I've been using the following set-up for quit some time.

The surface is 1/2"x 2' x 6 1/2' OSB:
  1/2" is plenty strong enough and keeps the weight down.
  2' x 8' sheeting is a convenient size stocked at some stores, such as
  Menards,
  2' width accommodates the motorcycle's parked footprint width,
  walking/standing on the platform next to it and two milk crates side-
  by-side supporting it.
  6 1/2' length keeps the weight down, but allows needed space for ramp
  positioning. (6' was too short)
  OSB is more stable through a range of temperatures and humidity
  changes than plywood i.e. less chance of warping.
  There is a red-tipped screw jack in the photo under the platform at
  the location of the kick stand where the motorcycle weight is  
  transferred.



The front and side top rails are pine 2 x 2s. They add rigidity and insure that if the motorcycle shifts, it stays on the platform.

Note that when the motorcycle is positioned completely forward the front tire can rest against the rails, keeping the front fork straight if desired.
The bottom rails are pine 2 x 2s that loosely hold the milk crates in position, keeping them from shifting when taking the motorcycle on or off the platform.

Note the hole in the platform on the right and approximately under the engine:

This is a pocket cut done AFTER assembly.  It measures 1' wide by 2' long and is positioned 2' back from the front edge of the OSB and 1 3/4" from the right edge of the OSB.
Unseen in the photo are two 2 x 2s running underneath and parallel to the length of the hole and positioned to create a 1/2" shoulder/lip for the cut-out piece OSB to rest on when taking the motorcycle on or off the platform. There's a finger hole in the panel to make it easier to take in and out.

The hole allows easy access to the underside of the motorcycle at the engine area.

I'm able to crawl/work under the platform at its milk crate height while laying on a piece of paneling. I'm 6' 1" and 200 lbs.



I use the ramp from my truck's receiver hitch motorcycle carrier, but many other types could be built or purchased.

I hope this will benefit someone as this forum has benefited me.

Rick in Indiana

And, WE have emergency firewood if needed. However, my OSB would pollute the atmosphere

Can't have enough crates in the shop. They're kind of like bungee cords and 5 gallon joint compound buckets.

(1) I've found discarded ones over the years.
(2) I've got some on long-term loan from my local grocer  
(3) You can buy them at Aerostich.com or, I'm sure other web resources.