Hello Vinny,

Now these are all measured on our homebuilt dyno which we only finished before Xmas.

we think it reads about 5% high .

We are not too bothered as long as it is consistent.

Had a similar thing on my dyno

Perhaps this helps, calculated my inertia on this way.

D=390

h=300

metal=7900

shaft 125 x 40 (two times)

V=pi x r2 x h

Drum

V=3,14x(0,195x0,195)x0.300=0,03582x7900=282,978kg

Shaft (coming out off the drum)

V=3.14x(0,020x0,020)x0,125=0,000157x7900=1,2403kg (that two time) =2,4806kg

Total weight 2,4806+282,978=285,4586kg

I = m/2 x r2

I = 285,4586/2 x (0,195x0,195)=5,427

if I take the bearing friction and the short pi (3,14) in stad of the whole number

Estimated that the internally mass is

**5,48**