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. :tup: 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?format=go&jsonp=vglnk_143108958535611&key=34762fb5761dc247f55c8a8e247c5fb4&libId=i9flsfgx0100j7ij000DA5sjscwlv&loc=http%3A%2F%2Fwww.chinariders.net%2Fshowthread. php%3Ft%3D14228&v=1&out=http%3A%2F%2Fcaliforniascooterco.com%2Frx3_mai ntenance_tutorials.htm&ref=http%3A%2F%2Fwww.chinariders.net%2Fforumdispla y.php%3Ff%3D136&title=Zongshen%20RX3%20(ZS250GY-3)%20Modifications%20%26%20Maintenance%20-%20ChinaRiders%20Forums&txt=CSC%20Maintenance%20Tutorial%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.

http://ecx.images-amazon.com/images/I/21AO6XRIGUL.jpg

http://californiascooterco.com/blog/wp-content/uploads/2015/03/Forks_0031-650.jpg.

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.

http://californiascooterco.com/blog/wp-content/uploads/2015/03/Forks_0035-650.jpg

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. :ohno: 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. :ohno: 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. :)

http://i.ebayimg.com/00/s/NzAwWDgwMA==/z/AawAAOSwVFlUDLB-/$_57.JPG

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-DCW-1-DOUBLE-ENDED-CONE-WRENCH-13MM-AND-14MM-BIKE-BICYCLE-TOOL/201165681749?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%2 6asc%3D30987%26meid%3D8951fbcabfdf4edf9f54f71ac632 cac9%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D3911 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]

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. :wtf:

http://www.peterverdone.com/archive/images/content/motorcycle/PVD-ISO-Viscosity-Data.gif

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. :wtf:

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/Lubes/PDS/GLXXENPVLMOMobil_1_Synthetic_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]

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?

[SpudRider]

To slow the damping rate?

Yes, that is exactly correct. :)

The fork springs provide the general support for the suspension. It is important for the fork springs to be well matched to the weight of the bike and rider. Perhaps CSC will provide a selection of aftermarket fork springs in the future. If so, we can then adjust the forks for riders of different weights, et cetera. As of now, we must accept the factory fork springs.

The viscosity of the fork oil moving through the damping cartridge provides the damping. A lighter fork oil, with lower viscosity, provides fast damping. A thicker fork oil, with higher viscosity, provides slower damping. As set up at the factory, the Zongshen RX3 forks have very fast damping. The stock fork oil has a viscosity of about 2.5W. The Mobil1 Synthetic ATF has a viscosity of about 10W. The thicker ATF slows the damping of the forks, and provides a much smoother, less choppy, fork action. :)

[fishman10]

since 330ml. Is about 11.2 ounces. I wonder if putting 12 ounces in rash leg would harm anything. ??

[SpudRider]

since 330ml. Is about 11.2 ounces. I wonder if putting 12 ounces in rash leg would harm anything. ??

Trust me, I don't think you could fit 12 ounces of oil in these forks. In fact, you can't pour all 330 ml of oil in at once, or you will surely make a mess while you are trying to work the oil into the damping cartridge. ;)

I have no doubt 330 ml is the correct amount which completely fills the fork to the proper level. :) If the fork oil is too high, you can create too much pressure in the fork, which can either damage the oil seals, and/or cause them to leak. :ohno: I strongly suggest you stick with the recommended volume of 330 ml. If you want an even slower rebound, try using a heavier weight of fork oil (15W).

These forks also need stronger springs to stiffen them. However, we don't have that option at the moment. Fortunately, Ryan told me CSC plans to address this issue in the future. ;)

[oldqwerty]

Diablo Rojo, my 3-year old grandson named my bike, is out for delivery today. :clap:

We may can do a little good with the stock springs with spacers. Cutting a spring makes it stiffer, and I've had several applications where it was possible to cut a few coils and use a longer spacer to stiffen the ride, but it is imperative to make sure doing so does not lead to coil bind or reduced suspension travel. I'll take a look while changing the fork oil. I intend to change the fork oil per SpudRider's recommendation as part of the initial set up and service. I'm fatter than the Spudster, but my riding will be less demanding on the bike, so I figure using the same Mobil1 Synthetic ATF will serve me well, and I already have a few quarts on the shelf.

[SpudRider]

You are wise to change the fork oil quickly; you will not be sorry you did so. ;)

I think it will difficult to put spacers at the top of the fork, since tightening and loosening the nut on the damping rod is the hardest part of the job, especially if you don't have a very thin, 14mm wrench. You might be able to put a spacer at the bottom of the spring, but you might not, depending on the ability of the cartridge to support the spacer. :shrug: When you have the forks apart, please do take a good look and evaluate this option for us. :)

[SpudRider]

Congratulations on the delivery of Diabo Rojo. :tup: Tell your grandson I love that name! :)

[AZRider]

Spud, if you have the spring dimensions, there's a good chance that Progressive Suspension will have something in their catalog that fits. I have Progressives on the front and rear of my Valkyrie and they make a substantial difference.

[SpudRider]

Since changing the fork oil can be a little messy, I didn't take any photographs, and I forgot to measure the springs. ;) Perhaps someone else can measure the springs when he changes the fork oil. :)

I have talked to Ryan at CSC regarding this matter. I believe CSC is going to contact one of the aftermarket spring manufacturers in the future, and encourage them to offer stiffer springs for the RX3. :) If stiffer springs are available, I will one of the first customers on the list. :tup:

[fishman10]

Of course you are correct spud, you cannot put 12 oz in each fork leg. . What a mess. An now my back tire mysteriously is flat

[SpudRider]

Of course you are correct spud, you cannot put 12 oz in each fork leg. . What a mess. An now my back tire mysteriously is flat

The rear tire of my RX3 also mysteriously went flat while I was riding about 5 miles from home. :wtf: I limped home on the flat tire, and seized the opportunity to install the Shinko 244 tire several days later.

When I changed the tire I noticed a very small nick in the inner tube. The small hole had not been caused by a puncture, since it was located on the inner portion of the tube, near the rim. The rim strip was in perfect condition, and none of the spokes were protruding from the nipples. I surmise the tube was probably damaged during installation of the tire at the factory. :shrug:

I replaced the inner tube, but it can certainly be patched. The tube was in very good condition, except for the small nick, which lasted about a week, and sustained about 500 miles of riding before it failed. :wtf:

[oldqwerty]

Spud, if you have the spring dimensions, there's a good chance that Progressive Suspension will have something in their catalog that fits. I have Progressives on the front and rear of my Valkyrie and they make a substantial difference.

I used Progressive products on a late Nighthawk 750, early CB550 Four (old 4 muffler model), and a CB400 Four (old 4 muffler model). I set the CB750 and CB550 up for me, the CB750 for a body mass of 280 pounds, the CB550 for a body mass of 180 pounds (cancer fight will do that to you), and the CB400 for a body mass of 108 pounds (my wife). Progressive's recommended bolt-ons, some decent fork oil, and some more current tire technologies on the smaller bikes transformed the ride and handling on all three bikes. I'm a firm believer in Progressive's engineering principles for street use.

[Weldangrind]

I used Progressive products on a late Nighthawk 750, early CB550 Four (old 4 muffler model), and a CB400 Four (old 4 muffler model). I set the CB750 and CB550 up for me, the CB750 for a body mass of 280 pounds, the CB550 for a body mass of 180 pounds (cancer fight will do that to you), and the CB400 for a body mass of 108 pounds (my wife). Progressive's recommended bolt-ons, some decent fork oil, and some more current tire technologies on the smaller bikes transformed the ride and handling on all three bikes. I'm a firm believer in Progressive's engineering principles for street use.



I can't help but notice that our tastes in bikes are quite similar, especially when TW's are factored in.

[katflap]

Changed my fork oil today .

With the Cap off, spring removed and fork fully retracted i measured the oil level within the fork.
Prior to measuring i collected all the oil that was dripping from the spring and added it back in to the fork.

The oil level was at a depth of 9.5cm from the top of the fork.

I knew that without fully stripping down the fork i wouldn't be able to remove all the oil and i was keen not to overfill or have un equall amounts in the forks.

What i didn't expect was the difference between the recommened refill amount of 330cc and the 280cc i used to fill mine back up to my measured level.
I double checked this by measuring the old oil i removed. It was 280cc.

I would be interested if others have the same oil level measurement. Perhaps mine was under filled from factory. :hmm:

[SpudRider]

I don't remember if I measured the used fork oil, or not. :shrug:

Did you work all the fork oil out of the cartridges? :hmm: I imagine the fork action is pretty soft with 50 cc less oil in each fork.

[katflap]

Hi spud
Yeah, I gave it quite a good workout. Perhaps not long enough but there only seemed to be a minimal amount of residual oil left :hmm:

Unfortunately I don't have anything to compare the fork action against. But they don't seem particularly stiff.

I'm hoping that some one who is planning to change there fork oil in the future will do a quick measurement :)

[Parker74]

I actually pulled the forks off last nite to added 10W.
I poured them out first and measured how much oil was in each and both were at exactly 250cc's.

Put the same amount back in.

[SpudRider]

I didn't measure my used fork oil. However, I can testify my forks work much better with 330 ml of Mobil1 Synthetic ATF in each fork. :tup:

[katflap]

I actually pulled the forks off last nite to added 10W.
I poured them out first and measured how much oil was in each and both were at exactly 250cc's.

Put the same amount back in.

Thanks for the feedback, parker :tup:

Have you noticed any difference since doing it.

I have now had chance to test mine and it feels much the same, perhaps a slight improvement. :)

[katflap]

I didn't measure my used fork oil. However, I can testify my forks work much better with 330 ml of Mobil1 Synthetic ATF in each fork. :tup:

I'm sure a lot of people will notice a marked improvement as you have spud :tup:

But there maybe a few who wish to do a fork service etc. and maintain the original factory setup after a fork oil change.

I'm starting to wonder if this is possible with 330cc of oil no matter what the grade. :hmm:

:)

[SpudRider]

I didn't decide on 330 ml of for oil, myself. I merely followed the specification listed in the CSC maintenance tutorial for fork service. ;)

http://www.cscmotorcycles.com/Articles.asp?ID=263

I also know from seven years of experience studying, and working with Chinese motorcycles, that the forks are almost invariably low on oil as configured at the factory. ;) However, I do understand if someone wants to keep the same amount of fork oil as received from the factory. Everyone is free to configure his motorcycle exactly as he wishes. :)

[Cyclone54]

Good for you. :tup: 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?format=go&jsonp=vglnk_143108958535611&key=34762fb5761dc247f55c8a8e247c5fb4&libId=i9flsfgx0100j7ij000DA5sjscwlv&loc=http%3A%2F%2Fwww.chinariders.net%2Fshowthread. php%3Ft%3D14228&v=1&out=http%3A%2F%2Fcaliforniascooterco.com%2Frx3_mai ntenance_tutorials.htm&ref=http%3A%2F%2Fwww.chinariders.net%2Fforumdispla y.php%3Ff%3D136&title=Zongshen%20RX3%20(ZS250GY-3)%20Modifications%20%26%20Maintenance%20-%20ChinaRiders%20Forums&txt=CSC%20Maintenance%20Tutorial%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.

http://ecx.images-amazon.com/images/I/21AO6XRIGUL.jpg

http://californiascooterco.com/blog/wp-content/uploads/2015/03/Forks_0031-650.jpg.

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


Is this a necessary step if all you are going to do is swap the oil??

[SpudRider]

A lot of oil is stored in the cartridge. If you want to get the oil out of the cartridge, yes, this step is necessary.

[Cyclone54]

A lot of oil is stored in the cartridge. If you want to get the oil out of the cartridge, yes, this step is necessary.

Hmm, Parker 74 and I did his this past weekend and skipped that step and only got 250cc's out of each fork. Wondering if the cartridge was holding that extra 80cc's now.

Might have to do his all over again. Damn..

[SpudRider]

I'm sorry to bear the bad news, but I'm betting there is a lot of oil in the cartridges. Even if you don't get 330 cc of oil when you empty the cartridges, I still suggest you follow the CSC specification. ;)

[Parker74]

Thanks for the feedback! We pulled the forks back off today and after removeing the spring and pumping the internal shaft many times and pouring the old oil repeatedly I was able to get much more oil out of the forks.

Just about 330 cc's:yay:

The frontend feels much firmer and less dive when braking.

[SpudRider]

You're welcome. :)

You experience corroborates mine. I knew the forks would perform much better with 330 cc of heavier fork oil. ;)

[Inroads]

Anyone have new info on aftermarket fork springs ?

[GSC]

Just a quick note of thanks to CSC fork oil change tutorial and Spud.
It goes well when following directions; I think I put springs back rightside down?
Especially pleased with Spuds recommended 10wt oil, of Mobil 1 ATF syn.

[SpudRider]

Just a quick note of thanks to CSC fork oil change tutorial and Spud.
It goes well when following directions; I think I put springs back rightside down?
Especially pleased with Spuds recommended 10wt oil, of Mobil 1 ATF syn.

Thanks for your report and the kind words. ;)

[AdventureDad]

Just a question reviving an old post.... would changing the stock oil be a bad idea for me, as I weigh 165, but occasionally ride 2up. Also, would the Mobil 1 ATF or the lighter Valvoline ATF be better? Lastly, after reading this thread and tutorial, would I remove the spring and pump the forks until 330ml comes out, or it's empty? If i don't get 330ml's out, I would just replace with the amount removed.

Ive not done fork oil before.

Thanks all!

[SpudRider]

Anyone have new info on aftermarket fork springs ?

I haven't heard any updates, but I might call CSC and ask about it. ;)

[SpudRider]

Just a question reviving an old post.... would changing the stock oil be a bad idea for me, as I weigh 165, but occasionally ride 2up. Also, would the Mobil 1 ATF or the lighter Valvoline ATF be better? Lastly, after reading this thread and tutorial, would I remove the spring and pump the forks until 330ml comes out, or it's empty? If i don't get 330ml's out, I would just replace with the amount removed.

Ive not done fork oil before.

Thanks all!

I believe changing your fork oil would be a good idea. I recommend the heavier, Mobil1 Synthetic ATF. ;)

I suggest you remove the spring and pump the forks to remove all the old fork oil. After removing all the old fork oil, I recommend you fill each fork with 330 ml of new fork oil.

The job isn't hard, and I'm sure you will be glad with the results. :)

[pete]

use fork oil not ATF....
ATF is for lubication and has a high firm strength compaired
to fork oil & that firm strength is the problum it captures air bubbles
to easly and dosn't release them quickly... so the oil
weight or CST rating is all over the place depending how
much air it is holding...
fork oil is designed not to froth up as it is pushed though the holes
/valves & has a low firm strength that dosn't capture air easy
but if it dose it releases it quickly...

but that being said the RX3 / hawk and others ATF is prob usable
as the suspension has limited quite slow travel in it's intended use..
but there is far better oil out there designed for the job...

Lintern the guy that builds my suspension has a saying..
"you only know as good as you have riden"



..

[RC]

"Assembly is the opposite of the disassembly procedure."

Can someone provide advice on getting the inner seal seated? I tried tapping with a screwdriver, but am reluctant to tap hard and damage the seal. I've tried pounding the upper and lowers together (opposite of the disassembly) but the dust seal gets into place and the inner seal still isn't seated enough to get the C clip in place. I then cut a 1" length of PVC pipe, hacked a section off so it in a C shape, stretched it over the lower tube, and trying slamming it the tubes together again, but the PVC is riding up on the dust seal and I don't want to damage it. I also tried some lite hammering with no advancement. I then cut a 5" length of PVC and stretched it over the tube and tried slamming it down onto the seal, but the PVC is just too lite.

I was able to get the washer and seal seated in the upper tube while the lower tube is removed, just to confirm it can go back in there. I'm wondering if I should try installing the lower tube with the seal already seated in the upper? There will be a few tricks on getting those bearing rings on, but maybe it can work.

[Rangerscott]

https://youtu.be/7DzZjW2p_H4

[SpudRider]

Setting the fork oil seal is easiest with a fork seal driver of the appropriate size. However, if you don't have a fork seal driver, you can use the method shown in the following video. ;)

https://www.youtube.com/watch?v=24kDZHsHwDI

[RC]

Old Fork seal! So simple! :doh: I knew I was on the right track with the PVC, but it was just missing the mark. I was going to reuse the old seals because they are still in perfect condition at 11k miles, and keep the new ones as spares. Maybe I'll stop by the local shop and see if I can find some cheap generic seals to cut and use. If not I'll buy a new set of backups because they are cheap.

Thanks for the tips!!

[Rangerscott]

When I was flipping a sport bike, I used Redline fork oil. On paper it has the best specs but who knows. Theres a guy on ebay (d_on_rr) that sells it at a good price.

[2LZ]

Revisiting this older thread.

For the first time in my life, I'm not completely happy with my tried and true Bel Ray 10W fork oil that I've run in every bike since I was a teenager. It just seems the RX3 has a bit too much jarring on the elbows (that goes all the way to your teeth) on some of our really pocky "paved and constantly patched" goat trails. I was first searching for some progressive rate springs (without success) but I may try the 7.5W ATF this time, just to see if it softens up the initial 2" of travel. After I get in to some heavier stuff and the forks are more compressed, it's fine. It's just that initial first couple of inches that need to be more forgiving.

Has anyone had success working with this?

[SpudRider]

I used the Valvoline MaxLife Dex/Merc ATF in the forks of my Zongshen ZS200GY-2. It has the viscosity you desire, and does an excellent job. If you like, refer to post #13 and post #14 in this thread. ;)

http://www.chinariders.net/showthread.php?t=14672