Originally Posted by
terrymorse
Yes, I can attest to this technique for straightening aluminum (and steel!) rims.
My dad's truing workbench had a 2x4 mounted with spacers to leave a gap about the width of a rim. He would insert the bent part of the rim and push down on the wheel. Loosening the spokes too much would make the rim "noodly" though, making it hard to isolate the bent section. After watching him and practicing on my own, I was able to bend back a bent rim to roughly straight, then true the wheel with spoke tension.
Other mechanics would lay the wheel on the ground and step on it. That always seemed pretty crude to me.
r.e. - bold At our store we had the horizontal gap made from steel not wood. I was shown how to straighten bent rims by the head mechanic/store manager and it never entailed loosening spokes and then re-bending. This method had been used for decades before I was taught in 1973.