Offset Front Sprocket Question

[kichigai]

I have an '82 1100E with a GSXR front end and rear wheel. It wasn't all that hard to do.
I used a '92 750 wheel. It is 5.5" wide with a 180 series tire on it. You will need to swap to a 530 chain to make it work. Swap the GS sprocket/hub onto the new wheel. The wheel will now fit where the old one did using the GS spacers in the same configuration.
You will need to shim out the front sprocket to line it up with the rear. Some guys on this site advocate using and offset sprocket. I found that by using large hardware store washers I was able to shim out the sprocket to the right spot and still have full contact with the splines on the countershaft.
Works great.
There are probably other ways to go about doing this swap, this was my approach and it works well. Good luck, it's worth the effort.

80GS1000, I dont know the answer to your question but sure want to find out! Check out even a quote from RJ, he used a some large washer to shim out a standard 530 sprocket which I cant imagine was much but was able to line the chain and sprocket up. I too am using my stock GS sprocket/hub on the GSXR 1100 wheel. I wonder if this is why it works?

Isleoman, thanks for the info! I really like the look of the 180 so I am determine to find a way to make it work. Question, If a 3/8 offset works for a 160 tire, shouldnt a 1/2 offset work for a 180? Right now with the 5/8 offset, I have lots of clearance from the tire but minimal from the frame which make me think that a 1/2 might work!

 

[tone]

Hi guys ive just read through this entire thread & have noticed a couple of things, i suppose they may have been covered in another thread but here goes anyway .......
theres no mention of checking wheel alignment, i just wondered if its correct as ive seen people align the sprockets & then find out the arm has a different ofset so the wheels are out, maybe a daft thing to do but it happens.......
a 6" busa rim is too wide for most 180 tyres it will be pulled out of shape & can cause clearance problems, a 180 is designed for a 5.5" rim, 6" rims need a 190 or 200, i know thers very little diference in actual measured size when fitted but the carcass is not the same

I've fitted numerous 5.5 rims with 180 tyres to various gs's & gsx sometimes using the stock arm, a modded stock arm or various gsxr & bandit arms & never yet have i had to cut the frame to attain chain clearance, mine have always lined up with a small ofsett to the front sprocket & a skim of the sprocket carrier so i'd guess these problems stem from using a 6" rim

 

[kichigai]

Tone when you say small offset to the front sprocket , how small?? You are the 3rd guy that have indicated that they were able to do the GSXR wheel conversion with only a little offset so I belive it is possible, though others have indicated that they needed to go with a 5/8. Humm, I wonder why the discrepancies in installation? Please let us know so I can give it a try!

 

[kichigai]

A 6" Hyabusa wheel will fit with a 190 and a 530 chain. I am running a Shinko drag tire and the "stock" rear shocks with a 5/8" offset front sprocket kit, it is tight but works.
:-D Justin

Here is another quote that I found!

 

[kichigai]

No, the 90's wheels are 6mm narrower and fit perfectly. IN fact, the early 90's wheels can use the gs sprocket carrier. If you use the gs sprocket carrier though you have to swap out the carrier spacer too as it is a couple mm shorter. quote]

Maybe Katmans quote explains why it works.

 

[tone]

Hi kichigai

I guess some of the differance is in the wheel hubs the latest blade type wheels (with the larger spindle) the straight spoke bandit type wheels & the curved spoke slingshot wheels all have a different hub & the sprocket carriers vary in depth too, A standard 630 chain is not always any bigger in width than a heavy duty 530

as a point of note the 4.5 curved spoke slingshot wheels are designed for a 170 max size tyre, squeezing a 180 over it is not a good idea

The last one i did was a gsx1100et i used a bandit arm a gsxr 5.5 wheel, with bridgestone 180 tyre the gsx sprocket carrier & a 630 chain the front sprocket was spaced out as far as poss on the splines & a new locking nut slimmed down from the back this bought the chain dead centre of the gap between the frame & tyre viewed from tha back, a few mm was removed from the sprocket carrier & the gap between the chain & tyre / chain & frame is exactly equal

sorry i cant be more specific on sizes but this one was done for someone else & it was around 8 months ago, i must point out that all mods i do like this are done on a jig & i'm very particular about alignment etc... i'm not saying this to disrespect anyone but i guess some peoples bikes & chain runs could be a couple of mm out, that not much of a problem as there is slight room for error

 

[80GS1000]

Alright, so the difference in required offset appears to be due to the rear wheel that you're using. The 90s 5.5x17" Gixxer wheels appear to require less offset than the 2000 era 5.5x17" wheels.

I used the stock GSXR 750 wheel spacers along with the 05 GSXR 750 5.5x17" on mine so I know the wheel alignment is good within the swingarm, also used the string method for checking front and rear wheel alignment. Chain alignment is straight as checked with a straightedge pressed against the inside edges of the front and rear sprockets.

 

[tone]

sounds good to me 80gs :-D

Heres an example of how things sometimes work out ..... i have a 86 1135 efe frame fitted with a 1127 oil cooled engine & i did have a poorly fitted slingshot swingarm wheel etc in there, the arm was fitted central & the front sprocket spaced out a few mm & i cant see anything else that was done by the po but the chain run was spot on, the rest was crap but the chain was right

I'm now fitting a gsxr600 k6 swingarm with a late 90's wp wheel :-D the chain run is so far out of whack i'd have to remake the frame on the left side to fit it with another random borrowed (poss srad) wheel & an unknown sprocket carrier out of the big box of usefull stuff i'm 11 mm out & theres clearance to get it all in & working

i suppose the moral is give it a go you never know till ya try

 

[kichigai]

Boy it sure is nice to have such knowlegable guys like you fellas here on this forum. I am going to do some meaurement checking on my bike and see what might work for my setup. As soon as I have some details, I will post up to share with everyone so other can apply it to their future projects. Thanks Kichigai.:-D

 

[80GS1000]

sounds good to me 80gs :-D

Heres an example of how things sometimes work out ..... i have a 86 1135 efe frame fitted with a 1127 oil cooled engine & i did have a poorly fitted slingshot swingarm wheel etc in there, the arm was fitted central & the front sprocket spaced out a few mm & i cant see anything else that was done by the po but the chain run was spot on, the rest was crap but the chain was right

I'm now fitting a gsxr600 k6 swingarm with a late 90's wp wheel :-D the chain run is so far out of whack i'd have to remake the frame on the left side to fit it with another random borrowed (poss srad) wheel & an unknown sprocket carrier out of the big box of usefull stuff i'm 11 mm out & theres clearance to get it all in & working

i suppose the moral is give it a go you never know till ya try

Can you skim the sprocket carrier on that setup?

You have a mate with a K6 600/750 rear wheel and sprocket carrier laying about?

 

[tone]

Can you skim the sprocket carrier on that setup?

You have a mate with a K6 600/750 rear wheel and sprocket carrier laying about?

yeah ive had these carriers skimmed down before, a few mm of the face where the sprocket fits is fine I'm not actually sure what this one is off so will be checking it out carefully to see how much i can get away with & keep the strength, anything else will me made up on the front sprocket

yep ive got a mate with srad stuff kicking around but were not sure which model, he's got to be free with lending it to me as its me who will be fitting it to his gs1000 in the end :-D

its my swingarm thats definately k6 600 btw, the front end is k4 750 i think so if anyone needs measurements shout up :-D

 

[80GS1000]

yeah ive had these carriers skimmed down before, a few mm of the face where the sprocket fits is fine I'm not actually sure what this one is off so will be checking it out carefully to see how much i can get away with & keep the strength, anything else will me made up on the front sprocket

yep ive got a mate with srad stuff kicking around but were not sure which model, he's got to be free with lending it to me as its me who will be fitting it to his gs1000 in the end :-D

its my swingarm thats definately k6 600 btw, the front end is k4 750 i think so if anyone needs measurements shout up :-D

Reason I ask is because getting wheel and chain alignment right will probably be easier using the K6 600/750 sprocket carrier, spacers and rear wheel if using that K6 swinger.

 

[tone]

i had thought that myself but as i'm not well off & k6 stuff goes at a premium over here i'm stuck with using my brain good looks & charm :-D

wheel alignment is not a problem with any of the wheels its only the chain that is causing a bit of a headache but i'll get there thanks for the suggestion though :-D

 

[kichigai]

Ok I am still need of some tech help here!

As you can see below I have the PMFR 5/8 offset sprocket installed on my bike but the clearance to the frame side is really close!

Here is the view of the top chain where it goes through the frame.

Here is a picture of the lower chain where it goes through the frame. Unfortunately I can not grind down the frame down anymore because it is were the shifter pivot is welded to the frame. I got it to clear but I think I only have about 1 mm clearance if even that much!

 

[kichigai]

Here is a better picture of the lower chain!

As you can see, the chain comes close to the center stand too!

As you can see here, I have more clearance on the tire side!

My question is: Cant I just use a sprocket with less offset like a 13mm or 1/2" instead of a 5/8" to bring
the chain a bit closer to the tire and further away from the frame?

I originally got the PMFR offset sprocket thinking if I decide to go with a suppport kit, I could do it at a later time but they dont make a 1/2" 530 sprocket in a 17 tooth.

Any suggestions?

 

[tone]

Theres a few options as i see it .....

scollop the frame & offending parts out & brace etc to allow clearance on the frame side
Depending on the front sprockets construction you may be able to remove a bit of material from the back to reduce the ofset slightly
If theres a spacer behind the sprocket you may be able to loose a little from there as well

a smaller ofset on the front sprocket & removing a bit from the rear carrier could work as there seems plenty of room tyre side of the chain although its difficult to tell from your pics

As a footnote its always been my way to get the chain central in the space betweeen frame & tyre by means of both ofset front sprockets & reducing the width of the rear carrier

Hope that little lot helps mate :-D

 

[kichigai]

As a footnote its always been my way to get the chain central in the space betweeen frame & tyre by means of both ofset front sprockets & reducing the width of the rear carrier

Bingo! Thats exactly my thought too!
Personally I rather not scalop the frame especially with the shifter pivot post being in one of the problem spots but the changing the sprocket is do-able. I think I might as well bite the bullet and just get the 13mm or 1/2 sprocket which is the next size down to find out for sure if it works. If it works, all is good, and if not, I can at least post this up too for future reference.

 

[kichigai]

Ok I placed an order for my 13mm offset sprocket thru SprocketCenter.com today.

The price was around $53.00 plus tax and shipping. I think the total was around $64.00 total which was not bad. I was told that they had it in stock and would have it delivered to me by this friday. I cant wait to give it a try! Hope it works!

 

[rapidray]

On EVERY GS frame I have put a 5/8 offset on I have had to "relieve" the frame where the chain would hit it. It is just the way it is with the 5/8 offset. Ray.

 

[RacingJake]

Also a non O-ring chain helps too.