Here’s an interesting product, from www.londonfixiebike.co.uk, a site for all things fixed. They’ve developed the ISO-cog, allowing a sprocket to be attached to a front mountain bike six-bolt disc hub and used as a rear hub.

They’ve used this setup to run a front mountain bike hub, in this example Shimano's Deore XT, with an upgraded spindle. The parts are custom manufactured in England by a leading international aftermarket motorcycle gear and sprocket engineering company with over 70 world champions riding its products.

Blanks are machined from solid EN36 chromoly steel stock. Teeth are precision milled and the sprocket drilled for mounting bolts to very tight tolerances before undergoing heat treatment. Finally each cog is bright silver passivated and laser engraved. Machined aluminium spacers are available along with the replacement EN19 steel spindle to allow spacing to 110mm, 120mm or 125mm depending on the dropout dimensions of the frame in use.

Anyway, take a look at www.londonfixiebike.co.uk and see what you think.