I think the Zeitgeist is a very nice looking bike, and I would love to try a full carbon electric bike... All that makes it disappointing to see these overly optimistic range comparisons (especially the alleged direct comparison with the ST2).
I sent the Zeitgeist people an email inquiring about the range and the 36v/11.6 aH battery (pictures of the bike show a 48v pack), and received the following reply:
Regarding the power train, you've well spotted a difference between the spec's and the photo's. We've decided to upgrade the battery and motor to a 48W version and you'll see this reflected on the campaign page soon.
Regarding the question of range, that's a question we get quite a lot; in fact, it was one of the first comments we received on the GeekWire article. Here's a copy of my response to that comment, which I hope you find helpful.
First of all, regarding the range: it is true that "your mileage will vary". For those readers who are maybe not as familiar with electric bikes as you seem to be, let me say that the actual range is dependent on the interaction of a variety of different factors that vary from rider to rider and even from ride to ride. These include the powertrain (motor and battery) characteristics, as you point out, but also the weight of the bike+rider+cargo, the terrain (hilly or flat), power contribution from the rider, power assist levels, battery condition and even ambient temperature. The Zeitgeist benefits from its carbon fiber frame, which is significantly lighter than the Stromer ST2 and, though, climbing repeatedly up and down the hills of Queen Anne at maximum power assist level (which we've done!
) will fairly dramatically shorten your range, we've road tested the Zeitgeist and have achieved the stated range in more of an "eco" mode.
As you suggest, it is simply impossible for a bike with approximately half the battery capacity to out distance another bike with a very similar motor (ST2 pack is advertised at 983Wh, with Zeitgeist (at best, assuming 48v/11.6 ah) is 556.8 Wh). Yes, the Zeitgeist is close to 20 lbs lighter, but that isn't going to make up for the significant difference in onboard battery capacity.
Despite all this, the Zeitgeist at $3,999 might still be reasonably priced, assuming you really want a full carbon eBike. When you look to their AL version at $2,999 the price starts to more seriously get in the way (especially with bikes like Juiced Rider's Cross Current available at $1,749 with 350w hub motor and 48v/10.6 ah pack).
In the end, it will be very interesting to see how they do in that price range Crowd Funding, as anyone who does any amount of research is going to find a ton of fully commercialized competitors available for similar or less money (including numerous Stromer models).