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I want to run a 190 rear on my X-11 its the same arm as the bird .. I am told the tyre will fit and the 190 / 50 will give the same approximate geometry as 180/55 which will take care of any handling issues ..

The 190 also looks much better :) ..

Any comments?
 

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I know people do it, but a 190 is designed for a 6" rim. Because you are pulling the sidewalls in there is a danger that you end up with less rubber on the road!
 

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Ah HA! I keep finding out sh-i mean stuff here.:smilebig: Last nights ride produced a couple corners where upon exiting under power, I felt the rear moving just a bit. Found I have a 190 but need to see what the wheel is but guessing a 5 1/2. Would it be better to reduce shim say to 3 or 4 if thats the case?:confused: Or is that what squishy ass means?:huh::idunno:
 

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No Perry.. As the Duck correctly says there will most likely be less tyre surface area on the road meaning less grip. This happens because when a tyre is designed as you would know it is meant to fit a certain size rim, when correctly fitted to the correct size rim the curved area that contacts the road is at its optimal. When you fit a larger tyre that a rim is supposed to take then you forcibly compress the bead width of the tyre, this also causes the curve on the grip area to become more pronounced. SUrface area contacting the road when running straight will definately be less (assuming manufacturers tyre pressure recommendations are met) so this will lead to pronounce wear at the top of the curve of the tread area. It also means that the curve on the side of the tyre may be more pronounced too when cornering and again less surfave area less grip.. (also as per straight running more wear on the narrower used surface)
 

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To quantify my squishy rotten ass term a bit . . . I found that the bike required more effort to change direction, and never felt planted when leaned over. The 190 in question was a Dunlop Sportmax Qualifier, it should have had at least as much grip as the BT-021 it replaced (and then some, I'd think) but it just felt squirrelly.
 

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Was the bt-021 also a 190?
 

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Then the feeling was most likely caused by the additional curve forced into the tread area.
 

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I have often run hand me down 190s on the bird that came from my other bikes. Performance wise there is bugger all difference. If you have a 190 laying around fit it. Otherwise just buy the 180s as they are cheaper. For what it is worth I do ride to the very edge of the tyre. Paul.
 

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i have a 190/55zr17 rear tire on mine and to me she feels alot better than a standard 180/55zr17. i normally run michelin power pure or pilot power. but i put on a set of shinkos same size efore i left for korea i only put about 300 miles on the new tires so can't really say if i like them.
 

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I had the Bridgestone Motorcycle European Product manager come along to our bike group.

Apparently when manufacturers make tyres they have an allowance of +/- ??%. I think it was 5% either way. Anyways you can fit a "190" which is narrower than a "180"

e.g. 190 - 5% = 180.5
180 + 5% = = 189

Yes I know I've not helped and have just confused the situation more!!

You can call the manufacturer and ask what the real sizes are.
 

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Ive always run the recommended tire sizes with the exception of my FZR which came speced for a 130 front (weird)/ 170 rear. I think if you don't like the grip or don't get confidence in how it holds a line you should just switch compounds/makes..FWIW
 

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It isn't idea, but it works fine, even for very "spirited" riding. the one thing I don't like about it is that you're not at all likely to get all the way to the edge of the tire, so if you do lots and lots of hardcore twisty riding at deep lean angles (or track days) the side area will wear down, but you end up with a raised ridge in the "chicken strip" area. Once that happens you get wierd mojo and reduced traction if you roll up onto that ridge. I put a new 190 on my bike before a deal's gap weekend a while back, and when I returned there was a ridge about 5mm wide and 3 or 4mm tall.

Note that this is only an issue if you're strafing twisties to such an extent that you're wearing down the sides of the tire faster than the middle. At reduced lean angles/wear rates this is a negligible effect.
 

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I've run both 180 and 190 on my ' 97. Bugger all difference to be honest. Both tires fit on the OEM rim without drama, but the 180 will give you quicker turn in while the 190 settles the bike down and makes it more predictable. I've settled on 180/55. Pilot Power 2CT. 36/38 cold. I'd avoid Pilot Pures as they made the scooter nervous as hell. They tried to turn the fat old lard-ass girl into a sports bike. Not good. Took them off after 500kms and put tried and tested 2CTs back on. My 2c. Gaz.
 

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I had the Bridgestone Motorcycle European Product manager come along to our bike group.

Apparently when manufacturers make tyres they have an allowance of +/- ??%. I think it was 5% either way. Anyways you can fit a "190" which is narrower than a "180"

e.g. 190 - 5% = 180.5
180 + 5% = = 189

Yes I know I've not helped and have just confused the situation more!!

You can call the manufacturer and ask what the real sizes are.
Yeh mate and to add a little more interest to the topic consider this. The predecessor to the bird, the cbr1000f, ran a 17x5.5 rim and was fitted with a 170/60 tyre. Take the actual smallest 170/60 and compare it with the largest 190/50 and the difference is obvious yet they all work perfectly well on a 5.5 inch rim. Paul.
 
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