RVF fork settings

[speedy231278]

Having finally done the seals on my forks this morning, I'm after a bit of advice on setting them up right. At some point I'm probably going to invest in an RO revalve and repsring kit, however I figure it's a bit wasted if I don't know what the hell I'm doing with it. I did the seals because the forks I got that had allegedly been rebuilt and fettled for a rider of my weight. After taking them apart I think the person who sold them to the person I got them from was telling tales. As far as I can tell, they are completely stock internally. When I fitted them to the bike, the preload was wound right out, and the damping rod adjuster was a couple of clicks from fully out. They were very firm, almost harsh, but gave a smooth if slightly understeery handling characteristic. Right now, I have the preload would right out, and the damping turned all the way out, then back around so the punch mark on the adjuster is aligned with the one on the fork cap.

One thing bothers me. The stock oil fill is 445ml. I got barely 350 out of either. What effect would such a drastic reduction in oil have on the characteristics of the forks? I'm off for a ride now, so I'm hoping the extra doesn't make it outrageously stiff. One of the legs has a tell-tale o-ring on it to show fork travel, so I'll be able to see how much I have spare.

[speedy231278]

Right, have done about 50 miles. I've not given ultimate grief to the front end, however it's had a few good tugs on the anchors. According to the ring on the fork leg, I've used about 50% of the travel, assuming the fork will bottom out just before the dust seal can collide with the lower leg. Steering is nice and neutral, although the new tyres might be a help there. Over general undulations the front end is firm, but not excessive. However, it is extremely harsh over significant lumps, bumps and holes in the road that I've failed to miss. Any tips?

[magg]

Oil level normally sets the spring rate under very heavy compression, ie last 10-15mm of travel. Helps stop bottoming, although this does not appear to be an issue for you. What oil did you use and how much, how do you know that the valving has not been changed. Are the springs std. Have you measured the static and rider sag.

[skinnydog0_0]

It sounds like the rebound damping may not be working. if the fork cant pass any oil through the damping holes it would feel very wooden and stiff. The more air you have in the fork the more cushion you get towards full fork compression (as Magg has said) as the air compresses and oil doesn't.
I have racetech gold valves and race springs in mine, and it feels firm, but it glides over bumps and even under very heavy braking it still tracks the road and deals with bumps very well.
Wing the rebound and preload right out, and see what it feels like (should be like a pogo stick)
then go the other way right in for both and see what it feels like (should be more wooden and harsher under braking)

[speedy231278]

I haven't done any measuring yet. Everything inside the forks looked like the stuff pictured in the Haynes, however after I posted the above I took my old forks apart to check them and I am not entirely unconvinced that something hasn't been altered somewhere along the line. I wasn't really looking out for it, but I don't remember if I saw whatever you would call the part that is attached to the damper rod inside the spring. On the exploded diagram, it is show as being very close to the bottom of the damper rod where it enters the tube at the bottom of the assembly (just above the '17' on the diagram), but on the old fork I took apart it was about half way up it.

The Haynes doesn't go into details such as the valves, and to be honest I didn't have anything suitable to compress the spring with to help remove the top cap from the damper rod. I also read horror stories about locknuts on the assembly and the exact positioning of it affecting the number of clicks you get on the adjuster. I believe there should be 15 from one extreme to the other if it is attached in the right position. I counted 19 on one of them and 25 on the other. The old fork that I tested had 9! Clearly there is some work to be done here. The bike is not unrideable, it's just rather less comfy in certain situations that I would like. Therefore, as time permits, I have the luxury of being able to pull the old forks to bits in order to work out how to get the damper assembly set correctly when I have the right tools. I used 450ml of Castrol synthetic 10W fork oil. At least when I've worked out a decent method of getting the top nut off the damper rod I will be able to have a play about and see how such things are affected. And now for the most stupid question of all, where exactly in the whole scheme of things will I find the valves? I cannot find any pics showing exactly where they are located and I keep convincing myself of various locations, most of which are probably stupid!

[magg]

The compression and rebound valves are inside the cartridge. What tool are you refering to for compressing which spring?

[skinnydog0_0]

The valves are at the bottom, you have to drill out the punch marks at the bottom of the damper rod housing that holds the black/grey valve. It looks liek a squashed cotton reel, and from memory you have around 5 sprung steel shimms against it to act as a damper.
I'll dig out teh standard one i removed from my forks and get a pic.
You will need a long castellated holding tool to get the damper rod assembly apart. I used a piece of steel tube with cut outs to fit the nut. I'll do a pic of that too.

[speedy231278]

The compression and rebound valves are inside the cartridge. What tool are you refering to for compressing which spring?

In order to remove the top nut from the damper rod it is necessary to compress the fork spring so that you can get at the flats on the shaft to turn it and the top nut against each other, isn't it? I've seen it done on a Kwak using hooks and ratchet straps. I suppose the alternative is to have someone heave on it while you do it, but that seems a bit agricultural to me.

[speedy231278]

The valves are at the bottom, you have to drill out the punch marks at the bottom of the damper rod housing that holds the black/grey valve. It looks liek a squashed cotton reel, and from memory you have around 5 sprung steel shimms against it to act as a damper.
I'll dig out teh standard one i removed from my forks and get a pic.
You will need a long castellated holding tool to get the damper rod assembly apart. I used a piece of steel tube with cut outs to fit the nut. I'll do a pic of that too.

Would be handy. I don't really fancy doing surgery on the cartridges, I'd rather just swap them out for ones fettled by RO!

[skinnydog0_0]

Yes if you watch this vid, it gives a good idea (although the forks are not exactly teh same) on how you need to do it.
On a side note - i will be braking my race bike mid september so the forks will be for sale if you get stuck.

http://www.youtube.com/watch?v=W2G-b66F3es

You need to watch all 3 vids :)