There is a product that I've fallen in love with. It's flavorless, oderless and you drop it into your water source. It's called ELETE. It comes in a little squeeze bottle so you can carry it with you. I usually put 5 - 8 drops of it in my Camelbak and I'm got to go on long, hot rides. It's difficult to find. For more info go to eletewater.com. It's a pure electrolyte concentrate/add-in.

From the website (OK I know this is all an ad - but I really think this product is worth a try):

Athletes love elete™ because it allows them to replace the essential electrolytes they lose without consuming all of the sugar and calories commonly found in most sports drinks. Also, elete™ doesn't cause many of the negative side effects, e.g., stomach cramping and nausea, that may occur with sugar-laden electrolyte "sports performance" products. Because elete™ is an electrolyte concentrate, it allows athletes to consume carbs in the manner that works best for them.

During a long, intense ride and/or hot weather, it's critical to stay hydrated. Use elete™ in your water bottle or hydration pack to deliver metered consumption of electrolytes throughout your ride.

Usage Tips:

If you use a hydration pack, either add the 6.75 ml rip pack, which is specially designed for 70-100 oz. packs, or 2-3 capfuls (2 capfuls for 70 oz. of water; 3 for 100 oz.—or double the dose if you tend to cramp a lot) of elete™ to your pack. Shake pack gently to disperse the electrolytes. Zip the bladder into your pack and you're ready to go. And when you're done, elete™ cleans up easily with water. It won't grow gross fuzzy things in the bladder or valves or leave a funny aftertaste.

For a 20-24 oz. water bottle, fill a cap of elete™ to the threads or add the water-bottle size (2.15 ml) rip pack to the water in your bottle, shake, and drink.

If you normally use a sports drink but dilute it to reduce the sweetness or overall sugar intake, you're also diluting electrolytes, which can lead to cramping as well as impaired performance and recovery. Use elete™ to top off the electrolytes in your bottle and stay hydrated. For people who like to use gels rather than sports drinks to replace calories during performance, elete™ is perfect to use in conjunction with gels because it adds a balanced blend of electrolytes.

For longer rides, take an extra rip pack along so you can stay hydrated and avoid muscle cramps. elete™ rip packs and bottles are light and compact and fit easily into your jersey.