81 GS750L rear wheel compatibilty.

[Jedz123]

I found a great price on a new tire sitting on a rear rim from a 85 GS750 ES. I was curious if this rim would fit correctly on my 81GS 750 L.
Thanks a million!

 

[makenzie71]

No. You're going to encounter too many brake issues...you can overcome them, but if you're going to go through that effort you need to focus on putting a real wheel back there. Doing it for the sake of running a cheap 120mm tire won't get you anything.

 

[Jedz123]

Cool thanks. Just looking for a lighter rim and I need a new tire anyway so I thought if the shoe fits I'll kill 2 birds with 1 stone. Lol just going to keep using that heavy as all hell stocker rim for now...
Anyone know of any light rims that would fit my bike with little to no modifications.
Thanks

 

[makenzie71]

Bandit 600 wheels are setup for a 20mm axle if I recall correctly...you would have to source the wheel, caliper hanger, caliper, axle, sprocket carrier, a proper sprocket, and all the axle spacers.

I opted for this:

I widened and braced my stock swingarm to do it, but you can pick up a GS1100 swingarm for pretty cheap and it'll fit. YZF600R rear wheel assembly. 160mm tire. All in all, even with the +30mm on the tire and the bracing on the swingarm, I still lost seven pounds...four of which were in the wheel.

 

[Nessism]

I think the ES wheel is almost a direct bolt on to your '81, although the diameter is different. The disc offset should be the same but you may need to mess around with a spacer or two.

 

[makenzie71]

Rotor diameter is different and I read the bolt patterns make them incompatible. The ES also has a 17mm rear axle.

 

[Nessism]

Bearings are easy enough to change, rotor may be different though.

 

[makenzie71]

Keep in mind, though, that it's more than bearings...there's also a spacer inside the wheel that keeps the bearings properly distanced. The bearings from the 81 wheel will pop right into the 85 wheel, but maybe not that spacer. Having a custom spacer cut is a little pricey for a lackluster wheel.

I'm not trying to say it cannot be done...please don't look at it like that. And I'm not saying it might not be worth it to the OP to do. All I'm trying to say is that, considering the work involved just to get a 120~130mm rear tire, it's just not at all worth it to me...unless I'm flat broke and this is my only option.

 

[blowerbike]

they never made an 85 750ES in the states so why this discussion
i will tell you this..
an 85/86 1150 rim is 3.5x17 and will bolt right on 90+% to his 81 750.
just needs one narrow spacer/washer added...josh knows the thickness.

 

[Leigh]

I widened and braced my stock swingarm to do it, but you can pick up a GS1100 swingarm for pretty cheap and it'll fit. YZF600R rear wheel assembly.

G'day Mackenzie.
Is there a write up on that conversion anywhere?
I just happen to have an '81 750 and a YZF600 wheel sitting in the very same shed.

I would like a little more meat out the back I think.

 

[makenzie71]

Widening the swingarm is not a "write up" topic..you have to make cuts that are perfectly true and solid welds. Unless you have access to a good industrial band saw and some high skill welding, go with the 1100 swingarm.

As far as the wheel...it has to be a YZF600R wheel. The first year YZF600 here in the states wasn't the Thundercat and had some small differences...I can't say it would work the same.

With the YZF600R wheel all you have to do is get all the YZF600R spacers, caliper hanger, caliper, and sprocket carrier. You'll need to run a 38 tooth Yamaha WR250R sprocket...just drill the holes out from the WR's 8.5mm to the YZF's 10mm. It all slips right in.

The full thread is here: http://www.thegsresources.com/_forum/showthread.php?t=163579

 

[Leigh]

Good stuff.
That looks great.
I have access to a machine shop and a pair of the best metal workers I have come across.
They are brothers, mates and mad keen riders. That helps.

This will become a future project once I've scared myself on the stock cheese cutter tyres.

Besides the only 1100 swingarms I could find look like shafties with one side a lot shorter than the other.

 

[makenzie71]

Good stuff.
That looks great.
I have access to a machine shop and a pair of the best metal workers I have come across.
They are brothers, mates and mad keen riders. That helps.

This will become a future project once I've scared myself on the stock cheese cutter tyres.

Besides the only 1100 swingarms I could find look like shafties with one side a lot shorter than the other.

I searched for swingarms and did not find any of the allow 1100 or 1150 arms. I know there's some for sale here, but I'm not sure how common they are in the your neck of the woods. IF you have competent machinists at your disposal, though, I wouldn't hesitate to widen the stock swingarm. Only things to really keep in mind is that you can only go about 2" wider...more and you just don't have a good base to weld back up to...and you'll have to make some adjustments to get your stock rear master cylinder to work.

When it comes closer to the time to try to do it hit me up and I'll get you measurements for where to cut.

 

[Leigh]

Thanks mate, that'd be marvellous.
You will be the first to know when the grinder is about to fall.