A 140 will be great for riding on seal..
But for anything with a lose surface it
will be all over the place...
A narrow tyre cuts though the lose top surface
into the hard base where the grip is easyer than a wide tyre,,
I run a 120 on my XTR for gravel roads etc...

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Harley Davidson..
The easyest way to turn gasoline into noise with out the side efect of horse power...