OFF SET SPROKETS

hi all as some of you know i have a winter project i am getting ready to start but in the meantime i am riding it and dont want to tear it apart to do any measurments.here is what is going on it is a 76 900 i have a extended swingarm @ i am putting a 190 tire on a 6" gsxr wheel. the question is the offset of the frt. sproket??? i heard that 3/8 offset is the most you can go without frame problems if that is true is that going to be enough to work with this setup??any help would be great i would like to get the sproket order so come winter i am ready to go thanks for your help

with that size of wheel your probably going to have to use a 5/8" sprocket which means your going to need to relieve the frame some right in the area the chain runs top and bottom. even with 530 chain. i know i had to myself at least.

how did that work out ?? did you have to go deep?

no i only had to flatten out the inner part of the tubes by about a 1/2" to get enough clearance i was i a rush so all i did was heat up the area with a set of torches and crushed it with a big c clamp just in the areas that needed it and it didn't even distort the front of the tube just take your time and don't go crazy with the heat. this was on my drag bike so i didn't have a fancy high doller paint job to worry about. if your taking it right down anyway you might want to notch it and then fill it back in nice but i was in a rush and was racing it that weekend so i had to do it fast and dirty.

12.5mm (~ 1/2") offset on mine no problems... It's close but with proper chain slack 1" to 1 1/4" I've had zero problems and I run a 180 tire on the rear....

Chain to tire clearance is no problem, way then more enough clearance... Frame is another story....

From others projects, 5/8" meant as mentioned, frame fabb work is required or offset the rear tire :pinch: an 1/8th inch....

Just in case... German machined extremely well made (one piece) CC sprockets in both 530 and 630 pitches....

americanclassix.com/streetfighter_conversions.html

dave is your wheel 6" wide or 5.5"

5.5" Rim width on the back...

The last time I was over at the website, the offsets are now 12mm versus 12.5mm... Unlike our wives :pinch: :whistle:, that additional .5mm makes a difference...

I could see where a 6" rim would cause some serious modifications... If I remember correctly (yeah right :blush: :laugh:) Mark1122 had to have his rear hub milled down for it...

As much as I love my KZ, I'll tell ya, that rear swingarm conversion (math, geometries, angles, measurements, alignments, modifications etc...) really messes with the brain.... :S :laugh: :laugh: :laugh:

I THINK I SHOULD WAIT TILL WINTER PULL THE COVER AND DO SOME MEASURING I AM GETTING ALITTLE MESSED UP NOW GETTING TO MANY SIZES . I MOCKED IT UP ON THE BIKE A FEW WEEKS AGO THE CHAIN CLEARED THE TIRE AND FRAME BUT I AM SURE THE CHAIN WASNT TRACKING RITE

i use a widened gsxr wheel that is actually 6" inside lip to inside lip i use a 5/8 sprocket with an irishwill made bearing support oh by the way you might want to look at going with a bearing support as well.with my swing arm setup i even had to offset the wheel to the right a bit. so it would clear properly.

is the wheel centered up in the swingarm now?
does the centerline of the tire and the centerline of pivot tube line up?
when i built my swingarm i centered my hub,and the rim was offset 3/8's to the right.i was able to get away with a 3/8's offset sprocket.i would definately check it myself before i spent any money.
a few moments with a string and a ruler could save you time and money.

leon

i think i will wait till winter which is very close to order so i can get out the tape & see what is up this is why i like this site everyone is ready to help out could not ask for more thanks alot

i had to do the same thing timebomb33 did. heat and flatten the inner frame, and use a 5/8" offset. then i milled my hub to get the chin loser to the tire. ended up with a 170 tire on a 5.5 zrx12 rim and arm.i run it on a rd race track with the rear rim offset from center of the front rim, and its fine.