GS1150 front wheel on GS700/750?

[Nessism]

Picked up some 1150 wheels to install on an '83 750. Stock wheel sizes are 2.15/2.50 (front/rear), and 1150's are 2.75/3.50.

The rear wheel seems like it will line up with the brake caliper and sprocket (using my stock brake rotor).

The 1150 front wheel is wider across where the disc's mount so it's not a bolt on using the stock 750 rotors.

The stock rotors are 260mm in diameter and have approx. 22mm of offset from the inside to outside. After measuring the 1150 wheel it looks like I need some rotors that have approx. 15.5mm of offset. I haven't measured the stock 1150 rotors yet (don't have any).

Can someone with an 1150 measure the front disc diameter and offset for me please. Fingers crossed the offset will allow the wheel to bolt on.

Thanks in advance for the help.

 

[Guest]

I measure the front rotor to be 280mm. I couldn't quite get an accurate measurement on the offset, but it seems to be close to 15.5. The total width fo the rotors installed, outside to outside is 140.8mm

 

[Billy Ricks]

Ed, sorry I don't have an 1150 wheel to measure for you, but are you sure it's not the calipers that make up the difference? I believe the 1150 used the same calipers as the first GSXR750, possibly even the same dimensions on the wheel hub and rotors. If so I can measure off my '86 750.

 

[Nessism]

I measure the front rotor to be 280mm. I couldn't quite get an accurate measurement on the offset, but it seems to be close to 15.5. The total width fo the rotors installed, outside to outside is 140.8mm

Outside to outside is a good way to measure it. Thanks Bruce. Not sure why I didn't think of that.

Unfortunately, 140.8 is way too wide, my 750 wheel measures 126.8 mm. Looks like the rotor offset is the same for both 750 and 1150. 1150 rotors are too large anyway so doesn't matter I suppose.

Looks like I need some 260 mm rotors that have 14.5 mm of offset measured inside to outside. Anyone know of a data base anywhere with rotor measurements?

 

[Billy Ricks]

Just measured outside to outside on the '86 GSX-R750 and it measures the same as Bruce's 1150. I'm really thinking the 1150 and first generation Gixxers used the same rotors and calipers. If you can't find the rotors you need to make it work you might have to go with brakes from one of the two. The GSX-R is a 5 bolt hub FWIW.

 

[Nessism]

Thanks for checking that Billy.

I don't think the later calipers will fit on my forks; they look to have different mounting lug dimensions and the calipers are very deep - thus the reason the rotors are so far outboard.

Easiest thing to do, failing finding some appropriate rotors, is machining the wheel to move the mounting flange spacing inboard. There is tons of meat on the hub so it's just a matter of finding a reasonably priced machinist.

 

[Guest]

Thanks for checking that Billy.

I don't think the later calipers will fit on my forks; they look to have different mounting lug dimensions and the calipers are very deep - thus the reason the rotors are so far outboard.

Easiest thing to do, failing finding some appropriate rotors, is machining the wheel to move the mounting flange spacing inboard. There is tons of meat on the hub so it's just a matter of finding a reasonably priced machinist.

Or you could go with an all-1150 front end. I have 1150 forks, the clip-ons, the upper bracket for the triple tree, and front calipers. I don't have the triple tree or the rotors or a fender. Maybe a trade for those cams?

 

[Frankenzuki]

rotors

rotors

GS700/750 wheels are wider at the rotor mounting hub than a standard GS wheel, GS1150 whees are wider than the 700/750 wheels The GS700/750 wheels are also 2.5" wide, the 1150 wheels are 2.75" wide

GS700/750 front rotors are smaller in diameter than a standard GS rotor

AFAIK All big (750-1150) GS rotors have the same offset but not necessarily the same diameter

1st generation GSXR calipers are a bolt on for the GS1150 forks but are 4-piston, not 2-piston

The GSXR calipers will not bolt-on the GS700/750 front forks without some fab work
the GSXR rotors are 5 bolt, all the GS wheels are 6 bolt

 

[Billy Ricks]

You need to see if the 1150 wheel is a 5 bolt hub or 6 bolt. If it's 6 then you should probably just commit to having the new wheel turned down so your stock rotors fit the new wheel.

 

[Billy Ricks]

GS700/750 wheels are wider at the rotor mounting hub than a standard GS wheel, GS1150 whees are wider than the 700/750 wheels The GS700/750 wheels are also 2.5" wide, the 1150 wheels are 2.75" wide

GS700/750 wheels are 2.15 up front and 2.50 in the rear.

 

[Frankenzuki]

wheel

wheel

I type so fast the "1" couldn't keep up with me!

 

[Frankenzuki]

Work

Work

Hey... It's the middle of the day... Doesn't anybody work anymore????

 

[Nessism]

Or you could go with an all-1150 front end. I have 1150 forks, the clip-ons, the upper bracket for the triple tree, and front calipers. I don't have the triple tree or the rotors or a fender. Maybe a trade for those cams?

Fair offer Bruce but I turned down an offer to buy Rapid Ray's 1150 rolling chassis the other day complete with brakes/wheels/suspension/etc. for only $75 more than I paid him for the wheels. Honestly, this 750 is most likely going to get sold anyway so don't want to commit to doing a compete front end swap. The wheels would have been nice though.

 

[rapidray]

Hey Ed, I'm back home & doing pretty well all considered after Sat. when you saw me last! If it needs to happen I still have the entire front end from that bike. I know you didn't want to go that route but if you need to I'll work you a deal on it. Ray.

 

[Guest]

Hey Ed, I'm back home & doing pretty well all considered after Sat. when you saw me last! If it needs to happen I still have the entire front end from that bike. I know you didn't want to go that route but if you need to I'll work you a deal on it. Ray.

Yeah, he ain't workin'...he needs the money! :lol:

 

[Nessism]

Hey Ed, I'm back home & doing pretty well all considered after Sat. when you saw me last! If it needs to happen I still have the entire front end from that bike. I know you didn't want to go that route but if you need to I'll work you a deal on it. Ray.

Glad to hear from you again Ray, and thanks for the offer. Not ready to commit to a completely new front end on this bike...yet. Going to have to spend some time in the saddle first and see if I fall in love.

Back to wheels...Frankenzuki is Da Man when it comes to this stuff. Wheels are 6 bolt and the rotors are indeed smaller than a regular GS - 260 mm vs. 270 mm.

Finding a machinist might be the easiest solution.

 

[rapidray]

Ed, GregB is an AWESOME machinist & he is local. Look him up in the forums & send him a PM. He's a great guy & an INCREDIBLE machinist! Ray.

 

[hillsy]

I remember putting my 1150 front end on my 750 for a while (while the 1150 motor was being re-built). It's a direct bolt-on fit and it made the 750 handle so much better. Worth doing IMO.