Hot to fit fresh head bearings
Say no to notchiness and banish bad feeling — refresh your bike’s bearings to leave it steering sweetly
1. Lift, loosen and support
You’ll need good access to both yokes, so remove any bodywork that’s getting in the way. Before raising the bike, crack off the front wheel spindle, pinch bolts and caliper bolts. You can also take a quarter turn off the yoke bolts, but no more for now. The bike needs to be supported upright via a stand that lifts from the swingarm pivot, and we supplemented it with a trolley jack carefully positioned under the sump.
2. Take off wheel and secure calipers
Remove the brake calipers (a couple of bungee cords looped around the bike are handy for supporting calipers out of the way without putting stress on the hoses), wheel and front mudguard. It’s a good opportunity to check or change front wheel bearings too. At this point, measure the amount of fork protrusion past the top yoke with a vernier caliper or a steel rule, and make a note of the measurement for later.
3. Twist out the fork legs
Slacken all the yoke clamp bolts, and you should be able to remove forks. They may be a bit sticky – grabbing the fork upper and twisting as you pull usually does the trick. Store them safely, upright if possible. Undo the top yoke nut, and remove. You may wish to remove or unplug the ignition barrel if you can’t securely place it out of harm’s way on the bike.
4. Loosen your nuts
You’ll need a small C-spanner or a large socket to remove the stem nuts – research this before starting and arm yourself with the right tool. Support the yoke as you slacken it so it doesn’t drop on to the floor. When it’s out, compare your new bearing kit with the old to be sure it’ll fit. Fit new seals too – especially the bottom one.
5. Drift out the races
Slide a long drift down the head tube and locate it on the inner lip of the lower race. Give it a few taps, then do the same on the direct opposite side. Work around the race to tap it out evenly. Do the same with the top race (or sealed bearing in the case of this Triumph) – drape a rag over the top so when it comes free it doesn’t fly up and land on painted parts.
6. Out with the old, in with the new
Removing the taper bearing (or inner race, if you have ball-bearings fitted) can be ugly – if you can’t get good purchase from underneath with a drift, or it’s seized on, take it to a local bike shop with a hydraulic press to get it off. Slide on a new lower seal, and use a drift to seat it hard on the stem. Use a bearing drift to fit new races in the frame – make sure they are fully seated.
7. Apply liberal lubrication
Grease the bearings – put a rubber glove on and spin the rollers with your fingers to work it into the cages. Slide the yoke into the bike, being sure to fit any top spacers and seals in the correct order as well as the top bearing. Tighten the locknuts gently – if you use a socket, take it off the ratchet and use it in your hand. If you need a C-spanner, turn until there’s light resistance.
8. Refit yoke and slip in fork legs
Fit the top yoke and turn the whole assembly by hand to feel for resistance or free play. Then refit the forks, being sure to set them at the same height in the yokes as before. Torque up the lower yoke first – if you have two bolts, tighten each little by little to spread the load. Then tighten the top yoke and double-check the forks have remained at the correct height.
9. Check, tweak and check again
Refit the wheel, calipers and mudguard, and do a final check for free play/binding while the wheel is off the floor – if it needs adjustment, remove the top yoke to tweak it up. Re-check after 50 miles – the bearings may ease as they settle, so you may find some light free-play develops. Check every 4000 miles to ensure your bearings never work loose and wear prematurely.
Photos: Joe Dick/Bauer Archive