I actually switched to these gels a few years ago b/c I read an article by a triathlete scientist sort of person who ran tests measuring the amount of water you need to drink along with the gel it takes for various gels to be easily digestible. Supposedly more water = a bit harder on the GI system. Hammer Gels were some of the best in terms of needing less water. There were a few that were better but they were much more expensive brands.
I cannot tell you I totally understood the tests or their accuracy ..... but Hammer Gels have always been easy on my stomach even in high-temps, long rides, and high heart rates. Gonna just stick with them.
After using Clif Shot for 20+ years, I was forced to look elsewhere with the demise of that product. I had tried GU many years ago and was not crazy about it. But, decided to try again after reading other reviews. Chose vanilla for flavor and minimal caffeine, as too much can be a problem for my heart rate. I like the taste and the boost from the caffeine is effective without causing an issue. The consistency works for me as well. Not runny, but not chewy. Two gels on a 30 mile ride that takes an hour and fifteen minutes or so works out well. For me there's a seven to eight minute delay before I feel the boost. The Clif Shots seemed to work a little quicker, but this is not a deal breaker. My only issue with GU is no Litter Leash type packaging as Clif Shots had. If that was in place, then this would be a 5 star rating.
I mounted this to my MOG and it fits like the dream, tucks perfectly behind the stem and makes no contact with legs even when out of the saddle. I used it with a gel mix and it works great, but definitely best to be on the lower viscosity end (more water less solid). Holds strong even over gravel terrain. Only notes for consideration are that the bottle itself is $60, no thank you, so if you are doing epics where you sub in bottles that will be a deterrent. Also consider adding a piece of frame protectant where the bottle touches the frame, as it will wear the paint.
Did a 90 mile ride on a hot humid day and these bottles kept my electrolyte and carb drink cold long after my insulated podium bottles would have. Also, appreciate that I'm not worrying about the plastic leaching into my drinks on hot summer days. Couple caveats that made me lower to 4 stars. I needed new water bottle cages because one of the bottles popped out of the carbon cages over rough roads which are plentiful in New Jersey. Fortunatly the cheaper recycled cages worked well and I'm not worried about them popping out anymore. One of the stone colored bottles, which looked great when I got them, was scratched up pretty good when it came out on a ride and both are getting a little scratched up in the cages. Still look decent, but you're probably better getting the stainless steal. Overall, the fact that my drinks stay cold made them worth the buy.
