fork oil change

[fishman10]

i remember long ago a how to on the csc blog on how to change the fork oil. I cant seem to find it now? Is there a link with pics on here and also is csc's way the best way or have any of you found a better way or different tips,, just got a quart of amsoil 10 wt. for $11.40 so i want to try an improve the front end.

[SpudRider]

Good for you. You are going to be very happy you replaced the stock fish oil in the forks with some legitimate, 10W fork oil.

Here is a link to the webpage containing the CSC maintenance tutorials. The RX3 Sticky Thread, located at the top of this forum, also contains a link to the CSC Tutorial page.

http://api.viglink.com/api/click?for...rial%20Webpage

Other than fork oil, the most important item you will need is a very thin, 14mm wrench! This wrench must fit between the coils of the spring so you can hold the nut at the top of the damping rod to unscrew the fork cap. Otherwise, you will not be able to remove the fork cap.



.

I strongly suggest you acquire a very thin, 14mm wrench before you start this job.

[SpudRider]

After you remove the fork cap, remove the spring from the fork. Then empty the old fork oil in a container. Finally, work the damping rod up and down until you remove all of the old fork oil from the cartridge.



Measure out 330cc of new fork oil. After all the old fork oil has been removed, add some of the new fork oil to the fork tube. However, don't add all of it at once, or it will overflow. Work the new fork oil into the outer tube by extending and contracting the inner tube. Then work the new fork oil into the cartridge by slowing extending and contracting the damping rod. Keep adding new fork oil until you have added all 330ml of the oil.

[SpudRider]

Those are my main tips. Otherwise, you basically follow the instructions posted on the CSC tutorial.

[SpudRider]

I jammed a 14mm, Harbor Freight wrench between the spring coils when I changed my fork oil. If you have access to the proper tools, you can also grind a regular wrench to make it thin enough. However, I bought a Park Tool, DCW-1 Cone Wrench for my next session working on the RX3 forks.



You can order this wrench on eBay for a great price, and get it shipped from Levittown, PA. If you order today, you should have it delivered very quickly.

http://www.ebay.com/itm/PARK-TOOLS-D...18898088&rt=nc

[Weldangrind]

That's a fair price, but a flat handle like that can be quite uncomfortable. I prefer to grind a fatter wrench to suit. If you choose to grind one, stop often and cool it in water.

[fishman10]

i think i have a thin 14mm ,, thanks for the great tip..i hope it goes well,,, not looking forward to it ,,,,doing the forkpoil change on my harley was so simple..Last time i tried to add a 1'2 ounce of oil to the upside down forks on a previous china bike,,,i just took of the caps an poured it in an it leaked right out past the the dust seals an on the ground so , that was not the correct way ,,,lol

[SpudRider]

Originally Posted by Weldangrind

That's a fair price, but a flat handle like that can be quite uncomfortable. I prefer to grind a fatter wrench to suit. If you choose to grind one, stop often and cool it in water.

I only intend to use the Park Tool Cone Wrench for this dedicated purpose. You have to break the loctite on the fork cap threads the first time, but thereafter the nut is very easy to remove.

[SpudRider]

I also suggest you remove the fuel tank/radiator shrouds. Technically, you can reach the triple tree bolts with the shrouds in place, but I removed the shrouds. I think the time spend removing the shrouds is well rewarded with an easier job.

All the orange and black pieces come off as a single unit. There is one Allen head bolt hidden on the inside of the shroud. It connects the shroud to a metal tab pointing forward from the radiator.

[jimjr21]

Cone wrenches are readily available at all bicycle shops if you need one in a hurry. 14 is a common size for them so shouldn't be an issue to obtain.

[SpudRider]

Thanks for posting the tip, Jim.

[fishman10]

thanks much for your tips spud,,they will make the job easier!!!

[SpudRider]

Incidentally, you need to check every manufacturer to see the actual viscosity of their fork oil. One company's 5W fork oil is another company's 10W fork oil.



Looking at Verdone's chart, I would estimate fork oil falls roughly into the following classifications.

2.5W is about 10 cSt viscosity
5W is about 16 cSt viscosity
7.5W is about 28 cSt viscosity
10W is about 36 cSt viscosity

Et cetera.

[SpudRider]

Looking at Peter Verdone's chart, you can quickly determine the 10W, 15W, oil weight designations from the sellers can't be trusted, since one vendor's 5W oil might have the same viscosity as another vendor's 10W oil.

http://www.peterverdone.com/wiki/ind...spension_Fluid

Also, one shouldn't completely trust the chart, either, since the viscosity of a particular brand of oil might change. The only sure way to determine viscosity is to read the product data sheet (PDS) or the manufacturer's safety data sheet (MSDS) for each individual oil. For example, the Verdone chart lists the viscosity of Mobil1 Synthetic ATF as 34.0 with a viscosity index (VI) of 199.00. However, the PDF for this ATF at the Mobil website lists the viscosity as 36.3, with a VI of 176.

http://www.mobil.com/USA-English/Lub...hetic_ATF.aspx

For the forks in my other motorcycles I have installed Valvoline MaxLife Dex/Merc ATF. I chose this fork oil for several reasons. First of all, it has the lowest viscosity of any ATF I have researched.

http://www.valvoline.com/pdf/maxlife_atf.pdf

As an added bonus, this ATF had the lowest price. I bought the Valvoline ATF for $13.50/gallon at my local AutoZone store. Contrast this price with the cost of the "boutique fork oils."

Last year I changed the fork oil in three motorcycles in one month, using the Valvoline MaxLife Dex/Merc ATF, and I still have over a quart of ATF left over. However, I did use Showa SS-7 Fork Oil for the inner cartridge of my CRF250X forks, since the valving is designed for an oil with a viscosity of 16 cSt.

Most of the Dexron VI ATFs also have a low viscosity around 30 cSt, which is very close to the Valvoline MaxLife Dex/Merc. However, none of them could match the price of the Valvoline.

I chose Mobil1 Synthetic ATF for the forks in the RX3 because it has a higher viscosity than the Valvoline MaxLife Dex/Merc ATF. I wanted a higher viscosity of 10W for the RX3 forks, instead of the 7.5W provided by the MaxLife Dex/Merc ATF.

[Weldangrind]

Originally Posted by SpudRider

I wanted a higher viscosity of 10W for the RX3 forks, instead of the 7.5W provided by the MaxLife Dex/Merc ATF.

To slow the damping rate?