520 sprocket conversions with offset front???

[Chuck78]

okay, so I have found a very informative thread that tells me what sprockets to use if I want a 520 conversion using a supersprox rear sprocket identical to the 5:30 that I am running on my '77 GS750-920cc. Now I am looking to run a 520 or possibly 525 conversion on both a GS425-475cc with GS1000 hubs/GS1100E swingarm, and a Rickman CR900 (GS550-789cc or GS750-894cc) with GS1000 hubs.

the front sprocket is the big issue. The twin in the 5:50 engines ran there are wheels, the sprocket carrier was not as thick, in the engine counter shaft sprocket was in board more than the big engines.

I'm not 100% sure the 425 uses at the same front counter shaft output sprocket, but I'm going to take a guess that it does use the same sprocket as a GS 550, and both likely have the same splines and diameter as a GS 750 or GS 1000. any one else ever look for a 520 or 525 off-set front sprocket?


very helpful thread on 520 conversions:

http://www.thegsresources.com/_forum/showthread.php?167060-520-Sprocket-to-fit-GS-sprocket-carrier&highlight=RF900R

98 Bandit 1200 Supersprox is what I am running, which is available in 520 as well. RF900R 94-97 run the same front and rear sprockets in a 530, so a 520 conversion for that would work also. Not sure on offset sprockets though. Thanks!

[RedLiner1100]

I searched all over myself and couldn't find any non stock/high offset 520 drive sprockets. You could either get a custom one made $$$$$ or possibly modify a 530 sprocket by having it narrowed to 1/4".

PBI offers some nice offset sprockets which are case hardened chromoly so you would lose the case hardening if you had one machined. I guess you could have it case hardened after machining although I don't know if it would cause any serious issues if it wasn't.

You could check the JT sprocket catalog as I think the GSXR 1100 had a drive sprocket with a small offset and I believe the same splines which are available in the 520 conversion.

Another possible solution is machining the drive hub by a small amount and/or using an offset driven sprocket if it doesn't interfere with your tire. Since you are ordering a Supersprox sprocket they could probably machine an offset for you. Their custom sprockets run about $120. I had them pop out a 48 tooth for me as they didn't carry one in that size for my 07 GSXR hub.

You could get lucky and get enough offset if you offset both the drive and driven sprockets. You can also gain a bit with a newer sprocket as they are narrower than the originals which had rubber dampeners (at least my 1100 is made like this)and a spacer on each side of the sprocket. You will have to make up for this anyway with spacers and can cheat it to your advantage which will actually let you gain you more than what the actual offset of the sprocket is.

[Fjbj40]

Yes it can be narrowed. I contacted the company that manufacturers the 530 offset sprocket that Katman sells. They said yes you can machine it down and it will have no effect on the strength/wear characteristics.

I however stayed with the 530 width.

Katman can also provide them in 520 width, at least he could a few years ago. He custom orders them from his sprocket supplier and the price was the same as the 530, back then.

[niclpnut]

I'm running a 520 offset sprocket on my 1100es. Started with 5/8 th 530 and milled it down to 1/2 inch for more frame clearance. The 520 fixed clearance issues. Think I mentioned starting with 530 and going down to 520 in my budget gsxr conversion thread. Also the vendor I purchased it from.

Nic

[RedLiner1100]

Yes it can be narrowed. I contacted the company that manufacturers the 530 offset sprocket that Katman sells. They said yes you can machine it down and it will have no effect on the strength/wear characteristics.

I however stayed with the 530 width.

Katman can also provide them in 520 width, at least he could a few years ago. He custom orders them from his sprocket supplier and the price was the same as the 530, back then.

Do you have a link to Katman? I did a search but didn't come up with anything but I did find an old thread that might be informational.

http://www.thegsresources.com/_forum/showthread.php?150085-520-Offset-sprockets

Apparently Sprocket Specialists have them.

[Big Rich]

Just a couple links for you Chuck. From JT Sprockets, here's a GS550:

http://www.jtsprockets.com/catalogue/model/5909

And a GS425:

http://www.jtsprockets.com/catalogue/model/1688

And an 04-10 GS500F sprocket, would work for the 520 conversion:

http://www.jtsprockets.com/catalogue/model/5902

I used some new OEM lock washers behind the front sprocket to space it out to where I wanted. Just make sure you're still able to get the nut threaded on enough after installing the sprocket (if the GS425 uses a nut that is....)

[Fjbj40]

Do you have a link to Katman? I did a search but didn't come up with anything but I did find an old thread that might be informational.

http://www.thegsresources.com/_forum/showthread.php?150085-520-Offset-sprockets

Apparently Sprocket Specialists have them.

http://www.suzuki-katana.com

Rob Wilton is his name, pretty nice fellow with lots of good info.

[steve murdoch]

A short article on Rob i saw in a recent magazine.

http://www.roadrunner.travel/magazine/read/november-december-2015/page/105/

[T8erbug]

Did you get this figured out Chuck? I did the 530 mod that some folks are doing. I just bought an offset 530 sprocket and threw it in the lathe to take it down to the 520 dimensions. Based on how it machined I think the teeth are flame hardened. The innermost portion of the sprocket machined easily but the teeth were gnarly. Rather than machine my next one I think I'll get in touch with the manufacturer and have a bunch made. I'll probably just list the extra on the interwebs somewhere (starting here, of course). It would be easier and cheaper in the long run. Machining hardened steel is a real pain. You could temper it then machine it, but then you'd have to reharden it. Better to have the manufacturer just face off the extra material while it's already on the lathe and before treatment of any kind.