Won't fit where? Clamp diameter can be fudged/shimmed.

Put the levers at the front bend (with the bars sweeping down instead of up) instead of the grip area and there's just as much room as on drops.

I'm just throwing this out there because it's my favourite non-drops setup. More relaxed and comfortable than drops, more agressive/versatile than cruiser-style. Better braking, too. Flat bars just suck.