Which fork oil weight should i choose?

[Graugaard]

Hi!
I have seen some topics about this, but still wonder which oil would fit me best. I got a liter of 10w fork oil. However it looks like i should use 5w instead?

Some info about me..

Weight with gear:
170lbs , 78kg

Bike with fuel
363lbs, 165kg

Riding style is standard/touring with aggresive weekend riding.

Stock springs.

Weather is about 63F, 17c in avarge at the spring/summer but can get as low to 46F, 8C.

Which oil weight would you suggest?
Thanks!

[cuong-nutz]

stock is 10w. You could try bumping up to 15w and it'll lessen the bottoming out under hard braking.

[Lychee]

You can also try playing with the amount of oil in the fork. This is measured in mm by sticking a small ruler or similar into the fork. The lower the measurement, the more oil is in the fork. The more oil, generally the more damping.

[tooblekain]

Go with Racetech's Recommendations: 15W with a 140mm air gap

http://racetech.com/ProductSearch/2/...20250R/2008-12

I have emulators installed with the heavier yellow springs and 3 rotations out from their recommended racer settings and I love it...works for me and I have not found the limits of trailbraking.

[Motofool]

Read this:

http://faq.ninja250.org/wiki/How_do_...he_fork_oil%3F

[alex.s]

you could always try it and see how it works out... that way you understand what the changes are doing to effect the ride... and you can then take a few attempts to perfect the oil weight by mixing heavier or lighter oil in

front end feel too stiff? probably should go lighter. feels too bouncey? go heavier. suspension tuning is like engine tuning... there is no universal "right" answer. the answer is always unique to a certain combination. so you'll have to figure out what the exact right answer really is for your combination of factors.

[tubarney]

This is how you tune fork oil.

Take two zip ties and tie one around each fork leg, tight enough that they don't move from vibrations but loose enough that they will not damage the fork seal when the fork compresses.

This will tell you how much fork travel you are using. A 08+ Ninja 250 forks stop 40mm from the bottom triple tree. This will tell you whether you need to add oil or take some out. You want to use the most you can without bottoming the forks.

A cheap tool is a syringe with a piece of rubber hose. Stick a certain amount of hose down and suck the oil out. Now you have your oil set.

The weight of the oil sets your overall rebound and compression. Always use the same brand as different brands have different weights. A 10w Ohlins is not the same as a 10w Motul fork oil.

Don't take peoples recommendations are they will be different for everyone.

If you want to talk preload, this changes where your forks sit in their travel when your sitting on the bike. More preload will give you more fork travel for compression, but less for rebound, so keep this the same when testing fork oil.

[tubarney]

Here a photo of my fork

[alex.s]

if you are being smooth on inputs and still bottoming out, it is not a damping (fork oil) problem. it is a spring rate problem.

[tubarney]

^^what he said. Spring rate should be sorted out first before you do anything

[Graugaard]

Thanks guys great information. Will wait a month before i change the oil then since i cant test itatm during winter. Will try the zipper tricks out. The stock oil hasnt been changed since it was build in 2008 so even using the stock oil should make a different i guess.