The front is a stock 40 spoke rim. My back rim is a 3 1/2 by 18 mag off a early model CBR. I want to keep with the nostalgia look and run a spoke rim with drum brakes on the back. The 3 1/2 & 4 1/4 were the same price on the internet, but very pricey at over $350 for the rim. Just trying to find out what my options are...