Framebuilders - How do you cut a keyway in a steerer tube?

I tried to serch for this topic, but the search function appears to be down.

I recently acquired a Sparton ST-500 fixed gear bicycle. So far the frame appears to be of good quality with no problems. The issue I have is that the fork was not cut with a keyway to hold allow the use of a toothed washer and as a result the headset needs occasional adjustment.

What is the best method for cutting this keyway? Is there a specialized tool required?

usually a guide and two hacksaw blades, or a file.

do you have enough room for a headset lock?

http://www.cambriabike.com/Images/product/gorilla_headlocks.jpg

I don't think there is enough room for a headset lock. What would I use for a guide to cut my own keyway?

Dumbest (useless, worse than nothing) features in bike design:

Keyways in steering tubes
Slots in the heads of spoke nipples (where aluminum nipple folds as it fails)
Springs on quick release skewers
Stem tube threads on presta tube valve stems

Any machine shop can cut you the exact slot you want......

A keyed washer makes headset adjustment easier since the adjustable cup won't turn when you snug down the top nut. Regardless of whether or not you have this keyed washer, once the top nut is tightened it shouldn't loosen. If your headset is coming out of adjustment there is most likely some other problem. Could be the frame needs the head tube faced. Best to start with the basics.

A keyed washer makes headset adjustment easier since the adjustable cup won't turn when you snug down the top nut. Regardless of whether or not you have this keyed washer, once the top nut is tightened it shouldn't loosen. If your headset is coming out of adjustment there is most likely some other problem. Could be the frame needs the head tube faced. Best to start with the basics.

Thanks for the advice. The headset worked its way loose after about 100 miles and I just had it adjusted yesterday. Maybe it was simply not installed properly in the first place? If it does occur again, I will face the head tube.

Once the head tube is faced, what protection can I use to keep the bare steel from corrosion? Can I depend on the proper seating of the headset cups to be enough to keep mointure out? (I think the answer is no, but I would like a professional opinion.)

Heavily greased headset bearings will weep onto the head tube and fork crown, and protect them for years. Ditto for greasing at bottom bracket, seat post and wheel bearings.

When I had to put internal keys on some gears, I went to my university machine shop, and they had a keyway cutter. It's a little shaft fit to the size of your hole with teeth sticking out of it. You press it through your hole and each pass of the tooth takes off a bit more of the material until you have a keyway of the proper depth.

Shaper, It works internal shapes a mill can't reach, though not a comon tool these days. This will give you the idea:

http://ca.youtube.com/watch?v=oZFFYIvTLiE

you can use a broach to do keyways on ID or OD, but OD you can mill a slot as well. A well stocked LBS will have the broach, and a quick phone book peek will find you a machine shop. It may cost you a bit though @ the machine shop, they usually charge by the hour or half hour even if the job takes 5 mins. I'd really look at a locking top nut. Tange makes one with little set screws. Cheng-shin does too i believe. Good luck.

Thanks for the advice. The headset worked its way loose after about 100 miles and I just had it adjusted yesterday. Maybe it was simply not installed properly in the first place? If it does occur again, I will face the head tube.

Once the head tube is faced, what protection can I use to keep the bare steel from corrosion? Can I depend on the proper seating of the headset cups to be enough to keep mointure out? (I think the answer is no, but I would like a professional opinion.)The fit is extremely close with a properly faced & installed headset, so no worries about the seal.

The only correct way to adjust and lock down a headset is with TWO wrenches. You unscrew the adjustable cup upwards into the locknut that you tighten downwards. It's simply isn't possible to get as strong of a lock with a single wrench and a keyed washer since a lot of that locking force goes into pinching the side of the tab on the washer into the threads leaving the adjustable cup still loose underneath it.

You'll notice that none of the high-end headsets ever come with a keyed washer anyway and no high-end bikes come with slots in their steerer-tubes. The cost of a 2nd wrench is obviously too much for 2nd-rate shops to affort.

You'll notice that none of the high-end headsets ever come with a keyed washer anyway and no high-end bikes come with slots in their steerer-tubes. The cost of a 2nd wrench is obviously too much for 2nd-rate shops to affort.

Funny, on the frame/fork I finished this week, I had to slot the steerer to fit the customer-supplied headset......brand new Campy Record. Or is that not high-end?:thumb:

Shaper, It works internal shapes a mill can't reach, though not a comon tool these days. This will give you the idea:

http://ca.youtube.com/watch?v=oZFFYIvTLiE


that old whipp sure brings back some memories...used to run one of them and a blanchard at the same time. just a watching the clock tick...

SSD, did you ever find a fix? I'm finding that my LBS does not have a broach, and neither do the better stock chain store. I'm planning on a steady hand and a dremel tool.