I'm looking for a 21" wheel/brake setup to go with my '76 DT400 forks. What are my options? I'd like aluminum rims, but I'd like to avoid the akront shouldered rims if possible. I've looked at the parts books to see that there are several different years/models that will get it done, but maybe there is a particular model to look for or avoid.

Ive sent my hubs to Buchananspokes.com and had them build up wheelsets for vintage bikes before. They laced a set of aluminum Excel rims for me on several bikes for whatever size you want. It really makes a big difference in the handling vs the old heavy steel rims.