3 wheels boards, turning radius, longboard truck vs mountainboard

Hi all, To all the 3 wheelers riders and dreamers… I am considering building a recumbent “bike/moutainboard” trike and would be very grateful for your critical opinions/advices… the idea would be to use a moutainboard or longboard truck to steer (+ suspension+ tilting effect at the same time) a recumbent bike… One could consider it like an eboard (see the fantastic @jaybird work for instance) but with my legs for only engine (see draft scheme bellow). I have never seen this design before and I am very worried about this steering idea. It would be very compact/no real need for handle and “easy to build”; hence fitting all my specifications… But I am afraid that the turning radius will be too wide for practical use (on long trekking journeys as well as everyday vehicle) and also that the drag of mountainboard wheels/hubs will significantly impact the performance of the bike (meaning I will get tired!!!) (road wheels do exist, 8 or down to 6,5 inch but are 45 to 50mm wide!). Unfortunately I have no mountainboard here with me to try out things, hence my doubts and online research before investing the little money I have in this project with high risk of failure… I see several points/questions: To avoid this turning issue:

  • I can use very soft strings/rubber (see MBS matrix truck for instance) and make the angle of the truck/bike fixation steep (but how steep? 50, 60°?). However could it be a risk of riding like a fish when I am on straight roads… It might be possible to create a system to adjust the strengths of the strings at any time while ridding though… That might be a relevant solution?!
  • I can reduce the front-back wheel distance but only within a good stability length limit!

Do you have any experience with all that and measurements examples (angles of the truck+lentght btw front and back wheels, turning radius?)

Would a longboard truck be better (in terms of turning radius; possibility to put finer and smaller tire wheels like scooter or Nordic roller wheels that would reduce friction). I read that longboard trucks are suppose to be lighter but weaker than mountainboard trucks (concived for heavier use…) but is it really the case? I mean they are both suppose to support a guy wait going potentially downhill or hitting bumps rights? I expect to ride on roads or very good/hard/clean earth track… Longboards are narrower though = providing less stability perhaps.

Hopping you will forgive my broken English. Thank you very much for your help and looking forward to share more of this project if I go further with it.

Recumbent mountainboard-bike draft scheme_ Scale 1/10th on a mm paper:

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