Hi jags!
You may wish to look at these reviews and discussions of the hub:
http://www.bikeradar.com/news/article/supernova-infinity-dynamo-hubs-first-look-31130/http://road.cc/content/review/56557-supernova-infinity-8-dynamo-hubIt has been well-discussed over at BNA (Bike Net Australia) with input offered by our own Pete (Il Padrone):
http://www.bicycles.net.au/forums/viewtopic.php?f=9&t=47808The hub has an on/off drag-reduction feature that works similarly in concept to that of Shutter Precision's clutch-equipped hub:
http://www.sp-dynamo.com/ in that you can choose to have it free-running /or/producing electricity/drag.
One difference is the Supernova uses a ring-magnet setup instead of a more conventional "claw-type" flux collector.
The Supernova hub has been well-reviewed and if it is like their other products, is likely superbly made. They tout gold-plated connectors and a forged shell with very well-sealed bearings, comes in pretty anodized colors, and will take a disc brake if needed. They claim high output at low speeds but I have not seen an y comparative or objective test data. There are a couple models (Infinity 8, Infinity S), so read carefully to choose the best option for your needs. The Infinity 8 comes with a clutch, but is only available in 32 holes. The Infinity S lacks the clutch but also is available only in 32 holes, so you're out of luck for either if you need 36 holes to match a rim of the same number.
I think -- especially given the cost -- I would again choose a SON28 for my own needs which tend toward more extreme environments where I prefer the hard-anodized surface finish and cartridge bearings with seals it offers. I can't speak for Andre, but in the past, he has made a very good good case for the Shimano for all more ordinary use, where the bearings are user-serviceable and a very good service life can be expected at a more modest price -- it is a very good value for the money. From all I can see, this does come at the expense of slightly more drag than the comparable SON units, but exactly how much is a matter of contention, as figures vary. I don't have a Shimano unit at hand to run comparison tests at present.
The Supernova and other clutch-type dynohubs seem to be me a bit of a solution in search of a problem. The drag in a SON28 Klassik (cylinder-hub design) is very minor -- I have read it compared (in 'Merkin units of measurement) to a 1ft climb every mile when off, a 7ft climb every mile when under load. That isn't much. The *new* SON28 (ball-hub design) is far less by my reckoning -- the hub spins very freely. Yes, the magnets make it hard to spin the axle and make it appear rough-running to finger pressure, but in practice, the repulsion-propulsion of the magnets largely canel out at speed, and the wheel spins very nicely on the bike. I didn't notice any drag with the SON28 Klassik when off, and when generating, the drag was far less than any other dynamo I've used. I don't have the *new* SON28 on the Nomad hooked-up yet, so I can't tell you how well it does when riding. When testing on the stationary bike, it seemed to have less drag with or without an electrical load.
I hope this helps, jags. To briefly sum up:
= The Supernova looks like a class approach in dynohubs, claims high output at low speeds, and has the option of a clutch on the more expensive model. It is only available in 32-hole drilling at present, so that will limit its application.
= The SON28-series of dynohubs offers proven performance in generating high output at low speeds with little drag, has great bearings and build quality, and you pay a price for all this. Best of all, it is available in a variety of hub drillings.
= The Shimano dynohub has much of the function of the SON at a lower price. It is the best value of the three and the bearings might ultimately not last as long but are user-serviceable and it has slightly-to-somewhat higher drag at the same output.
Hope this helps.
All the best,
Dan. (...who is replacing all the house thermostats today)
