I have a SR-500 all Shimano 105 Components.The bike came from factory with six speed 13 tooth thru 23,at some point before I got it it was changed to 14 tooth to 24.Know that there was a option for a 53 tooth Biopace but don't see any on the normal sites.I think the 53 will work with 14 tooth,anyone ever try this gear ratio?
When looking for something unusual it's best not to go to a specific site. All you have to do is a Google search for "53 tooth Biopace," but it's going to be pricey compared to a 52 tooth, and too little diff in gear ratio to bother. A 53/14 is only going to be good for downhill and stiff tailwinds.
What is your current larch chainwheel - not generally worth it to just increase the large chainwheel by a few teeth.