WP advice

[Brian VT]

I have an '03 EC300 with WP front, .42 springs, and the previous owner changed the stack to something recommended by a shop in upstate NY. I like it fine but that may be because I don't know any better. I'm 160 lbs. + gear and backpack.
I'm sending my forks in for regular maintenance. I have a set of .40 springs. What effect would I notice from changing springs ? How about if I changed from 5 wt. oil to 2 1/2 wt. ?
I'm a slow C enduro rider and can use all the help I can get for nasty rocks and roots in tight trails that are often muddy.

 

[GMP]

Brian,

I would say the .40s may be better for the rocks. I'm a bit heavier and a B rider and I ran the .42s. If you can, send the forks to Les. He will do more than swap shims and you will like it. The midvalve/checkplate shims in that fork take a beating and need regular replacement or you can loose rebound control.

 

[Brian VT]

Thanks for the confirmation on the springs.
I'd like to send them to Les and see if his magic works for me.
I'm just afraid of what the end cost might be and then possibly not even noticing much difference, since I'm just a wannabe.
I'm thinking I'll just have the local guy freshen them up, replace what's worn, and put the .40s in.
I guess I won't know if they can be better, but they seem pretty good to me. They're much better than my XR650R.

 

[Brian VT]

It was suggested that I do them myself and, since we just got 4" of snow and my next race isn't for a while, I think I will try it. I'm sure the 1st time sucks but I might learn to enjoy it as I do some other bike chores.
A little help to start, please:
-Pivot Works doesn't list a fork kit for GG.
KTM EXC300 2000-2001 = PWFFK-T01-531
KTM EXC300 2002 = PWFFK-T03-531
KTM EXC300 2003-2005 = PWFFK-T04-531
All the same ? Which for my '03 Gasser with 43mm WP ?
-What are the signs that other parts need replacing (shims, etc.)?
-Thoughts on going from 5 wt. to 2 1/2 wt. oil ?
-Tools that are worth buying instead of improvising ?

 

[Dave]

Pivot Works doesn't list a fork kit for GG.
KTM EXC300 2000-2001 = PWFFK-T01-531
KTM EXC300 2002 = PWFFK-T03-531
KTM EXC300 2003-2005 = PWFFK-T04-531

Get the earlier EXC kit for your 43s - the later kit is for 48mm tubes.

What are the signs that other parts need replacing (shims, etc.)?

As Glenn mentioned, the check plate shims on the rebound piston might be cupped. If they aren't too bad some folks simply flip them over.
If the fork tubes have front to back play it's time for new bushings.

Thoughts on going from 5 wt. to 2 1/2 wt. oil ?

When it's warm I've noticed little overall performance difference between different weight oils (ATF @ 35cSt to hydraulic oil @ 10cSt). In cold weather oils with a high pour point result in a brutally stiff ride. If you change oil viscosity you'll end up adjusting the clickers to compensate for a different oil, but high speed operation doesn't noticibly change.

Tools that are worth buying instead of improvising ?

For a mid level overhaul, fork tube bushings (leave the damper rod bushing alone for now), seals, piston bands and o-rings, a seal driver and a way to set oil level is all you'll need.

 

[KTMLew]

Get the earlier EXC kit for your 43s - the later kit is for 48mm tubes.

For a mid level overhaul, fork tube bushings (leave the damper rod bushing alone for now), seals, piston bands and o-rings, a seal driver and a way to set oil level is all you'll need.

You want the 00-01 kit. All the parts he recommended above come with the Pivotworks kits!!!

Try this place for a good seal driver.

http://www.pitposse.com/suspension.html

I have used PVC as a driver but a real driver works much better. I don't really care for the oil level guages that use a syringe. You are better of buying a Mity-Vac for brake bleeding & a 12" piece of steel tubing. Then you have a multi-purpose tool!

 

[skid jackson]

Any idea what the name of the shop in NY is?? There is a joint called HY Gear suspension that does alot of sled work and bikes. I've delt with them for sled stuff. Seemed to know what they were doing.

 

[Brian VT]

Any idea what the name of the shop in NY is??

Nope. I think he said it was near Albany ?
Thanks for all the advice guys.
Any downfalls to the universal seal driver as opposed to the dedicated 43mm ?

 

[Brian VT]

I decided to dig in today. I didn't get too far.
The manual says to pull the spring down and use a # 20 spanner. I don't have a 20mm so I tried a 13/16" (20.64 mm) but it was too thick so I ground it down. Wrong size.
I'm guessing it takes a 21mm ? I'll buy one tomorrow. I assume I'll have to grind that one thinner too. If that doesn't do it I'll be grinding down my adjustable wrench. lol

 

[KTMLew]

Takes a 22mm wrench.

 

[Brian VT]

Takes a 22mm wrench.

I didn't have access to the 'net yesterday due to a storm. I bought a 21mm, ground it down, and took it home to find that it's too small. $15 down the tube. lol

 

[Brian VT]

Any suggestions to get the job done without buying this tool ?
I almost tried it by just running a rod through the holes but thought I'd ask for permission from you guys before I damage it.

 

[GMP]

STOP!!!!

Never do that!! You will ruin the cartridge.

On a WP cartridge, the spring guide can be unscrewed from the damper rod and the damper rod assembly drops out the bottom of the cartridge. The rebound/midvalve stacks can be serviced without removing the rebound tap from the damper rod.The one thing the WP fork has going for it is its ease of service.

Get the right size tools and read the manual, forks are eaisly damaged by ghetto methods.

 

[Brian VT]

STOP!!!!
forks are easily damaged by ghetto methods.

LOL ! I did have a bad feeling when I started looking for an appropriate sized metal rod. That's when I decided to wait. Thanks for watching my back.

 

[Brian VT]

Using the cap and spring guide as a jam nut worked great.
Everything's apart (on 1 leg) except the screwsleeve/DU-bush.
Should I mess with that ? I'm sure it's '03 OEM. I couldn't find any tips on getting that out with ghetto methods.
I'll post the shim stacks in hopes of getting opinions.
I read that I should polish my rod. I've got some experience in that department but wonder what materials/tools to use in this instance.

 

[GMP]

I wouldn't worry about the damper rod bushings unless there is abnormal wear marks on the rod. To do that requires more tools than your likely to buy. Besides valving changes, you definately want to change the midvalve shims. Check the bushings for signs that the teflon coating has worn through and change if neccessary, for an '03 its likely due. Seals, wipers and your done. Get a seal/bushing driver. I made a PVC one and it works, but the real tool is eaiser and safer. When you install the seals on the inner tube, cut the ziplock end off a plastic bag, put it over the end of the tube and grease it up with seal grease, and slide the wiper and seal over. You must do this to prevent cutting the seal on the bushing groove.

I've never heard that polishing your rod has anything to do with improved fork action.

 

[Brian VT]

When you install the seals on the inner tube, cut the ziplock end off a plastic bag, put it over the end of the tube and grease it up with seal grease

Good idea. I was gonna tape it. Thanks.
Is there a substitute for "seal grease" or is it commonly available ?
I read to put some oil-soaked sponge between the wiper and seal. Any opinion ? Seems logical to me.

 

[GMP]

Go to a bicycle shop and get the grease that they use in mountain bike forks to lube the elastomer inserts or springs.

Something under the wiper to catch dirt is a good idea. I used nylon cord (like lawnmower starter cord) wrapped once around the fork and packed with seal grease. This fits pretty good with a slight compression. You can take it out and clean it easy. My seals lasted over a year doing this in all kinds of trash. I used the seal savers when it was really muddy.

 

[KTMLew]

Using the cap and spring guide as a jam nut worked great. Everything's apart (on 1 leg) except the screwsleeve/DU-bush.

I still don't understand where the confusion came from? Once the cap and spring is removed you dump the oil, hold the cartridge rod without scratching it, soft vise jaws are nice, and remove the spring guide? Then the rod will drop out the bottom (base-valve end) of the cartridge...

 

[Brian VT]

I still don't understand where the confusion came from?

This is my 1st time and I was going by the WP manual. All the tips from you guys make alot more sense after you've done it but I was really scared of screwing something up along the way. I'll probably continue to be paranoid until I get 'em back together and see that all is good. Bear with me please ?