Hi, I just bought two 05 Yamaha Zumas. Took it on a ride of 100+ miles already on both. One of my Zuma´s had only 21 miles on it, so still need to do some breaking in. The other had a little over 600 miles on it, and I went on hills fine. I weight 125lbs. My friend weighs 115lbs. We both rode uphill on both Zuma´s. Our speed only dropped to 35mph on the hill. On flat road, one of my Zuma goes 45mph (the 600+ miles one), and the other only 37mph (the now 100 miles one).