Racing this past weekend there was a short section of tarmac that was buttery smooth, but alas it was short and soon I was back on the usual Texas bumpy stuff & going noticeably slower. This got me wondering how much the road was impacting my times vs aerodynamics.

Running the numbers in best bike split my predicted times for average, poor and rough road were 2:18:57, 2:22:33 & 2:26:21 respectively. My actual split being 2:27:03.

Using the aero analyser all the CdA points were scattered for average, pretty close with poor & somewhat close for rough, with CdA’s of 0.25, 0.226 & 0.217.

So, it looks like the road surface is having a pretty significant impact. Question is is there anything I can do to minimize it, given that slow road is somewhat expected?

I’m running 25mm GPTTs with latex at 85/80 PSI (176lb) & considering experimenting with lower pressures but with some concern around pinch flats.