Two words of caution Marv:
- One these rollers cause some very serious heat inside your tires (because the smaller rollers spin 4 times more revolutions than a 40+ inch roller set up)... if they are old or at all compromised this will make the deterioration worse and it will not show on the outside. Tires on dynos self-destruct from the inside out.
- Two, the double rollers pinch your tires and deform them and advancing further compromising of your tires. Keep in mind that you cannot see this deterioration and it is not something that gives you a lot of advanced warning.
The bottom line is that I wouldn't mess around with this type of dyno.
That's my $.02...