Starting a new topic regarding the suspension upgrade of my '85 Limited Edition.
I have mentioned it in my thread, GL1200 Engine Rebuild - Part 5 - Post Getting to the Road: viewtopic.php?f=24&t=14374
Front suspension: Race Tech front fork springs 1.0 kg/mm, RT emulators - 33.5/26.1/17.0
Rear Suspension: Hagon shocks with remote preload adjuster (RAP) - 30 KG spring, 350 mm damper, piston size 18.3 mm
Have some 400 Kms on the rear shocks and think I'm close in having the rear shocks setup.
Having mentioned the above, intend to check the front/rear sag of the bike. This requires a preload adjustment front/rear. At this time my '85 Limited Edition only has preload adjustment on the rear. The other issue is you need to determine the riding profile to get the best setup; ie solo versus two up, or a percentage of both. I will be adjusting the sag on my '85 Limited Edition for solo riding. Will be able to accommodate two up riding because of the rear preload adjustment.
Preload and sag are not synonymous, but preload affects the ride height of the bike and is a necessary component of setting bike sag.
Have the Race Tech Motorcycle Suspension bible that is a very good read. This book has a sag setup procedure that is probably similar to other sag setup procedures, but it is what I have on hand and so far, I understand it.
The recommended required sag is between 1/3 to 1/4 of the suspension travel. To determine the suspension travel, you take all the weight of the front and rear suspension.
For the front suspension, with all the weight off the front suspension and without a rider, you measure the exposed upper fork tube between the triple tree and where the upper fork joins the lower fork tube. This is the L1 measurement. You then secure the bike in an upright position, and with rider on the bike, push down on the suspension and let rise slowly. Take a measurement as you did with L1, and this is your L2 measurement. Next measurement is to lift the front suspension and let settle slowly. Take a measurement as per L1 and L2, this becomes measurement L3.
With these figures, use the formula L1-((L2+L3)/2) to determine the sag. If it is more than 1/4 of the suspension travel L1, the spring is too soft. Increase the preload to bring the sag into spec range. If the reading is less than 1/3 of the suspension travel, the spring is too stiff, reduce the spring preload to bring the sag into spec range. If you do not have adjustable fork spring preload, you may have to get a fork spring with a stiffer/softer rating. The best solution is to get a front fork suspension setup that has an adjustable preload. There are preload caps that can be purchased and found on Amazon and eBay for a reasonable price - least expensive option.
You repeat the above procedure for the rear of the bike as well. You want to set the sag with the minimum amount of preload on the rear shocks and front fork springs.
The second phase of the suspension setup will be adjusting the rebound function of the front suspension. The installed RT emulators require me to disassemble the front forks, remove the emulators, adjust as required, put back in the front fork(s), reassemble, then road test. Rebound affects ride quality and bike performance, as does compression. Too quick a rebound, not good - riding a bucking horse - too little and loose affective shock travel, and if hitting a plethora of bumps in a row, terrible ride quality and bike performance.
Lots to do and finalize. Will do rear first, then get onto the front. Will be talking to my suspension guru at RMR suspensions and determine if Andriani can provide a set of 41 mm front forks for my '85. 50/50 chance of getting a positive response.
More to follow.
I have mentioned it in my thread, GL1200 Engine Rebuild - Part 5 - Post Getting to the Road: viewtopic.php?f=24&t=14374
Front suspension: Race Tech front fork springs 1.0 kg/mm, RT emulators - 33.5/26.1/17.0
Rear Suspension: Hagon shocks with remote preload adjuster (RAP) - 30 KG spring, 350 mm damper, piston size 18.3 mm
Have some 400 Kms on the rear shocks and think I'm close in having the rear shocks setup.
Having mentioned the above, intend to check the front/rear sag of the bike. This requires a preload adjustment front/rear. At this time my '85 Limited Edition only has preload adjustment on the rear. The other issue is you need to determine the riding profile to get the best setup; ie solo versus two up, or a percentage of both. I will be adjusting the sag on my '85 Limited Edition for solo riding. Will be able to accommodate two up riding because of the rear preload adjustment.
Preload and sag are not synonymous, but preload affects the ride height of the bike and is a necessary component of setting bike sag.
Have the Race Tech Motorcycle Suspension bible that is a very good read. This book has a sag setup procedure that is probably similar to other sag setup procedures, but it is what I have on hand and so far, I understand it.
The recommended required sag is between 1/3 to 1/4 of the suspension travel. To determine the suspension travel, you take all the weight of the front and rear suspension.
For the front suspension, with all the weight off the front suspension and without a rider, you measure the exposed upper fork tube between the triple tree and where the upper fork joins the lower fork tube. This is the L1 measurement. You then secure the bike in an upright position, and with rider on the bike, push down on the suspension and let rise slowly. Take a measurement as you did with L1, and this is your L2 measurement. Next measurement is to lift the front suspension and let settle slowly. Take a measurement as per L1 and L2, this becomes measurement L3.
With these figures, use the formula L1-((L2+L3)/2) to determine the sag. If it is more than 1/4 of the suspension travel L1, the spring is too soft. Increase the preload to bring the sag into spec range. If the reading is less than 1/3 of the suspension travel, the spring is too stiff, reduce the spring preload to bring the sag into spec range. If you do not have adjustable fork spring preload, you may have to get a fork spring with a stiffer/softer rating. The best solution is to get a front fork suspension setup that has an adjustable preload. There are preload caps that can be purchased and found on Amazon and eBay for a reasonable price - least expensive option.
You repeat the above procedure for the rear of the bike as well. You want to set the sag with the minimum amount of preload on the rear shocks and front fork springs.
The second phase of the suspension setup will be adjusting the rebound function of the front suspension. The installed RT emulators require me to disassemble the front forks, remove the emulators, adjust as required, put back in the front fork(s), reassemble, then road test. Rebound affects ride quality and bike performance, as does compression. Too quick a rebound, not good - riding a bucking horse - too little and loose affective shock travel, and if hitting a plethora of bumps in a row, terrible ride quality and bike performance.
Lots to do and finalize. Will do rear first, then get onto the front. Will be talking to my suspension guru at RMR suspensions and determine if Andriani can provide a set of 41 mm front forks for my '85. 50/50 chance of getting a positive response.
More to follow.