I thought 14" may be the max for that cap- I had a set at one time that were very heavy. Maybe I'm too concerned about that aspect- heck, I'm no racer, but always just like light! I like Rallys though, and I know they have the center register. At one time you could get light plastic centers for them that looked like the CONE style, not sure if they are still around. I may even go the dog dish route although I never loved them............