RCinNC
Well-Known Member
Changing my fork oil today. Everything is stock. I'm doing the right fork now. I've removed the spring, washer, spacer, nut and collar, so all that's left is the damper rod. The service manual says it should take 505 ml of fluid. I drained off just a shade over 485 ml, after pumping the damper rod until I got no resistance, so I drained about 20 ml less than what's supposed to be in there. I refilled the fork with 505 ml of oil, knowing that I would use my fork oil fork oil air gap gauge to vacuum off whatever excess there might be in the fork. I pumped the damper rod at least 10 times, until I felt real resistance. Then I let the fork sit for 10 minutes. The air gap is supposed to be 150 mm. I have a homemade air gap measuring tool that I can vacuum off any excess fluid in order to set the proper air gap. When I set the 150 mm air gap, I found that I had to pull out 45 ml of the fork oil that I'd just put in.
So if I there was 20 ml left in the fork when I drained it, and I added 505 ml, that's a total of 525 ml in the fork. In order to set the air gap I had to drain off 45 ml, so now there is 480 ml in the fork.
The service manual says that if the air gap isn't correct, to "make adjustments", which I assume is to either remove or add oil until the air gap is right. My question is, which is more critical, the amount of fork oil or the air gap? My instinct is that the air gap should be correct regardless of the amount of oil, since if the air gap is according to spec then it means you have enough oil in the fork, no matter how much you've added or pulled out. But I've also read that too much or too little oil can cause problems too. I'd like to hear from someone more knowledgeable than I am about this.
Apologies if I sound like a moron, but like I said, this is my first time at this, and I'd hate to get it all done and back on the bike and then find out I'd messed it up (and worse yet, possibly caused a handling problem).
So if I there was 20 ml left in the fork when I drained it, and I added 505 ml, that's a total of 525 ml in the fork. In order to set the air gap I had to drain off 45 ml, so now there is 480 ml in the fork.
The service manual says that if the air gap isn't correct, to "make adjustments", which I assume is to either remove or add oil until the air gap is right. My question is, which is more critical, the amount of fork oil or the air gap? My instinct is that the air gap should be correct regardless of the amount of oil, since if the air gap is according to spec then it means you have enough oil in the fork, no matter how much you've added or pulled out. But I've also read that too much or too little oil can cause problems too. I'd like to hear from someone more knowledgeable than I am about this.
Apologies if I sound like a moron, but like I said, this is my first time at this, and I'd hate to get it all done and back on the bike and then find out I'd messed it up (and worse yet, possibly caused a handling problem).
