[sw3dl1]

The project is as follows: Swap the rear end from a 1983 Silverwing Interstate (GL650I) to a 1980 CX500 Delux (CX500D).
I have both bikes and the Silverwing is a donor at this point. I like the appearance of Cast wheels that are on the Interstate and have swapped the front end to the CX500 to make use of the Interstate's heavier front forks and dual disk front brakes. To complete the modification, I would like to use the Interstates rear cast wheel on the CX500 as well. The problem is, the Interstate's rear axle is of a larger diameter then the one used on the stock CX500. The axles appear to be the same length. I believe I can over come the larger diameter problem by reducing the shouldered portion of the axle where it is held in place at the swing arm and using the Interstate's rear axle and rear end.
My question is this: Is the rear end ratio the same for both bikes? Are the Transmission gear ratios the same for both bikes? Does anyone know if the Interstate's drive line splines will match with those on the CX500D?
Any help or suggestions will be appreciated.

[odie]

Pull the diff off and try it, only real way of telling, wont take you long, one problem might be the size of the rear wheel in relation to the swinging arm width / length.
Hold on, major thourght, isnt the boss on the opposit side from the diff going to be a different size due to the spindle dia, is the thread size the same?
Odie
(uk)

[Randall-in-Mpls]

You won't be able to use the GL final drive unit on the CX, unless you figure out how to work around the missing shock mount. The Silverwing, with its mono-shock rear suspension, doesn't have the necessary stud on the drive unit for the right-side shock absorber.

Both the Deluxe and the Silverwing have Reverse Comstar rims. Aren't they both 16 inches?
Strike that. I forgot that the 650 wheels are different.

R

[Randall-in-Mpls]

odie, on 11 January 2011 - 12:46 PM, said:

Pull the diff off and try it, only real way of telling, wont take you long, one problem might be the size of the rear wheel in relation to the swinging arm width / length.
Hold on, major thourght, isnt the boss on the opposit side from the diff going to be a different size due to the spindle dia, is the thread size the same?
Odie
(uk)

Odie, you are on this board. Did you get the email I sent through your Google profile? It was regarding this thread.

R

[odie]

Randall-in-Mpls, on 11 January 2011 - 07:00 PM, said:

Odie, you are on this board. Did you get the email I sent through your Google profile? It was regarding this thread.

R

yes i did thank you, even though i dont ride any more due to back / spinal problems my brain is still working (some times! lol), i forgot about the mono shock but he should check the width of his swinging arm to see if the rear wheel will fit, also might not fit due to bolts on diff being different positions to the stock one he has at the moment.

[Hanful]

sw3dl1, on 11 January 2011 - 01:37 PM, said:

The project is as follows: Swap the rear end from a 1983 Silverwing Interstate (GL650I) to a 1980 CX500 Delux (CX500D).
I have both bikes and the Silverwing is a donor at this point. I like the appearance of Cast wheels that are on the Interstate and have swapped the front end to the CX500 to make use of the Interstate's heavier front forks and dual disk front brakes. To complete the modification, I would like to use the Interstates rear cast wheel on the CX500 as well. The problem is, the Interstate's rear axle is of a larger diameter then the one used on the stock CX500. The axles appear to be the same length. I believe I can over come the larger diameter problem by reducing the shouldered portion of the axle where it is held in place at the swing arm and using the Interstate's rear axle and rear end.
My question is this: Is the rear end ratio the same for both bikes? Are the Transmission gear ratios the same for both bikes? Does anyone know if the Interstate's drive line splines will match with those on the CX500D?
Any help or suggestions will be appreciated.

Disregard my post

[RichNCT]

I think the 650 to 500 swap is fraught with difficulties, but if you procured a CX650C differential, at least it would have a shock mounting stud. They're not particularly rare or expensive. I don't know about the specific tranny gear ratios (I've seen the table somewhere) but the overall ratio is higher, that is the 650 engines run at lower rpm at the same speed relative to 500s. Usually the clutch assembly is used from a 650 to lower the 500's rpm, it's been written about numerous times and is well tested. I'm thinking I remember Panther and David/WI have had experience in this area. My memory isn't as sharp as it never was.

[DaveF]

The CX650C rear end has four mounting studs instead of three.

Nothing is ever easy.

[Shadowjack]

Think a GL1000 rear drive unit would bolt up to a GL650 swingarm? I have a '77 GL1000, a '78 CX500, and an '83 CX650C. When I had the rear wheels off at various times, it seems like the wheel drive splines are the same on the CX500 and the GL1000, but different from the CX650C--at least a Lester wheel for a GL1000 will line up on a CX500 rear unit. The GL1000 has three bolts on the swing arm, like the CX500, and it has a shock mount assembly, although while looking at it just now, it may not line up right. I don't know how the axle sizes, the driveshaft splines, or gear ratios compare to each other since I don't have any loose assemblies at this time--they're all bolted up again.

[sw3dl1]

Thanks to all for the posts and information. About 5 minutes after I posted this I realized the problem with the shock mount. This modification was for no other reason then to be able to run the cast wheel from the GL650I on the back of my cx500D. The front Mod went surprisingly easy with some minor set backs. I thought the rear would be as easy. It's really not worth the effort. I'll think about it and see if there is another way, but for now, I'll run the Com Star on the back with the cast on the front. The rear wheel is mostly covered by bags any way. Again, thanks.

Randall-in-Mpls, on 11 January 2011 - 11:55 AM, said:

You won't be able to use the GL final drive unit on the CX, unless you figure out how to work around the missing shock mount. The Silverwing, with its mono-shock rear suspension, doesn't have the necessary stud on the drive unit for the right-side shock absorber.

Both the Deluxe and the Silverwing have Reverse Comstar rims. Aren't they both 16 inches?
Strike that. I forgot that the 650 wheels are different.

R

[Randall-in-Mpls]

RichNCT, on 11 January 2011 - 04:01 PM, said:

... if you procured a CX650C differential, at least it would have a shock mounting stud.

That has possibilities, buit you'd need the CX650C swingarm, as well, as suggested by the following:

DaveF, on 11 January 2011 - 04:32 PM, said:

The CX650C rear end has four mounting studs instead of three.

How similar are the swingarms at the pivot?

R

[DaveF]

Randall-in-Mpls, on 12 January 2011 - 10:09 AM, said:

...How similar are the swingarms at the pivot?

Good question. I have a couple of GL650 swingarms but no CX650 ones to compare.

[Blindstitch]

The flange is the same and the rim is probably mostly the same. Th only part I see that isn't the same is the bearings.

Maybe you should measure your bearings because as long as the outside diameters are the same I don't see why you couldn't replace them with the bearings that the 500's have.

[RichNCT]

While we're on the topic, I believe the drive spline (my term, for the internal male and female connection, one part on the wheel, the other on the differential) for the CX650 is unique also, different than the GL650.

[David from Wisconsin]

I hate to be a wet blanket, but the CX650 rear end is entirely different an any other transverse twin.

You would need to put a CX650 output shaft on the engine, use a CX650 drive shaft, swingarm and rear wheel.

[Panther]

Blindstitch, on 12 January 2011 - 08:30 AM, said:

The flange is the same and the rim is probably mostly the same. Th only part I see that isn't the same is the bearings.

Maybe you should measure your bearings because as long as the outside diameters are the same I don't see why you couldn't replace them with the bearings that the 500's have.

You can not get bearings to adapt a 650 rear wheel to a 500 axle or vise versa.
different diameters and no cross over.

[Blindstitch]

There has to be a way. How much bigger could the axle difference be? And if that's the problem why cant you make a sleeve like shim to go on the 500 axle and take up the space on the 650 rim.

Or a friend with a lathe to make a custom axle.

[David from Wisconsin]

The GL & CX rear wheels have female part on the wheel to mount on a male part on the rear axle ... except on the CX650 ... on which it is reversed.

That means you must use a CX650 rear wheel with a CX650 rear end ... and the CX650 rear wheel is a 15 inch tire.

[DaveF]

Not at all encouraging. Talk about wet blankets...