I like biking to my local gym, whether it be one of the 3 school gyms on campus, or the local chain back home. It gives me a good warm-up and cardio, plus sometimes you just have to be an arrogant ass and bike with your shirt off after a good workout to boost your self esteem.
My problem is carrying all the little necessary things (I.D., cellphone, wallet, maybe some water/protein bar, multi-tool, patch kit). A backpack or my messenger back is out of the question as I don't want back-sweat to turn the thing rancid, plus the space is way more than I need. Also on long rides one of those addidas workout-drawstring bags really get annoying.
What I'm looking for is something I can attach to my bike, and detach with ease as I go in the gym. Imagine a fanny pack that clips on a bike's tubes. I was thinking a good place to put it would be the intersection of the top tube and seat tube, or the top-head-down tube area. (this is a seperate question upon itself, which location would get in the way of my legs less and thus avoid chaffing/scratching the hell out of em). An acceptable but less desirable alternative is behind the saddle, such as this
These are less desirable because I want to have the bag where I can keep an eye on it in case it starts unbuckling or zippers come loose.
My requirements for the bag are that it be reasonably sized for a 50cm frame (wont have straps dangling near the cranks, wont be so huge that it significantly catches crosswinds). Waterproofing and multiple compartments are a definite plus, but not necessary. Reasonable price range is appreciated, and by reasonable I mean definitely not topping 50$. 30$ or less is ideal. Clamps/straps that dont scratch a frame would be nice, But I could always tape them over.
And obviously this thing has to be stable as hell when clipped in to the frame. Last thing I want to worry about is a 5-10 pound fanny pack whipping around my knees.
Anyone know of any good quality bags that fit this criteria? I feel like ive seen this type of bag around before but I dont know where to start looking.