Ah right, so even if the derailleur will take a 28t cog, it'll cause shifting problems with the spacing of the cogs. Hmm, I guess it'll just be cheaper to find a 13t sprocket and keep it running like that. It's not my main bike or anything, but I like fixing things up
Are the new freewheels labelled 'Sunrace' at all related to Suntour or is it just a naming thing? Is there any chance that they would have the older Suntour spacing or is everything made to Shimano spec. now?