There are a number of jobs around your bike that are really best left to professionals. Fitting a headset is one of them. It’s a job that, done properly, involves all sorts of specialist (and expensive) tools. With the right tools it’s dead quick and easy. Without them it’s a bit awkward with a high risk of permanently damaging something.
Despite which, we’re going to show you how to do it without the right tools. Partially in the hope that it’ll act as a warning not to, partially because, well, if you’re going to do it you might as well do it right. OK, not right as such, but at least minimally wrong. If you’ve got an expensive lightweight frame and/or an expensive lightweight headset, then stop now. It’s not guaranteed to work even with suitably robust tackle – if anything looks like going wrong, bail out before it gets terminal…
1. As well as typical bike tools like a selection of Allen keys and some grease, this method of headset fitting also requires favourite bodging equipment like a hammer and a selection of stout lumps of wood. You’ll also need a solid surface like a workbench. Put off yet?
2. Before getting a new headset in, you need to get the old one out. Unless of course you’re working with a new frame. And to be honest, if you’ve just spent out on a new frame then flailing about trying to fit your own headset isn’t a great idea. But if you’re confident, it didn’t cost you much anyway and you’re desperate to ride it and the bike shop’s shut, then go ahead. First you’ll need to undo the top cap, loosen the stem bolts, lift the stem off the steerer and pull the fork out. It might need some gentle percussive persuasion to shift it. Mind it doesn’t fall on your foot. Pull out all the various seals and bearings in the headset so you’re left with just the cups in the frame.
3. Now it’s time to drive the cups out. The proper tool for this job is the ‘rocket’ tool, a thing with sprung flanges at the bottom and a solid tip that you can whack the top of and it’ll apply even pressure around the inside of the headset cup. Deprived of such a luxury item, you’ll need to use something else. We’re using an old hub axle here. Old screwdrivers are popular, but you’ve got a much better chance of gouging something or piercing your own hand with one of those. Rest the business end of your chosen tool on the inside lip of the headset cup and tap the other end with a hammer. Work evenly around the cup and it should begin to ease out. If it ain’t shifting, don’t try too hard – give up and take it to the shop.
4. Once both cups are out, you can breathe a sigh of relief. The next hurdle is getting the new ones in. Clean out the inside of the head tube first. If the frame’s never had a headset in, you should make sure that the ends of the headtube are ‘faced’ – ground smooth and parallel to one another. If there’s paint on them this hasn’t been done and you’ll have to get a shop to do it. And really they might as well put the headset in for you while they’re at it. If all is well, you should find that it’s possible to push a headset cup part-way into the head tube by hand. Make sure it’s straight, with any logos pointing in a pleasing direction and that you’ve got the right one in the right end of the head tube…
5. Now comes the scary bit. Find a solid surface and rest the other end of the headtube on a nice block of wood on said solid surface. You may need to enlist assistance to hold everything in place. Then use another block of wood on the cup and tap firmly (that’s TAP, not wallop) with a hammer. Again, work around the cup so it goes in evenly. If you clout it in at an angle you’ve got problems. Keep checking it’s straight and if it’s drifting off tap it back into line. Once it’s straight it tends to stay straight, though. Keep going until the cup is fully home, that is, there’s no gap between the end of the head tube and the cup.
6. Once one cup is in, repeat the process with the other one. Then turn your attention to the fork. We’re massive fans of FSA headsets because they use a cunning split crown race that easily levers off and pushes on. If yours has a more conventional crown race you’ll need a subtle combination of levering and tapping to shift it. If there’s not enough crown race sticking out over the fork crown to get anything in, then pop into your local shop with your fork, new crown race and some tasty baked comestibles and smile sweetly.
7. Once the old crown race is off, put the new one on. Again, the FSA ones just push on by hand. Conventional ones will need persuading in. Old frame tubes are handy for this if you happen to have one the right size. Ideally you’ll only tap the upper edge of the crown race to avoid damaging the bearing surface, but tools with enough of a point to tap there are also the ones most likely to make a nice gouge. We find that a decent bit of wood with a reasonable corner on it does the job without such a risk of gouging.
8. That’s the hard part over with. To finish off simply grease up the inside of all the bits of headset and refer to the instructions to find out what order all the bearings, flanges, washers, O-rings and other assorted gubbinses are meant to go in. Most manufacturers recommend leaving the steerer dry where the stem clamps on, although a bit of grease lower down where any spacers you’re using sit can help to ease adjustment. Stick the stem back on, pop the top cap in, use the top cap bolt to load the headset bearings and tighten the stem clamp bolts. Job’s a good’un…
There’s hundreds of top maintenance tips in the BM archive.