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[Jester]

Good Moaning All,
A question about front tyre profiles and the unscubbed areas at the side - why? There's an immense amount of discussion about chicken strips on the rear tyre, but not much out there about the unscrubbed strips on the front.
I've heard a few reasons why this may be, such as the profile needing to be like that for the handling to be correct, but I can't see how an area of the tyre you never use can contribute to handling characteristics.
I've also read that suspension settings and tyre pressure can affect whether you use this bit of the front, but I would not of thought it would affect it all that much.

Most of the bikes I've had generally have matched tyres re make\model, or as close as damn it, and on some even getting right to the edge of the rear tyre I've loads left on the front edges. Every road sportsbike I've ever bothered to check shows the same.

Race tyres seem to get the edges scrubbed, but they usually run quite different pressures\profiles etc to road tyres and they're usually starting to get off the edge of rear so not sure we can look at that for an explanation.

I would of though it would be better for road tyres to either soften the curve so we use the front edges more (which thinking about it would also increase the contact patch), or just make the tyre thinner and do away with the unrequired rubber - probably cheaper and lighter.

The only time I've ever got close to scrubbing to the edge of the front is when lowsiding a bike 

Thoughts please!

[NinjaPaul]

The only time I've ever got close to scrubbing to the edge of the front is when lowsiding a bike 

Think you might have answered your own question with that statement.

[Jester]

Not really. I'd expect the contact area to be in the same place on both tyres on the same bike for a given lean angle. This doesn't appear to be the case in vast majority of cases.

[Chrisblack10r]

Braking under steering can load up the front tyre giving greater pressure through tyres and scrubbing them

accelerating under steering will lighten front and cause less scrub

this is what ive found on the tyres i've had on bikes

[Bobtra69]

I have found that the wear pattern on my Aprilia Dorso 750 twin is totally different to the ZX and the Blackbird I ride, with much more unused tyre on the Dorso. I use the engine braking on the twin so much more and less actual front end braking so I'm guessing this is reason for it.

On the fours I load the front end as much as i can and brake quite late into a corner, almost to the apex so this would scrub the outside of the tyre more.

I guess it's how you ride individually....

[Luwi Kawasaki]

I found the bridgestones wore evenly on the front and back, scrubbed to the edges front and back.
Pirellis on the other hand, seems to be a little more difficult to get the front tyre scrubbed right to the edge.

I think the shape of the front tyre has something to do with it. Pirelli fronts seem to be more triangle in shape compared to the bridgestones, if you know what I mean 

[doug_zx10r]

If you ran a 190/55 on the front then the wear would probably be identical, it stands to reason that a thinner tyre can't have the same profile as a wider rear.

[mc101]

Good Moaning All,
A question about front tyre profiles and the unscubbed areas at the side - why? There's an immense amount of discussion about chicken strips on the rear tyre, but not much out there about the unscrubbed strips on the front.
I've heard a few reasons why this may be, such as the profile needing to be like that for the handling to be correct, but I can't see how an area of the tyre you never use can contribute to handling characteristics.
I've also read that suspension settings and tyre pressure can affect whether you use this bit of the front, but I would not of thought it would affect it all that much.

Most of the bikes I've had generally have matched tyres re make\model, or as close as damn it, and on some even getting right to the edge of the rear tyre I've loads left on the front edges. Every road sportsbike I've ever bothered to check shows the same.

Race tyres seem to get the edges scrubbed, but they usually run quite different pressures\profiles etc to road tyres and they're usually starting to get off the edge of rear so not sure we can look at that for an explanation.

I would of though it would be better for road tyres to either soften the curve so we use the front edges more (which thinking about it would also increase the contact patch), or just make the tyre thinner and do away with the unrequired rubber - probably cheaper and lighter.

The only time I've ever got close to scrubbing to the edge of the front is when lowsiding a bike 

Thoughts please!

Profile and geometry of the bike dictate how much of the front tyre is used.  Road bikes (and road tyres)  are setup conservatively - simply because most of us wouldn't save the front end if we rode off the edge of the front tyre.  So they are setup so its next to impossible to ride of the edge of the front.

Race bikes (and race tyre profiles) are setup to allow you to push to the edge of the tyre and use the largest possible contact patch at the same time.  Mega grip but a knife edge if you get it wrong ..

[Jester]

Cheers for the info everyone, makes more sense. Looks like I'm also not taking weight transfer\tyre load and deformation in to account. Thinking about my riding style I'm slow in, fast out and generally don't trail brake\push the front into bends so unlikely to use the front edge anyway.

[robbosliding]

I melt my front tyres (racetecs) almost to the edge on the track at track pressures (29 on the front) but I don't do that on the brakes - I would have thought any braking over at that angle would wash out - I don't use the brake over 30 degrees of lean. Even through the heaviest deformation the tyre would not scrub the edge I wouldn't have thought. Certainly as stated the slicks or race profile tyres are more pointed giving a better contact patch when leant over. The last 5mm on my racetecs are almost untouchable, in my cack hands anyway 

[doug_zx10r]

There's some good slo-mo shots of tyre deformation on some of the TT clips on youtube.