For many years I've been a fan of the Shinko 705 tires. Over the years I've mounted six fronts and thirteen rears. I never got the kinds of mileages out of them that many people seemed to get, but then again, I never seem to get 9 or 10 thousand miles out of any brand of rear tire. The Shinko fronts lasted about 7500-8500 miles for me, and the rears were always in that 4500-5500 mile range. I do a lot of two up riding though, so that's to be expected.
They were good all around tires at a very economical price. The front tires tended to cup in a really weird way when they got up near 7000 miles, but that was probably my only gripe about them. They were good on wet roads, and did well in dirt and gravel. However, my most recent experience with them has sent me on a quest to find a different tire.
This month I put on a front replacement Shinko 705, and noticed a handlebar oscillation in the 30-40 mph range. I went through all the standard procedures; tire pressure, headset adjustment check, fork alignment, wheel bearing check, wheel runout, etc, and still had the oscillation. I put the old 705 I had just taken off back on the bike, and the oscillation was gone.
So I returned the tire as a warranty claim, and got another Shinko 705 for the front. And the same thing happened. Same oscillation, same speed range, and one again I went through all those maintenance procedures to rule out everything. I still had the oscillation after doing all that. So I borrowed an old Anakee 3 off a buddy and put that on, and boom, no more oscillation. I ended up returning this Shinko 705 as another warranty claim, and now I'm waiting on a Bridgestone A41.
The first tire had a date code of 1722, and the second was 0223, so that's about 9 months in between manufacturing dates. So it's kind of tough to write it off as a fluke during a single manufacturing run. The old Shinko 705 I used when I did the first swap had a date code of 4720, and that tire did not induce the handlebar shake. Maybe it's a pandemic hangover induced quality control issue, or a change in the manufacturing process, or something else; I don't know. But sadly I'm going to have to move on from these tires, at least for now.
I expect I'll go back to the Mitas E07 tires (not the "+" version) once I burn off this A41 and the remaining Shinko 705 rear.