1150 3.5" wheel in an 1100 swingarm

[salty_monk]

Regardless your chain/sprocket issue (with the spacer pack you are using) is caused by the spacer being on the wrong side of the sprocket...

[greg78gs750]

quick update. i think i have everything sorted, mostly. it did take milling that drive side spacer down 5 mm and adding an additional 5mm outboard of the brake stay to center the wheel in the swingarm. (well, to be honest, it is still about 1mm to the right, but i am ok with that, for now.) everything seems to line up well now, chain alignment seems to be within spec, rear wheel aligned with the front, no drag in the system. i think i am going to run this chain/sprocket till this winter, the chain seem to be in ok shape still, a calculated risk, i guess, but based on my assessment i'm comfortable with it.

thanks for all the feedback on this, it really helps to bounce ideas around like this. i will post pics when i get a chance. Learned a lot here!

incidentally, at my local m/c breaker yesterday i saw a beautiful, very clean 81 1100e with flatslides that he said would be for sale soon....for $4000!!!! pretty proud price, for sure. i will get some pics soon if i can. This place is a football field sized warehouse literally PACKED with bikes in various states of disassembly, pretty cool place. all metric stuff.

thanks again guys!!

greg

[John Kat]

quick update. i think i have everything sorted, mostly. it did take milling that drive side spacer down 5 mm and adding an additional 5mm outboard of the brake stay to center the wheel in the swingarm. (well, to be honest, it is still about 1mm to the right, but i am ok with that, for now.) everything seems to line up well now, chain alignment seems to be within spec, rear wheel aligned with the front, no drag in the system. i think i am going to run this chain/sprocket till this winter, the chain seem to be in ok shape still, a calculated risk, i guess, but based on my assessment i'm comfortable with it.

thanks for all the feedback on this, it really helps to bounce ideas around like this. i will post pics when i get a chance. Learned a lot here!

incidentally, at my local m/c breaker yesterday i saw a beautiful, very clean 81 1100e with flatslides that he said would be for sale soon....for $4000!!!! pretty proud price, for sure. i will get some pics soon if i can. This place is a football field sized warehouse literally PACKED with bikes in various states of disassembly, pretty cool place. all metric stuff.

thanks again guys!!

greg

Greg, I'm glad to see that these posts were usefull in the end
The mystery remains on why Suzuki issued two different types of "1150" rear wheels?

[salty_monk]

Glad you got it sorted.

[Joe Nardy]

Other concerns....

Okay, I have read through this thread and conversed with Dan, Greg, And Dallas regarding their results prior to attempting to mount the Enkei 3.5 GS1150 rear wheel I have. I did a bunch of measurements today with Baatfam graciously assisting and verifying. I do not see anything in the thread regarding the offset of the sprocket and brake rotor compared to the stock 2.5 inch wheel, at least my stock '83 GS1100ED wheel. We found that, measured from the center of the wheel, the sprocket on the 1150 wheel is offset 4mm outboard compared to the 1100 wheel and the brake rotor is offset 9mm inboard compared to the 1100 wheel. This means that to properly do this swap, the countershaft sprocket would need to be spaced out 4mm and the brake rotor would need to be spaced in 9mm in order for the wheel to be centered and have a straight chain run and the brake caliper in alignment.

For reference, here are my measurements:

Wheel center to sprocket inner edge:
1100 wheel - 86mm
1150 wheel - 90mm

Wheel center to rotor inner edge:
1100 wheel - 80mm
1150 wheel - 71mm

I would appreciate if someone could verify these measurements. If my measurements are correct and anyone has done this swap without making adjustments to the countershaft sprocket and rear brake caliper you will have chain alignment and brake alignment issues. The first is probably minor, the second could be very serious.

Thanks,
Joe

[posplayr]

Okay, I have read through this thread and conversed with Dan, Greg, And Dallas regarding their results prior to attempting to mount the Enkei 3.5 GS1150 rear wheel I have. I did a bunch of measurements today with Baatfam graciously assisting and verifying. I do not see anything in the thread regarding the offset of the sprocket and brake rotor compared to the stock 2.5 inch wheel, at least my stock '83 GS1100ED wheel. We found that, measured from the center of the wheel, the sprocket on the 1150 wheel is offset 4mm outboard compared to the 1100 wheel and the brake rotor is offset 9mm inboard compared to the 1100 wheel. This means that to properly do this swap, the countershaft sprocket would need to be spaced out 4mm and the brake rotor would need to be spaced in 9mm in order for the wheel to be centered and have a straight chain run and the brake caliper in alignment.

For reference, here are my measurements:

Wheel center to sprocket inner edge:
1100 wheel - 86mm
1150 wheel - 90mm

Wheel center to rotor inner edge:
1100 wheel - 80mm
1150 wheel - 71mm

I would appreciate if someone could verify these measurements. If my measurements are correct and anyone has done this swap without making adjustments to the countershaft sprocket and rear brake caliper you will have chain alignment and brake alignment issues. The first is probably minor, the second could be very serious.

Thanks,
Joe

It is intuitive and I think correct that the counter sprocket offset is almost entirely a function of rear wheel width (assuming you are running 530 or less) and really nothing else.

For a 5.5" wheel Katman has been specifying a 5/8" offset counter sprocket
and for a 4.5" wheel that is a 3/8" offset contersproket(what I have verified produces very close to about 0.080" chain alignment). IRC I would need to machine the sprocket carrier to get it any closer.
That is a 1/4" difference so dropping yest another 1" in rear wheel width you should figure to drop another 1/4" off of the offset. That would be 0.125" or 1/8" (3.175mm) That is pretty close to your 4mm measurements.

[Joe Nardy]

It is intuitive and I think correct that the counter sprocket offset is almost entirely a function of rear wheel width (assuming you are running 530 or less) and really nothing else.

For a 5.5" wheel Katman has been specifying a 5/8" offset counter sprocket
and for a 4.5" wheel that is a 3/8" offset contersproket(what I have verified produces very close to about 0.080" chain alignment). IRC I would need to machine the sprocket carrier to get it any closer.
That is a 1/4" difference so dropping yest another 1" in rear wheel width you should figure to drop another 1/4" off of the offset. That would be 0.125" or 1/8" (3.175mm) That is pretty close to your 4mm measurements.

Jim,

Agreed and understood. It is intuitive that a wider wheel will require more sprocket offset to allow chain clearance. However, I don't think it can be said that for a given width of rear wheel a specific amount of offset is required. While it is likely that two rear wheels of the same width would have similar offsets it is not a given. The offset can be easily determined by measuring from the center of the wheel to the sprocket and comparing to the original wheel.

My main point is that this thread seems to focus mostly on axle spacers and does little to address the brake caliper and countershaft sprocket offset. Dallas (Grand Rouge) mentions spacing the rotor and carrier 7mm (my measurements indicate 9mm and only the rotor would need to be spaced to match the original caliper position) but makes no mention of spacing the countershaft sprocket. There is little information about countershaft spacers specific to this modification. I just wanted to make the point that, according to my measurements, the countershaft sprocket and rotor would need spacers besides the axle spacers for everything to line up properly.

Some of the differences may be due to different components being used. In my case I am using an Enkei 3.5 inch rear wheel with the rotor and sprocket/carrier from my '83 GS1100ED.

Thanks,
Joe

[posplayr]

Jim,

Agreed and understood. It is intuitive that a wider wheel will require more sprocket offset to allow chain clearance. However, I don't think it can be said that for a given width of rear wheel a specific amount of offset is required. While it is likely that two rear wheels of the same width would have similar offsets it is not a given. The offset can be easily determined by measuring from the center of the wheel to the sprocket and comparing to the original wheel.

My main point is that this thread seems to focus mostly on axle spacers and does little to address the brake caliper and countershaft sprocket offset. Dallas (Grand Rouge) mentions spacing the rotor and carrier 7mm (my measurements indicate 9mm and only the rotor would need to be spaced to match the original caliper position) but makes no mention of spacing the countershaft sprocket. There is little information about countershaft spacers specific to this modification. I just wanted to make the point that, according to my measurements, the countershaft sprocket and rotor would need spacers besides the axle spacers for everything to line up properly.

Some of the differences may be due to different components being used. In my case I am using an Enkei 3.5 inch rear wheel with the rotor and sprocket/carrier from my '83 GS1100ED.

Thanks,
Joe

Joe,
I went around and around with Katman on wheel spacers and offsets when I did my 4.5" rear wheel. In the end his final conclusions for a 5/8" offset for 5.5" wheel are correct as was his recommendation for 3/8" offset for the 4.5" wheel. Having said that we had a lot of trouble coming up with exact measurements and predictions spacer sizing. Ultimately we just did offsets to what he knew was correct (having fitted and measured the setup on multiple bikes) and everything fell into place.

One thing I would be leary of is measuring the chain offset. As I recall the runout of the sprocket (as it is mounted to a carrier mounted in rubber cushions) was not very accurate for projecting forward a line to the counter sprocket.I run a straight edge off the tire (preferably the rim) to see how skew that is to the chain.

So all the data I have seen including yours says that (for bigger GS Suzukis) the counter sprocket offset should be

CSO = 5/8"-(5.5-Wheel Width)/4.0

where substituting for Wheel Width you get

CSO Wheel Width Reference
5/8" 5.5" Katman standard offset
3/8" 4.5" My GS1100ED and other bikes Katman has done
1/8" 3.5" Your data (4.0mm is only 0.033" off)
-1/8" 2.5" Computed for consistence check.

From there you can fine tune by milling or spacing the counter sprocket if it is not close enough.

Jim
P.S. the reason that the total with difference is divided by 4 is that if you drop the wheel width by 1" then you have an extra 0.5" on either side. And to center the chain in the available space you only more it over 0.25" to realign with the new center of the frame tire space. So a 1" diff in width needs a 0.25" shift to recenter the chain.

[jwhelan65]

Wheel swap threads are like political debates, after reading them your usually more confused and uncertain than when you started.

[jwhelan65]

Here is one that worked with my own recipe

1150 rear in a stock 700 swinger..sounds kinda naughty

[posplayr]

Wheel swap threads are like political debates, after reading them your usually more confused and uncertain than when you started.

Have you tried a straight edge against the tire to see how much skew there is between the edge and the chain? I put a 6' level under the chain to take this picture.

[salty_monk]

Joe,

What sprocket hub and axle spacer pack are you going to use?
I intend to use the stock ones for my bike not the 1150 one and that could impact things....

Dan

[rapidray]

Just to throw another curve at you guys, if you use the 86/87 GSXR 1100 rear wheel, which is the same 6 spoke design as the 1150 wheels, the front sprocket offset needs to be 6mm. Ray.

[John Kat]

Here is one that worked with my own recipe

1150 rear in a stock 700 swinger..sounds kinda naughty

I believe the monoshocked 1150 and the 700 have the same swingarm?
If that's true, it would be interesting to measure the total width of the wheel and all it's spacers at the axle level. We could then compare that to the identical "stacked" height on a normal GS 1000.
I bet they are not the same by...8 mm which would explain why the 1150 wheel on a GS 1000 has to be moved by 4 mm to the left.
This would also confirm why the engine sprocket spacer on an 1150 is 4 mm longer than on the GS 1000

[John Kat]

Have you tried a straight edge against the tire to see how much skew there is between the edge and the chain? I put a 6' level under the chain to take this picture.

I've used this handy laser device ( from germany!) to check my chain alignment