Fitting a longer shock

[yuri2085]

I am not quite sure I understand fully how the all the rear suspension parts work but. I tried to fit a K1 GSXR600 shock to my bandit (99). THe GSXR shock is about 2cm longer, I didn't think this would be a huge problem but whatever the moving thing that the bottom end of the shock goes into is at maximum downwards travel with the stock shock.

I can't get my head around a way to increase the distance between those two things, as I think they are both attached to the frame.

Am I right in thinking the shock is fixed to two solid points on the frame (the bottom point has some upwards travel, for purposes which I cannot fathom) and then some (dogbones?) connect something to the swingarm and this is what does the suspending?.

Sorry for confusing post but the old shock is back in now so I can't fiddle, would like...lifting the back of the bike up from above extend the distance?

[Pete.]

Well 20mm longer is about 1/3 the total travel of the original shock so I guess that's why it makes so much difference. You're trying to jack the back-end up by 1/3 the total movement at the end of the arm.

The shock pushes down on the bottom lever, which is attached to the swingarm via the dogbones. This acts as a multiplier of movement between the shock travel and swingarm. The dogbones travel less than the shock but fix near the front of the swingarm so travel at the arm is greatly multiplied.

You can't just go stuffing a 20mm longer shock in there and hope it will work. You could try removing the lower lever, and flipping it over. It might get you in the right ball-park for shock length since the lever isn't straight but it might also have undesirable effects on the spring-rate.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[yuri2085]

Hmm ok, I was under the impression this shock would have only been a few mm longer but no shock charts in the world include the length of the 99 bandit 600 ^^.

What kind of effects on the spring rate?
Thanks.

[Pete.]

[yuri2085]

Well, that might be worth a go then.


Thanks for the chart, will be useful if I sell this shock and try and get a new one. Clear information about which shock has been very hard to find, I was sure I had it right with this one .

[Pete.]

If you want to experiment with the shock you have by flipping the lower arms, to get the ride-height you're looking for you have to do this:

Figure out your preferred ride-height, by putting planks of wood under the rear wheel and sitting on the seat until you get the feel you want.
Get off the bike and measure the height off the floor at a point on the tail just for reference, support the bike with the weight off the wheel at your ride-height.

Now fit your new shock with flipped-over lower arm and then measure the distance between the dogbone holes with the wheel resting on the floor. This is how long you need to make your new dogbones.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good