Springy Spokes

I wonder if springs or a more elastic material could be incorporated into spokes,

Springy spokes would eliminate the hub from the un sprung weight which is desirable especially in hub motor wheels.

Problem is there is no drop in springy spoke solution from the geometry of a conventional bike/wheel.

When they build a wheel they usually try to get it round before true because it takes ~6X more turns of the nipple to get it round 1mm than true 1mm. Truing a perfectly round wheel won't really make it too far out of round. If the wheel is true but out of round its difficult to get it round without making it horrifically out of true. It's better to start over with a round wheel.

The same geometry would make the lateral displacements from a springy spoke wheel as large or larger than where you want to orient the travel: in the radial direction.

Three changes to the geometry of the bike could make springy spokes work:

1. Change the geometry of the wheel to reduce the lateral displacement: Instead of a 4" wide hub make it 1 - 3' wide. The forks / chain stays would need to angle out radically from the headset / BB as well. (As Musk says it's gotta be cool looking.) The bike would need to be an inch or so longer to accommodate the pedal path. Wind drag would increase however the rims could be lighter weight.

2. Live with or celebrate as a "new experience" large lateral displacements with a conventional geometry springy wheel. (Children love bouncy rides.) Angle the forks / chain stays and seat stays the other way to accommodate large deflections, narrow at the hub and wide at the headset/BB. If the rim is stiff enough the lateral displacement could go negative dish, beyond the hub, without buckling. The bike would need to be 7" longer so the cranks don't hang up on the stays.

3. A hybrid combination of the above geometries. The forks and stays are wider than conventional but less angled than the above solutions.

Slightly springy spokes would be easy enough to make. Just use spokes an inch or so longer and wrap them around a dowel.

For large displacements you need a springy material. Conventional spoke material is ductile so they can press / roll in the threads so the springy material needs to be attached to the threaded end of a conventional spoke.

Maybe play around with heavy nylon fishing leader material. Nylon may have a damping effect so you don't need shocks. Keep everything in the elastic range.

Stiff spokes only need ~ 1 cm of threads to tighten up the wheel. An elastic spoke wheel would require several inches of threads rolled into the spoke ends so that the spoke end can reach the nipple when lacing the wheel. After the spokes are tightened and stretched an inch or so the excess threads must be cut off so they don't puncture the tube.

Bret Cahill