headstock bearings

[bythesea84]

Hi just wondering if anyone has done their headstock bearings recently and could give a quick description of how to do it. Also if any specialist tools are needed? many thanks , pete

[a_morti]

Hi just wondering if anyone has done their headstock bearings recently and could give a quick description of how to do it. Also if any specialist tools are needed? many thanks , pete

It's easy enough to do. Procedure:

Centre stand.
Slacken front spindle and top yoke nut (36mm IIRC)
Jack up front of bike, or wedge a convenient pile of wood and bricks under exhausts
Remove front wheel, remove forks. It helps to remove mirrors as they are heavy and might stress the cables or brake hose or get broken. Remember to unplug horn!
Remove top yoke, bottom yoke will fall through as you undo the adjusting rings.
Remove and replace bottom yoke race. This can be done with patience and a big hammer, but it's the hardest part of the job.
Remove races from frame. This isn't too hard, there is enough space to get a drift in.
Replace races in frame. Best way is a long piece of thick threaded rod with big nuts on each end, tighten to draw together. Or use a hammer to bash them in, the bottom one is awkward for access though and you wouldn't want to knock the bike over.

After that, it's just a case of putting everything back together. You will want two C-spanners of suitable size to tighten up the bearing lockrings. These are the same size as the one in the bike's tool kit, IIRC. Doing them up by tapping with a drift is inaccurate and likely to come loose over time as you can't get the tightening torque.

Tighten up the top yoke nut when the bike is secure on the ground, don't be hasty!

Above all, take your time with this job as it'd be quite easy to end up with your bike on the floor and no front wheel in there. That'd be embarassing.

[a_morti]

I use something like this for the bearing insertion tool, my dad got it from the workshop.

http://www.ebay.co.uk/itm/2-Threaded-Bars-Rod-Stud-M-16mm-x-200mm-4-Nuts-washers-/280701747541?pt=UK_DIY_Material_Nails_Fixing_MJ&hash=item415b20c155

No idea where you would get suitable washers if you can't make them though. You might grind the outers of the old races so they don't stay in the seats, and use a bit of flat steel against them? The other beauty of this method is it's almost impossible to get the bearing in off-square, so you avoid damaging the bearing or bearing seat.


From here:
http://www.dansmc.com/steering_bearings.htm

[Drewski]

There is a special tool available nowadays for the races in the frame, (shame someone didn't invent it 30 years ago - could have saved me a lot of hassle ), but Mortis suggestion looks just as good. I use scissor jacks to hold the bike up but once placed under the exhaust the bike tends to want to "fall" to either side so I also use wooden props under the side of the motor. If you're feeling flush, get yerself a headstock type front paddock stand - it'll last a lifetime. Take your time and, once done, the bike'll feel a lot better for it.

[a_morti]

There is a special tool available nowadays for the races in the frame, (shame someone didn't invent it 30 years ago - could have saved me a lot of hassle ), but Mortis suggestion looks just as good. I use scissor jacks to hold the bike up but once placed under the exhaust the bike tends to want to "fall" to either side so I also use wooden props under the side of the motor. If you're feeling flush, get yerself a headstock type front paddock stand - it'll last a lifetime. Take your time and, once done, the bike'll feel a lot better for it.

Drew, think about that one for a minute

ps, do you remember the colour code for that tank? My dad's thinking of matching his fairings to it.

[bythesea84]

Thanks for the replies guys! Not sure my bodging a tool will do but I'll probably attempt it! Got a more pressing problem though as my alternator is knackered! Anyone know of compatible models? Or where else they can be found? Tried electrex but out of stock. The alternator seems smaller than any I have seen. Failing that is it possible to swap the rotor stator bit as well on a motorbike? Thanks, pete

[a_morti]

Thanks for the replies guys! Not sure my bodging a tool will do but I'll probably attempt it! Got a more pressing problem though as my alternator is knackered! Anyone know of compatible models? Or where else they can be found? Tried electrex but out of stock. The alternator seems smaller than any I have seen. Failing that is it possible to swap the rotor stator bit as well on a motorbike? Thanks, pete

Contact Graeme France. He races 400's so tends to have stuff like alternators lying about. Cbr4000 Parts are compatible but not much else.
gfracinguk@live.co.uk
He is a busy man so you might wait a day or two for an answer but he will have what you need.

[Drewski]

There is a special tool available nowadays for the races in the frame, (shame someone didn't invent it 30 years ago - could have saved me a lot of hassle ), but Mortis suggestion looks just as good. I use scissor jacks to hold the bike up but once placed under the exhaust the bike tends to want to "fall" to either side so I also use wooden props under the side of the motor. If you're feeling flush, get yerself a headstock type front paddock stand - it'll last a lifetime. Take your time and, once done, the bike'll feel a lot better for it.

Drew, think about that one for a minute

ps, do you remember the colour code for that tank? My dad's thinking of matching his fairings to it.

Ooops

I don 't know that colour code but it looks a lot like the one they use for the MG ZT



There's also a similar blue that was used on the '75 Kawasaki 250 S1C called "Halibut Blue".
HTH