Seriously, I don't think I've ever gotten leg cramps riding. Do you notice if maybe you're tensing up expecting to have to shift suddenly? That would be my guess that you're just not relaxing your leg. Otherwise, try stretching a bit before riding and see if that helps. Oh, and hydrate.
I did sometimes get a cramp in my left leg... on my ST1100. Determined it was poor circulation and the seat in combination with also being out of shape. I'm still out of shape but now sit on a MUCH better seat (and my ST1100 had a Saddlemens Stealth aftermarket seat with a gel pad). Before I couldn't go 100 feet before my leg would cramp, when it did. Now it just hasn't happened, yet. (like I said, I'm still out of shape).
Of course, everyone is a different shape and has a different body, legs, arms, etc. Check if the way you are sitting on the bike might be cutting off circulation on the back side of your thigh. May need some special exercises to fix that, or just change how your are sitting on it.
Hydration is number one.
Not trying to start anything here, but those of us that are elderly often have calcium or magnesium shortage that can cause cramps. New or changing activities can bring focus to things we hadn't noticed before. When mine started, I went to see the Doc and I was short on potassium.
Well guys i do have hemocrotomosis for12 years; in short its iron eating at me heart, arteries, i take adavastarin for collestrol and it hurts the mussels like heck ,, never had collestrol But a massive 100% blockage MASSIVE HEART ATTACK has me on it will a ton of other pills; i was hoping somebody would say it was the seat but i really dont know what to do its the pills. Mabe i will put a wrap with a couple straps arouNd it . That i can take off and put on real quick.
Thanks getting old bad shape sickness; i will make it some how . ITS NOT BOTHERING THE ONE I HAD THE ARTERIE TAKEN OUT OF THE LEG;THE ONE THE BLOOD CLOT WENT AND LODGED IN THE LUNG. oh well i will figure something out.
As has been mentioned on a more than a few posts in other threads here. No bike is "just right" for everyone. That goes for the seat too. It's no secret that a few members have or are replacing their seat for aftermarket "improvements" that fit them better. Maybe for you it IS the seat, at least a little. Do what you can without changing the bike to resolve this issue (that's usually the easy stuff), but if the problem persists maybe consider finding someone local who can do some seat reshaping. Maybe it's just a very little bit off the sides where your legs rest on it while riding. Maybe something else. Gel pad? Better foam layer? Just some things to think on.
I found that the stock peg position was making me to keep my legs tensed up more than I liked, never noticed that on other bikes before so I followed the other guy's advice and tried the Kuryakyn mini-boards.
Such a simple change but being able to rest your whole foot while riding makes the ride so much more relaxing. You may not notice that your legs are tensed up trying to hold your foot in position on the pegs.
Worth checking out on your next ride. That unnoticed tension may be causing your leg muscles to revolt!