|Suspension Spokes wheel||StephanF|
Nov 14, 2001 9:23 AM
|Why not one of these - like a spingergy 4 spoke, but with a little bit of "bump soak-up" suspension movement at the hub (low rotation speed/weight) for a smooth ride - that way, no maintainance, and a totally true for life aero wheel?
I set 'em up, you knock 'em down....
|Just don't tighten the spokes....||mr_spin|
Nov 14, 2001 9:42 AM
|It will have same effect--a totally unreliable, probably deadly wheel, if you can get it to roll without collapsing under weight.
If you want a suspension feel, play with the tires. Don't mess with the spokes.
Nov 14, 2001 9:48 AM
|Those things? I can picture a spoke that simply moves a little toward and away from the hub, perhaps sliding up and down a damped "sleeve", within a given range of movement (which would only need to be small I would imagine)- nothing like loose spokes. Could see it lighter than suspension too (better for CX/MTB though)?
On point 2 - soft tyres = rolling resistance etc.
I think it's an interesting idea - more details on design though please.
Nov 14, 2001 11:57 AM
|I seriously doubt you could build a wheel that had floating spokes like you describe. For one thing, that would mean that you would need not only a special hub, but a flexible rim as well (something has to give at both ends of the spoke). Rims aren't designed to do that, and most existing rims probably can't, especially the curved top and V-shaped ones.
Furthermore, having one spoke travel relative to the other spokes only puts stress on the other spokes, and at angles they are not designed to handle. With all that fatigue, you'll be snapping spokes in no time. That's one reason why all spokes in a wheel should be in equal tension, at near-maximum tension.
The Pantour suspension hub mentioned doesn't allow the spokes to travel. The hub body floats, but the spokes do not.
As far as soft tires having more rolling resistance, that's true. But it's a tradeoff. Less air equals more comfortable ride; More air equals less rolling resistance. It's your choice.
Nov 14, 2001 9:54 AM
|This was tried in Japan with motorcycle wheels for racing. The idea worked, but they couldn't get the travel needed, without screwing up the geo too much - under heavy breaking etc.
Can't see why it wouldn't work for cycles though. Only query need for road riding - carbon forks, tubs etc take about all the pounding out of riding that we need taking out, and simpler and lighter. MTBs - mebbe...
|here ya go||gtx|
Nov 14, 2001 10:23 AM
|My LBS....||Len J|
Nov 14, 2001 10:31 AM
|is currently building a wheel up with this hub. He is interested in it for a recumbent application (He is comparing it to a shock fork (weight vs. effectiveness)). I will let you know how it works. It's a little pricey but compared to a new fork, if it works you are spending the money for the weight difference.
|Not enough travel to make a difference.||MB1|
Nov 14, 2001 11:52 AM
|Been there, done that. At the advent of modern suspension several hub/wheel/spoke suspension ideas were tried. All failed. The main problems were incompatable requirements for lateral stiffness and suspension travel along with the usual weight, cost and quality issues.|
|this one might be okay, but...||gtx|
Nov 14, 2001 12:23 PM
|seems silly to me. Just get a bike that fits properly, and if you still think the ride is too harsh, quit using those 700x20s pumped up to 150psi.
-Hank (who likes his Conti 700x25s at 100psi)
|Amen brother....28's at 85-100psi.....[nm]||Ahimsa|
Nov 14, 2001 5:09 PM
Nov 14, 2001 3:12 PM
|You need to read the Bicycle Wheel by Brandt for starters. |
Ultimately you're working at cross pruposes by making the wheel soft. Part of the design is that with sufficient spoke tension localized loads are distrubuted througout the remaining structure. Take this away and you're looking at rim failure or some very heavy rims. Now couple this concept that true suspension is a mass-spring-dampener dynamic system. Remove the dampener and you're missing a critical part of the system. Ever driven a car with blown (or no) shocks? You need to let the wheel do it's thing and the frame/suspension do theirs.
Reality check: you really think that the MTB world would be where it is today if springy spokes offered a solution? Next, think about a steering input and getting little or no repsonse. Ever driven a 70's hunk of Detroit Iron with soft tires? You're all over the road. Rolf or Spinergy will probably recycle this idea and foist a bunch of new, but crappy products on the bike industry. they're nothing more than snake oil salesmen.
I'm willing to bet that there was probably a patent issued in the late 1800's for this idea. Also, recognize that the spokes already are like little springs, but with a fairly high spring constant. You're just proposing a much lower spring constant.