silverbird1100 Posted December 26, 2007 Share Posted December 26, 2007 I started with .95 springs, 5 wt oil and c33 stack . It was too soft and went to 7wt and c34. It's still wallowing in fast corners but pretty good in tight ones with sharp bumps. Anyone else had to go up to c35 and beyond? Quote Link to comment Share on other sites More sharing options...
bartonmd Posted December 26, 2007 Share Posted December 26, 2007 Your weight will matter... I am very happy all around with what RaceTech reccomended... I have 1.0 springs, and 5W oil, and whatever damping stacks they said to use for that spring rate and oil... Mike Quote Link to comment Share on other sites More sharing options...
MrBadExxample Posted December 26, 2007 Share Posted December 26, 2007 I have 1.0 kg springs and 10wt fork oil. I use what racetech recommended for a 200# moderate street rider . Quote Link to comment Share on other sites More sharing options...
silverbird1100 Posted December 27, 2007 Author Share Posted December 27, 2007 I have 1.0 kg springs and 10wt fork oil. I use what racetech recommended for a 200# moderate street rider . c33 or 34 is probably what they recommended, I wonder why mine is so soft? Quote Link to comment Share on other sites More sharing options...
Pat830 Posted December 27, 2007 Share Posted December 27, 2007 Me too. Works well. Mike did good. Now, if I could only ride as good as my valves do their job. If you need any advice about installing an Ohlins in backwards the first time, just ask. Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 Yes I went beyond. I use 2.5 wt oil and shim like so: (4) .15x17 - Low speed damping .10x9 - spacer (2) .15x17 - Med speed damping .10x9 - spacer (2) .15x17 - High speed damping then the: 15 13 12 11 10 9 normal RT stack finish I used to be fatter and did a 5,3,2, L, M, H shim stack basically a C40 (even though one is not listed in the instructions) _________________ _________________ _________________ low speed damping for the small bumps (soory my indent did not work) _________________ _________ _________________ _________________ medium bumps pick up these shims _________ _________________ _________________ big nasty bumps hit this high speed damping area ______________ ____________ __________ _______ What is your fork oil level? How's your sag look? How big a pre-load spacer do you have in? Quote Link to comment Share on other sites More sharing options...
silverbird1100 Posted December 27, 2007 Author Share Posted December 27, 2007 I'm a little confused, with the _______________ reference Low speed damping hits closers to the valve and high speed towards the top? I don't recall using spacers either, how does that wrok? If that's correct THANK YOU. I understand how complex it is but for street application on a 560lb bike, it's not rocket science like just about everyone I've asked has implied. Anyway I'm using the stock oil level, preloading the spring a lot, I don't remember how much but it's more than racetech recommendes and getting 35mm or more of sag with that. I'd go with 1.0's but only if the difference would be worth the $$. It's definitly riding in the bottom of the stroke but isn't a symptom of that riding stiff, not soft? Thank you very much! Quote Link to comment Share on other sites More sharing options...
bartonmd Posted December 27, 2007 Share Posted December 27, 2007 I'm a little confused, with the _______________ reference Low speed damping hits closers to the valve and high speed towards the top? I don't recall using spacers either, how does that wrok? If that's correct THANK YOU. I understand how complex it is but for street application on a 560lb bike, it's not rocket science like just about everyone I've asked has implied. Anyway I'm using the stock oil level, preloading the spring a lot, I don't remember how much but it's more than racetech recommendes and getting 35mm or more of sag with that. I'd go with 1.0's but only if the difference would be worth the $$. It's definitly riding in the bottom of the stroke but isn't a symptom of that riding stiff, not soft? Thank you very much! That's probably your issue... If the spring is too light for you, their formula will not work right... You will have to over-damp it a bit to make it not as spongy... I have "correct" sag with the 1.0 springs, with literally almost no preload on the springs, when the threads start, so maybe 5mm of preload when the caps are all the way on, tight... Mike Quote Link to comment Share on other sites More sharing options...
silverbird1100 Posted December 27, 2007 Author Share Posted December 27, 2007 So going from .95 to 1.0 would be enough to make a difference, right? Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 If you bought gold valves then this should look familiar as it is from the instruction sheet. For reference lets look at the overall cutaway too. keep in mind the XX is blessed with comp and reb valves that are not externally adjustable. So here is our Showa typical cartridge fork with compression and rebound valves all parts labeled. Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 Our stock compression and rebound strokes look similar to these. You my have to look at them for a bit to see what happening as this is the low speed or small bump reaction. But Paul Thede (all honor, glory, and praise be to him for these) has been kind enough to label the oil containing parts. The Compression Stroke flows from A to B to C to D (D - remember is the portion of the fork above the cartridge where the spring is) The Rebound Stroke flows from B to D to C to A Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 Now if you look at the high speed stroke (big, nasty, square edged bumps) pictures you can see a little more takes place. Note how the shims get tweaked on the highspeed stroke. Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 So what if we just threw out Mr. Thede's c## code system for shim stack design as described in the instructions and played a little with it? Lets add a smaller diameter spacer to the compression valve shim stack and create another level of damping. Quote Link to comment Share on other sites More sharing options...
silverbird1100 Posted December 27, 2007 Author Share Posted December 27, 2007 O.K so it's a little more complicated than I thought So with your shim stack, what are your other numbers and how much do you weigh? I only weigh 165 but carry around 30 lbs sometimes. I'll also be getting some 1.0's soon. Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 So what I did was just add one more spacer to create yet another level of damping. I've had my forks apart so many times I cant count them. I did a. 5, spacer, 5 stack a 2, spacer, 8 stack a 3, spacer, 7 stack and then it hit me..........Why must I limit myself to one spacer..... so then I did a 2,4,4 stack a 3,3,4 stack and I finally (currently is more accurate) run a 2,3,5 stack (oh sh!t or is it a 5,3,2.............oh well I'll have to check the BB log and get back to yas on it) The point I'd like to make is that there are only 3 forces that act on our suspension (yes 4 if you count gravity) FRICTION - We hate it so we keep our linkages clean and the oil fresh thus keeping the friction as close to zero as possible. SPRING - with a straight rate spring this force is constant so easily managible. DAMPING - This is the force we should be most concerned about as this is ultimately how we get the rubber to stay on the road. Quote Link to comment Share on other sites More sharing options...
dunedain Posted December 27, 2007 Share Posted December 27, 2007 O.K so it's a little more complicated than I thought So with your shim stack, what are your other numbers and how much do you weigh? I only weigh 165 but carry around 30 lbs sometimes. I'll also be getting some 1.0's soon. No, no no! The point is that this is not that complicated at all. I was just trying to point out that if you are truly "wallowing" due to the damping in your gold valves you have options. That's why I asked about the sag, and oil height and I forgot to mention you must balance the front and rear. A really stiff rear can push the front around madly. Wallowing comes from the following: oil level too low not enough low or high speed compression damping spring rate too soft not enough pre-load dirt in valving, broken, bent or a bur on the piston damping rod bushing worn out compression valve o-ring broken damping rod not attached to cap I'm a motorcycle racer trapped in a lumberjacks body. 275#, 1.0 kg/mm, 10mm pre-load, spring in the front with 2.5 wt. oil and a 5,3,2 stack on my compression valve, I only added one shim to my rebound valve and I got 27mm sag. I have an Ohlins on the rear and a big nasty spring on it and my damping turned way down soft. There are some super smart suspension folk out there and they all have one thing in common.......they like to treat this stuff like it's some black art or something. "You can do it!" Yes I'm on vacation but if you guys want more info than you'd ever care to view on this stuff I'll keep posting. Quote Link to comment Share on other sites More sharing options...
silverbird1100 Posted December 27, 2007 Author Share Posted December 27, 2007 There are some super smart suspension folk out there and they all have one thing in common.......they like to treat this stuff like it's some black art or something. Exactly. Now me being a light weight can you recommend a stack that will keep me from wallowing but still ride like a sportbike? Oil level, shim size, spacers the works. I have a Penske rear that works really well so I'm good there but still pretty lost on what you think I should use as a baseline in my forks. Thanks again, it's nice to not have to deal with the guys you described above. Quote Link to comment Share on other sites More sharing options...
bartonmd Posted December 27, 2007 Share Posted December 27, 2007 So going from .95 to 1.0 would be enough to make a difference, right? I just saw that you weigh 165... .95 is probably the right rate for you... What did the race-tech website say for your weight? Also, if you have exactly what they advise for your weight, it may be a little bit soft for REALLY hard riding, but should not feel like a pogo stick... If it feels like a pogo stick, you might check and make sure you don't have a spring that's bound up in the check-plate on the valve, keeping it open, and negating one way (rebound or compression) of the damping of one of the forks... Mike Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.