I currently have a BMW rear shock on my 88.
I will be getting a rpm rear shock soon and need to know what the ideal dog bone length should be
I can't say what length is ideal. The length that currently is on my RPM shock equipped '89 is 110mm hole center to hole center. With a Suzuki 17" rear wheel, my tire is about 1 inch off of the ground while on the center stand.
Fred
I put 115mm bones on mine, with the RPM shock, but I think the geometry is different for the later bikes.
I am using the stock dogbone on my '89 with the RPM shock. The rear 180 x 17 just clears the ground on the center stand (about 3/4 inch drop of the rear wheel). No handling issues, I did 60 miles of twisty roads last Sunday (my first shakedown run) and enjoyed every twisted mile.
Oddly I do not think that anyone has ever made a list comparing the dogbone length for each model FJ.
It would be interesting to get this information into the files.
I suggest that we get measurements for all of the stock lengths for the bikes with dogbones as well as the various length mods. From there I will be more than happy to create a list showing the results.
It would be very helpful if some of us could get before and after measurements on how much the modified length affected the rife hight of the bike at a point common to all models. I will look at Deans tonight to see if there is an obvious choice unless someone else who is more familiar with the bike can chime in. Unfortunately Deans does not have stock bones on it so I can't use it as a reference.
Wait on the bones until you install the RPM shock.
Install the shock, put a spacer** under the back tire and only then measure.
Clamp your bones together and drill both holes on each end at the same time. You want those holes dead nuts even between your bones or you will fubar your swing arm bearings....don't ask.
** space the wheel according to your taste. I used a 1/2" piece of plywood under my tire. Some shorter legged folks don't like it that high.
Quote from: Pat Conlon on March 17, 2015, 03:38:04 PM
Wait on the bones until you install the RPM shock.
Install the shock, put a spacer** under the back tire and only then measure.
Clamp your bones together and drill both holes on each end at the same time. You want those holes dead nuts even between your bones or you will fubar your swing arm bearings....don't ask.
** space the wheel according to your taste. I used a 1/2" piece of plywood under my tire. Some shorter legged folks don't like it that high.
+1 I tack welded two corners. Drilled the holes, marked the outside tops and ground off the corners. A little black paint and they look like factory.
Kurt