"The first thing I think when i see those hub motors is that thing has to weigh a lot."
Yup, I think the hub motor weighs about 20 pounds. OTOH it's capable of putting out bursts of 1600W+ and continuous power of around 1200-1300W, which is 3-4X what most of the cheaper e-bikes on the market produce. Also, since it's a rear hub motor, traction is superb and stability quite good. I routinely take sharp curves at 25 mph without a problem. I ditched the factory battery (Saft NIMH) hub four years ago due to technical glitches and inadequate range (8 Ah) and instead run a rear rack-mounted third party 24Ah 37V lipoly pack. The new lipoly RC cells I'm using exhibit incredibly low sag at full throttle (under 2V) and have been very solid performers this season but cycle and calendar life are still big question marks.
One of the best things about the Tidalforce and E+ hub motors is their total silence--and I do mean total--very easy to sneak up on grazing whitetails and the like on these bikes. Also, the controllers are built into the hub and like the motors have been essentially flawless, which is a first as far as I know, especially for a high-power e-bike motor. The Chinese-made Crystalyte
hub motors are crude, noisy beasts in comparison, and very prone to controller glitches/meltdowns when run at high voltages/amps. Reports are that somewhere between $20-30 million went into the development of the Tidalforce motors and Wavecrest (now reborn as BluWave) is still trying to sell a larger version of the motor to automakers for use in hybrids.
Matra, the former French race car company, purchased some of the patents on the smaller motors from Wavecrest several years ago and is using it in a new e-scooter they're developing for the European markets.
But getting back to the weight issue, a high powered, decent-ranged e-bike capable of 25-35 mph performance is hard to bring in at much under 70 pounds total, and my bike is closer to 80 lbs fully loaded. Even the handmade $9K Optibike made in Boulder is over 60 pounds I think. This is simply the price of power and range. And compared to the weight of most e-motos the e-bikes are actually featherweights in comparison. It's all relative.
I will say that IMO both the Tidalforce and E+ are basically blacktop/packed dirt road bikes. For high performance offroad riding the new Stealth bikes out of Australia look intriguing--have you seen them? I'm a board manager at the Googlegroups Tidalforce forum and one of our members there recently posted this great review. Enjoy:
http://tiny.cc/9mPWU Larry Hayes