Not sure what you mean by 52-54 but basically there are two gear selections or two chain lines which cause excessive wear and tear on the transmission. Most bikes have a 53-39 on a 12-25 so let's go with this default. Using the 53-25 or the 39-11 will cause advance wear on chain and rings and on your wallet. But these combos are still useable if you want to. On my old set up from 1990 I used to have a 52-42 on a 7spd 13-22. I used to use the 52-22 a lot cos it was a damn nice gear and the chain line was not so sever in the day. The chain was pretty worn by then anyway and it was almost a winter bike. If you physically look at all the chain lines in al lthe gears on your bike you can see that the 39 when paired onto your 4th gear ( or 4th largest sprocket) represents oneof the smoothest chainlines. One of my friends has purposely chosen a 12-27 so that his smoothest gear is a 39-21 which is his favourite climbing gear and which offers the best chainline for him. Petty smart, however he never uses the 27.