Road CyclingIt is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle. -- Ernest Hemingway
I have an FSA SLK crank that has a worn top chain ring. It's currently running 53-39 chainrings. Can I install a 52 or 50 tooth ring, or will I have to buy a new crankset to install a ring with different sized teeth?
I'll probably go for a 48/38. What is it about the design on the crankset that prevents you from fitting a 36 or 34 on the inner ring?
Is the difference between a 48x11 and 50x11 negligible?
You have to make sure the Bolt Circle Diameter matches on the new rings. A 53/39 is usually a 130mm BCD, while a 50/34 is a 110mm BCD.
The bolt circle diameter also sets a lower limit on the number of teeth a ring can have. Here's a 38T 130BCD chainring, but the maker notes that the chain will probably contact the crank spider so realistically 39T is as small as you can go.
48 x 11 and 50 x 11 difference being negligible really depends on you and the riding you do on the bike. I'd notice it on the road but not on a limestone trail, for instance.