reverse gear for my trike

[gearman]

As some here know my first attempt using a sprag clutch was a failure.As some here said I should making a retractable motor assy. Well it is now done .The slide assy was a pain. However when testing it backing  up the  wheel would only climb a piece of 3/4 in. plywood.Anything thicker and the drive roller will slip on the tire.I have done tons of net searches and  saw gear tooth looking rollers,knurled ones,even a herringbone profile one.All of these had a much finer pitch than mine,but they were made for lawn mowers or bicycle conversions.,not a big bag mc.I was thinking of re machining my roller and remove 50% of the present crown width,the theory being the roller would imbed  deeper into the tire.Ideas   thanks

[Markcarovilli]

Slippage - how about roller with rubber around it?   That’s all I got...

Mark

[rtbickel]

It needs more friction surface.

[stubbie]

Would it be from where you are trying to push the tyre from? IE the middle, top, bottom.