spannerman Posted May 21, 2014 Report Share Posted May 21, 2014 is there a post or a link to a suspension site anywhere, im looking for a bit more traction from the rear of the trackbike but every site i seem to go on doesn't fill me with confidence. they all talk of the back of the bike squatting under power yet i am sure the rear extends under power, i think i read this somewhere and have witnessed it rising on the dyno as power is applied. am i getting it wrong. sag seems to be as close as i can get to what is reccomended, springs are suited to my weight and i have dropped a little rideheight from the rear, im wondering if rear compression or rebound is the way to go to stop the slides which are low speed ones. Link to comment Share on other sites More sharing options...
Jenny Pryde Posted May 21, 2014 Report Share Posted May 21, 2014 Try dropping a little more ride height to put more weight on the rear. If that sorts it, great. Otherwise, experiment with a very small amount of extra rebound damping.* *If this doesn't work, try sitting cross-legged in the Lotus, chanting Om Mani Padme Hum repeatedly. Perhaps the Universe will help you to come to terms with it. Although, it is more likely that the management will call the police and have you thrown out of the Lotus dealership. Link to comment Share on other sites More sharing options...
Superdunc Posted May 21, 2014 Report Share Posted May 21, 2014 What you are witnessing on the dyno when the rear rises is the torque reaction of the swingarm, and the chain pull. you can only change this by moving swing arm pivots or counter shaft positions, and to a lesser extent front sprocket size, swinger angle will also effect this. It's not the work of a moment, and you really need to know what you are doing when you start playing with these factors.What you don't get on a dyno is weight transfer from forward acceleration. The weight transfer rearwards, loads up the rear suspension and counter acts the rising effects explained above. Ideally the should cancel each other out and the rear damper will only move to absorb bumps.If the bike runs wide on exits the rear is squatting to much on the power, so you need to stiffen the rear spring or compression dampingif you have traction problems the rear isn't squatting enough so you need soften the spring or compression damping,If you can feel the bike squatting at the rear on the power but still have traction issues,I would look to reduce the rebound damping.I am only a Suspension Gnu, so my opinions may not be valid. Link to comment Share on other sites More sharing options...
porter_jamie Posted May 21, 2014 Report Share Posted May 21, 2014 Wot dunc said. Also racetech website is your friend. Link to comment Share on other sites More sharing options...
spannerman Posted May 21, 2014 Author Report Share Posted May 21, 2014 What you are witnessing on the dyno when the rear rises is the torque reaction of the swingarm, and the chain pull. you can only change this by moving swing arm pivots or counter shaft positions, and to a lesser extent front sprocket size, swinger angle will also effect this. It's not the work of a moment, and you really need to know what you are doing when you start playing with these factors. What you don't get on a dyno is weight transfer from forward acceleration. The weight transfer rearwards, loads up the rear suspension and counter acts the rising effects explained above. Ideally the should cancel each other out and the rear damper will only move to absorb bumps. If the bike runs wide on exits the rear is squatting to much on the power, so you need to stiffen the rear spring or compression damping if you have traction problems the rear isn't squatting enough so you need soften the spring or compression damping, If you can feel the bike squatting at the rear on the power but still have traction issues,I would look to reduce the rebound damping. I am only a Suspension Gnu, so my opinions may not be valid. gnu i fuckin lovit* *not norman lovit that would be something else Link to comment Share on other sites More sharing options...
spannerman Posted May 21, 2014 Author Report Share Posted May 21, 2014 cant feel it squating, it doesnt run wide on exits under power so i think you are onto something, it seems to be very pointy ie. the steering is fine goes exactly where you point it or want it to go its just loose at the rear. ie not enough weight / grip / traction. running supercorsa sc2 30psi cold with warmers, and its sliding driving out of negative camber hairpins (really tight hairpins) bike is a bastardised zxr 400 70brake at the wheel Link to comment Share on other sites More sharing options...
Superdunc Posted May 21, 2014 Report Share Posted May 21, 2014 Drop the rear tyre pressure. 27 psi hot. Link to comment Share on other sites More sharing options...
spannerman Posted May 21, 2014 Author Report Share Posted May 21, 2014 so what would you run the front sc1 on warmers Link to comment Share on other sites More sharing options...
Superdunc Posted May 21, 2014 Report Share Posted May 21, 2014 30-32 hot. Link to comment Share on other sites More sharing options...
spannerman Posted May 21, 2014 Author Report Share Posted May 21, 2014 cheers dunc ill try that on tuesday, and if its no better ill try a tweek on the damping Link to comment Share on other sites More sharing options...
suspensionsmith Posted May 22, 2014 Report Share Posted May 22, 2014 Yep sounds like the high rear tyre pressure is the problem....now you may be able to get harder on the gas and a whole new set of issues will present....ahhh the lovely world of suspension/bike setup. Link to comment Share on other sites More sharing options...
spannerman Posted May 27, 2014 Author Report Share Posted May 27, 2014 all hail the suspension guru's allthough it was damp tonight and the broken ribs are still healing the bike was a revelation i do think that in the dry it may need a bit more but congratulations to all you who know your stuff. to those who may have been winging it congratulations like me you have learned as well Link to comment Share on other sites More sharing options...
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