I put a 60T on my swift. I got it at http://www.hostelshoppe.com/. I also had to buy a new chain to go with it because a larger ring needs a longer chain. I had a full stock setup and installed the new ring on the inside chainring position, just as the stock one is mounted. To see more on that you go to: http://www.bikeforums.net/showthread...+gearing+xootr

Be aware that is hard to find chainguards for these larger rings. But of course chainguards are not essential and for some not preferable. For more on that see this: http://www.bikeforums.net/showthread...light=longshot