The husqvarna 40mm forks??

I have a few of the older 86's/'87 front 500cr forks. I was wondering if anyone shims these older forks?? The springs are quite old and probably have more than the standard factory sag. I was wondering is anyone adds a pvc shim? One or two inches?
Or is there new fork springs for these 40mm forks?

first off, the 86 model and 87 model have much different fork internals. you can tell the difference by the earlier having single piston caliper and later 87-88 having dual piston brembo.they have different mounting to accomodate this.
husqvarna themselves shimmed them with alum spacers, pvc can be used as well. care must be used to avoid coil bind. i prefer to cut them and replace what was cut with spacer to maintain same ride height. there are some places that offer stiffer springs, such as racetech or wer. would perform best contacting a shop telling them rider weight and having them send a set of springs that would give correct sag. the internals are much better on the 87-88 forks, teflon/modern bushings, rudimentary valving, not to mention the caliper that is waaaay better than the 86 single piston unit.
almost positive if you have forks that are 87-88 and they are from a cr, they are inverted white power units. only wr and xc still had "husky" forks.

We have progressive springs for these for a rider about 14 / 15 stone in riding gear.

Adding spacers to firm them up means you 'pull' the rebound damping out of the fork. Not ideal.

Max. of 400ml of 7.5w oil per leg (doesn't matter too much as the damping is done at the bottom of the fork - not like the 82 - 84 forks).

Andy

Yes I have found pvc sections in 40mm forks. I am using forks from my 86 ae430 on my Norton hillclimber with cut springs and longer pvc than you state in post 1 and if it spring binds I don't know it. The idea I think is to shorten the spring which increases the spring constant and then get the ride height with the pvc. I have found and used a fender washer between the pvc and spring. One can not modify the cut end of the spring like origional, at least not easily. I would think there is a chance brand x dual sport bike springs would be stiffer and about the same size, not sure exactly what model though.

If one doesn't cut the spring what is different than just pumping air into the valve on top? The bike is supposed to settle 3/4 inch on it's own weight and 4 inches with the rider in position. At least those are ball park numbers.

Some more modern manufacturers put adjustable fork top screw in pieces on the motox versions but I think the adjustability is 5mm or so for fine tuning.

Post 1 86 and 87 forks are significantly different. Maybe not an issue for what is being discussed here.

Post 2 pretty much on target except about the spring binding business though decide for yourself should be pretty easy to measure a space multiply by #of coils and see if it is more or less than travel.

Post 3 What I have seen at least remember is that the fork internals not counting whether bronze bussing or teflon coated inserts, are pretty much the same up to the 87-88. I fill the tubes to about 5 inches down so the dampening stuff surely is covered. I though I was using liter bottles for the cr/xc length ones, I know the spec is a bit less.

while the caliper, seal and slider design is better there is nothing wrong with the 86-86 dampening
my brother put the guts of an 85 CR500 into his 87 XC430 forks

the CR and XC used a spacer to set the height and the WR did not due to being a shorter fork
putting spacers in as Andy said will affect you suspension dampening

I don't remember a spacer on 83xc and don't see one parts sheet.

The title is generic 40mm, If I was going to use 40mm forks probably would just opt for the simplicity of the bronze bushing version. If one was racing it would most likelly be the most modern stuff inside that is legal.

he states in the first post what forks hes dealing with.

so,,,,,, 14/15 stone, hahahahaha
you English
i was prepared to offer the dimensions in cubits

On some forks they install a piece of 1" pvc pipe to preload the fork springs. I was just wondering if anyone skimmed there's.

I'm going to try them with my weight stock at first. If I remember correctly the smaller and larger diameter forks worked ok for me but I was thinking about trying to dial them in closer to my body weight. My 98 250wr we changed the springs and the same results
Nothing changed. Then I hop on my older husqvarna with the original stock suspension and she's rideable to me. I'm just trying to sort it all out and have a plan.

Cubits and rods?

I initially installed a one inch spacer in mine and was surprised at the change, ended up cutting it down to about 3/8 inch and went with 15W Motorex about 5 inches from top. This was on my '82 250XC used for trail riding. I weigh about 255 with gear on. Worked fine for me.

i dont know bill, if you weigh 300+ like you say plus gear then im not understanding how the stock fork springs will work. i cut mine 1"-1 1/2" and install spacer to make up difference to make mine correct, and i weigh 240 with gear..i also use atf in mine. this is on the 87-88 style, which is much different internally than the earlier style.
are the forks you are going to use 87-88 style or earlier?