Nesting tubes for expanding boom

[bentbuilder_jawnn]

I need nesting tubes for expanding crank boom and I am sure that I can't get it in square tubing....

Unfortunatly wicks air craft has also disontinued their 1-7/8 tube that fit snugly in to the 2" by .058"

[AtomicZombie]

I have heard from several comercial trike owners that the nested round tube extending boom slips sideways easily. Square tubing with a plastic sleeve may be better?

Brad

[TheKid]

If you already have the round tube, try 1 1/2" black steel plumbing or railing pipe. (Schedule 40) They have an OD of 1.90", which is .025 larger than you need. It may fit snugly, or you may have to grind it down a bit. That shouldn't be a problem, since it only has to be about a foot long.
For square tubing, you could make your own with 1 3/4" angle iron. You'll have to trim it to fit, and don't forget to allow for the welding filler on the corners.

[savarin]

dont know if this would be strong enough but I've found that quite a few bikes have tubes that can be slid inside each other.
cross bars of OD 32.1mm (1.21") can fit OD 28.8mm (1.13") tubes inside them.

[bentbuilder_jawnn]

the ones I did find was 1.75" x .058" wall fits an inch and 5/8th tube.

but thats not easy to put a hole in for the head tube.