Like I say not that happy at how it was done but bike is fine, at my current pace, this is just a learning thing, not because I'm having issues but because I'm off to cartagena in a week and going to have a fiddle ;-) especially as I expect to be going considerably faster this time out
Rebound is such a feel thing. You can set everything else with measurements and tie wraps etc but how the suspension comes back to its normal position is hard to set, very subjective. I was always looking for balance between front and back in terms of speed of return, usually starting at the front by setting to get a good transition from hard braking to hard on the gas without the top yolk flying up and unloading the front, or traction at the back accelerating and on the brakes. I changed it quite often depending on how tight or bumpy or smooth the surface was. I found it only needed a few clicks either way to make a big difference to how the bike behaved (TZ 250 V twin with Ohlins). Once I had a base setting (along with all the other variables it was pretty easy to work out what needed doing. Don't want to sound like I'm teaching my Granny to suck eggs cos you seem to be well experienced on track, if you are happy with your sag, ride height, compression etc and feel rebound is somewhere near do the old push the back of the tank down to compress both ends and see how they return. I always wanted it to be pretty much the same at both ends. Then on track I started with the front. What did it feel like turning in leant over coming off the brakes onto the throttle? If it was coming back to hard and unloading the front or running wide add a bit to the front, tucking, take a bit off. At the back I was looking for stability especially on bumpy bits, but this was more dependant on what compression settings were on in relation to track surface, generally pattering on entry or exit more rebound less compression. Have you got datalogging? Movement sensors will tell you a lot and confirm (or otherwise) what you think you feel. My bike only weighed 110Kgs all fuelled up so small changes made big differences but rebound was really important for being quick. Best of luck, OGR
Would a heavier rider need less rebound ?? Surely he needs more preload to compensate for the weight and hence an appropriate amount more of rebound to compensate for the extra ?? Davy
Preload is a different issue. A heavier rider needs less rebound than a lighter rider simply because there is more weight acting against the spring, slowing it's extension. It's not a certainty that increasing preload demands an increase in rebound. Will a spring rebound harder if it has more preload? I don't know the answer to that I'm afraid.
Ok, I've looked it up, and sure enough I have a headache now:frown: I can only tell what I was told by a suspension expert, and he said fat fkers need less rebound. So there.
The SHM, thats mostly to do with the spring. Look up damped oscillations. damn I used to love these when I was at Uni.
My understanding is: Preload sets the static sag............. On mine, the static sag should be about 26 - 28mm............. That's the amount the front end drops from fully extended to the fully clothed rider sitting on the bike with feet off the ground. Rebound and compression settings are completely different to preload. Dive, for example shouldn't be corrected by preload adjustment, but by compression damping and in general, rebound setting should be similar to compression. AL
Not sure if problem is me or new bike. It turns slower than I expect and does come back a little sharp off the brakes compared to my old race bike. I have settings written down but think I'll add 2 clicks of preload and see what happens. Like I say tyres are super clean so don't want to upset it too much...but my question has been more than answered
From my experience I would expect suspension settings would have very little effect on geometry............If you want it to turn faster, lower the profile of the front tyre, or drop the front end or increase the rear end....... My SS turns very quickly because my front end is pretty low..... AL
No because adding preload doesn't change the spring rate. That's set at the factory. At least that is my understanding. Preload should only be used to make sure you are using as much of the suspension range as possible without the bike topping out or bottoming out.
There is a great book worth buying which explains suspension working and set up in as simple a form as you will ever get it IMHO. http://www.amazon.co.uk/dp/1893618455/?tag=ducatiforum-21
