Originally Posted by
onespeedbiker
If you want to use the 22.2 stem with a French Thread, then you may have to sand down the stem to make it fit the steerer and/or headset locknut. From Sheldon Brown.
French stems are 0.2mm narrower than others where they fit into the steering column. A standard 7/8" / 22.2mm stem won't usually fit. In many cases, the limiting factor for fitting the stem in will be the headset locknut, rather than the steerer itself. Try removing the locknut before sanding down a stem. If the headset locknut is slightly tighter than the steerer, it can be enlarged easily with a small grinding wheel. If you convert from a French stem to a standard one, you will also need to replace the handlebars, which are a different diameter. French Bicycles
But the best option depends on how important it is the keep the French threading. With BSC threading you have an endless supply of stems and headsets, but it won't be French. Also, if you want to use your BSC stem, you may need to replace the handlebar. Many of the PX10 came with Cinelli stems with the old 26.4 size. . The catalogs show the 79-81 Super Competition coming with the Peugeot ATAX Quill Handlebar Stem which should be 25mm. My 85 PH105 came with a CTA stem with a 1" clamp, but early bikes came with the smaller French sizes 23.5mm/ 25mm
I actually found (hard to come by as it ewas) the correct french sized 1A Cinelli stem in the size I was looking for. Ironically now I'm thinking about having it fixed with standard brit sized steer tube,.. but that's my question now,..
Do I have him keep it french to stay original or just say to heck with it and make it brit thread and diameter instead to keep things easy...after all they did have "some" that went to brit sizing at this time??
Mine came with the Atax stem and Phillipe handlebars,.. I got an early 1980s Cinelli handlebars and have both the french quill sized stem and the brit sized stem here,.. so I can go either way very easy.
FYI this is a 1981 Super Comp bike,.... so that may play a part in the consideration of what to do on the stter tube????