I'm trying to decide which cassette I should go with for a climbing granfondo I will be riding this september, the Alpine Loop Granfondo. It will feature 11,500ft of climbing over 104 miles with two climbs being gravel with quite steep switch-backs. I rode the ride last year with a 11-28t last year and although I finished it got quite tough, especially with steep gravel climbs where I had to sit so I don't spin out. I'm more of a seated climber as is anyway. In the front I will be running a plan on keeping a 53/39 Rotor Q-Ring set up. I've been very happy with them and shifting is perfect so no compacts. I'm also aware that I will have to get a WiFli RD for either option.
It seems like 11-32t will give me slightly more range at the cost of bigger gaps between cogs. There is also the 12-32t. The 12-30t will have closer ratios but top out at 30t as the largest cog. Will the difference from 28t to 30t be that noticeable?
12-30t = Gears: 12-13-14-15-17-19-21-24-27-30
12-32t = Gears: 12-13-14-15-17-19-22-25-28-32
11-32t = Gears: 11-12-13-15-17-19-22-25-28-32
Thoughts, tips, opinions?