Sartorius muscle cramps... again

Once again, on today's ride, I had sartorius muscle cramps. The
Sartorius muscle runs from the outside of the hip to the inside of the
knee. It's very long and very thin. I've had cramps in that muscle
ever since I first started riding the Catrike.

It only happens on long rides. I'll have first one side cramp and then
the other. A short rest is all it takes for it to go away. No other
muscles are a problem. Yes, I drink lots of water. I drank four 24 oz
bottles of Gatorade and one of clear water today on a 60 mile ride. I
had oatmeal for breakfast with a banana, and my usual two cups of
coffee.

Does anyone else have that problem?

Or is it just me with the Catrike.

https://en.wikipedia.org/wiki/Sartorius_muscle