For me it worked best to take actual food on the bike with me. Now, not everyone can tolerate this while exercising, but something like a combination salty nuts, and dried cranberries worked well for me and sometimes I add small pieces of nitrate-free jerky - though I am more likely to do this when hiking but I used to do it when I was still mountain biking as well. I don't eat processed food and can't abide the gels and so forth. Skratch is really my one exception, it fills the need and my body tolerates it well. I can also tolerate Heed, but not when it gets really hot, I don't have that problem with Skratch.