These extensions are great, I can flip mine upright to carry my 1892 Chestnut canoe on my 97 GMC 4x4. Great for bringing home 16' boards as well.
I bought mine in the US but easily made with medium wall tubing. I got mine at the LL Bean outlet store in Ellsworth ME, it was being offered at half price as a return - someone bought it for a canoeing run in Acadia Park and returned it thereafter.
