TIRE TALK - when the rubber meets the road

Not a stupid question at all! Much better to double check on something that important. Ed

One thing I've noticed since my Shinko 712s were put on, my front end bounces a little from 30-40mph. I checked the tire run out and it doesn't look bad. The spokes were tightened by the shop but i don't think they trued it. The fork oil is 20+ years old so I should probably change that. The bounce isn't too bad, but you always want everything to be perfect.

And you're totally right about the look, much more modern. I like 'em.

Be sure to check the air pressure, it might be too high if you're getting bounce.

i never thought this mattered much ...but learned(here on kzr 4 years back) i was wrong for years and riding around problems rather than spend money when tires(old-used-worn-or new but sliders) were the issue all the time ...but all tires are not the same...i will never buy anything but avon roadriders for a street kz now that i am used to em...and will replace em once a year just to have the softness of a new tire....i was wrong before...dead wrong


but ed is right about bounce imo...whatever the tire

always works...... change it around some too and it will respond

for me 34-36 front is a good start...36- 38 rear

32-36 is what i put friends bikes at ... whatever it is i like...2-4 more in back than in front

650ed wrote: Be sure to check the air pressure, it might be too high if you're getting bounce.

650ed wrote: Since the inception of the internet I have bought my tires online from motorcycle tire or accessories dealers (not private parties or eBay). Prior to that I bought them from a Commercial Tire center (they would order them in for me at a good price) - never from a motorcycle dealer because of their crazy markup.

Yeah, the kids today don't know how good they have it with the internet. When I bought my KZ750 back in '79, the only sources for tires around here was the dealer or JC Whitney who only sold cheap tires like Cheng Shin and charged up the wazoo for shipping.

Around 1981, I read an ad in one of my bike magazines where Avon was selling their Roadrunner tires direct to customers and at a very good price. I bought three of them. When they arrived, I took one and the rear wheel to the dealer to get it mounted.... I swear this actually happened:

The guy at the dealer happened to be the manager, I handed him the tire and the wheel. He looked in the tire, and saw a piece of paper (I hadn't noticed it). It was the invoice from Avon. His face turned beet red and the veins in his forehead popped out as he yelled:

"I don't believe it! This is the same price I'm paying! They're not going to get away with this!"

What I didn't realize was the reason there were no "discount" places for name brand tires back then was because the dealers would boycott any brand that discounted, so it was a gouge fest at the dealer for tire prices. The magazine ad never appeared again for the Avon tires, I remember kicking myself for not buying more at the time I had the chance.

Of course now the dealers are getting squeezed to death by the internet sellers..... it's true what they say: Karma's a bitch.

Ed, you're correct, it was the rear tyre. Doubt I'd be able to save a front end collapse.

I just put on a set of Avon Roadrider AM26 on my 1978 KZ (spoke wheels).

3.25V19 in the front and 4.0V18 on the rear.

I am still a little bit away from having the bike running so I don't have any personal first hand experience with this tire yet. But from what I have been told by a friend of mine is, who raced the CCS Southwest Vintage Champion Series, that these tires are the Bomb!

We'll see how the work hopefully soon.

I wish Shinko made their 007 Hookup series for an 18" rim.
The drag race guy's swear by them.

I just put a set of GT501's on my 650F1 and like then
so far. Their the old K591 carcass with a more modern tread.

So I have to admit, when I took the new Shinko's out for a spin (~60 miles or so) I experienced a serious high-speed wobble. I have to assume it was above 80mph, as I was passing caged traffic on the interstate between IC/CR IA. This is a 70mph high-traffic corridor between two more active Iowa cities so I may have been hitting 90mph+ as I passed the cages.

Once I relaxed and hit the 'groove' of four-square wear it settled down a bit; still it was way more than I'd ever experienced with the old dunlops until I hit triple digits.

Certainly got me thinking; I'm not one to roll off the throttle outside of regular traffic/speed control but this got my attention.

Is this typical of new tires on the bigger bikes or what? Biggest I rode, with hours in the saddle before, was a 650 sport/crotch rocket. Aside from the usual body positioning, I never felt the wobble like this.

I'm going to adjust TP a few pounds lower once I get back on the road for the front, but...as always, advice is welcome from KZ1000/1100 riders. Not tryin to tank-slap at highway speeds after I spent 10 hours working on the bike aye?

Not normal. Things to check would be tyre/rim runout, air pressure (at least 36 PSI in the rear, can go as high as 42), wheel alignment, steering stem bearings and swingarm bearings.

faffi wrote: Not normal. Things to check would be tyre/rim runout, air pressure (at least 36 PSI in the rear, can go as high as 42), wheel alignment, steering stem bearings and swingarm bearings.

Bike rode well on the old tires, I haven't changed anything on the steering stem or swingarm bearings aside from installing the rims, everything went back together without any issues AFAICT. Hoping it was just an over-inflated front. Seemed like the bike settled once I was in the usual left/right groove on the road, changing lanes and riding the center crest was what gave me the 'wobble'.

I'll update soon. Waiting for an accurate tire pressure gauge and some other stuffs

Not normal.