Yes certainly. The R4 is indeed legal. The device itself does not break any . laws (I believe). Where the biggest problem is, is that the R4, and all the other flashcarts are primarily used to download DS roms. THIS is illegal. No matter what people tell you that if you own it you can download it legally, you can't. Unless you own the game yourself, then you dump the ROM yourself from the Game Card (a very difficult process), then it is not legal. This is how I have interpreted the . copyright laws and yes, there are many unreliable answers. Using one goes against Nintendo's usage policy, but purchasing and using one is perfectly legal.
1. Make the plastic parts in one piece using an injection molder. I know that there are services like Proto-Mold that will do small injection-mold runs, but I don't want to spend a lot of money, and would like to play with the injection molder myself. Anyone here in the San Francisco Bay Area have an injection molder that will accommodate a food-safe plastic?
2. I've added a three-way wye valve that will allow me to switch between two bottles with a twist of a knob while pedalling hard. I'm using this most excellent nalgene stopcock but it's very expensive. Anyone know of a similar food-safe product at a more reasonable price?
3. Make it easier to pour powders and squirt gels into the bottles . . the small opening compared to ordinary bike water bottles is a disadvantage.
4. Find cheap replacements or less expensive sources for the pricier components.