rhm

Well, I wonder about that myself, and I'm not sure I will give you a satisfactory answer. I think we all know the feeling, that a bike isn't as much fun to ride as its predecessor, and it's hard to pinpoint its shortcoming(s). But here is my sense of it:

First of all, the new bike has the Shimano hub whereas the old ones had Sturmey Archer. I like the Sturmey Archer better. The gears are more evenly spaced. So I start out with a prejudice.

Next, obviously, the new bike is geared too low. The designer had to pick a combination of chain ring, cog, and belt that fit the chain stay length, and evidently they don't make them in a sufficient variety of sizes. I'm sure he picked the best one, but it's too low. I spin out at 25 or 26 mph coming down off the Queensborough Bridge where on the old bike I could go 32, and now I'm getting passed by guys on fixies whom I just passed on the way up. Argh!

Belt tension is tricky. If I make it too tight, it feels really inefficient, but if I make it too loose it skips when I pedal hard, even in the lowest gears. There should be a happy medium, where it feels efficient and doesn't skip, but it seems I have to pick a compromise position where it doesn't skip much and turns fairly easily.

And finally there's alignment. The belt drive is unforgiving of poor alignment. Get the rear wheel askew by the tiniest amount, and the belt becomes noisy (and even less efficient). I don't know how many times I diddled with the dropout adjusters in search of the sweet spot, and it's never quite as sweet as I wish.

Please don't take this as a rejection of the system. All in all, I'm in favor of it, at least in principle. I understand the compromises the designer made, and I applaud his ongoing attempt to make the perfect bike. But I would be reluctant to build my dream bike around this system. Hence my question: have you tried it?