Wider Tires = More Traction . . . maybe not!

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Shuey, you should try a 190/55 rear tire on your scoot next time you need a tire.... it's only 10mm wider, a smidge taller. Give one a whirl. I personally won't go back.
 
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I jumped on the "wider tyres must be better" bandwagon back in 1986, and thought it might be good idea to fit a 160/60 x 18 back tyre on my VFR750, in place of the weedy 130/80 that was stock. The tyre fitted the rim OK, and cleared the swingarm, but ended up with a weird profile, flat in the centre and severely pulled in on the edges. Did not make for a confidence-inspiring leaning experience. As a slow learner, I also put a 120/80 on the front of the same bike, in place of the 110/80 stock tyre. This just added bump steer. Moral of the story is that IMHO going up one size on the back is OK, but no more, and be very wary of oversize front tyres. I am a stickler for staying with the OEM sizes now. Modern tyres have more than enough grip.
 
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+1 on this. Also,, consider a heavy wall carcass. Different tire builders designate differently,,, like Pirelli = A-spec,, or Metzeler = HWM (for heavy weight motorcycle). I find they track better when loaded up. cheers,, Cat'

Shuey, you should try a 190/55 rear tire on your scoot next time you need a tire.... it's only 10mm wider, a smidge taller. Give one a whirl. I personally won't go back.
 

ST Gui

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TerryS said:
flat in the centre and severely pulled in on the edges.
I've seen this on car where the tire is designed for a wider rim than the one it's on. I don't know there's that much difference in rim with for ST1100s an 1300s but I'd want to check that out.
 

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Good point ... video isn't showing (for me).

But those of us who've spent a lot of time working with snow and ice on the ground (such as on a farm where lack of traction is quite noticeable), have learned that too-wide of tires are usually worse for traction. Conversely, there's also a point at which the tire is too narrow. There's a tire contact patch size that is best for every surface. I'm not sure of the best size for a motorcycle, but generally the same points apply...
 
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Shuey

Shuey

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Shuey, you should try a 190/55 rear tire on your scoot next time you need a tire.... it's only 10mm wider, a smidge taller. Give one a whirl. I personally won't go back.
Thanks for the recommendation Ray, I'll give it a try this year.

"a smidge taller" . . . what's the impact on the ODO and Speedo?

Shuey
 
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Shuey, different manufacturer's tyres won't always be the same physical size, even though they are described as the same dimension. However as a general rule you can approximate the tyre height as width x aspect ratio%, so your 190 x 55 is 104.5mm. If you add in the wheel diameter/2 you will get the approximate radius, e.g. 17" x 25.4 / 2 = 215.9mm. Add that to you tyre height and you have 215.9+104.5 = 320.4mm radius. The effect on speed or distance will then be proportional to the change in radius. If you stuck a stock 180/55 tyre on the 17" rim the radius is 314.9. So the 190/55 tyre would rotate at 314.9/320.2 or 98.3% of the speed of the 180/55, or to put it another way, you would be travelling 1.7% faster/further on the bigger tyre than you were on the smaller, for the same speedo/odo reading. Given the usual speedo over-reading, that would probably be more accurate!
 
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Shuey

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Shuey, different manufacturer's tyres won't always be the same physical size, even though they are described as the same dimension. However as a general rule you can approximate the tyre height as width x aspect ratio%, so your 190 x 55 is 104.5mm. If you add in the wheel diameter/2 you will get the approximate radius, e.g. 17" x 25.4 / 2 = 215.9mm. Add that to you tyre height and you have 215.9+104.5 = 320.4mm radius. The effect on speed or distance will then be proportional to the change in radius. If you stuck a stock 180/55 tyre on the 17" rim the radius is 314.9. So the 190/55 tyre would rotate at 314.9/320.2 or 98.3% of the speed of the 180/55, or to put it another way, you would be travelling 1.7% faster/further on the bigger tyre than you were on the smaller, for the same speedo/odo reading. Given the usual speedo over-reading, that would probably be more accurate!
Awesome Terry, thanks for the detailed answer, so . . . what's a "tyre?"

;) Just kidding. I really do appreciate your response.

Shuey
 
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When I went to the dark side and mounted a CT on my ST, I found that wider tires have bad handling if you use high pressure. With my jeep I learned that off road was way more enjoyable if you aired down.... So I tried that with the wide CT on the bike and started airing down. The handing came back and the ride is way more comfortable. The traction is amazing. Lets just say I have fun instantly getting up to speed on the freeway on ramp.... It is also better on gravel or dirt roads. You can not compare today's tires to those made many years ago. Today we have sand in the tires which give them longer wear and better traction.... I run my wide CT at 28 psi. I will be changing it soon and will be on my third CT. My 70k+ miles of using a wide tire on my ST gives me the opposite opinion .....
 
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I replace them at 35k with a lot of tread left, just getting to the wear bars. I could put on another 5k+. That's two car tires vs ten MC tires. When you ride 20k per year that would be a lot of time lost in the shop. So it saves time and money.....
 
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