RChung

That depends on how well you can balance without wobbling. I live in Berkeley and I used to ride up Marin every once in a while as a "how far up can I make it?" check. You may know that it was originally intended not as a driveable street but as the track for a planned funicular. Anyway, Marin averages 17% for almost 1.2km, but it has pitches in excess of 25%. I used to struggle up on my road bike with 36-26 gearing and make it roughly half way. It was very unpleasant. One year I was out riding MTBs with a buddy who, on the spur of the moment, decided we should ride up Marin. My MTB has a lowest gear of 26-32. It was drama free, at 2 mph.

So, balance at low speed is one problem; but the greater problem is pedal force. While climbing Marin up the 24% pitches, on a road bike with 36-26 gearing at 30 rpm I was going 3 mph -- but the average pedal force was way more than half my body weight. Max pedal force across the crank revolution is, ballpark, about twice average pedal force, so max pedal force was about 1.5x my body weight -- and that's hard. On the other hand, with 26-32 gearing at 30 rpm I was climbing up the steepest pitches at less than 2 mph, my average pedal force was about 2/3rds that of my road bike, and my max pedal force was *just under* my body weight.

Both the Creo and Aethos are nice bikes.