Just got back from a ride on the mountain trails nearby. I'm really happy how the Fusin performed. With weather in the mid 50's F, the motor never got very hot at all, but I pushed it pretty hard. the first 3 miles from the car climb hard, some of the dips in the gullies might be as steep as 25%. With energetic pedaling in the lowest gear, I was able to scamper up some hills I normaly have to dismount and walk. A few, like the 25% er I still had to get off part way up. The bike worked good too, I did bottom out the forks a few times, but in most cases I could ride the 5-10 mph I am comfortable with without suspension issues.
48v would have helped, but with my 36v 20 ah ping I got up 95% of the hills no problems, and I was able to ride twice as far as I would dream of on the pedals only mtb. I had a blast taking the long cut at every trail fork, and rode at least 12-15 miles. I really like the two wheel drive, with pedals driving the rear and motor driving the front. I had to learn to back off the throttle some to avoid spinning the front wheel, but on most grades, 10-15% on these trails I was able to learn to throttle just right to get power without spinning the wheel. I was using the low speed setting for the entire ride, which really does work great.
Along the way I came across a large group of riders waiting for the slower ones. Announcing that I was a cheater, I hit the throttle and threw gravel all over. Man they were all eyes and facinated. I let some of them take a spin, and they were all just blown away how easy they could climb. They were all testing it on a short but very steep hill, and just couldn't believe it.
Then they'd try to pick up the bike, and couldn't belive the weight either
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE
Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum
See battery technology section, FAQ thread at the top of the page for lipo noob info.