Longer sprocket bolts?

CJF · Post by **CJF** » Sun Feb 22, 2009 7:03 am

I ran into a bit of an issue with my rear sprocket mount bolts. I'm fitting a wider rear wheel and tire and made up a sprocket spacer to allow for more chain clearance and a 520 chain and sprocket. I was thinking there would be no need for longer bolts with the 520 sprocket, but I was wrong! The issue now is that the sprocket bolts are about 10mm too short. Does anyone know of another bike that may have longer sprocket bolts than the T500, but still fit wth the sprocket carrier? I know... kind of a long shot, but just checking in case anyone else has tried this mod before.

tz375 · Post by **tz375** » Sun Feb 22, 2009 9:48 am

Chris,

Which bike are we talking and how long are yours and what diameter? Last tie I had to do that, I used bolts from the hardware store and ground the head on one side to match the flats in the sprocket carrier.

H2RICK · Post by **H2RICK** » Sun Feb 22, 2009 2:20 pm

And you DO want to use good bolts.....minimum class 8.8, but preferably class 9.8 or 10.9.
And you want to make sure there are NO threads anywhere below the outboard face of the sprocket i.e. just enough threads to cater for the lock plate and the nut with 1 thread left over for insurance.
Check the old bolt and you'll see what I mean....assuming some wanker hasn't thrown away the original bolts.

CJF · Post by **CJF** » Sun Feb 22, 2009 9:52 pm

tz375 wrote:Chris,

Which bike are we talking and how long are yours and what diameter? Last tie I had to do that, I used bolts from the hardware store and ground the head on one side to match the flats in the sprocket carrier.

It'sfor the GT500 racer project bike I'm working on. I double checked the length and they are currently 42MM long and 10MM diameter. The bolts need to be 47MM long. I didn't think about using a normal bolt and grinding it down. I guess I could try that if there aren't any other options.

tz375 · Post by **tz375** » Mon Feb 23, 2009 9:22 am

I checked a set of GT750 bolts and they are 42mm overall, so they are probably the same part.

On the GSXR they appear to be either studs or cast in place, so that won't work either, unless you find a GSXR sprocket carrier that happens to work with the same cush drive rubbers.

I'd just go and buy some bolts and grind them.

diamondj · Post by **diamondj** » Mon Feb 23, 2009 9:48 am

Hey Chris,

Just wondering two things -

1. Would a GT750 hub work in place of the T500 hub?

2. How wide are you going on the rear tire? Is this for the race bike? Pretty much anything wider than a 120 is going to slow the bike on turn in.....

Studs off a GSXR might be a better way to go and then you can use locking sprocket nuts. You will need to make sure you don't make the assembly so wide (tall?) that it strikes the swing-arm though.....

Jim

CJF · Post by **CJF** » Tue Feb 24, 2009 6:51 am

diamondj wrote:Hey Chris,

Just wondering two things -

1. Would a GT750 hub work in place of the T500 hub?

2. How wide are you going on the rear tire? Is this for the race bike? Pretty much anything wider than a 120 is going to slow the bike on turn in.....

Studs off a GSXR might be a better way to go and then you can use locking sprocket nuts. You will need to make sure you don't make the assembly so wide (tall?) that it strikes the swing-arm though.....

Jim

I went with a 5.00 rear tire thinking that was the way to go. I'm pretty sure desmocat is using the same and he seemed to be getting around tracks pretty well. He did the same rear sprocket spacer mod, but I didn't ask him what he did about the bolts. Looks like tz375 measured the gt750 bolts and they use the same length as the gt500. I'll look into the GSXR option or if that doesn't work try grinding down the side of some stong harware store bolts.