I wanted to pass along my experience with the Shinko 712's. A lot of people ask about them as they are a popular budget alternative for vintage bikes. I just put a set on my K8. My reasoning was that I don't push this bike as hard as my modern bikes and as far as tire performance, they will be superior to anything from that era anyway.
I mounted the front and the tire shop did the rear (because I was getting another set mounted on another bike and only have 1 front stand). My first time out was to meet up with a friend for a ride and the front had a bad wobble. When I got on the highway it was frighteningly bad, so I had to get off and ride slower speeds. I got to his house and notice the light spot mark was a few inches off the valve stem, guess I didn't notice it moved slightly when I was mounting. So we let air out and spin it while still mounted, but that made no difference. So off to the tire guy for a balance. It was off several ounces! He spun the light spot to the opposite side of the valve stem and it balanced and needed no weight. He said he's seen that before even though the rear was opposite. So I mount it back on the bike. Well, the wobble was still there just as bad. So now I take it to the only guy I know who will still true rims an hour away and I have to drop it off! He calls and says the rim was nearly perfect and bearing were good. He tweaked it a little bit but basically the tire was bad. I sent the tire back and got a new one and not taking any chances, took it back to the tire mounting guy this time. He mounted with the light spot at valve stem and it didn't take any weight and this one is fine.
If I would have reviewed them as they are now I would have said they really feel great and were an excellent bargain. But, the reality is, because of quality control issues, I drove to mounting/balancing guy 20 minutes away 2 extra times, drove 4 hours total to rim truing guy, gave him a $20 just for taking the time, paid $35 for 2 balances and 1 mounting that I didn't need, the bike was down for 2 weeks, both guys gave hell for buying cheap tires and I didn't even get to ride with my buddy because we were in his garage screwing with it. Was it a bargain? Not at all. This is the first time I've ever purchased motorcycle tires that were not manufactured in Europe or Japan and I can't imagine I'll ever do that again. Figured I'd pass this along in the interest of helping others make an informed decision.