Cycling hard gives me BAD cramps. Or it does in spells, with no difference I could ever ID in fitness or diet. @Cowboy254 will likely know this, cycle a lot (and neglect your stretches) and you'll get an IT band as tight as a piano wire ( tbf, it is very hard to stretch effectively) . Cycle a lot with a tight IT band and your inside thigh (abductors??) Work very hard to counter the it band. I'll tell you now a cramped abductor is very painful. Both legs cramping is really painful.... Both legs cramping abductor muscles and outer/upper thigh at the same time just leads to agony, screaming, writhing on the floor and crying. 3 am usually after a long Sunday ride.... For up to 30 mins.
Tonic water helps.
Tonic water helps.