The teeth certainly look a bit on the puny side... and why only 2 'pawls'? Looks like you could squeeze 3 in quite happily or even 4. I don't think the spring is what makes the hub 'lock' though- the 'pawl' type things doesn't actually rotate as with normal hub systems, it rides up the ramp and when the rider puts pressure on the drive the teeth will interlock and be pulled more tightly together. The spring is simply to keep the teeth in loose contact while freewheeling until power is required. That's the way I can see it working. Edit: and yeah, you'd want the drive ring/pawls to be steel rather than Ti.