There are at least two San Francisco bikes in Sacramento, and I’ve come across them and ridden them. The most obvious, though subtle, difference is that the SF bikes have eight gears and the Sacramento bikes three, as befits the terrain. The shifting direction is reversed.
Since I rode these bikes on the same day that I rode Sacramento bikes, I could compare them directly, and the feeling I’d had when I’d ridden them several days apart turned out to be accurate. The bikes accelerate the same, but once reaching top speed of 15 mph for Sacramento bikes and 20 mph for San Francisco, the Sacramento bikes drop out of assist roughly, and continue to go in and out of it, surging and bogging down. The San Francisco bikes have a smooth transition, noticeable, but much smoother, going from assist to not in a comfortable manner.
The Sacramento bikes make a lot more noise than the San Francisco bikes. Sometimes people turn their head to look. Though I don’t know for sure, I suspect this is the result of whatever was implemented to limit the Sacramento bikes to 15 mph, which is not their design speed but a limitation imposed by the City of Sacramento. I’m concerned that the bikes may actually be damaged by this. I do know that when mechanical devices make a lot of noise, it is not a good sign.
I continue to believe that the 15 mph limitation was unnecessary and inappropriate.