Join Date: Nov 2018
Location: Regina, Saskatchewan, Canada
S4RS Top Mount Ohlins Damper Installation
So this thread won't be of interest to most people unless you are cheap like me and want to do a top mount damper installation. This mounting setup cost me $11. I originally wanted to do a side mount on my S4RS but decided that I wanted the convenience of top mount adjustment ease and also thought that in the case of a slide a top mount is less likely to be damaged. I couldn't find any options for a top mount but did see a few DIY's of different bikes that gave me idea's. I know my work is not pretty but I couldn't care less because a pretty boy I am not. I just care about things working well. I also cannot figure out any reason why it is not correct to mount to the handle bar itself. I have not seen anyone do it online. I imagine there is a lot of different ways to get this job done. I couldn't find much info. I am only sharing this so perhaps it will make things a bit easier for anyone else going down this road.
The center mount is attached to the top of the ignition mount. The first post mount plate I made was out of 4mm aluminum plate. In the end I found that to be slightly more flexible than I wanted. I ended up using a piece of 6.25mm plate that I had laying around. For the bar clamp and post I bought a bar of 1" x 2" aluminum. I don't know what grade it is but it is good and hard. I had my pocket knife with me to give it a little test.
Since a mounting plate is being added, longer studs have to replace the oem studs in the ignition housing. Mine were put in with red locktite so I just used a set of vise grips to remove them. I first made a couple of studs by cutting a couple of 6mm x 75mm bolts to a length of 58mm and then ran a die on it to create two threaded ends. I used nuts and washers as stoppers for the bottom and the shoulder at the top for the ignition case and damper post plate. It worked fine but the bolts I bought were grade 5 and I thought that was a bit soft so I made a couple of studs out of stainless. The oem studs are 50.37mm long and the base plate that I was adding is 6.25mm thick so I made the studs 58mm so I had a little length because I like to taper the rod end a little when I am going to run a die. My lathe is SAE so the lengths of each section I cut are: top - .756". Center - .794". bottom - .694". Most people won't have a lathe and so that's why I showed the bolt modification. Just try to find a grade 8 is all I would say.
For the bar clamp I cut a 3" piece out of my 2" x 1" bar. I drilled a 1" hole about 1/4" from an end then drilled holes where I would be inserting mounting bolts with a 5 mm bit. I then cut the part across the center of the hole I drilled. I knew that I would be routing the mounting bolts from the back of the clamp so drilled the holes out a bit more on the bolt insert side so that 6mm bolts would slide through easily. I then tapped 6mm threads into the larger end of the clamp. The handle bars are tapered at the point where I would be mounting this clamp so I used a die grinder to shape the 1" hole a bit closer to the taper of my bars. I just held the clamp on the bar with my damper to find an estimated angle to shape the mounting surface for the damper rod end. I don't have a mill so I just used (obviously) a side grinder with grinding wheels and sanding pads to shape the clamp. I drilled a 7mm hole and tapped for an 8mm mounting bolt for the damper. For both the rod end mount and the damper body mount I bought 8mm x 45mm bolts so that I would have shoulders for inside the damper balls. I cut them to about a 25mm length. I wanted stainless but my bolt supply doesn't have any in stock. I will find stainless and replace them. I mounted the clamp with rubber against the bars. For my center post I cut a 87mm length out of my 2" x 1" bar. I drilled and tapped for 2 - 6mm mounting bolts to mount the bottom plate and an 8mm on top for the mount of the damper body. I shaped the bottom plate to fit around the ignition housing and to give clearance between the plate and my handle bar mounts. Check yours but my studs are spaced 54mm apart. I mounted the post to the plate and got my side grinder out and shaped it so that there is clearance from my handle bar mounts.
With this setup I am using 1 1/4" or about 31.5mm of stroke of the 63mm stroke damper. Honestly I was hoping to find a combination of angles to use a little more but couldn't find one. I think I am using the maximum that is possible with the top mount based on what I have seen in videos of others installations.
My bike has risers so lengths may differ if you do not have risers.
To repeat, I know this is not a pretty build but it works very well. It is super stout and there is no flex at all. You use this information at your own risk.
Last edited by syazoo; 08-28-2019 at 05:27 PM.