Built a rear wheel for the commuter with a free rim from a mate, 520g and 20mm wide better than the 820g 35mm wide velocity psycho I had on there! Put 1.5 slicks on it for training/ general commuting and road training. Probably saved at least 800g with rim and tyres , had semi slicks. If I get a lightish fork on there and replace the stem and bars, maybe seat post as well, it could be an interesting little steel frame bike ...
Also put new DTH tyres on the bmx, haven't given them a go yet but saved about 300g all up over the holy rollers