car rear tire for KZ1000ST

:huh: I am running a 1979 KZ1000ST, Shaft (E1) with a Friendship California II sidecar. Right now there is a 150/70 17 rear tire on the bike. When replacement time comes (not too far away) I would like to put an automobile tire on the back for longer tire life. Has anyone done this? What size would fit? It doesn't look like there is very much clearance now and the smallest car tires I see are either 210 or maybe one 195 width. Thanks for any help advise, etc. Any bike tire that has looong life?

You may want to check these out. Ed

Really, car tires are designed for cars motorcycle tires are designed for motorcycles. Motorcycle tires are designed to allow the bike to corner smoothly and safely. Car tires are designed not to lean over on it's edges in a corner but sit flat on the ground for a large contact patch. Once the car tire is leaned over the contact patch goes away unlike a motorcycle tire you will notice the contact patch while leaned over still remains large a lot larger than a car tire leaned over. Just put tires on that were designed for motorcycles. Yes the bike tires do wear out quicker but who cares for the price it's not an issue.

but I'm running a sidecar rig and do not lean over, also wear tires much quicker than the usual 4-5,000 miles if I'm lucky

Im guessing you still lean in left hand corners anyway.
Those good year motorcycle tires back in the 80s looked more like car tire when viewed from rear.

Not really, more of a hang off to keep the rear wheel on the ground. If anything, I usually don't turn that fast any more. I use front brake and the hack goes around the front wheel to the left.
Mel

I think it's called going to The Dark Side when you put a car tire on a motorcycle. Not that I would do it, but it's not uncommon w cruiser type of motorcycles, such as the Vulcans. Not that I agree, but some of those guys are adamant that it is perfectly safe & that the contact patch is the same as a motorcycle tire. There are discussions about it over at the kawasakimotorcycle.org site. I have no idea how a car tire would perform w a sidecar, but I'd guess it would be safer on a hack than on a motorcycle w no sidecar.

Another possibility was to change the rear wheel with a 16 or 15 inch wheel off of a Vulcan or other Kawasaki shaft driver. Does anyone know if the wheel off a different bike will fit on the KZ1000ST drive gear? There are more suitable tires for what I want in those sizes.
Thanks,
MotoMel

I'd be really surprised if you could find such a narrow car tire that fits a 17 inch wheel. Generally cars run smaller wheels, if they have a 17" they probably trying to be sporty, and so they'll opt for a wide tire as well. I can't find anything under 195, admittedly I didn't look all that hard, but I can imagine finding too much that's narrower than that, don't know what kind of car would run something like that.

I can see what you're saying about not leaning over though. I'd probably be inclined to agree with you that it should work for a sidecar scenario. You'll probably lose a decent bit of traction though. I'm guessing cars uses harder tire compounds to get the extra miles, so they'll probably grab less, make sure to adjust your riding to suit.

Del_Herring wrote: ..... You'll probably lose a decent bit of traction though. I'm guessing cars uses harder tire compounds to get the extra miles, so they'll probably grab less, make sure to adjust your riding to suit.

I think that is an excellent point. If a car tire is going to go approx 60k miles before needing to be replaced the compound must be different than that of a bike's tire. I wouldn't think the longer life is simply because the car tire has a larger contact patch and 4 tires vs. 2 on a bike, because that would be offset by the fact that a full size car weighs about 8 times as much as a bike. Ed

it is very common to use car tires with sidehacks.
they do not lean either direction(unless it is a leaning sidecar)so they can get away with running car tires.







i believe i would buy another rear wheel for your bike and send it to www.kosmanspecialties.com/
and have them widen it to fit the tire you want to run.
that way you know it bolts on and won't have any fitment issues.

here is a leaning side car so you fellers can see the difference.


hth,
leon

531blackbanshee wrote: it is very common to use car tires with sidehacks.
they do not lean either direction(unless it is a leaning sidecar)so they can get away with running car tires.
...
leon

That is only true is sissy types. :laugh: :laugh: :laugh: When I worked in D.C. I saw D.C. cops lean their sidecar bikes WAY over on the left hand turns every day on Rock Creek Parkway. But I suspect if you're gonna be a cop in our nation's capital you better come equipped with industrial strength balls. :laugh: :laugh: Here's a pic of a D.C. cop with a mild lean; I wish I had pics of some of those guys that were really flying high; they were so used to doing it they thought nothing of it. Ed