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Fitting Forking Loose Ball Bearings
Posted: Thu Mar 21, 2013 10:57 pm
by Starwave
Hello
A couple of us are re-building an old Bajaj / Sportique copy for a mate.
Struggling with fitting the forks as the steering bearings are the loose type. Trying to fit the nut / top race whilst retaining the top loose ball bearings is an absolute prick. The balls seem to be able to fall in towards the fork stem, and get pushed outward when fitting the top race nut.
I'm thinking very thick, almost lard-like grease would help. I've tried putting the balls in the race after the forks are in position but the nut seems to dislodge the feckin things.
Any other top tips at all please? Getting close to ramming a screwdriver in my eye so I am excused from this duty.
cheers
Re: Fitting Forking Loose Ball Bearings
Posted: Fri Mar 22, 2013 12:13 am
by Knowledge
Keep all the balls in place with grease. You won't need heavy grease - a light medium grease will do fine. In fact, you MUST use grease, or the movement will be awful.
Re: Fitting Forking Loose Ball Bearings
Posted: Fri Mar 22, 2013 6:42 pm
by Starwave
Oh ai, I'm using grease alright, it's just that I reckon something proper thick n nasty to keep the bearings still whilst doing the nut up would help. They must have a had a neat little trick on the production line when building them otherwise each scoot would've taken around 12 years to assemble.
May attempt it again tomorrow morning if my hangover isn't too savage.
cheers
Re: Fitting Forking Loose Ball Bearings
Posted: Fri Mar 22, 2013 7:55 pm
by GLscoot
If grease is not doing the trick, try gaffa tape around the edge. Make sure the joint on the tape is where you can get to it. To be honest you can now buy cadged bearings for this.
Re: Fitting Forking Loose Ball Bearings
Posted: Sat Mar 23, 2013 3:08 pm
by goldeneye
ive used cadged bearings, cadged exhausts, cadged tyres, cadged oil, cadged sleeping bags....
Re: Fitting Forking Loose Ball Bearings
Posted: Sun Mar 24, 2013 6:51 am
by Richjak
Can they be replaced with Vespa items ???
Re: Fitting Forking Loose Ball Bearings
Posted: Sun Mar 24, 2013 10:51 am
by GLscoot
Yes i have used them in all my vintage vespas, there not as big as the loose bearings, but do the job. They also make fitting the forks slightly easier when you tighten the column nut and lining up the headset bolt because there slightly smaller. Its the same as the bearings on the head of the forks, there even smaller and dont look as if they will work, but they do. They also have the advantage, that if the forks come loose over time you dont loose any of the bearings, which will happen with loose bearings. Go overboard with the grease. Cover the bearings in grease until you can see them. Its a case of you can never have enough grease on this part.
Re: Fitting Forking Loose Ball Bearings
Posted: Tue Mar 26, 2013 1:46 pm
by Starwave
Sorted it in the end cheers.
Chocked the forks in place and strapped the front of the scoot down so I knew the fork bottom bearings were seated home. I dug out some waterproof grease I'd bought years ago from a cycle shop and stuck the balls in place using this. Nice and sticky it be. When I wound the top race / nut on I had to gently push the fork stem forward slightly to centralise the forks so the nut didn't dislodge the balls.
Caged bearings have to be the way forward. Can you use standard Vespa caged ones ok on these races then? I had a feeling you needed to change the race on the frame to a PK type? The loose balls are 5/32" diameter, which is a touch under 4mm.
If the nut did come loose the loose balls will drop out. Invariably this will be in the rain and fog and at night, and possibly near a hoodies' lair. If if you found some, you've then gotta fit them....this was a pr1ck in my garage. Pretty well impossible at the roadside I reckon.
cheers