Zongshen 200GY-2, USD Forks: What Viscosity is HQ-10 Oil?
 

I have ridden over 34,000 miles on my Zong, so I have decided to change my fork oil. I have not yet taken my forks apart, but I think I have a pretty good idea of their construction. The Zongshen forks employ a cartridge, and are 37mm in diameter. I believe a partially disassembled, Zongshen, USD fork is shown in the photograph below, which was posted by forum member, Forchetto. :)

http://i442.photobucket.com/albums/q...dgeForkjpg.jpg

The Zongshen, USD forks are very nice, and I have been quite pleased with their performance. :) However, I think I might experiment with a different weight of fork oil, and/or preload spacers.

However, I have a question; the Zongshen Service Manual specifies HQ-10 as the stock fork oil. Has anyone ever heard of HQ-10 oil? :?: I searched the internet, and could only find three references, all of them Chinese, to HQ-10 oil. :roll:

http://www.chang-jiang.com/cj750/con6.htm
http://www.veloteq.com/service_manua...ers_manual.pdf (See page 15)
http://www.masson-marine.com/fic_bdd...ice_manual.pdf (See page 28 )

If the valves in the Zongshen fork cartridge will permit, I plan on using either ATF, or motorcycle fork oil. However, I would like to know the viscosity of my present fork oil, the HQ-10 oil. Can anyone help me discover this information? Thank you. :)

Spud :)

Only a guess, but it seems reasonable that 10W fork oil would be the equivalent. Maybe you'd like to try 15W for comparison.

As always, thank you for your willingness to help, W&G. :) Actually, I would like to try a lighter fork oil, to soften the damping. ;)

I believe a given weight of motorcycle fork oil is much less viscous than the same weight motor oil. Also, different brands of motorcycle fork oil have different viscosities for the same weight oil, as shown in the following link. ;)

http://mahonkin.com/~milktree/motorcycles/fork-oil.html

Examining the following link, it seems HQ-10 is a summer weight motor oil.

http://www.chang-jiang.com/cj750/con6.htm

Therefore, I am still confused. :?

Spud :)

hit up the motorcycle shops or dealers, ive found them to be very nice and more then willing to help out even for a little ol quad rider (me)

just becareful you dont want a super bouncey ride..

My guess would be 10 weight.

It could be that they use regular motor oil in China. I would reason though that if the fork assembly is a copy of Japanees modle that it would benifit from the use of a specific fork oil.

Not sure how easy it would be to drain the fork oil out, but you could probally tell where you ant to be after a couple of tries. Maybe while you have the forks off or apart you could come up with a hose the proper length/diameter to suck the oil out so that a different weight could be added.

Re: Zongshen 200GY-2, USD Forks: What Viscosity is HQ-10 Oi
 

It's from the OLD "GB485" standard which HQ-10 = SAE30
Stolen from a journal
https://s14.postimg.cc/7gkpmln4h/gf2.gif

Seems most dual sport bikes run between 5 and 10 so I'd bet it's 10.

If you want to go a little lighter mix 5W and 10W 50/50 and see how it rides.

Do you have drain screws? If so fluid changes are easy. You can even inject new fluid in through the drain holes with a 60cc syringe.

If you don't have drain holes adding a couple with a little drill and tap wouls be a good Spudification for future oil viscosity fiddiling.

JMO.

Bill

If the oil in there now is the equivalent to SAE30, no wonder you're looking to soften the forks. 8O

As a point of trivia, Yamalube is available in SAE5, 10, 15 and 20. It's a little more money, but you don't need much. See page 64: http://www.yamaha-motor.com/Yamalube...be_Catalog.pdf

Yet another step towards full Yamafication.

Thank you for finding the journal oil chart, Humanbeing. :)
The Zongshen, USD forks work very well, W&G; they are not excessively firm. ;) SAE 30 motor oil has a kinematic viscosity of 100 Cst at 40 degrees Celsius, which does seem very high. 8O

http://www.bobistheoilguy.com/visc.html

After doing some more research, I am inclined to believe my fork oil is closer in viscosity to SAE 10W, or SAE 10W/30, both of which have an approximate viscosity of 26 Cst at 40 degrees Celsius. Page 15 at the following link seems to confirm that HQ-10 lubricating oil is approximately equivalent in viscosity to both #26 universal gear oil, and SAE 10W/30 engine oil. Perhaps HQ-10 lubricating oil is different from HQ-10 motor oil?

http://www.veloteq.com/service_manua...ers_manual.pdf

Also, my Zongshen forks are very similar in design to the USD forks employed by the QLink, XF200 supermoto. According to Crazy Carl, Qingqi specifies #32-#46 viscosity oil for the XF200 forks.

http://www.mychinamoto.com/forums/sh...rks-info/page2

The Portuguese version of the Qingqi service manual specifies ATF for the USD forks, which has a viscosity of approximately 34 Cst at 40 degrees Celsius. Also, many brands of 10-weight, motorcycle fork oils have the same viscosity.

http://mahonkin.com/~milktree/motorcycles/fork-oil.html

I think both you, and W&G, are correct, Doc. ;) I am inclined to use either Mobil 1, Synthetic ATF, or a slightly lighter, motorcycle fork oil with a rating of 26 Cst at 40 degrees Celsius. The Mobil 1, Synthetic ATF gets very good reviews from many of the riders over at Thumper Talk. I doubt Zongshen deviated so far in design from all the other motorcycle forks. ;)

Spud :)

The "historical" chinese recipe for absorber oil :? =
25# transformer oil http://english.sinolube.com/products...927/2689.shtml
20# turbine oil
http://a.imageshack.us/img64/1471/image6t.gif

Thank you for you help, Humanbeing. :) I have studied Koine Greek, but I must admit I cannot read Chinese. ;) However, here is my understanding of the information you presented.

HQ-10 oil approximates the viscosity of a 50/50 mixture of #25 transformer oil, and #20 turbine oil. The link you provided indicates that #25 transformer oil has a viscosity of 9.395 Cst (mm2/s) at 40 degrees Celsius. According to ISO standards, I believe #20 turbine oil has a viscosity of 20 Cst at 40 degrees Celsius; however, I don't know if the Chinese follow the ISO rating system for turbine oil. ;)

If my information, and my calculations are accurate, a 50/50 mixture of both oils would yield a viscosity of approximately 15 Cst at 40 degrees Celsius. Therefore, an HQ-10 viscosity of 26 Cst at 40 degrees Celsius would be quite close to this figure. :)

Based upon this additional information, I am increasingly convinced the proper viscosity for the Zongshen, USD fork oil should be somewhere in the range of #26-#40 Cst at 40 degrees Celsius. :) Therefore, I am further encouraged to experiment with either Mobil 1, Synthetic ATF, or a slightly lighter, motorcycle fork oil with a rating of 26 Cst at 40 degrees Celsius. ;)

Spud :)

HQ-10 is the Motor oil for Gasoline engine in '72 . (Viscosity as the 1st conversion chart ) which will knock ur nuts at every uneven surface , so there's a "shock absorber oil" reciepe.
These "histroical" chinese standard is based on 50s USSR standard (which I can't made a clue. IF u can find it, "machine translated" is easier than chinese).
The "machine translated" article about these :?:
Since 80s Chinese using a system similar to API: (H)QB= SB ...

did the lighter fork oil make a big chnge in dampening?

I haven't yet changed the fork oil, Shawn. ;) However, I will certainly post my impressions after I do. :)

Spud :)

if you are planning on braking down the forks dude, any chance of pics that i could use to change my seals