'95 R100R Ohlins problem
My '95 R100R has an Ohlins shock installed by the previous owner. There is a serial number on the spring that reads 1096-24/80 487, and a number on the plate at the bottom of the spring that reads 629-01. I recently had the shock recharged and the bushings replaced. I have the pre-load set to maximum. The problem is the plate at the bottom of the spring hits the paralever. I'm not sure if it's under compression or extension. I'm not talking about "catching air" or major "whoop-de-doos". Just normal spirited riding. I cannot feel when it hits and the bike rides great, but the clamp holding the boot in place and some of the aluminum is being damaged. Any ideas or suggestions as to whether or not this is fixable. Many thanks.
Can you mount the shock the other way around and would it make a difference if you did?
The plate hits the paralever?...sure seems like the spring sticks out further? Can the spring be rotated such that the gap in the spring or a different curved part of the spring is nearest the paralever? I wonder if it would be possible to exercise the shock manually so that you can really visualize what might be happing.
I have the same shock on my '91 GS and do not have this issue. Looks like the static position of the swing arm is too high... Thinking the sag setting is not right or someone tried to lower the bike through a shorter spring and preload adjustment as it does not look you have much adjustment left to increase the lift on the shock adjustment.
I'm going to guess it hits under compression.
The numbers on the spring indicate its rate and free length. The number on the collar is a part number.
- Do you know if this was happening before?
- Is it the same shock? Even at full compression it shouldn't touch anything.
- Is it the same spring which was on before? Its been known to happen that, during the rebuild process, one spring gets mixed up with others.
- If yes, are you sure its at max preload? From the picture it looks like there's only about 3/4" preload in there. Ohlins typically have a lot of thread with which to play.
- Do you have the stock shock with which to compare this one?
- Has the bike somehow been lowered? Different torque arm?
Thanks for all the helpful suggestions. Rotating the spring does not make a difference. The remote hydraulic pre-load is set to maximum, I have not adjusted the mechanical pre-load. Can I increase the shock length with the mechanical pre-load? I think that the shock has been hitting the paralever since I bought the bike, although it took some time for me to notice any damage to the paralever. I hadn't considered that the spring may be short. I am currently looking for someone who can decifer the serial number to determine if it is the appropriate spring. My guess now is that I may be able to solve the problem by increasing the length of the shock. I am always impressed with the quick responses from you all.
Have you thought about calling Ohlins? In my experience, an engineer has gotten on the phone with me to discuss the application and provided relevant solutions.
These shocks take up quite a bit more room than their stock counterparts.
Have you considered that perhaps you have the incorrect part for your bike?
why do you have it set for max preload on the remote adjuster? you should only be doing that if you are carrying max load (2up, all the gear for touring)- which implies that you either have an incorrect spring for your weight, the basic maechanical preload is incorrectly set, or possibly the shock is not the right one for the bike.
ascertain from Ohlins that the spring is matched to you, and shock is matched to bike, then proceed from there, including the ALL important setting of correct sag.
I called Ohlins USA, left a message with an engineer to call me back regarding the spring and whether or not it's correct. I agree that's the best place to start. The remote pre-load was set at maximum only to determine if it would fix the problem of the shock hitting the paralever, it didn't. Mechanical preload has not been adjusted. If the spring is too short that may be the issue, on the other hand, it also may be why I've had no driveshaft issues in 90k miles. ;)
[QUOTE=bikerfish1100;860025].....the ALL important setting of correct sag.[/QUOTE]
Agree that this is important. Also it is easy to check and a useful data point for review with the Ohlins guys.
Step 1 SET SAG!!! Set the loaded sag properly then make sure you have some static sag (just the bike weight compresses the shock slightly)
If you can set the sag properly, the spring length makes NO difference. It is the spring rate that determines travel, not the length. (note length and coil thickness do effect spring rate) but SAG measurements will determine that.
You mentioned bushings were replaced, were you talking about the eyelet bushings at the mounting points?? If they were bad, it could definitely cause the clearances to change.
Most shocks I have seen have a "bump stop" on the shaft, which is a cone shaped cushion that stops the shock from slamming hard parts over a large bump, it limits the travel too, and I cant see one in your pictures, if it is missing it could cause the shock to over compress, if it were designed to have one.
It is obvious the damage is occurring as the rear suspension is compressed and the angles intersect. If all the other stuff is correct, the only other solution is to see if ohlins made different spring seats, that would move the spring seat further up the shaft. I have no clue if this is something they make, but with the multitude of applications I would think it is reasonable that different ones exist.
My opinion is that something is seriously wrong. That shock should not bang on the swingarm with any setting from full hard to full soft at any point in its range from fully compressed to fully extended. That kind of impact load puts a hammering shear force on the lower shock mount stud, which could if extreme break the stud.
From looking at the picture it appears that the impact happens when the shock is fully compressed. It looks like the shock is too short for the geometry of the Paralever setup. Does the bike per chance have a shortened lower control arm? If the control arm is shorter than OEM it will roll the entire final drive counterclockwise viewed from the right side as in the photo. If so, that places the shock mount lower relative to the back of the swingarm.
Something is not right, I think it's the spring (although the paralever link is a good possibility as well). If you can use this picture from my '90 R100GSPD as a guide you will notice that the spring has more turns (it seems to me that the spring continues up under the side cover) and I think that the coils are thicker. Of course I don't know if the R100R used a lighter spring. This is the only picture I have and the bike is in storage so I can't get at it for any other pictures or to get spring numbers.
Here is the same shock on my r100gs.
Off the centre stand, no load.
[QUOTE=grahamm;860639]Here is the same shock on my r100gs.
Off the centre stand, no load.[/quote]
Does your shock have a bump stop? (the tapered rubber ring on the shaft inside the spring)
Paul's question is valid too. Spring length by itself, does not effect travel, a shorter spring with smaller diameter stock, can have the same spring rate as a longer spring with bigger stock.