Posted on Thursday, September 23, 2010 - 07:09 am:
I should be speaking with my contact from Ohlin's in the next few days, I will definitely pass these questions along. I know that the guys are working on a better spring set up for us, one that uses shorter straight wound springs with a longer preload spacer. This is going to eliminate quite a bit of weight, and also eliminate the crappy progressively wound spring. I will keep you all posted, and thanks for the interest!
From what I understand, the spring is going to be less than half the size of the stock spring. I don't know that the spring would change from model to model, I think it is just going to be the size of the preload spacer. The purpose of the spring is just to combat gravity, therefore it is not necisary to have such a long spring. I have not heard the final word, but I would imagine that Ohlin's is going to make different preload spacers to fit the different length forks?
The shorter they make the spring, the stiffer the spring rate will have to be to support the same rider/bike weight because it will have to do so with a smaller amount of spring compression. And the spring rate does add somewhat to compression/rebound because the spring resists compression and assists on rebound. Which also means the damping has to be able to regulate wheel movement and spring energy. Obviously Ohlins knows more about suspension than I do, but it makes me wonder if they are trying to force a solution using forks springs they already have, not making something specifically designed for our bike.
Posted on Saturday, September 25, 2010 - 04:04 am:
Just road the bike a bit, got home late and took it for a 5 mile spin on the highway. Will do a twisty road ride tomorrow, should be a warm day so I should be able to ride pretty hard.
One thing I noticed is that turn in actually seems slower, probably because the front is considerably stiffer, and the rear went from max preload to 4 (damping stiffened it up, but that wouldn't effect ride height).
So the rear is lower in relation to the front than before. I'll probably drop the front end 5mm or so when I take the wheel off to put slicks on before my trackday.
Did a 100 or so mile twisty ride. Bike feels great. Turn in was great with sport riding position before I was just cruising around. Still need some knobs turned but felt really good especially after a five week hiatus from riding. Rear diablo corsa Rossi tire went from small chicken strips to fully scrubbed and with perfect looking wear. Zip tie on forks still goes down as far as before (near bottom out) when doing stoppies or hard wheelie drops but the linear rate means it's stiffed at top stroke than stock spring. Bit more compression and it shouldn't come close to bottoming at the track. Installing 5mm finned rotor, ebr hardware and EBC extreme performance brake pads.
Then pirellis new pro slick that wears like a brick then two days of amazing lap time dropping.
Vospertw- in regards to your comment about the spring lengths and spring rates, Every spring is designed with a specific rate and stroke no matter how you build them. A 400 pound, 50 foot long spring will perform equally with a 2 ounce spring in it specific designed Parameters. A piece of rubber also has these same characteristics but not for long. The springs designed for your bike need to fit into something so there is an Outside Diameter (maximum w/spring growth), an Inside Diameter minimum to fit around the cartridge, a stroke more than the travel of your fork, and lastly the rate which Ohlins measures in Newtons per millimeter. THe Buell team uses Ohlins 30 mm cartridges in their Big Piston fork Shells. Ohlins springs are also used.