Alright so I need to get back in shape, and lets face it I'm a fatass. Schwinn makes HD frame cruisers we use at refineries. Only thing is they are single speed. Would they still be good exercise? I'm 6'6 330 and they fit me half way like they should. I walk but the last few times I've went the muscles in my ankles seize up and I have to start plopping my foot down flat which doesn't help. Any advice on this also? It's happens te last 2 times I've went walking I tried jogging today and the ankle stiffness set in faster.