I had to compare those gears and weights...

I checked the MK SS gear - they do use 3mm struts. Wheels designed for 1/8" struts should also work but the MK wheels are so nice. I'd use them on a glow model and would stick to Dave Brown Lectra Lite's for electric models.

The aluminum MK's are 5g lighter than the plastic Robart's! Maybe just a slice of ham but every little bit counts. 20 size mains only are in the 54g range. 10 size Hobbico mains are 32g (1.1 oz). I think that the full retract setup for the 10's could end up in the 4 oz range with wheels, collars, linkage and servo's (1 oz for two).

Here are some pics. 20 sized MK gear is anodized red; Robart gear is gray. 10 sized Hobbico gear is blue. I'm missing the 10 sized Robart nose gear.

Robart specs pneumatic 20's at 125g (4.4 oz) - gear only - so mechanicals are definitely lighter even using two servo's. We're just missing the pneumatic Spring Air 20 sized weights.