Originally Posted by waterrockets
skinny First off, you've got a lot of great summaries in your post, but a couple points...
:
Well, thank you!
Originally Posted by waterrockets
It's not wasted, almost all of it gets returned as torque decreases (every pedal stroke). It's most desirable to eliminate because of spoke fatigue. You want as close to a static structure as possible for a durable wheel, so I agree that it's important to eliminate wrap up.:
Actually, a wheel as a static structure is only desirable if you have other suspension systems built into the mechanism, as a car does with springs and shocks. The wheel functions as part of the suspension system, which is why solid disc wheels have very limited application in cycling. And unlike the frame, the spokes do not return torque since they are loose in their spoke holes at the hub, the rim, or both. While a frame tube can return torque when it returns to it's original shape, a spoke's movement in the spoke hole dissipates this return. Now if you have one continuous spoke threaded through the hub and rim like I think one manufacturer does, then you could make the argument for a return of torque.
Originally Posted by waterrockets
Well, any wire departing the hub radially cannot apply torque to the rim regardless of spoke hole orientation. The wires are just too flexible. .
True, the wire cannot apply torque unless it is
pulling the rim or leaving the hub tangenitally to the rear, and then it is technically transfering torque. This is why most hubs today have flanges that facilitate the spoke exiting the flange tangenitally to the rear, and also to the front for the transfer of braking torque.
Originally Posted by waterrockets
If you go radial on both sides, the spokes are only radial when no power is applied. Once the rider applies power, the hub will wind up until the spokes are tangential enough to transfer the torque to the rim...
Here is were the inefficiency occurs.
Originally Posted by waterrockets
With straight-pull spokes, you can increase the tension enough that this windup is minimized, but it still has to occur, as the thin wire spokes do not have the stiffness to drive the rim..
And this is the design conundrum that all manufacturers address in different ways. If you increase the tension to much on to light equipment, you run the risk of component failure. So in the past few years, parts were redesigned, flanges shaped differently and made thicker, rims have deeper cross sections and are heavier, spokes are thicker and leave the rim and attach to the hub. Some alter flange design, some increase the weight of the rim, some offset rim spoke holes, on and on. The bottom line is the elimination of inefficiency in the wheel, while still providing some shock absorption/suspension.
