I've got a bit of a dilemma with regards to brakes on my fixed wheel bike. Currently I've got both brakes on, as standard road levers on the hoods of the drops, but now I'm running fixed instead of free, I've got no need for the rear brake. I'm looking to get a single lever on the top of the drops, similar to a standard mountain/hybrid bike lever. However this seems problematic as I only need one lever, and most come in pairs, but more importantly, the diameter of the bars is odd - 25.4 mm where the stem clamps and 24.8mm (not the more standard 23.8mm) at the top of the drop.
What's the best way to proceed?