Re-Tapping Pedal Threads

Who wouldn't want a classic Stronglight or TA crankset on their Randonneur, especially if they could get it at a bargain price. Okay, some of you (Neil) wouldn't, but pretend for a minute. One way to save money on old French cranks is to buy the ones that have French pedal threads. Some cranks are rare with anything but French threads. French threaded pedals are getting hard to come by, though VO can still get them, and the price for those pedals seems to be climbing, while the prices of the cranks drop.

French pedals have 14mm x 1.25mm thread while the far more common and slightly larger English size is 9/16" x 20. It's about 10 minutes work to convert French threads to English. Most bike shops can do this, but with about $35 worth of tools you can do it yourself. You'll need a set of English pedal taps. Park, VAR, and other tool companies make these. You'll also need a tap handle and a little cutting oil (thin machine oil or kerosene will do).

First wrap a rag around the crankarm and secure it in a vice or ask a friend to hold it on a flat surface. Next, remember that there is a left hand and a right hand tap; select the one that matches the crank. Put the tap in the handle and squirt some oil on it. Thread the tap into the pedal hole. After each half turn, reverse direction for about a quarter turn. This breaks and helps clear the aluminum chips that would otherwise clog and damage the threads.

You can get an even better deal, like free, on cranks that have stripped threads. Stripped threads can usually be repaired by tapping the hole to a larger size and screwing in an insert called a helicoil.

Be sure to put a little grease on your pedal's threads before installing them. And use pedal washers so they don't damage the crank and can be easily removed later.