So a standard with a 12/28 will be okay? I'm doing the 300. I guess its not the steepness, its duration of it
The first time I climbed Potrero I did it with a 39 x 27t and while it was rather brutal, it was do-able. The next several years I used a triple, 30 x 27t and the last couple of years my compact double, 34 x 32t.
Plus, you should know that there are three Potrero climbs. First is what I call pre-Potrero, which is a long climb but not super steep and kind of gets your legs warmed up for the Real (middle) Potrero. This is the brutal one, prepare to suffer. Then Post-Potrero (you are still on Potrero road) is another long but not killer steep climb with usually (last few years, anyway) a checkpoint near the top, on the left.
Lots of climbs to come, of course, with Grimes Canyon, the Dennison Grade and Casidas Pass but Potrero is the steepest, for sure.
K K, I think by the time it comes, I should be able to swap a few parts around and have the compact/11-28 on the bike I wanna do it in. You know I'm old school, I have to do it on a '95 or older steel bike. Older the better!