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So when most 250cc bikes come with a 130 at their widest? Significant difference between that and a 190...

For a tyre to maintain traction it needs to run at a certain temperature, too cold = lack of traction, too hot = increased rate of break down with no increase of traction.

The rear tyre disperses heat under the power of the drive train so that it's temperature can remain in this 'sweet spot'. Larger bikes produce more heat and friction therefore needing a bigger tyre. Smaller bikes don't so they don't need a big tyre. This is why front tyres don't differ as much in size, because they are not under pressure from the drive train. You'll find the actual contact patch on the road is quite similar between different tyre sizes, providing the bike's set up correctly.

Putting a larger tyre on a small bike would just reduce the overall temperature of the rubber = less traction, stability of the bike, make it heavier and less aerodynamic. So if you're running out of grip it's probably going to be one of the other things I mentioned, not the size of the tyre :)

I'm talking about the wet...the thinner tyre is going to be better in adverse conditions for a new learner like Rimon. See motorcycle section in this wiki:

http://en.m.wikipedia.org/wiki/Aquaplaning

These advantages diminish on lighter motorcycles with naturally wide tires, like those in the supersport class.

Supersport is 600cc. Light bike, wide tyre. So this 'dimishing' is only specific to this kind, and probably not by much. You said 'the wider the tyre the worse it makes you in the wet' but it's more about matching the weight to the width of the tyre, like the Wikipedia article states.

Most likely the bike won't be the thing to make the major difference in this situation. Learn to control a rear wheel slide and that may save you.

Edited by JEPPE

This guy explains it better than me:

http://indianmotosblog.com/aquaplaning

Case in point, Rimon thought that bigger tyres on a bigger bike would be safer to ride with, not always the case.

Congrats Rimon. One day or two? www.bikesales.com.au :thumbsup:

lol... I read the first line. 'Monsoon time in India'. I don't think we'll be getting those conditions here.

Motorcycle Weight: Lighter motorcycles are likely to hydroplane more than heavy motorcycles. More weight causes the tires to stay in contact with the road and clear out water more easily.

Like the wikipedia article said, 600cc bikes are more likely to plane because they are lighter plus they have wider tyres.

So you should be encouraging him to not buy a 600. Only a 1000 or 250/125.

This guy explains it better than me:

http://indianmotosblog.com/aquaplaning

Case in point, Rimon thought that bigger tyres on a bigger bike would be safer to ride with, not always the case.

Congrats Rimon. One day or two? www.bikesales.com.au :thumbsup:

thanks was a 1 day course. money first then bikesales lol

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