newcastlecycling

You must ride A grade, yes?

60 k/hr with 53x12 is about a cadence of 100 (http://www.velominati.com/blog/about/cadence-calculator/).

Use an 11T and the cadence is only 94.

Maybe an 11 at the back would be an option?

Or, considering the 12 again, a cadence of 112 gets you 65k and 120 gets you 70k.  Would these speeds be enough?  It would win C grade