6061 or 6082 or 7020

[Broesel33]

which aluminium must I use?
and why.
A friend sayed I must use 7020....

thanks 

[jBernard]

7000 series doesnt need to be heat treated after welding, you can get away with artificial aging.
however, i'm under the impression that 7000 series is more difficult to weld. and i dont know how it will react/adhere to the 6000 series that the rest of the frame is.
6061 is fully annealed, its not going to be as malleable as a non heat treated alum. this is what most people use though and seem to get away with it.

i chose 6063, bent it (bends easy). then will heat treat back to full T6.

[jfabmotorsports.com]

The frame rails that I sell are 6063. 6061t6  will make the radius needed to make a frame rail but is not needed. Use 6061t6 for all the brackets. Unless you want them to look like my personal bike, then use Titanium!

JFAB