Originally Posted by
AlmostTrick
Flat ground with no wind means the rider must be pedaling. Bikepedia says that bike has a 50/11 top gear and 700x23mm tires. Sheldons gear calculator puts him at 42.6 mph IF he can spin that gear at 120 RPM. (haha)
Decide for yourself if your brother in law is stronger and can spin the cranks faster than this.
I have hit 38 mph on flat ground with 53*13 and was starting to want to upshift. Bicycles without some sort of customized grearing just to not have high enough gears to go at 50 mph.
Also figure the a great time trial by a world class time trial specialist is around 34 mph. That is just to give you an idea.
I have heard of people hitting over 50 on a bike but that has always been on descents. I have never heard anyone even claim to hit 50 mph on the flats.
I suspect that there was a glitch on the equipment and your brother and law bought it at face value.
Of course, his speed is nothing. I once "averaged" 115 mph on a club ride which was going at a "C" pace. Now who wouldn't believe that? I rather suspected that there was something fishy going on with my bike computer.