WP advice

[Brian VT]

I measured all my shims. MX-Tech sells all of them except:
6mm x 10mm x .2mm
6mm x 11mm x .15mm
8mm x 24mm x .4mm
I guess I'll just throw the old ones back in ?
Do these stacks sound OEM ? I assume the "rebound" is since I had to file the lock off. The previous owner said he had changed the valving ? Any advice/recommendations before I order shims ? I was content before I got into this, except for a leaking seal, but would make a change if advised by you pros.

Rebound:
14 x .1 x 6
16 x .1 x 6
18 x .1 x 6
20 x .1 x 6
12 x .15 x 6
24 x .1 x 6 delta
24 x .1 x 6 delta
Check: (4x) 24 x .1 x 8 i.d.

Compression:
Check: 24 x .4 x 8 i.d.
10 x .2 x 6
24 x .1 x 6
11 x .15 x 6
20 x .1 x 6
18 x .1 x 6
16 x .1 x 6
14 x .1 x 6
10 x .2 x 6
11 x .15 x 6

 

[Brian VT]

The KTM and Husaberg guys recommend drilling a 5mm hole through inner leg "to halt air bilging". Your opinions please ?

 

[Dave]

Your compression stack is far from stock. Glenn posted his '03 OEM stack on Talking Smack which is the same as what my '03 had.
24x.1
11x.15 (crossover)
22x.1
20x.1
18x.1
16x.1
14x.1
11x.2

 

[Brian VT]

This place has a large list of available shim sizes:
http://www.mei-inc.com/machine/shim/

 

[GMP]

http://www.racingsuspensionproducts.com/

This guy is in CT. He used to own CCycle suspension, now just sells components. Good service, I've delt with him before.

 

[Brian VT]

I'm getting there. I like learning how stuff works but the fear of screwing up makes for slow going.

1-It seems I have no preload. When I screw the top cap with the 2 white nylon spacers (9.8mm total) onto the rod, hand tight, there is @ 1.5mm space to the spring. Do I need more spacer or do I need to crank down on the top cap more ? I'm afraid I'll trash the o-ring in the cap by over-tightening before I get some preload.

2-There is no mention of the o-ring on the rebound adjuster tube in the manual. Do I tuck this o-ring into the piston rod or does it sit on top ?

3-Anyone know the volume of oil to dump in ? I'm just hoping to save a bit of time. I'm behind schedule.
If I do have to measure I'll try to record the volume and post it here.

-Does anyone need any pics while I've got these apart ?

 

[GMP]

Brian,


1) Assuming everything is correctly in place, there should be a few mm of preload. The o-ring in the cap seals the rebound needle push rod and top of the damper rod. You woun't trash it. Hold the damper rod and crank it down hard by hand. Add preload washers to get about 3-6mm preload. Its also possible that the fork springs have sacked out. Measure the length and let me know.

2) The o-ring is forced between the push rod and the ID of the damper rod when the cap is tightened as described in #1

3) Go by height, not volume. Fill just over the 4 holes in the inner tube and wait for all the air bubbles to stop, indicating that the gap between the tubes is full. Now bleed the cartridge and fill to level. I'd set it to 140 - 145mm.

 

[Brian VT]

Thanks.

Its also possible that the fork springs have sacked out. Measure the length and let me know.

50.5 cm (19 7/8").
These are the .40s that I bought used. The .42s that I took out measure the same.

 

[GMP]

I have a set of 4.2 WP43 springs at home I'll check tonight. Maybe the guy that previously did the suspension took all the preload out. I'll bet that fork rode really low, with no preload and all that bleed.

 

[Brian VT]

I managed to get 'em done. The 1st time was slow but I think I could do it in a few hours now.
I'll give them a quick try tonight and a better test on our club ride tomorrow night.
I never did manage to get any preload. There was no metal washer in there, just the nylon spacers. I guess I'll try to dig up some washers.
What effect will lack of preload have on the action of the fork ?

 

[GMP]

Brian,

Spring length seems OK. Sorrry I didn't get back to you, I've been busy at night setting up my '07.

There should be a steel washer between the spring and the preload spacers, the last guy probably left it out. You should add preload, I think the fork will sag too much without any, expecially with the 4.0s. This can be done with the forks on the bike, bike on stand. Just remove the bars, loosen the top clamp bolts, and the fork cap. Put something under the front wheel to raise the fork caps and springs out of the fork for access.

Also consider you have a set of each 4.0 and 4.2, and can run one of each for a 4.1 if you choose to experiment.