crank bearings gs850

[Guest]

Can anyone tell me where i can get heaving duty crank bearings from, to suit a 1981 gs850 ?
Thanks

[Nessism]

Under normal usage the stock crank bearings rarely wear out, even after being subject to 100,000+ miles.

If for some reason you have a bad bearing it's most likely due to some sort of contamination getting into the rolling elements.

Changing the bearings requires specialized equipment and know how. It's cheaper to source a good used crank than try to break down and change a bad bearing.

The parts fishe suggests there are two sized bearings used on the crank: 30X72X19 and 32X78X21

If you are up for a challenging project you could research what bearings are available on the market and try to source some of the highest load rating possible. Sourcing the proper bearings requires knowing what the internal clearance specs is though and I'm not sure how one would go about that. There are various guys that rebuild GS cranks so you could try emailing some of these guys and see if they can provide suggestions. Two names that get bantered about on this forum is Pearson and Gardener. My spelling may be off but if you search the archives here you should be able to find contact info so you can ask for suggestions. Good luck (I think you are going to need it).

[Brendan W]

Have you got a bad bearing or are you planning something interesting ?

[kingofvenus]

Probably would be cheaper to buy a whole bike....

[tkent02]

Your local bearing supply shop should be able to get the best bearings that exist anywhere if you don't mind paying a little bit and possibly waiting a few days.
Finding someone to install them will take a little more effort.

But yeah 850 engines are dirt cheap, and the cranks generally go forever.

[Tyrin76]

Thanks to all of you people,
I have a speedway car, and they run the gs-gsx1100 engine,
Im in the build of another motor, which is going to be 1220cc (the capacity rule for my division is 1200 + 2% = 1224cc) so im going to use the 850 crank and a 83mm piston, i just wanna put some good bearings on the crank cause ill have about 14-15:1 compression 😍

[GregT]

Thanks to all of you people,
I have a speedway car, and they run the gs-gsx1100 engine,
Im in the build of another motor, which is going to be 1220cc (the capacity rule for my division is 1200 + 2% = 1224cc) so im going to use the 850 crank and a 83mm piston, i just wanna put some good bearings on the crank cause ill have about 14-15:1 compression ��

Compact Speedcar ? Our equivalent in NZ would be TQ's. If you're stuck with the air cooled 1100's can i point out that the air/oil GSXR's were accepted here as being an air cooled motor...

Talking to a dragrace guy local to me the other day about rebuilding the roller GS/GSX cranks, he's been pointed at a dragrace crank specialist in Queensland. The gs's and Z's run in TQ's here are around 1000cc high com and methanol. Stock cranks last quite well but the serious guys are sending cranks to the US to be rebuilt.

[Tyrin76]

Yeah ive got a gsxr head for it with a bit of work done to it, i know the specialist your talking about, just thought id try and see what other drag race people use on here.
Nah mines a gp midget with the motor mounted behind the seat, were the compacts over here in Australia are at the front of the seat

[GregT]

Yeah ive got a gsxr head for it with a bit of work done to it, i know the specialist your talking about, just thought id try and see what other drag race people use on here.
Nah mines a gp midget with the motor mounted behind the seat, were the compacts over here in Australia are at the front of the seat

Our TQ rules are 750 watercooled, around 1000 2V aircooled. I suggested some years back to a guy here running at the front in TQ's that a GS1000 top end on a plain bearing GSXR bottom end would be worth a try. It is....Don't know why you'd want to go roller bearing as the plain bearing cranks are way lighter.
I was involved a few years back trying to get F500 going here. No idea now what is being run in Oz, I'm out of speedway work now.