Yes, I have a set of Taiwan/Chinese tubes a set on a 1984 Yamaha RZ350. I bought them off a guy in HongKong. His Ebay name is aaamotorhk
I did it as we were discussing the subject on another 2-stroke board and I volunteered to take one for the team. I figured for $130 and the fact that I could return them meant my only risk was the postage.
Before I give you my thoughts, the RZ had quite a few fork permutations which ended up causing some fitting problems. All were 35mm, however they came in 2 different lengths, I believe around 580mm and 595mm (Later bikes had clip-ons above the top clamp). Internally the diameter of the tubes was either 27.2 mm on the eariler bikes and 28.2mm on the later ones. There are also 3 different variations on the damping rods, 2 different top fork bushes and a 3 different types of fork caps. Some tubes are waisted between the triple clamps, some are not. Its not a one size fits all with the RZ forks as nothing mixes and matches, so I think that contributed a great deal to a fitment issue
The Good:
I put between 2 vblocks and put a dial gauge on them when they arrived. The runout was around 2 thousands of an inch so they were well within Yamaha spec.
Measured the thickness of the tube with a micrometer and compared it to the original. It was just over 1 thou more but I would expect that as the originals had worn
The chrome was polished really well and there is not much stiction
I would also say that the quality of the chrome is up to or close to OEM 1980’s Japanese standard. I’ve put about 5k on the bike and there is no obvious chips, wear or pitting.
The Bad:
I bought them for a 1984 bike and they were 595mm so an inch too long. Its not a huge problem as they just stick through the top clamp about an inch and its only a daily driver. Someday I’ll make a spacer for the damping rod and shorten them.
The inside diameter was 28.2mm so they would not work with my 1984 damping rods as there was too much play between the rod top and fork tube so there would have been no damping. Fortunately, I had a set of internals from a 1988 and these rods fitted perfectly, so clearly, they were made for the later bike.
The fork caps were screw in like the earlier shorter fork tubes, not the press in with the clip that came on the longer forks. This caused a problem as screw in caps have air valves and sit another inch above the top of the fork so they interfered with the handlebars. I managed to get a set of caps from a 1985 Canadian/European that had screw in caps but the valve is recessed into the cap.
Anyway, to cut a long story short after mixing and matching the right components I got them installed and they work well. I have a set of emulators and racetech springs and I can’t complain. Thinking about it afterwards, I believe he copied a set of fork tubes from a 1985 bike as it required all the bits common to a 1985 in order to make it work. Its unfortunate as the 85 was sold in the smallest numbers.
Would I buy again? Probably not for the RZ, just because of the PITA fitting issues but so far, the quality seems fine and I cant complain. The CB is probably different as I think the K is identical for all years, but you can check the online fiche to make sure.
I would also think that many of the US on line stores are just selling the Taiwan/Chinese stuff they don't tell you were they came from
As mentioned above, Franks are good but certainly more expensive.
Anyway, just my $0.02
If I do buy I'll buy from the guy in Canada, and I'll also ask on the SOHC4 board.