Easiest wheel swap for 1986 750 without fork/swingarm changes

[slabgix750]

Sorry if this has been done to death...  I have a 1986 750 with stock 18" wheels.  Would like to know which 17" wheels to buy to give the easiest swap without fork/swingarm changes.  I am not looking for a 180 back tyre, just something that 17" and bigger than the 140 with wider availability.  Could someone let me know exactly which years/models I can choose from?  Guessing at the very least I will need to swap my rotors and possibly bearings? In the UK if anyone has a spare set.  Thanks.

*EDIT* I see the 88-89 750 17" wheel is a 4.5 width and allows a 160 tyre which I really like the sound of.  It has a 240mm rotor though, but guessing I can use my old one?  The front wheel from this year has a bigger axle and bigger rotor, so not sure what to do axle wise.  Also, it appears that the front end is a little more involved to the point where the disc is 310mm and potentially I have to source different calipers.  I believe the general feeling is that it's easier in every way just to replace the whole front end from the newer bike which I don't want to do, so may just stick with the 18" after all.

 

Edited October 3 by slabgix750
Found more info

[jorge]

I have a 1986 750 and the easiest and most unmodified thing is to put a 1988 750 (J) rear tire on it. Regarding the front tire, I recommend that you put the entire set of forks of the same model mentioned above for safety... 

[Jonny]

There is a great deal of knowledge on this site, so I’m sure someone will be able to give you a better answer than me, but here’s what I got:

Any Slingshot (3-spoke) 17” wheels will fit within the standard forks, although they don’t centre. It will sit 2mm to the right , so you will need to lose 2mm from the left side. I believe shimming it from the speedo is a popular solution.

You’ll need to use a slingy speedo, as a slabbie one won’t work on the 17” slingy wheel. And the cables are slightly different, you need to modify the speedo cable to fit or buy a slingy one.

You can bore the spindle holes in the forks out for the 20mm spindle (yours should be 15mm), or you could sleeve everything down to 15mm. You’ll need the right bearings  and the slingy speedo will need a bush.

All 88 to 91 750s and 89 to 91 1100s all use a 20mm spindle and have a 17 x 3.5 inch rim.

You’ll need the slingshot discs and the calipers from a slabby 1100, as the 86 750 discs were only 300mm, as opposed to the 310mm on the slabby 1100 and on slingshots. Of course, slingshot calipers won’t fit your slabby forks, so need to make sure you get 1100 slabby calipers.

On the rear it is easier. I believe the disc bolt pattern between the 86 750 and the 88 750 is the same, although the discs are different. So, I think you can bolt your original disc onto the new wheel and use your original caliper and caliper bracket (don’t quote me on that).

The 90 750 and 89 1100 (and later) wheels are different and you would need to use the later sprocket carrier and disc, caliper and caliper hanger. You will also need to file a bit of the caliper torque arm for clearance. You’ll have to do a bit of dicking about with spacers, however, you can probably get the whole lot quite cheap. All rears use the 20mm spindle. They went from 4.5 to 5.5 width in 1990 (on the 1100, possibly 91 on the 750 - not sure) so if you want to fit a 180 after all, this is what you need.

Edited November 20 by Jonny

[slabgix750]

Thanks for this everyone, a massive help.

[Crass]

1990 750 also has 5.5" rear wheel