Dirt Bikes banned from sled trails that allow quads?

 I was out behind Garrison Hill in Dover, NH the other day when I came
across some (to me) strange signage.  There is a good sized trail out
there, big enough to drive a small truck through in many parts.  It's
posted as ok for ATV's & snowmobiles, but bans dirt bikes.

Is this common in NH?


What's the logic?


Who makes these rules?


Who enforces these rules?


I understand the sled vs OHV argument with the frozen ground, lack of
crops, etc.  I understand 2-stroke vs 4-stroke.  What I don't
understand is the difference between an ATV & a dirt bike in the eyes
of whoever sets up the trail rules.  My best guess is ruts, but that
strikes me as a bogus reason.  Perhaps it's a leftover from when most
dirt bikes were 2-stoke & most quads were 4?  Anyone know?

 
Bikes good.
Kwads evil.

Evil is winning.

DDave (from the land of the snowmobile trail that is illegal to qwads
and bikes)

 
Please take a picture of the sign and link to it - I'd like to see it.

I recently read something about this type of language, but I thought
it was in Maine.  It seemed like a glitch in the way a law was
written.  The other explanation could be regarding owner permissions.
If an ATV club does the trail maintainance, they could've put up the
sign.

Personally, I'd ignore it.

JayC
Hudson/Claremont