I know, it's been nearly beat to death, Tires

[BLUEKNIGHT911]

Hey Mike,

Looking to replace my Kumho Ecsta rear very soon. I know the fronts on earlier Spyders were a different size so I want to make sure about the rear. Will the Riken Raptor HR 215/60-15 fit on my 2012 RT?
Apologies if you already answered this, but I didn't see it in any of the Riken posts. TIA!

P.S. Love, love, love the Vredestein Quatrac 5's on the front!

...... read what Ron just posted ( #25 ) ..... and glad you Looooooooooooooooooove the Quatrac's ....Mike Folks here who bought and mounted that Riken are also very happy with it ....especially at that price ....

[TRBorslien]

Thanks Ron and Mike!

I will order a Riken Raptor and I always appreciate the advice you both provide.

[Steve W.]

MNF3, the tire rating of 1477# @ 44psi = 33.57#/psi. ...

I like your train of thought, but please be aware that it's not quite a linear relationship. That is, there is some strength in the empty tire, and additional air will add to it.

That said, your formula is close, and is also the foundation for figuring recommended pressures for tires that are not rated at 44 psi.

Also, while this formula may not give you the exact pressure to run, it will at least give you an idea where to start.

.

[ButterSmooth]

I like your train of thought, but please be aware that it's not quite a linear relationship. That is, there is some strength in the empty tire, and additional air will add to it.

That said, your formula is close, and is also the foundation for figuring recommended pressures for tires that are not rated at 44 psi.

Also, while this formula may not give you the exact pressure to run, it will at least give you an idea where to start.

.

Absolutely; The intercept is not zero, so it's just a way to get a reasonable starting pressure. How it handles, wears and rides are the biggest factors -- and checking the pressure rise as the tire warms is another good indicator. I think it's a move from "...in my experience..." to a SWAG that at least uses the specific tire's specifications and load.

[MNF3]

I’ll see what kind of pressure rise I get with 18psi. I didn’t get a chance to check it at 20psi when we were at SITO.

[BLUEKNIGHT911]

I’ll see what kind of pressure rise I get with 18psi. I didn’t get a chance to check it at 20psi when we were at SITO.

Just to clarify, the PSI's that both Peter and I recommend are based on the Normal rise in pressure caused by heat from Riding your Spyder...... Peter & I rely on TIRE SCIENCE ...... not " feeling's " ..... good luck .... Mike