Sorry for the BK comment above...it was early and I hadn't checked my sugar. LOL!

But now that I got a pill and coffee in me?...let me add this as it may actually be of some value....

I'm an old guy who's new back into cycling...more specifically?...I'm calling it "ROURING"...(trying to set my old entry level road bike up for touring/commuting)...and one of the things I read recently regarding "Cramping Quads" states that....

"this condition is a good indication that your seat height is set a bit too low."

Remedy?: Raise your seat a CM at a time...ride...repeat as necessary.

And maybe it is because I'm "Newly Back At This w/ Weak Legs" that maybe I'm a bit more sensitive towards such matters but for me it seems to work like this...

It has occurred to me that adjusting my own personal seat height has become somewhat of a "Balance Of Pain" i.e.?....

Too Low: and my quads begin to cramp first.

Too High?: and my calves tend to give up the ghost first.

So along with taking a look at the nutritional supplements recommended herein?...it might not be a bad idea to revisit "fine tuning" your seat height.

Hope that helps and L8R, Bill. :)

Carry one of these with you on long rides

Hansen's Natural | Tonic Water

Er ya go :D

Lots of varying but good advice. Basically what works for me, might not work for you. But, one trick from the old days was a packet or two of mustard. Yep, just basic mustard has been very effective for me at preventing cramps . . . learned from Nat Team cycling coaches back in the day. Pickle juice is also effective. Google them both, probably something to do with the vinegar.

Most pickle recipes contain alum

(Potassium aluminum sulfate)

and a LOT of salt

(I think mustard does too)

mustard also contains Tumeric. (The bright yellow color) and it's known to have anti-inflammatory properties.

First thing in my mouth after water for a long ride recovery is a dill pickle half.

no cramps

Not withstanding, everyone's body chemistry and diet is unique at least to some extent so experiment.

Well a "decent" breakfast might be coffee and donuts, cold water is going to cramp your stomach if it's hot, leg cramps are your body's way of saying, stop, at least feed me(oxygen).
Time is the main ingredient here, if you don't have time to condition properly then don't try to do something you cannot condition yourself for, chipping away with slightly longer rides after finding a workable duration is a good start.
Potassium, and some more, hydrate or die, resting the muscles between workouts, listening to your body, drinking more water, and now...seat height, could be mechanically related?

Now why did I just get a craving to throw some dill pickle spears covered in mustard in a baggy with a couple ice cubes for my next ride? LOL!

Here's what works for me. When it's in the 90s and I'm riding a long one, 50 to 100 miles for me, I keep one bottle of water and one bottle of powerade in the cages. I carry powerade powder in small plastic bags and reload as needed. Assuming rest stops are 15 to 20 miles apart, I make it a point to drink at least one bottle of powerade and a lot of the water between stops. I take an endurolyte at each stop.

Also, in the latter stages of the ride, I tend run a slightly higher cadence than I do in the earlier stages. During the latter portion of the ride, if I start doing a lot of "mashing", my legs will "twinge" and let me know they're not happy and will start to cramp if I don't let up a little. They have a happy medium of cadence where they will be content and propel me for a long way as long as I keep them hydrated and fed with calories and electrolytes.

This business of cramps reminds me of discussions of shorts, bibs, saddles, and clothing for winter cycling. There's not a single prescription that will work for everyone. Unfortunately, you're going to have to read the experiences of others and run some experiments to see what combination works for you.

Keep working your mileage up a little at a time, run some experiments, and eventually you'll find the magic combination of what works for you.

Throw in a few dairy queens and you'll get a balanced diet.

+1 on the cadence. If you're climbing in too high a gear or are under-geared for your terrain or conditioning you can induce the whole cramp cycle (starting with those "twinges") with one excessive effort. My wife and I rode tandem well into our 60's and the cramps I would experience at the end of a 100K would start with just such an effort. Certainly, there are contributing factors, but these seem highly individual as demonstrated in the range of remedies suggested above. BTW, only on the 50+ forum would one get so many lengthy, thoughtful responses!

Bingo!!! DILL PICKLE JUICE...I train a lot, and I ride a lot, and I get leg (including shin) and foot crams frequently. I heard from someone that pickle juice or yellow mustard would help and I thought it was a joke. At the Six Gap Century last weekend they served pickle juice and dill pickle spears at the SAG's on top of each mountain. I completed the Century and drove back to Orlando (8+ hours) and had no leg cramps. Rode another century yesterday and drank pickle juice before and immediately after the ride...no leg cramps. The thought has crossed my mind that perhaps it is all in my head...but then I thought a little more and realized that even if it is in my head I don't care since I no longer get leg cramps.

Why Every Athlete Should Have Pickle Juice | ACTIVE

Can Pickle Juice Really Cure Muscle Cramps? : Runners Connect

Probably nothing that a muli vitamin and mineral pill daily wont cure.

I have Ed Burke and Ed Pavelka's "Long Distancs Cycling" which having read, browse again from time to time. Just a few days ago I read again but had forgotten, tests were done on cyclists after the Furnace Creek 500. Those who suffered cramps were found to have low magnesium levels. I have no experience specifically with magnesium supplements but do take Sport Legs which contains calcium and magnesium. My experience is it stops insipient cramps within a few minutes. Sportlegs Nutritional Support for Body's Lactate Energy System, Capsules | drugstore.com

Sorry late to the "party" everyone has good advice. Just an observance on my part. I seldom if ever got leg cramps on a ride (thank goodness) but after, my toes and fingers would cramp and if not careful I would get those horrible hamstring cramps. I was told by my doctor to take calcium, Slo-Mag and potassium supplements and they helped alot but I still got cramps, espcially after a long hot ride.

I started posting about this about 2 months ago - I brought a Nutribullet and have been drinking a nutriblast shake every morning (definately before a ride, even if the ride is late in the afternoon). The shakes can include whatever you prefer my mine are generally: spinach, parsley, ginger, banana, mixed fruit, some berries (for color and seeds), sunflower seeds, whole oats, raisins, chia seeds, pinapple, greek yogurt and water. I know it sounds like alot but I add only small amounts of each thing. I've noticed since "blasting" no more hand and feet or leg cramps. While just generally feeling better, this was an unexpected but added bonus!

Thanks again to all for the thoughtful and thorough responses. There's a lot of good info here and I appreciate your taking the time to share your wisdom. You covered hydration, nutrition, conditioning, cadence, bike fit, literature, and "rouring"... with some mustard and pickles thrown in.

I'll use your sage advice to do a better job of preparing for my future longer rides with the goal of completing that metric century later this fall.

Thanks again for your responses.

I too have found that Tonic Water helps with cramps, I'm told its the quinine that does the trick.

Potassium, Magnesium, Sodium, (PMS) you should see my jersey after a long ride. Salt could be mined from the dried out residuals.

Last Saturday I did not heed my own advice.... it was a toasty day and my legs basically froze extended.

I hydrate and watch my electrolyte intake but I find that if I do not warm up properly before riding hard I will get cramps about 20 miles in. Ride for 2-5 miles at a reduced pace alternating spinning and mashing until you get the blood flowing and the lactic acid washed out then ride away.

I didn't have issues with cramping on hot centuries and doubles with lots of climbing until I reached around 65. I had to quit a century with about 10,000 feet of climbing after about 6000 feet. The next year I used Endurolytes and had minimal cramping. I did the same 100 mile ride on my new bike this year at 72 with a 50/34 and 11-28 with Endurolytes with "0" cramping. In fact it was the easiest climbing hundred I remember. Apparently I can no longer climb for long periods in a 39x28. So it looks like electrolytes and easier gearing is needed for aging cyclists.

I got some calf cramps last weekend on the Silver State 508. I was able to keep them in check with plenty of Endurolytes and Tums.

Hammer Enduralytes work for me. I take more if there is more climbing or if the day is going to be hot. Normally I dont need them unless I am riding a century or more. Some who I ride centuries and doubles also will take some packets of salt. I have not done this, but might for the Heart of Arizona Century in November.