: Sun, 09 Mar 2003 09:45:40 -0800 From: Jay Sexton <jvs@sonic.net> To: classicrendezvous@bikelist.org Subject: [CR]Stronglight Mod 93 Cranks and Lyotard pedals Message-ID: <3E6B7DC4.7040205@sonic.net> References: <CATFOODy8VBDUfdfdhN000005ef@catfood.nt.phred.org> Content-Type: text/plain; charset=us-ascii; format=flowed MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 12
Hello all,
I want to re-tap French threaded Mod 93 cranks to English, and found good info in the archives, but one comment has me wondering. It was suggested to run the tap from the backside of the crankarm. Why would this be? Will re-tapping remove too much material, thus potentially weakening the threading? Is it considered sacreligious to change the pedal threading? I am also thinking of restamping the crankarms to reflect the altered threading. Any thoughts or comments on all of this business?
And.....where can I find information on the different models of Lyotard pedals? Hopefully with photos. I need to identify a set of Lyotard pedals I have so I can determine the threading. Sorry if this has all been gone over before. It's new to me. Offlist replies welcomed.
Jay Sexton
Sebastopol, CA