Cornering

[Mickle]

Evening org.

I can't work this out so what do you lot think?

I have 2 bikes my sv650s k2 fun, and a ****ty old honda dullsville for plodding around, in 18 months I have put over 10000 miles on each ( I don't have a car! ) both are fitted with pr3's front and rear. I also like a pie or three so am about as round as I am tall.

The honda corners ok and the rear tyre has wear on the entire threaded area right to the edges,

The Suzuki will corner at higher speed but I have close to an inch of untouched tread on either edge of the rear tyre!!

I'm surprised at this, the Suzuki is quite a bit faster in the corners and a LOT more nimble.

I'm not at all bothered about changing this but am baffled as to why and it is doing my head in, so anyone got any ideas ?

The SV's contact patch is a quite a small radius and maybe 160º of a circle. The dulllville is not set for cornering at such large lean angles, the contact patch has a larger radius and is only maybe 140º of a circle, hence no chicken strips for the same lean angle or less. If you've got an inch on your SV, then there's a lot more lean available.

[Bibio]

i would say that the front of the SV is sitting lower. whats the CS like on the front tyre?

BTW see those blobby bits on the foot pegs.. well thats your maximum road tyre lean angle of 45deg, once you start scraping those then your running out of rubber but this all depends if your bike is set up properly e.g. sprung for your weight.

[Stilo]

[QUOTE e.g. sprung for your weight.[/QUOTE]

Is there a definitive guide to this somewhere?

[Red Herring]

Personally at this time of year I'd be quite content with an inch of chicken strip....

My advice is don't worry about it. As has been pointed out different bikes with different rim widths will behave and report accordingly, just continue to corner in your comfort zone and pay some attention to what the bike is saying to you. As your confidence builds so will your ability and performance. The only time I go to the edges of my SV tyres is on the track.

Example: the edge of a 160 tyre is harder to get to than 180.

[Red Herring]

Originally Posted by nutzboutbikes

Example: the edge of a 160 tyre is harder to get to than 180.

That rather depends on the rim it is mounted on. Mount a 180 tyre on an SV rim which is designed for a 160 and the edge of the 180 will be pulled in and be harder to reach. Reverse it however and put the 160 on the 180 rim and it's really easy to fall off the side of the 160.

It was a generalization. not taking in wrong size tyres for rims.

[Red ones]

I'm always cautious about grip on an SV anyway. I think you are right that the contact area is small. Again this winter I have demonstrated how you can be doing 55 mph on the motorway and still spin the rear on acceleration!

[Bibio]

its got fekal (as such) to do with tyre sizes. its to do with geometry. a bike sitting nose up will use more rear tyre width and a bike sitting nose down will use more front tyre width. and this my friends is why bike sag settings and the correct spring rate for the rider are important.

try it out.. mark the front/rear CS line with a bit of paint, wind your rear preload down and your front preload up and go for a careful spin on the bike then have a look at the paint mark.. bets the rear is gone and the front is still there. now go and do it in reverse of above and you will get the reverse.

oohhh and contact patch.. dont make me laugh its not that important and can actually be a hindrance as it slows the steering down, its all willy waiving at the local bike night. honda cub.. you can throw those things about silly but they have skinny little tyres. ok if your rossie doing a gazillion mph on a track with tyres/bike designed to go too greater lean angles but for road use ermm no.

its all to do with how you sit on a bike and how you counter steer and throttle/gear control. the amount of people i see counter leaning is unreal which is about the worst thing you can do while cornering.