Triumphrat

ssevy · 04-03-2009, 10:17 AM

I pulled the forks off my 99 Legend last night, and left them draining overnight. Boy does that fork oil ever stink! I have the progressive springs to put in and just wanted to double check the steps. I have read every thread, but a couple of things were not clear. How does this sound:
1- With the forks dry (no oil), drop in the springs, the flat washer, and pvc spacers. With the fork held upright and fully extended, draw a line on the pvc spacer at the top of the fork tube. Use an electric mitre box and cut the two spacers to length. (I assume if there is a slight variation in the marks for the pvc spacers for the right and left sides, you split the difference when cutting)
2- With the fork still fully extended and the spring only(?)in place, fill with oil to 120mm from the top of the tube. (This is where it wasn't clear whether to include the pvc spacers in the tube during the fill or leave them out). Pump the forks a bit to get any air out and doublecheck the oil level. Do this several times.
3-Once the oil level is set and the air is all removed, put the flat washer and the spacer back in, then put the end caps back on. These can be torqued once they are mounted back on the bike.

I noticed that the dust seals are dried out a bit, but there is no oil leakage. I also bought some of those cool bellecourse gaiters to put on. Should I replace the dust seals now, or let them go?

Last comment - I bought one of the Sears Professional model motorcycle jacks, and it works on my Legend perfectly with no spacer board or other jury rigging necessary.

Overall, pulling the forks was very easy and straighforward.

Whoops, one more question - I seem to recall something about not doing the final tightening of the lower fork brace until I compress the front end a couple of times for alignment or something? Can anyone clarify this for me?

Thanks!

bigred900 · 04-03-2009, 12:09 PM

Hi ssevy,

that all sound about right to me. Oil measured with forks extended and spacers in. Pump forks to remove trapped air. Yup, I reckon you are spot on.

As for the seals, if they aint leaking, leave 'em be

You are also correct about not tightening the lower yokes until you have bounced the front end a bit to align the forks in the yokes. I always forget that bit.

A note on the fork gators, I took mine off after a while because they were trapping moisture inside. Not sure if that could be a bad thing but It bothered me. Might not be a problem but keep an eye on it.

Nicely done,

Wayne

KD5QOQ · 04-03-2009, 12:34 PM

That oil does stink!!!
The level is usually checked with the springs out and the tubes fully collapsed.
The height I have is 126mm.

bigred900 · 04-03-2009, 01:06 PM

Ooops,

Sorry. I'm giving out incorrect information. Fork oil is indeed measured with forks compressed and springs removed. I remember I did it wrong the first time I changed my oil. Man that was a solid front end until I realised

Glad you picked that up KD5QOQ, I need to do mine again soon and I'd have done it wrong if not for the reminder

Sorry Ssevy.

Wayne

ssevy · 04-03-2009, 01:12 PM

Does the 126mm fork compressed fill height apply to the factory springs, or do you have the progressives? I was using Jim's directions, but the inclusion or the exclusion of the pvc spacer when measuring the oil height is unclear when reviewing his old posts - something about a concussion, I think

I did notice that the progressive springs were much shorter than the stock ones, so the pvc spacers will have to be longer than the metal ones which came out. I hope someone can clarify which method of oil measurement is the correct one, and if it is "forks extended and springs installed", does the spacer go in as well before measuring the oil?

Also, the instructions from progressive said that installing with the tight coils down might be quieter, but that the orientation of the springs did not matter. Does anyone have any experience with these springs that would cause you to disagree with that?

I also made a nice little oil measuring device from a small cork and a piece of brazing rod. I'll see how it works tonight.

Thanks for all the help.

bigred900 · 04-03-2009, 01:32 PM

I can't tell you about progressive springs I'm afraid Ssevy, I'm going by the instructions for stock springs. I'm not sure on the fill height for your bike either. Its either 109mm for kayaba forks (<vin43509) or 126mm for showa forks (>vin43510)

I could be wrong (see previous post) but I would think that compressed and spring out would be the same for progressive and stock. I don't think either spring would displace more oil than the other. As long as both forks are the same you should be ok.

But don't quote me on it

Wayne

Slinky · 04-03-2009, 02:32 PM

There's a coincidence, I just came in from the garage after changing fork seals and oil. My understanding is the fork level is checked with the spring out and the tube fully pushed in.

I was surprised to find that my forks already have progressive springs installed, maybe the early ones came from the factory that way.

patrol21 · 04-03-2009, 03:25 PM

correct, the springs should be removed to check the oil height as well as compressed fully. Dont' forget to draw the forks back and forth a couple of times to remove the air pockets..trust me there in their....also, let the tube sit for a few minute after pumping especially if you went with a heavier oil to give the bubbles a chance to move to the surface. Once you have the right measurement, it's just a matter of putting everything back together....

I also noticed on my 95 that the stock springs are progressive.

IrlMike · 04-03-2009, 04:19 PM

Spacer length - I would consider it this way. The spacer is to set the sag, usually at around 1/3 of suspension travel, say 40mm on ours, bike off stand with rider on board. With progressive rate springs, I would choose at least that, & no less, maybe 45mm. What was your sag before ? (If you don't know, I'd guess at 35mm.) Make a note of the difference - that must be subtracted from your old spacer length (our new spacer starting point). Now, make an adjustment to that figure for the difference in free length of the springs. But...we're not finished yet, what about the different rate of the new spring ? If you don't know the rate of the original spring is compared to, say, the 'early' part of the new progressive, you'll have to guess. Let's say the new spring is 15% lower rate over the 1st 1/3 of travel, 40mm. Therefore you'll need to add another 15% of 40, or 6 mm to your spacer length to get you back to where you were. With those three adjustments to your old spacer (stock is 100mm, I think?), you now have your new spacer length.

One more thing, when using a PVC pipe spacer the extra volume of the plastic is quite significant over the skinny metal spacer. The 'heavy gauge' pipe I used came out with a 35 mm lower oil level needed for 90mm of pipe (spacer) length. The pipe was 24mm ID, 34mm OD (25.4=1"), is that similar to yours?

And another...for reasons of lower unsprung weight (& spring momentum for valve springs) the heavier coiled section is always placed at the stationary end - top for forks.

1 more...spring volume - the difference may not be much (unless you ignore my last point..) but you could try each spring in turn when you've got about the right oil amount in & see if the level moves.

Good luck

Mike

KD5QOQ · 04-03-2009, 06:39 PM

If you doubt what I say about oil level try this: fill to 120 or 126 mm (it won't matter) while the forks are fully extended, now compress them fully and see how much spills all over your hands.
How could you expect them not to blow the seals out of the sliders once you hit the first bump?