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Extending threads on a 1" fork

I've replaced the fork for my Bridgestone RB-1 single speed with a crowned 1" steerer Raleigh (24 tpi) fork. I have the Park Tool FTS-1 for cutting the threads, have used it before & understand the process but what I can't remember & need help with is how one gets the groove cut in the threads that allows for the headset spacers with the 'spline' to be put on the fork.

If someone knows how to cut that vertical groove in the threads, I'd greatly appreciate some help!


PS: I'd like the proper answer; the 'bike shop answer'. Also, no, none of the local bike shops know how to do this...pathetic. I live in Alaska & I don't think the art of bicycle Mx has migrated up here yet!
Hi elangerman,
I really do not know the "bike shop answer" but this is all I could find from the people who made the FTS-1. Personally looks like a very nice tool!! Here is the link... .
If that doesn't answer your question then use the contact link on the same website.

Good luck ,
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
Try to take a look at the framebuilder mailing list archive the question might have been asked in the past. Good luck!
Well, I think the 'bike shop answer' is that you shouldn't cut that groove in the threads at all. The groove allows you to use a toothed spacer. That tooth is there so you can tighten the headset locknut without it turning the adjusting cup. However, this is there for convenience at the time of assembly of the bike. The 'proper' way to adjust the headset is to hold the adjustment cup with one tool while you tighten the locknut with another. Since shops will always have adequate tools, the convenience of the toothed spacer is not needed. The problem with the toothed spacer is that you are removing threads from the fork and weakening the contact between the headset parts and the fork.

It's not that big a deal and the loss of that small area of threads is not critical. But I'd rather file the little tooth off my spacer than start grinding off threads on a brand new fork.

You're right and that's the answer I needed. I've installed many threaded headsets before but couldn't remember if that spline was integral to the locknut staying tight or not. I'll slice the tooth off my spacers and will be on my way. Thank you!

Bill, that's a good link! I hadn't seen that before. Thank you all!


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