I used to carry my trials bike on a trailer . the easiest way I found , was to have 2 x loops in trailer floor (providing base is good) made with good strong webbing / strap material . determine what length they need to be with suspension about half / three quarters compressed . wheel bike onto trailer , put 1 loop over footrest pull bike to opposite side - put 2nd loop over footrest .make sure straps are on pivot part of footrests , not on sharp serrated part . just a couple of secondary straps to bars or frame . if in any doubt , where loops go over footrests , use a wear sleeve or pad to stop loops getting worn . hoe this makes sense .