Need an explanation of cassettes and cranks. I am looking at a bike with a cassette that has ultegra 11-23T / 9 speed and a crank Ultegra 39/53T.
Are these good components on a bike?
What would be considered better components (cassettes and cranks)?
What do the numbers mean?
Are there different number configurations?
Do higher numbers mean harder to pedal or easier to pedal?
Are there better components for different courses (i.e. flats, rolling terrain, hills and mountains)?