Situation: Bought as is- 99 SV650 forks Revalved by Traxxion .9kg springs oil weight ?? Old rider weight/riding style unknown New rider- weight ~170lbs former 250 racer (rides front end hard) Replacing fork oil for new season. Any thoughts on recommended starting fork oil weight? Cheers, Scott
Agree, 20wt is a good place to start, even 30wt if you don't have emulators. Use one of the thicker brands like Bel Ray or Spectro.
There really isn't anything to re-valve in SV forks. So you've (probably) gotta have emulators... If you have emulators then you'll most likely want 20W fork oil. If you tell Traxxion the name of the previous owner they'll be able to tell you what you need as well...
Oh - like dsting mentioned there are different "weights" by brand. I always used the BelRay 20W myself...
As suggested first call traxxion. Here is a useful site that helps explain real "weights". See the chart at the bottom of the page to help make your selection. For reference I use Silkolene Pro RSF 10 and 15 mixed 50/50. This is roughly the same "weight" (70.2cSt@40C) as their normal 20wt (67.7cSt@40C) fork oil. Oil Weights
Gents, Thanks all for the input. I was thinking along the same lines, ie. 20wt. Good to hear I may not be off the mark. Also, roger, on there are subtle differences between brands. Cheers, Scott
ALCON, I would like to share with everyone the fact that Traxxion PM'd me upon my first starting of the thread, and have been very helpful in getting me sorted out. Unsolicited KUDO's go out to Traxxion for their assistance. Cheers, Scott
Also, be aware that racing in cold temps is going to be tough with 20 wt. I changed mine from 15 wt with emulators before Tally. It was really cold at tally and the thing was chattering through the sweeper and tore of up the front tire pretty good. I will most likely leave it in there for Savanah but I may just switch it back to 15 as it never chewed up a tire like that on 15 wt. If your season starts cold, go with the 15wt.
I run 20 weight if the ambient temp is under 70F and 25-30 weight if the ambient temp is over 70F. I always use Bellray or Spectro fork oil.
This is why it is important to pick an oil with the highest Viscosity Index rating possible. See the chart that I linked to above. The higher the number the less the viscosity of the oil will change due to temperature changes. This is part of the reason I am switching to Silkolene's Pro RSF fluids. This is even more important when dealing with shocks as they generate a lot more heat than forks do.
I agree with RISING. 20wt. is not always the same between brands. Stick with one brand and experiment from there. The Silkolene Pro RSF and Redline products are the best from my experience. Another advantage of a high Vis. index is that it will also last longer. Right below that chart is a mixing chart link if you want to customize your own weight fluid.
