RE: [ST] 190 on rear

["David J. Hughes" <bambi@xxxxxxxxxxxxx>]

> There is no perceptible/measureable differences in contact patch size
> between a 160, 170, 180 or 190 (assuming you are running at
> standard/recommended pressures (this from a Dunlop Tire rep

Interesting.  If that's the case then why would the size of the
rear assist a more potent engine in getting it's power down?  I
mean, if it's all the same then running an R1 on a 160 should
give you the same ability to grab a handful of throttle without
spinning up, right?  Simplistically, doesn't contact area + tyre
compound = adhesion ?


> My tz250 has vastly more "agility" than the Daytona could dream
> of having. And it runs a 160 in the rear on a 5 1/2" rim. At ~88hp,
> it doesn't need anything bigger.

Sure.  The adhesion of a tyre must be greater than the combined
forces being applied to it at any time or it will lose grip.  So,
if you are cornering heavily, applying a significant lateral load
on the tyre, the amount of power (or braking) you apply will
determine if you lose traction.  And, if the Daytona is more agile
AND can pump more ponies through the rear then you'll need more
traction to ensure you don't spin it up all the time.

But, if your initial comment was right, what difference would it
make if the Daytona had a 180 or a 190 - it's all the same remember.
In fact you should be able to swap the rear from your tz250 onto
your 748 (or even 998R for that matter) and not experience any
difference.  All because the contact area is identical regardless
of tyre size....


> At ~100hp the ST just doesn't need anyting bigger than a 180 (and
> debatable that it needs bigger than a 170). The 190 is on that Daytona so
> it will hold together/last when you grab some big throttle.

It may not _need_ it but is it going to detract from the bike?  Or,
is it nice to have something that provides more adhesion than the
bike _needs_ just because sometimes we all do things that are not
in the best interest of bike and rider?


David  -  amazed that his initial comments could generate this
	    much response.


     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
      The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
          http://www.TriumphNet.com/st/lilley for more info
   http://www.TriumphNet.com/st for ST, RS and Mailing List info

=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=