Relaxation length with FIALA model

Hello

I am using the classic fiala model for landing gear modelling.

I saw the example fiala_195_55_R16.tir in the Altair folder and I see the rlenx is a very very small value.

I tried to use a value I gussed from NASA-TR-T64 model which for my tire is approx 25inches. When I use this value I get a very weird response (I would say not phisical).

Are we sure the rlenx must be input with some sort of scaling? The example indicated 0.242 mm ???

Thanks