Hola Eduardo, 20x30 mm tubing with 0.9 mm wall is even more exotic. Never saw this here in Germany. For my homebuilds I used 20x30x1.5 mm. The space between the chainwheel and the tire was too narrow and I had to insert thinner tubing here, as you can see here http://www.python.tieflieger.net/pics/front_part_without_wheel_detail.jpg good luck, Jürgen. ============================================================ This is the Python Mailinglist at freelists.org Listmaster: Juergen Mages jmages@xxxxxx ============================================================