Clarification of dimensions

[Rick L]

I am mulling over building the load runner so that it will be a sociable trike with pedals for each rider. There will be boom tubes for each set of pedals. Now, I could just make each boom tube 58" since we are both under 6' tall. Does this seem reasonable? Or could I get away with a shorter set of boom tubes since we don't pedal with our legs fully extended? The dimension I came up with for this was 48". The main boom tube would then be 58" or 60" to provide clearance for the front wheel (don't want to buff my sneakers :)).

The plans don't show a measurement of the distance between the center of the axle and the center of the seat mount. This would help clear up how long I ought to make each pedal boom tube. The seats would be in front of the cargo area.

The pedal boom tubes will also have truss tubes to keep things nice and strong. I'm planning on using 2" square tubing for the pedal booms unless this would be overkill.

The drive system would remain pretty much the same although there would be a bearing support tube for each pedal boom tube. I'm looking at using .75" CroMoly (4130-cold rolled) for the axle shaft for added bend resistance.

This wild idea came to me while looking at the Kyoto plans. I'm kind of combining ideas from both trikes. I also just gone done with a welding class so I'm getting the itch to build!

Thanks

Rick L

[AtomicZombie]

Sounds like you have a good plan so far. The front wheel will not be your concern, but mainly the tube that will need join the two booms just like the Kyoto at the front. If you want to find the max length, sit in a kitchen chair and extend your leg so that it is about 5 inches off the ground. Add about 6 inches to that for a margin of error.

Brad

[Sparky]

having a few extra inches of adjustment could be handy if your 6'5 friend wants to ride. and why do you not fully extend your legs while pedaling? i find it much easier to ride (an upright, anyway) with full extension.

also, we've all used unhardened axleshafts. not sure, but i think the hardened stuff wont weld as easy? someone else can answer that better than I. i think 3/4 inch with pillow blocks everywhere you mentioned would be plenty strong. heck, you could go up to 1 inch i suppose, though i'm quite sure thats overkill. plus REALLY heavy.

[TheKid]

3/4" is plenty strong. Cromo is overkill, and probably not the best choice anyway. 1" poses problems if you have to have the axle going through a freewheel. It won't fit, so it's no good for the driver side of the KC.

[Rick L]

I'll stick with the 0.75" dia regular mild steel for the axle shaft. That kitchen chair measurement did the trick!

Rick L