That's not a very big swap...you should be able to tell by looking. If the 28s are close, no go. If there's room, worth a try. You COULD go to a bike shop and ask to try one on, but then you'd be obligated to buy the tires there. Which isn't a bad idea, actually. You'll establish yourself as a customer, and by the time you figure shipping, probably pay about the same as Internet shopping.