A question for Tangsheungpak, or anyone who can help. Where did you obtain a a 53 tooth chain ring for your 'Nova" ? Brand name, model #, or internet source would be appreciated. Is it a simple bolt on replacement ? I think it would be just what I need for a little more top end. Would the chain need lengthening ? Using the SB calculator it looks like my 7th gear would become 6th and down the line. As I stated above I don't use any gear below 5th here in flat old Florida ... This might be the easy / best approach. Thanks for all info.