Originally Posted by
bikepro
If you only put water in them, they stay fairly clean. Drinks containing sugar are the worst. Best to rinse out after using and disassemble and clean throughly periodically.
I almost always have gatorade in one or both bottles so that's not it. My technique, which apparently works well, is to put a drop of detergent in each bottle, fill the bottle halfway with very hot water, shake it like hell and then squirt the hot, soapy water through the nozzle. I then rinse thoroughly, squeezing the hot, clean water through the nozzle until no suds remain. I then let the bottles dry in the rack with the caps on a towel. It sounds like a process but it takes me all of 3 minutes and there's no sign of gunk in any of my bottles. If you clean it properly you shouldn't have to take cap apart.