Best 2005 Yamaha Tmax Tyres?

[rjc1944]

OK, I'm not a technical whizz. BUT, what causes "rolling resistance" in a tyre if it's not its grip level? I can understand getting lower rolling resistance by swapping to narrower and/or higher profile tyres but if they're the same size how do you reduce rolling resistance without compromising grip?

[michaelphillips]

im no techi on tyres but i would reckon its down to the compound , think of bridgestone tyres technology in motogp etc.. not sure if any muppet has tried the sc ecopia, it came out about 6 months ago.., i have always found bridgestone to confidence inspiring the SC Ecopia is a new compound in their words ' Advanced compound with patented NanoPro-Techâ„¢ technology '

[Greyerbeard]

I rode a friends MK3 with Pirelli Diablo and found the rear end to be squirrely in the dry... dread to think what it would be like in the wet. (500 miles on the tires, scrubbed in to the edges, correct pressure)

I am on Bridgestone BT's at the moment as that's what the new TMax (5 year old) came with... I don't want to chuck money away by just changing to SC's or SC Ecopia but on my first TMax when I got SC's it was so much better, they felt so much more planted.

Thanks.

[gn2]

OK, I'm not a technical whizz. BUT, what causes "rolling resistance" in a tyre if it's not its grip level? I can understand getting lower rolling resistance by swapping to narrower and/or higher profile tyres but if they're the same size how do you reduce rolling resistance without compromising grip?

From my experience on a bicycle, air pressure.
High pressure means less resistance from the same tyre, so maybe its about how the tyre bends as it moves.
Bendier tyre, more resistance?
Bluebottle might be along in a minute with the science.

[Bluebottle]

You rang....

Welcome Ricstar


Rolling resistance is how hard it is to roll something.

Ignore grip for now, it plays a very tiny part but isn't the same.

With a tyre the resistance is mostly because the tyre gets squashed out of shape where it touches the ground. The energy used to deform the tyre is energy you can't use for moving forward so it is wasted. The tyre puts up resistance againt getting squished, it resists the roll.
Much of that energy becomes heat because you are moving the molecules of the tyre, stressing their bonds and rubbing them against each other, which is why your tyres get hot.

Think of a marble on a tile floor, easy to roll and keeps going because nothing is wasted deforming any materials.

It might seem like a very small thing but grab hold of your front wheel and try to squeeze the tyre until it has a flat spot.

Some energy is recovered as the tyre springs back but not all of it. Even though you are returning to the original shape you are pushing all the molecules about again and they get grumpy when you do that.

As GN2 said, high tyre pressure reduces rolling resistance (the tyre deforms less), and low pressure makes it worse.
An over inflated tyre rolls easier but loses grip. An under inflated tyre will run hot because it is rubbing molecules against each other.

So...
The real problems is that we want the tyre to deform because it gives us a bigger contact patch, shapes itself to the road, doesn't skip over bumps, increases grip and gives a smoother ride.

Making the tyre more supple helps. Modern tyres replace a lot of the carbon content with other substances that allow better movement within the material, the molecules are a bit more laid back about their neighbours movements. They still flex but they rob less energy when they do it. After that we get into seriously technical stuff.

So a bendy material gives a different result to a bendy under-inflated tyre.

Another source of rolling resistance is the tread pattern. Notice how modern tyre patterns tend to go along the tyre instead of across it like they did years ago.
An off road or M&S tyre will tend to have a chunky tread. On a smooth road the bike has to climb up each little block of tread.
The blocks also squirm around and throw away useful energy.

You can view deformation in this way too, the tyre is constantly trying to climb out of the flat spot.

A good low rolling resistance tyre will make a difference but it is only ever a tiny fraction of the benefits that aerodynamic changes can give.

Hope that isn't too much like gobbledygook ?