popefelix

The saga of my Motobecane Mirage continues. I had mistakenly thrown away the wedge from my stem. I found a replacement wedge that fit the stem bolt. I put the stem in my fork, tightened it up (finger tight) and... It's loose. I can move it around pretty easily - no need to apply torque by holding the front wheel between my legs or anything. Is this stem too small for the fork? I went from a French threaded fork to a standard fork, maybe the stem width is different?

nlerner

Yeah, you have a French-sized stem, unfortunately, which is just .2 mm narrow than every other stem, but that's enough to rattle around in a 22.2mm sized steerer.

grizzly59

As soon as you say "french", you need a caliper to measure any replacement part vs the original. Almost everything is just a bit different.

deconstructeur

I can't post the URL here since I haven't yet made ten posts, but Sheldon Brown's site has a helpful chart giving the measurements of French bikes versus their British/ISO equivalents. The Motobecane Mirage is basically a French bike with a Swiss bottom bracket (French threads, but the drive-side reversed). At least that's the case with the 1978 or 79 frame I just built up.

nlerner

What’s the reach of your current stem (distance from fixing bolt to center of bar clamp)?

steve sumner

I thought I remember you being advised to replace your French fork
with a French fork. ah well. if you replace the stem it won't fit the French
bars so you"ll have to replace both. an alternative would be to add a shim
to your stem so that it's a tight fit in the fork.

grizzly59

I am slow, and I don’t understand how you got your headset to fit a standard fork in a french frame. I’m not saying you didn’t, I’m just scratching my head as to how that works. French stuff always seemed to be an extra challenge.

popefelix

I put a new headset on.

popefelix

Center to center looks to be about 7 cm.

popefelix

Bought a new 22.2mm stem from FleaBay and it fits perfectly. Thanks, all, for your help.