I'm ready to change the oil in my forks. I reading the manual for SP1, and don't understand these numbers. Picture below.
Is Motul 5w to light?
All I want to do, since my seals dont leak, is change the fluid and see how it acts. Then maybe springs and valving, but that's for later. I just want to see how the factory set-up will work with fresh oil. I chose 5w at the recommendation of Robert at WestCoastMotors in Citrus Heights. Does that sound right to you guys? I'm about 185 lbs. with gear.
1) You get yourself something like this
that it measures up to 500ml (half a liter).
2) Take off the top nut of the suspension like the manual says. Pump it up side down so that is spits all the old oil in a pan
3) At this point, I use clear gazoline (not fuel like, more like stain cleaner for pants like) to wash the tubes inside.
It does NOT harm the oil seals or any other rubber part inside. Guarantied.....Then again, you can choose your own cleaner, you're comfortable with.
All that matters is to get the "mudy" stuff out of the forks (if any).
You pour it inside each fork and pump it so that the cleaner can go through the hydraulic holes and clean everything. Then discard it. It evaporates very fast, that is why it doesn't damage anything inside the fork.
4) Your bike is SP1 so you will follow the '00-'01 dose in the manual (longer tubes than SP2)
You measure 500ml and you pour it in the tube. Then you measure 15ml and pour it in the same tube and your done.
The manual says 513 plus/minus 2.5ml and that's because the oil's volume changes with the temperature's variations. I would make sure that the oil is stored at 20 deg. Celsius the last 24 hours before measurement and I would use 515 in each fork. That amount of oil is just fine for a commuter, all rounder bike.
My oil choice would be (in preference order):
2) White Power
3) Bel Ray Fork oil
I've also heard really nice feedback on this fork oil
However, no matter the brand, I would go for a 7W SAE oil because where I live we have smooth winter conditions and very hot summers. If that's your case too then Madbuyer is right you know. The 5W is too thin for a commuter bike and you will have to change it again next spring.
In my RC right now, I have used Bel Ray 7W fork oil and it is almost 3 years that I replaced it. An my suspension still work fine (not 100% though but it covers my needs). I am planing to change them next winter with Ohlins 7W along with fork springs set.