Camilo

Yea commercial shims work fine. I've used them for years because I have a couple of 1" handlebars that I really like and use them with 1-1/8" stems without incident. I torque properly, use friction paste for the CF bar, nothing with the aluminum bar. I've fabricated shims for a seat post that just won't stay put in my old titanium frame even though both are 27.2 and I use friction paste. I use beer cans and have been successful in keeping the post from slipping. But slippage is an inconvenience not the possibility of going over the front wheel. I wouldn't screw around with a home made handle bar shim either for the steer tube or the handlebar. Plus the commercial shims can be bought in black or silver and the edges are finished nicely so they won't scar the handlebar material, they're hardly noticeable, and if so, look better than something cut from sheet metal.