Sagar: There is a common mis-conception about the basics of 'friction'. That friction depends on the area of contact. It does not. It depends upon the weight over that area of contact. One reason why you get more effective braking from the front wheel than the rear. And also why the rider is aked to squeeze the front brake lever rather than grab a handful of it for max braking. The point is to have a substantial weight transfer onto the front tyre before it is expected to provide a large braking force. And the 'one' reason why, even with a larger contact patch, the rear tyre cannot provide braking anywhere close to what the narrower front does.

Getting back from the digression, less lean allows you more traction reserve: true.

But the reason is not a larger contact patch. Modern symmetrical design tyres give you an alomst similar contact patch over the useable lean angle range. Hanging off keeps the bike relatively upright and this reduces the tangential component of the force that tries to slide the bike out of the turn, i.e. going off on a tangent to the turn's curvature. The steeper the lean angle - the greater is the tangential force that the traction has to counter. So, steeper lean angles of the bike allow you lesser traction reserves. Hanging off, and so 'un-leaning' the bike, gets you a 'traction-credit' that you can encash in case the already loaded suspension bottoms on a bump, the roads' coefficient of friction changes for the worse (shiny tar, old oil residue, gravel n dust etc etc) or you need to tighten the turn still further.

Hanging off though is a trade-off, as killer and joel have repeatedly reiterated. In that the rider is not in the ideal position to control the bike, to receive feedback from his 'seat-of-the-pants', his feet are not where they can provide maximum weight transfer and the arms are unsymmetrically stretched. BUT the 'traction-credit' is SO VERY important to get that this trade-off does not actually seem like one.

Also in my opinion more contact does not reduce speed when you are leaning a fair bit.

Woh Joke tha bhai

Woh Joke tha bhai

Hi Oldfox,
Okay now even I am a little bit confused So if I understand you correctly, it is the tangential forces rather than the reducing contact patch of the tire of your leaning bike that reduce traction at a given corner and hanging off the bike in turn helps you counter these forces. Please correct me if I am wrong and help me get this right.

Pranay : I believe most of us have solved various physics numericals on leaning and road banking in 9th class

And by the way "banking" of roads exists in India too.

But the reason is not a larger contact patch. Modern symmetrical design tyres give you an alomst similar contact patch over the useable lean angle range.

The race track at Chennai does not have banking angles. Its pure flat surface. Banking is on public roads normally. Unless its a NASCAR or Indycar race track.

....Maybe its because they want the rider/driver to do most of the work and not the banking angle to help you out.....

@ Pranay : I think the banking of roads is referred to as cambering

I quote from : Camber - Wikipedia, the free encyclopedia

"In road construction, the convex curvature of a road surface, see cant (road/rail)"

I'd like to add something here. While what old fox said is true, at the limits of lean you are always going to run out of tire contact patch and that WILL become an issue. So you have to take both the forces acting on the bike / tire as well as the contact patch into consideration. For example even on the superbikes with race profile tires, we are running past the shoulder of the tire and basically rounding it off. Thats how far we carry the lean and at that angle you're riding on VERY little tire. Ofcourse none of this is one the road. On an indian bike (apart from the R15) tire profiles are designed to provide the most contact patch while riding in a straight line and as you lean the bike you will run out of contact patch much sooner.