front end

im new to this forum but ive been on the kz650 forum for quite awhile now...i have a 1978 KZ650B.but anyways,

i heard it mentioned over there about someone switching out their front end to use GSXR750 front forks,triple tree, etc.they said the 00-03 model years fit pretty close to perfectly.i was wondering how true this is because i would like to do this.i would just basically switch over to that whole front end just to make things that much easier instead of piecing everything together...

im looking to do this as soon as i can but want to know how easy this will be or what issues i may run into so i can assess this swap before i dive in.

I have read that the GSXR forks are a lot shorter than the KZ forks, so you may want to check into that aspect.

GSX forks are real close to the same length and an easy swap.

GSX are right side up forks, unlike the GSXR upside down forks.

KZ650 forks are roughly 31"and some change.I measured my buddies '08 GSXR1000 forks and they are about 1" shorter than the stock KZ forks.

grinch77 wrote:

KZ650 forks are roughly 31"and some change.I measured my buddies '08 GSXR1000 forks and they are about 1" shorter than the stock KZ forks.

how can i compensate for that 1 inch difference so i dont affect the trail, and the general height of the front end.

steell wrote:

GSX forks are real close to the same length and an easy swap.

GSX are right side up forks, unlike the GSXR upside down forks.

i like the look of the inverted forks like the concept of them.that is why i would like to know more about this.

i know that anything can be done,with customizing,but at the same time no one wants to take on a project that cant be finished.

Also when you make the swap don't forget that you'll lose 1-2" just from going from a 19" to 17" rim/tire. So make sure you compensate for that as well as the shorter forks.

Later, Doug

PunkRawkKid wrote:

grinch77 wrote:

KZ650 forks are roughly 31"and some change.I measured my buddies '08 GSXR1000 forks and they are about 1" shorter than the stock KZ forks.

how can i compensate for that 1 inch difference so i dont affect the trail, and the general height of the front end.

Make new Triple clamps that move the forks down?

PunkRawkKid wrote:

i like the look of the inverted forks like the concept of them.that is why i would like to know more about this.

It's my understanding that inverted forks are supposed to be stiffer than conventional forks.

My question is, does it make any difference? Can the average rider tell the difference in stiffness between the inverted forks and conventional forks?

Or is it just the coolness factor?


I don't know, so I'm asking.

before you go and do anything measure your front tire and wheel combo and compare it to measurements from a gsxr front wheel/tire the rim might be only a 17 but the tire is wider and has a different aspect ratio ill bet there isn't a whole lot of differance between those 2 tire/wheel combos in overall heights.

I have no first-hand experience with the USD forks but a few guys who do says the bike is smoother, LOTS more stable at speed and lighter with the new forks. They are much stronger then stock forks while shaving weight. I have bben told that once you ride with a set, you won't want to ride anything else.

timebomb33 wrote:

before you go and do anything measure your front tire and wheel combo and compare it to measurements from a gsxr front wheel/tire the rim might be only a 17 but the tire is wider and has a different aspect ratio ill bet there isn't a whole lot of differance between those 2 tire/wheel combos in overall heights.

does the measuring have any effect if i was planning to go to the 17inch front wheel that is stock with those forks.im planning on switching to the whole front end from the GSXR...forks,wheel,triple tree,brakes,etc.

so that would be a total of 3 inch difference?what can be done to compensate?i know someone said something about the triple clamps and that is definitely an option that i will have to most likely do.what else can be done so i dont drastically affect the current trail?i know the trail affects the handling..

this is about the only part that im unsure about.

timebomb33 wrote:

before you go and do anything measure your front tire and wheel combo and compare it to measurements from a gsxr front wheel/tire the rim might be only a 17 but the tire is wider and has a different aspect ratio ill bet there isn't a whole lot of differance between those 2 tire/wheel combos in overall heights.

Courtesy of Powerdog Industries...

A 19" and 17" tire has a 1.6" difference in radius so like I said 1-2" difference.

Later, Doug