I'm trying to put a 70ies Peugeot PR/PS back on the road and that involved finding a replacement fork. Next step will be cutting the fork down. Now the slot that holds the Mafac-type cableholder in place will obviously disappear. Will just filing off the tab on the cableholder work OK? I'd rather not have to tamper with the threading on that fork more than the bare minimum. That slot is there for a reason I suppose, but I can't imagine the cable holder/headset start to behave badly without it?!

The slot is there to prevent the washer from spinning and makes it much easier to adjust the headset bearings. Many folks simply file a flat spot on the threads where the groove would be. The flat will be wider than the groove but the same depth.

Those slots are a cause of many a messed up steerer tube threads when the tab on the headset washer sometimes eats into the threads when you tighten or loosen the headset locknut. I usually just file off the tab on the washer to avoid that and always use two headet wrenches to install, adjust or remove the headset.

Chombi

I'm a bit reluctant to start filing away on that steerer, Frank, finding a 2nd replacement fork might just prove too much . Chombi's approach is probably the way to go. Some extra fiddling in adjusting the headset is not too big a deal. Thank you, early risers.

Personally if your only talking 1/4 to 1/2 inch of steerer I would not even cut it. If you (or the next owner) needs to change the HS something taller like a nice Stronglight alloy or CampI HS may not fit. Also iy gives you and extra bit of vertical height on your stem.

I agree with both of the above answers, the slot/tab can make HS adjusting/tightening easier but I have seen lots of buggered up threads but mostly on kids bikes from reflector brackets.

The reason for the tab on the housing stop bracket is to ensure it stays centered on the brake keeping the properly adjusted. If you remove the tab and get the bracket centered you should be OK unless the bike falls or the bracket gets bumped and knocked off center.

My French steerer has a flat spot and not a groove. Maybe that's for the type of headset they used.

It's because it's French and that's the French way.

Was Campagnolo the only French headset that used a flat on the washer? Can't be, eh? I can't remember if my Gitane has a flat on the steerer too....but I think so.

just ignore the tabbed washers. Use washers/hangers without the tab and make sure you get some nice torque.

You never noticed that MAFAC front hangers are made for French forks with a flat and with a tab for everything else? The tabs and flats have a purpose and they've always worked well for me. It's possible to do without them, but I don't see a good reason why.

For finding the right length: assemble the headset (dry ok, but with bearings) Run the top cup down to where its adjusted well, put the top nut screwed on until it bottoms out. The space between the top cup and the top nut is how much you need to shorten. I use my calipers to measure.

Hold the unthreaded part of the fork in a vice. Run and old headset onto the threads. Cut against that at your mark to keep the cut square. It'll clean up the threads a little when you remove, but flatten and champher it on a grinder. Don't forget to clean the inside with a halfround file.

The washers; I never seem to have the one I need. I usually remove whatever is there with my Dremel.

Because sometimes that's the least invasive and involved way to make the bike go together and get it ready for the road before morning. Sometimes you don't have time to search out the exact washer, and the file just calls you ...

You must be a better man than I am, being able to resist the seductive call of the Files, singing to a C&Ver's heart in French.

Have you thought about just using 1" spacers to fill the void? That. Way you could keep the slot. Just a thought. My Woodrup (thanks again Roadfan) doesn't have the slot on the steering tube, I had a heck of a time adjusting the headset with the hanger/washer tab filed off. I'm going to have some work done to the frame and fork, and having a slot machined/filed in the steer tube will be on the list of things to do. I imagine you could continue the slot with the right file if Yup were careful.

Cheers,
Chris

^^^
The new fork is well over an inch too long, that's too much, plus I really dislike the sight of stacks of washers on a classic headset. But I'll use the old fork for all kind of slots and flats filing experiments!

This is an original late 70ies Peugeot fork. On my other French bikes I have steerers with a flat and others with a groove, but it's like Rootboy says, once the topnut is tightened you forget which is which.

Just savouring that.

Some people don't like the look of a stack of spacers and that's okay with me. I actually sized cut my steer tube intentionally long so that I could incorporate a bell mount and help support the extra long stem. Rivendell does the same on some of their bikes.

I'm planning on trying the same on a frame with a replacement fork with a too long steerer. Grant can't be all wrong all the time.

Maybe you'll believe Sheldon Brown regarding French forks:

"French headsets use a different type of keyed washer than others. Instead of having a groove machined in the threads, the rear part of the threads is filed flat. French headsets commonly used a serrated keyed washer, with matching serrations on the threaded bearing race. This makes French headsets slightly harder to adjust, but once they are adjusted, they hold their adjustment better than conventional designs."

It's not about believing or not, I was just giving some info on the French forks I've seen (not too many either). This Peugeot fork has a slot is all I''m saying. Not ALL the French headsets have the serrated washer either (type Stronglight Competition). Maybe that went away sometime after the mid-seventies, I don't know. And I would never contradict the inventor of the black PX10

There are definitely lots of exceptions. I have a Raleigh Competition with the French-style flat.