[rdurider]

Hi All!

Does anyone know if the fork uppers from the 92-93 GSX-R600 can be swapped into 91-92 GSX-R750 forks?

The upper and lower tube diameters are 50mm and 54mm, respectively, and the fork caps and upper adjusters are the same part numbers, but the dampers are different part numbers and the fork tube lengths are probably different. I can't find much info on GSX-R600 fork dimensions, but I think they're longer than the 750 forks.

I have several sets of 750 forks, but I'd like to have a one-piece upper for the forks that are going on a bike I'm building.

Thanks in advance for any info you can provide!

 

[rdurider]

On a whim, I bought a set of 92/3 GSX-R600 forks. When they arrive, I'll disassemble them and compare the aluminum fork uppers and damper rod to the corresponding parts on the 91/2 GSX-R750 forks. For posterity, I'll report my findings here.

 

[rdurider]

Well, color me embarrassed, the forks I'm looking at aren't 600 forks. I'll have to look for another set.

 

[86gixxxer]

well, to answer your fork question; yes, 92-93 gsxr 600 forks will fit into 91-92 750 triples. not sure what you mean about "once piece uppers" for the forks, though. the WC forks are a bit shorter than the OC forks.

 

[rdurider]

The 750 fork uppers are two pieces. The lower piece hold the oil and dust seals. I find it to be a pain in the ass to drive in the seal. The 600 fork uppers are one piece, and it should be much easier to driving in the seals.

OK, proper forks sourced and arrived. The 600 fork stanchions and uppers are very nearly the same length, so no win there. The good news is that the uppers are in great shape.

The 91/2 750 and the 92/3 600 share nearly half the parts:
BUSH, SLIDE 51121-48B31
PIECE, ADJUSTER LOWER 51830-07D00
O RING 51834-17C00 09280-14011
GASKET 09161-10009
BOLT 51147-17C00
NUT, LOD 51827-17C00
SPACER, SEAL 51168-38B00
SEAL, OIL 51153-08D00
RING, STOPPER 51556-38B00
SEAL, DUST 51173-08D00 51173-15D00
RUBBER, SEAT 51193-17D00
BOLT, FORK 51189-18D00
O RING, FORK BOLT 51187-08D00
ADJUSTER, SPRING 51828-17D00
O RING, ADJUSTER OUTER 51199-17D00
PLATE, SPRING ADJUSTER 51823-17D00/51823-22D30
O RING 51824-17C00 09280-03002
RING, STOPPER 51837-17D00
PLATE, FRONT FENDER RH 51590-17D1V
PLATE, FRONT FENDER LH 51580-17D10 51580-17D1V
BOLT 01517-08128 01550-08127

The list includes the oil and dust seals and fork caps, so swapping the 600 fork uppers onto the 750 forks should be no problem. The only difference I can find on the rebound and compression dampers is that the 750 parts have a ball bearing and retaining spring-assisted adjustment and the 600 forks do no. Otherwise, those parts are also interchangeable.

The sliders are different and take different bushings. I haven't examined the dampers closely yet, but they are different

 

[ghostrider.1127]

The 750 fork uppers are two pieces. The lower piece hold the oil and dust seals. I find it to be a pain in the ass to drive in the seal. The 600 fork uppers are one piece, and it should be much easier to driving in the seals.

Hard to find a sense to this...