Cassette choice is a balance between range and spacing. An 11-28 gives tight, closely spaced gears — great for flat racing where finding the exact right cadence matters. An 11-34 gives a much easier climbing gear but bigger jumps between sprockets, which can leave you searching for a comfortable gear on rolling terrain. The trend in modern road cycling has been firmly toward wider-range cassettes: even professional riders frequently use 11-30 or 11-32. For sportive riders tackling long Alpine climbs, an 11-34 paired with a compact crankset is sensible, not a sign of weakness. The cassette is the cheapest and easiest way to change your bike's gearing.