Brick Lane Bikes in London stock 20” 406 Velocity rims in black and silver with machined sidewalls for £47 per rim, though that is £17 more than the Sun CR18 rim sold by SJS Cycles.

However, because they are not too far from me I think I will go with them and build a set of wheels up myself. Even though I have never done it before I’m confident of getting a good round wheel though will probably need help with the final tensioning. I will do a little more research before I purchase them to try and find out if the Velocity rim is actually any better. In the 406 version I don’t think the Sun rim has a machined sidewall.