I have a similar climb near me. My bike is set up with an 11-28 11 speed cassette and 52-36 chain rings. I am one of those heathens that cross chains, so I usually do the ascent on my large chain ring and have a couple cogs to spare. I think the third to the last is 23, so 52/23. I usually average around 12 mph on the ascent, so I would cover 4 miles in around 20 minutes. I have never tried it on my smaller chain ring.