In order to avoid the gym as much as possible I have found these places to get great workouts and great ideas to improve workouts.
The workouts are not "bike specific". So use what you want and leave the rest.
rosstraining.com and the Itunes Podcast called "Fit for Duty".
I love Ross's site. He really does answer all emails personally. He inspired me to create my own personal gym with found objects and to create odd objects. The bonus is his Tabata training. If you have tried interval training on a bike try tabata training. Higher intensity and much more pain. Tabata is described as 1 minute of full on go, I mean go. Everything you have pour it into the exercise. 10 seconds of recovery and repeat for 4 one minute rounds or four 2 minute rounds or four 3 minute rounds. Yes ideally this is fighter conditioning, but wouldn't it be great to be able to drop a guy on a hill due to this type of training.
The podcasts are good 30 minute workouts that are not terribly intense, but do give you a good workout. Some are weightless, some require resistance bands, and some require weights or weighted objects (medicine balls, kettle bells, or free weights). Still others use the TRX system, yoga, pilates, or Swiss ball. They do take a while to load the vid on my machine but they are free and that is important.
I completed two of the ab workouts one regular sit up and flutter kick based and the other was a pilates based. Both kicked my core hard but did not leave me so sore that I could not function.
I am not affiliated with Ross I just like his site and I am not in the military or work at the Pentagon.