[CR]Re:Nuts and Bolts with French Threads

(Example: Framebuilders:Cecil Behringer)

From: "Jim Merz" <jmerz@schat.com>
To: <classicrendezvous@bikelist.org>
Subject: [CR]Re:Nuts and Bolts with French Threads
Date: Sun, 4 Jan 2009 09:58:42 -0800
Thread-Index: AcluiK32yEshjoL/TMqmoTU11nGV+AAApAoQAAKvEqA=


Taps in metric diameters with many non ISO pitch are available from MSC. They also have metric pitch gauge tools. This very good company will sell to anyone with a credit card. I have made many fasteners for pre 1967 Japanese motorcycles as some of these threads are not available either. If you really want nice reproduction parts a lathe is really needed, along with a milling machine to do the hex head. I also was able to buy metric hex stock from a company in the USA, Parker Steel. They will sell small qty. also, but not cheap. They even have 4130 CrMo in sizes above 10mm.

I noticed some concern from some on the list of so called "counterfeit" parts. I have been involved in the highest level of vintage motorcycle restoration and here is my opinion. First of all what exactly are you trying to do? In the case of vintage cars or motorcycle, it is to show or race. If it is to show, then the reproduction parts must me indistinguishable from the original parts by a judge. This is the key, there is no problem with even making a new body as long as it meets the test stated above. If some judge can notice some very small detail such as no Logo on the brake washer, then maybe some points will come off. However if you must take the brake apart to see this I can't see getting worked up about this. The other case is vintage racing. Here much more leeway for making new parts is allowed. I have see the whole machine made from new parts, and most racers use many newly made parts. The rules say what you can and cannot do, but the idea is they must be mostly like the period in question.

In any case I can assure you that someone who makes reproduction Campagnolo parts that look even close to the original is not going to make a killing. I have made chainrings for Campi cranks in the old days. I actually thought about making some 31 tooth inner triple rings a while ago, but I don't think it's worth it. So my point is, if you see parts on Ebay that look like copies either don't buy them or ask the seller if they are copies. If you need them and they are rare it's up to you to buy. But I can't see going ballistic over the seller being a criminal. Just my opinion.

Jim Merz Big Sur CA

-----Original Message----- From: classicrendezvous-bounces@bikelist.org [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of Jan Heine Sent: Sunday, January 04, 2009 8:23 AM To: festiva90lx@yahoo.com Cc: classicrendezvous@bikelist.org Subject: [SPAM][CR]Re:Nuts and Bolts with French Threads
>Thanks for the information on the thread dimensions, that explains
>why the hardware store did not have the right size metric screws.
>I wonder if hardware stores in France stock them.

The old sizes are not used in France any more, either. When you deal with older French bikes, you get in the habit of machining your own screws. Especially when the makers made their own anyhow, with special head shapes to make inferior quality replacement bolts obvious at the first glance.

Getting taps in the old sizes can be a nightmare. If it's for aluminum, you can make your own, but for steel, the hardening, etc. is a bit tricky. I suspect the taps must be available in France - perhaps I should invest in a set next time I am over there.

Jan Heine
Editor
Bicycle Quarterly
140 Lakeside Ave #C
Seattle WA 98122
http://www.vintagebicyclepress.com