Double checking wheel compatibility between different model years of gs750

[the_zander]

Good afternoon, i have been lurking around this forum for about a month now, purchased my first GS, a 1978 750E, a few weeks ago and am thrilled to have found "the motherload" of enthusists and information.

The model i have purchased is equipped with dual disc wire wheels up front and i have a line on a set of cast wheels from a 1982 GS750 (referred to i believe as "spoke pattern" as opposed to the more common star pattern).

I have throughly read everything returned by the forums search engine, and it all points to the front wheels of all GS models as being compatible. However there is less information regarding fitment of the rear wheels.

Most threads site differences in the spacers used on different years/displacments. As the wheels im purchasing are not equipped with their original axles/spacers i was hoping someone with similar experience could verify that i will be able to use my '78 stock rear axle and spacers with the rear cast wheel off a '82 GS750.

Many Thanks in Advance,
Zander

[Steve]

The axle should not be a problem, but you might have to come up with some different spacers.

By the way, the "star" (or "snowflake") design is just the original pattern. The "spoke" pattern you are looking at started with some of the '82 models.

EDIT: if you look at the picture in my sig of my son's '81 850, you will note that it has the newer wheels. They came off an '82 1100.

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[the_zander]

Fair enough, do mismatched wheel combinations typically require spacers machined to specific/critical dimensions? or will washers combined with some test fitting (safely) do the trick?

-Zander

[Steve]

Washers are usually sufficient.

The only 'critical' areas would be if you are right up against something that needs to be supported farther than a washer would reach.

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[TheCafeKid]

For the front, you probably won't need any different spacers. For the rear you will need different spacers for the caliper side (outboard of the caliper hanger for sure). Washers will work as steve said but it's critical that even if it feels tight already to get a washer or two in there, you need it tight enough that you leave enough threads on the axle to generate the "squish" necessary to press everything on the axle together. So if you can get another washer in there even if it looks ok, do so. If you have even so much as 5 thou of an inch of play in there it will lead to wonky handling under breaking and your bearings may wear prematurely because they will be loaded unevenly, and can walk on the axle.

[the_zander]

Noted, i'll ensure an interference fit of the axle and spacers in the swingarm.

Out of curiosity will the change from a 18" rear (stock '78 spokes are 18") to the 17" cast rear wheel adversely affect the bikes manners? the front diameter is staying the same at 19"

-Zander

[TheCafeKid]

Noted, i'll ensure an interference fit of the axle and spacers in the swingarm.

Out of curiosity will the change from a 18" rear (stock '78 spokes are 18") to the 17" cast rear wheel adversely affect the bikes manners? the front diameter is staying the same at 19"

-Zander

Not at all. They went to a 17" rear and continued on with the 19" front until 83 when the 750 got a 16" front, and the 1150 did the same in 84. Some of the L models and I believe the GK came stock with a 16" rear with a 19" front. No ill effects. Though you MAY want to check the shock length stayed the same 13" or 13.5" something like that. I'm pretty sure they did. On the "Standard" models anyway.