Author Topic: Follow up to '03 GSX-R 750 shock installation (Read 6722 times)

millsi1 · « **Reply #15 on:** July 07, 2005, 04:42:34 PM »

looks the goods dude!!! you wouldnt know it wa there unless you were looking for it!

TheKillerB · « **Reply #16 on:** July 12, 2005, 11:56:42 PM »

Nice job on the install Russ. Since you fabricated your dog bones, is there any chance you have the stock ones handy where you could measure them and let us know the distance from center of hole to center of hole? If you can, that would be great. If not, no worries. Thanks!

Racerruss-ducati · « **Reply #17 on:** July 13, 2005, 09:14:45 AM »

Quote

TheKillerB wrote:
Since you fabricated your dog bones, is there any chance you have the stock ones handy where you could measure them and let us know the distance from center of hole to center of hole? If you can, that would be great. If not, no worries. Thanks!

The old dog bones were 198.5mm give or take a half mm.

TheKillerB · « **Reply #18 on:** July 13, 2005, 01:37:28 PM »

Cool! Thanks for the measurement. Just picked up an '04 gixxer shock off eBay last night.

Racerruss-ducati · « **Reply #19 on:** July 13, 2005, 02:55:38 PM »

The '04 and '05 Gixxer shock is about 15 mm longer ( I can't remember exactly how much) than the '00-03 shock. You will definately have to make some new dog bones, luckily they are not that hard to make.

Good luck and let us know how it goes.

TheKillerB · « **Reply #20 on:** July 13, 2005, 10:22:38 PM »

Ohlins web site says the difference between the '00-'03 and '04-'05 is 7.5mm. Are changes in shock length and dog bone length directly proportional? Like if a shock is 25mm longer than stock, and you install dog bones that are 25mm longer, does seat/tail height remain the same? I'm thinking no. So does anyone know the ratio?

Racerruss-ducati · « **Reply #21 on:** July 13, 2005, 11:32:19 PM »

Teach me to work from memory, you are correct. I think you will need to remove more material from the end of the shock (see sketch I directed you to in other parts of this thread) to prevent it from mechanically locking prior to the full shock extension.

The ratio for shock length to dog bone is not linear, i.e. the ratio at 10% compression is not the same as it is at 20% compression. And at closer to 0 compression, it is a big difference. Without taking pretty accurate measurements of the linkage and angles of the swing arm, it is impossible to solve, and if you did get the data and solve it, the result would not be a ratio, but instead a formula dependent on swing arm angle.

Luckily several of us have experience with this mod. My new shock was about 13mm longer than stock (again, from my memory, no gaurentee)
I wanted to raise mine up a lot, but the new shock made it too tall for the centerstand. So I placed a 1/2" board under my rear tire with the bike on the centerstand and physically marked up new dogbones that happened to be 15mm longer than stock. I would suggest using the same method as it resulted in exactly the correct attitude I was looking for. Maybe others have different experience (or better have solved the math problem) and have other advice.

Good luck, Russ