Zongshen 200GY-2: Fork Service at 41,922 Miles

[SpudRider]

After doing some research, I have discovered Lifan forks have the following designations written upon them.

Left Fork: CAQ-30-L CM-1
Right Fork: CAQ-30-R CM-1



My Zong's forks have the same travel (6.5 inches) as Lifan CM-1 forks, but are slightly different in design. My forks have the following designations written upon them.

Left Fork: CAQ-30-L CM-2
Right Fork: CAQ-30-R CM-2

The inner tubes of my CM-2 forks have a longer, outer sleeve on the bottom of the fork tube than the CM-1 forks. Therefore, when my forks use up the 6.5 inches of available travel, the upper fork tube comes close to contacting the lower sleeve on the inner fork tube.



Perhaps the CM-2 designation indicates my forks are a later design. :?: I previously thought the CM-1 forks might have a longer travel than my CM-2 forks, but apparently they don't.

Spud

[SpudRider]

Here are the dimensions of the CM-1 and CM-2, 37mm, USD Chinese forks.

Diameter of inner fork tube: 37mm
Diameter of fork at upper triple clamp: 48mm
Diameter of fork at lower triple clamp: 51mm
Overall length from tops of fork caps to bottom of fork tube: 33.5 inches
Axle diameter: 12mm

Both pairs of forks have the same travel and dimensions. However, one would probably need to switch front wheels if he decided to switch between these two forks, since the brake caliper and speedometer tabs are different.

Spud

[SpudRider]

Several days ago I changed the fork oil in my Honda XR650L and CRF250X motorcycles, so I decided it was probably time to once again change the fork oil in my Zong.

After 12,000 miles of riding my Zong, the Mobil1 Synthetic ATF appeared to be in very good condition. Therefore, I can probably postpone the next fork oil change until another 25,000 miles or two years, whichever comes first.

While changing the fork oil, I inspected the bushings, fork oil seals, and dust wipers. All of these components were in excellent condition, and I don't have any oil leaks. Therefore, I declined to replace any of these items. I was particularly pleased to note the cleanliness of my dust wipers and oil seals. I ride my Zong in a lot of nasty, muddy conditions, yet the oil seals and dust wipers looked as clean as the day I installed them. My lower fork protectors are obviously doing a very good job protecting the oil seals.

At the last fork oil change, I installed 200 ml of Mobil1 Synthetic ATF, with a viscosity of 36.3 cSt at 40 degress Celcius.

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



This time I installed 225 ml of Valvoline MaxLife Dex/Merc ATF with a viscosity of 28.2 cSt at 40 degrees Celsius.

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



I had intended to add much more fork oil, but I discovered the oil level rises greatly after the fork springs are installed. Therefore, I installed enough ATF to cover the fork springs, which left an air space of about 90mm after the springs were installed. Perhaps I might add another 25 ml the next time I change the fork oil. However, I think about 250 ml is the maximum amount of fork oil one should install in these Zongshen forks. I rode for 12,000 miles with 200 ml of fork oil, and the forks worked very well. I will report if I notice any difference with the additional 25 ml of fork oil.

After changing the fork oil, I went for a test ride.





The lighter, Valvoline MaxLife Dex/Merc ATF does seem to have softened the damping a little, which I enjoy. I will report if the higher oil level also dampens the full compression of the forks. Based upon my initial ride, I will certainly consider installing even lighter fork oil in the future. Since the Zong only requires 200-225 ml of fork oil, one only needs a pint (16 ounces) of oil to change the oil in both forks.

Spud

[Weldangrind]

Thanks for the update, Spud. When simply changing the oil (and not the seals), do you drain and refill from the top of the fork leg? Do you have a drain point on the underside of the very bottom, or perhaps a schrader valve?

[SpudRider]

Originally Posted by Weldangrind

Thanks for the update, Spud. When simply changing the oil (and not the seals), do you drain and refill from the top of the fork leg? Do you have a drain point on the underside of the very bottom, or perhaps a schrader valve?

Yes, I followed the same procedure I documented on page one of this thread. I merely inspected the bushings and fork seals, and declined to replace them, since they were in excellent condition.

As with the rest of the motorcycle, the Zongshen forks are very easy to service. I removed the forks from the triple tree and drained the oil from the top. Then I separated the outer fork from the inner fork, and place the outer fork upside down to drain in an oil pan. Next, I pumped the damper rod to eliminate the rest of the oil from the inner fork tube.

I then resumed working on the outer fork tube. I removed the dust wiper, and was prepared to clean it. However, the dust wiper and the area beneath it were spotlessly clean. I inspected the fork oil seal and all the bushings; they were in excellent condition.

The inner fork tube has a beveled edge, and the guide bushing is located inside the outer fork tube. Therefore, I merely inserted the inner fork inside the outer fork to reassemble the fork.

Next, I added 200ml of ATF, and worked the oil into the cartridge by extending and compressing the damper rod. Then I installed the fork spring. Next, I added enough ATF to cover the top of the damper rod and the spring. Then I installed the preload spacer bushing, and the preload spacer. Finally, I attached the fork cap to the top of the damping rod, completing the assemble.

After installing the forks back in the triple tree, I reattached the wheel, brake caliper, et cetera, and the job was complete.

Spud

[SpudRider]

The Zong's forks don't have oil drain plugs. However, the forks on my Honda XR650L and CRF250X don't have drain plugs, either. I don't consider this a disadvantage, since it's necessary to remove the forks if you want to properly drain all of the old fork oil.

My Zong's forks are far easier to service than either of the forks on my Honda bikes. The suspension feels remarkably better after you remove the Chinese oil from the Zong's forks, and install some ATF. This job isn't very difficult at all. Therefore, I strongly encourage all Zong owners, and the owners of other, Chinese motorcycles, to change the fork oil every two years, or 25,000 miles, whichever comes first.

Spud

[FastDoc]

There's no other way to put it, but NO PLACE is more beautiful than Idaho.

[humanbeing]

They're made by: http://www.yuanchina.com/aspx/yajz/

[SpudRider]

Originally Posted by humanbeing

They're made by: http://www.yuanchina.com/aspx/yajz/

Thanks for posting the link, HumanBeing.

Are you sure Yuan manufactures the forks for my Zong? I can't find any USD (upside down) forks at the Yuan website. :?

http://www.yuanchina.com/aspx/yajz/list.aspx?classid=9

Spud

[humanbeing]

The trademark matches ur picture.
http://www.yuanchina.com/aspx/yajz/s...assid=11&id=41

[SpudRider]

Originally Posted by humanbeing

The trademark matches ur picture.
http://www.yuanchina.com/aspx/yajz/s...assid=11&id=41

Those forks are fully adjustable, and the brake caliper bracket is slightly different from mine.



My Zongshen forks don't have any adjustment capabilities, and the brake caliper is placed higher on the bottom of the fork.



Spud

[Weldangrind]

The forks on my Roketa are not salvageable, so I installed a pair of low-mile Gio forks that have adjustable clickers on top of the fork legs. i haven't yet figured out how to dismantle them for an oil change. The caliper bolts onto the same spot as the originals, but I had to make a spacer on the speedo side, since these forks were originally used with a non-speedo 19" rim.

[SpudRider]

Originally Posted by Weldangrind

The forks on my Roketa are not salvageable, so I installed a pair of low-mile Gio forks that have adjustable clickers on top of the fork legs. i haven't yet figured out how to dismantle them for an oil change. The caliper bolts onto the same spot as the originals, but I had to make a spacer on the speedo side, since these forks were originally used with a non-speedo 19" rim.

Just to be safe, make sure you back the adjuster out all the way, counterclockwise, before you remove the fork cap.

You drain the oil pretty much the same way with all of these forks. Unscrew the fork cap, then slowly lower the outer fork tube. Pour the oil out of the fork as you remove the fork spring. Unless you have a twin chamber fork, you drain the rest of the oil by pumping the damping rod. If you have a twin chamber fork, you need to remove the damper from the fork, and remove the cap from the damping unit before you pump the oil out of the inner chamber.

If possible, measure the oil level after you remove the spring, and before you pour the old oil from the fork. Also, collect the old oil, and measure it's volume so you know how much new fork oil to install. Unless you are replacing the fork oil seals, you don't need to separate the fork tubes.

Spud

[Weldangrind]

I presume that I must remove the clickers, and that will reveal a nut underneath that I can remove. I'll report in my Roketa thread.

[SpudRider]

Originally Posted by Weldangrind

I presume that I must remove the clickers, and that will reveal a nut underneath that I can remove. I'll report in my Roketa thread.

That would be my guess. I know it's a messy job. :roll: However, if you can take some photographs, I'm sure everyone would appreciate your efforts.

Spud