I forgot to comment on your question regarding changing the rear wheel. I am not familiar with such technical aspects as changing the rear wheel or what the cost might be. My advice would be to leave the rear wheel as it is as this bike is so large that the rear wheel that comes with it is necessary to keep it on the road. To change that mix might be dangerous and might void the warranty. However I am no expert on matters such as this so I may not be a good person to judge. I have heard from the Canadian dealer I went to that to replace the rear wheel would cost approximately $400 Canadian dollars.