Originally Posted by
bogriver
+1 the Onyx Hub is of the Sprag Clutch design. Its proven clutch technology is Aerospace approved. It's probably the most robust clutch on the market. Used commonly in helicopter rotor drives!
Also, its freewheel/coast parasitic drag is the lowest of any bicycle free-hub available according to a recent test by a team at Duke University.
For those of you with reliability concerns and or Tandem MTB applications, give this serious look.
I can't believe anyone makes such a bid deal about freewheel drag. If you don't want (a very little bit of) coasting drag, keep pedaling!
Not to badmouth the Onyx, but the drag advantage is pretty silly. And this is a hub that weighs 120g more than the King, so you're gaining a minuscule amount on drag, but carrying more weight up every hill. I'm guessing the weight penalty has a much higher impact on overall effort over the course of a mountain bike ride than a little bit of drag. And don't forget, the most drag a bike experiences is wind resistance. You'd be better off working on you aero positioning, wearing a skinsuit and aero helmet than worrying about freehub drag. (And this is why ceramic bearings are a cost/benefit loser in my opinion. Nice, but over the top expense at very little gain.)
But the weight penalty is worth considering; if it prevents high torque load failures. I made this exact decision when choosing Phil Wood over King; I hoped the weight penalty would be worth the added durability. But I discovered this was not necessarily the case. And King appears to have addressed the issue and offers a durable hub that has an excellent track record among mountain tandem riders. The Rholoff Speedhub has also proven to be highly durable; but again, with a considerable weight (and cost) penalty.
Plus, the more seals a bearing possesses, the more drag it has. And grease viscosity adds drag as well. So if you REALLY want to reduce drag, remove your BB and hub seals, use lightweight oil instead of grease, and upgrade your derailleur pulley wheels with cartridge bearings. Those things gum up and add drivetrain drag like nothing I've seen before! Problem is, you'd be sacrificing durability and longevity to gain a little reduction in drag. Rather pointless pursuit when, again, most drag a rider encounters is air resistance.
Not to be too much of a stick in the mud, but that's how I see it.