Metal ones skitter on polished concrete.  Probably not so much on the
rougher stuff.  Metal ramps are loud as hello when you're throwing them
around to put in position.
I use metal ramps and pieces of plywood cut into 2ftx8ft sections for doing
redneck work in my backyard, and jack stands on my level garage floor.
BTW, harbor freight sells a 6 ton jack stand; base is 11x9 and pretty
stable.  Still wouldn't use it on anything but near level concrete.

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Mike "Rocket J Squirrel"
Sent: Tuesday, May 25, 2010 7:19 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Good types of drive-on lift ramps?

David Beierl wrote:
> At 06:08 PM 5/25/2010, Mike \"Rocket J Squirrel\" wrote:
>> The kind I had were the heavy plastic ones. They had a nice pocket on
>> top to prevent the vehicle from rolling. Pretty good, all 'round but
>> they were a bit shorter than I wanted, and didn't have lead-in skirt
>> which caused them to skitter forward in front of the tires.
>
> Never seen a metal one on concrete skitter.  YMMV.

That's good to know. For everyone's information, the plastic ones
certainly do. I felt like sinking studs into the driveway to keep them
in place.

--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.)
Bend, OR
KG6RCR