New tires / tyres

If it's broken or just needs tweaked

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larsenpedersen
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New tires / tyres

Postby larsenpedersen » Wed Dec 02, 2015 10:38 am

Hi guys,

I'm looking for new tires / tyres for my CB650 from 1979.

The bike is currently running 12 years old(!) Bridgestone Battlax BT-45 on the comstar rims:

Front: 100/90-19M/C 57V
Rear: 120/90-18M/C 65V

I would love to spice the bike up with a couple of Shinko 705s, but I'm in doubt whether they'll fit.

I'm looking towards:

Shinko 705 120/70R19 (front)
Shinko 705 70R18 (rear)

Do you guys know whether they'll fit?
Recently bought a Honda CB650

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Thu Jun 02, 2016 9:32 pm

Twelve years old? Ha. I'm pretty sure the tires on my 1980 CB650 are OEM. The bike had just 6226 miles on it when I purchased it, and I know the guy before me didn't put tires on it... and the guy before him, the original owner, had garaged it for 20 or so years before selling it.

So I'm also in the market for tires. I'm interested in knowing what the best value is, that is, the tire that gives the most for the least. Not the cheapest, necessarily, but the least expensive good tires.

Any suggestions? What are you all running?

navydad
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Re: New tires / tyres

Postby navydad » Thu Jun 02, 2016 9:47 pm

Shinko 712's and I am very happy with them.

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Thu Jun 02, 2016 11:24 pm

Check me on this... the 3.50H19 front tire converts to 100/90H-19, and the 4.50H17 rear converts to 110/90H-17 or 120/90H-17 in metric, right? Every time I read the explanation of converting the sizes, I think I understand, and then somehow the understanding leaks out of my brain.

... it's not like I do much thinking, I'm only a computer programmer ...

I have found the Shinko 712 in a 100/90H-19 for the front, but I don't find that tire in the sizes above for the rear; the closest is 130/90H-17. Is this what you are running, navydad?

navydad
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Re: New tires / tyres

Postby navydad » Fri Jun 03, 2016 9:44 pm

130/90 16 on the rear, but my bike is the Custom version with a 16 inch rear wheel. The front tire is the 100/90 19.

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sat Jun 04, 2016 9:36 am

Finding a rear tire for this bike is driving me nuts.

According to the conversion chart here:

http://www.maxxis.com/other-motorcycle- ... ire-school

... the rear 4.50H-17 translates to a 110/90-17 or 120/90-17 in metric. I reviewed the metric sizing rules once again (let's see if it sticks this time) and my math agrees more or less with the chart... a 110mm wide tire is about 4.3 inches, while a 120mm tire is about 4.7 inches.

So I go looking for these sizes. As a rear tire, the 110/90-17 basically doesn't seem to exist. I can find 120/90-17 rear tires in tubeless, but there are few tube-type, and when you eliminate the dual sport tires (I'm not building a scrambler, after all), the list gets very short indeed... like, non-existent. Using Bike Bandit's sizing tool, I find three dual-sport tires in the 120/90-17 size as tube type tires. No street-style at all. Gah.

The 110/90 tire size would be 99mm tall, while the 120/90 would be 108mm tall. navydad says he has a 130mm tire on his bike's back end; while he has the custom, and I have the standard, I have no reason to believe that width wouldn't fit my bike just fine. A 130/80 tire would be 104mm tall, so it would fall in the height range of the suggested tires.

Back to Bike Bandit. Searching for that size, I find three dual-sport tires and the Bridgestone Battlax BT45. Looking at the listing, I discover that the only tube-type tire in the rear tire section is the 130/80-17... all the rest are tubeless. But the darn thing is $132.95... ack.

Guess I'm cheap.

The nice thing is, the same tire is available as a front tire in 100/90-19. It's $109.97, not quite as much, but there you go. At least they'll match.

Am I missing something? Are there other options I haven't found yet?

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sat Jun 04, 2016 9:52 am

I should mention, I just found the Kenda K676 RetroActive, which is available in a 100/90-19 size. One vendor on Amazon.com has it for 49.99 plus 12.20 shipping, which is the best price for that tire I've found. Sadly, the K676 doesn't come in the 120/90-17 size at all; the smallest 17" rear tire size is 140/80-17. That would be a 112mm tire height; the extra 4mm probably won't make a difference, but the tire (according to Kenda) is about 5.6" wide; that's about a half inch more than the 130, reducing the side clearance by a quarter inch on each side. And then there's the question of rim width... would a tire that wide work correctly on the stock rear rim?

I wish I knew more about this. I know just enough mechanical stuff to be dangerous.

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sat Jun 04, 2016 10:02 am

Just found the Bridgestone Battlax 130/80-17 on Amazon.com for $103.45 with Prime shipping. I can get that and the Kenda front for a total of $153.44... that's a price I can live with. The Kenda is described as a sport tire, while the Bridgestone is a touring model... I take that to mean the front will have more traction than the rear, and again, I can live with that (the opposite can be painfully surprising, I've discovered).

I'm going to wait until tonight, to see if anyone jumps in with a warning here... and then I'll probably go ahead and order them.

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tario
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Re: New tires / tyres

Postby tario » Sat Jun 04, 2016 10:52 am

I just picked up those Bridgestones in 120/90 17 and 100/90 19 from the local shop. Last year I had bought Durotour rs-310 tires in the same sizes. On my 1979 they are about as big as i would go. Although my 1980 has a 130/90 17 with a bit more clearance. I think it's a slightly wider swingarm. Can't remember what tire is on it.

Durotour rs-310 seemed fine. Rear lasted me 7000-8000 kms, front is still going strong. I don't know that they are any cheaper than the B-stone Battleaxe though.
1979 cb650
1980 cb650

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sat Jun 04, 2016 10:42 pm

Huh. The 120/90-17 Battlax is tubeless only, according to Dennis Kirk anyway. But the fact that you have a 130/90-17 on a 1980 CB650 gives me confidence the tube-type 130/80-17 Battlax will work on mine.

I'm right now placing an order with Dennis Kirk for the 100/90-19 front and 130/80-17 rear Battlax tires; they have the best price I've found on those tires, especially when accounting for shipping costs, and I've had positive results doing business with them before. With IRC tubes and some rim strips thrown in, the total is just under $220.00, which I consider reasonable.

Incidentally, I looked closer at the tires on the bike and they are Cheng Shin. If I remember rightly from back in the 80's, Honda sourced a lot of tires from them, but I'm not sure they are even still around. I'm about 100% certain mine has 36 year old OEM tires on it, and I've gone 650 miles on them... egad. Not riding it any more until I have new tires on it, that's for sure.

cb650
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Re: New tires / tyres

Postby cb650 » Sun Jun 05, 2016 7:48 am

Why has no one asked where he is from? Or looked at his bike? he does not have a 17 rear. He has a 18.
The 17 wont fit your bike. Unfortunately chen shin is no longer around. I have been using dunlop 404's and like them well.
Dont know if you can get it in a 18 rear though.
Did you clean the tank out?!?!?!?!

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sun Jun 05, 2016 10:33 pm

HOO BOY. You just caused me some alarm... I thought I had the wrong thing on order, but I don't think I do.

The tires on my 1980 CB650 are Cheng Shin 100/90-19 front, 120/90-17 rear. Read right off the tire, just a minute or two ago, with a bright flashlight so I'd be sure I read it right (even though I have overhead lighting in my garage). The rim measures 3 inches wide as best as I can tell without removing the tire (i.e. holding the tape measure in there and eyeballing it) so I think I meet the stated requirements for the Bridgestone Battlax 130/80-17 rear that I ordered.

INCIDENTALLY, Cheng Shin DOES still exist... Google led me here:

http://www.csttires.com/int/moto/

I have no idea why they aren't carried by the likes of Dennis Kirk, Rocky Mountain, or Motorcycle Superstore (places where I buy stuff online). Their model C6017 tire comes in the 100/90-19 and 130/80-17 sizes I ordered as tube type tires, so I could have gotten them just as easily. They don't have the 120/90-17 in tube type; it seems to be rare everywhere.

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sun Jun 05, 2016 10:39 pm

... okay, so Motorcycle Superstore does carry Cheng Shin tires, but only for off-road purposes. Likewise Amazon.com sells their off-road tires, and one 10 inch tire that must be for scooters. Bike Bandit sells their off-road tires as well as their bicycle tires.

Are they, perhaps, no longer DOT approved? Strange.

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Solomoriah
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Re: New tires / tyres

Postby Solomoriah » Sun Jun 05, 2016 10:48 pm

... and now I see that you were talking about the OP. Sorry for confusing the issue.

Does he have the Custom, then? The rear wheel on the standard CB650 from 1979 was (according to the shop manual anyway) a 17 inch.

EDIT: As far as I can tell looking at the parts fiche, the 1979 CB650 had 17 inch Comstar rims. For 1980, they split off the Custom with a 17 inch rear Comstar and put spoked wheels on the "standard" CB650's like mine, but again with a 17 inch rear.

cb650
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Re: New tires / tyres

Postby cb650 » Mon Jun 06, 2016 1:53 am

look at his bike!! it is a non USA Z model that got regular comstars with a 18 inch rear. Thats why in his original post he asked about 18 then you steered him to 17 NO
Did you clean the tank out?!?!?!?!


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