The "silly GIF" is a Gaussian distribution. You see it in many places in nature/engineering. It was brought up to answer the other poster's "Pressure" comment.
thisisatest wrote:
if the cleat/pedal interface is 10cm wide, and there is 1mm of wear at the sides, it would allow for 0.57degrees of roll.
if the cleat/pedal interface is a mere 1mm wide, and there is 1mm of wear at the sides, it would allow for 45degrees of roll.
the load on the edges of the cleat with respect to foot rolling forces would also be 100 times as great as the 10cm pedal/cleat, greatly increasing the wear rate.
This is utter nonsense. 1mm wide interface and 1mm wear, leaves 0 sum, yet you get 45 deg of Roll/Bank for a disconnected system. I don't see where you get the rest of the derivations without saying anything about the kinematics of the system.
I never mentioned anything about "Wear" to unnecessarily complicate the problem, you did! We simply talk about the orientation of the SP cleat to maximize the stability on given pedal. I already said this.
horse wrote:
Bottom line is, as mentioned earlier, when engaged the SP pedal and cleat function as one unit. The rocking sensation you feel is only because the entire unit (in particular the cleat) is not as wide as the shoe.
If you increase the diameter of the pedal, you also have to increase the size of the cleat. But maximum benefit will arise from simply increasing the size/diameter of the cleat. If you keep the cleat the same size but increase the diameter of the pedal (and thereby the shoe having no additional contact with the pedal because of limited cleat size) the system will not be any more stable.
Moving-On..
djconnel wrote:
It would be interesting to test a ball-and-socket cleat to test all of this hot spot theory.
Anyway, I agree pedal quality is more important then weight differences, but I'd personally like to try these anyway.
On float, I don't think I use it when pedaling, but I do like the Speedplay float when I'm coasting to shift my foot around. It may be psychological, however.
Another factor for me is riding in street shoes, which I need to do occasionally. Speedplays work fine for me when I've got reasonably stiff soles. This doesn't look too bad for that, however.
A ball-socket system is less preferable. Because with a flat shoe, the point contact is only at the pole of the ball. Unless the shoe can be made to accommodate a crescent shaped cleat but for all practical purposes the simpler solutions are just more effective.
Hi,
fdegrove wrote:
Hi,
Quote:
im·pulse/ˈimˌpəls/
Noun:
1.A sudden strong urge or desire to act: "an impulse to giggle"; "impulse buying".
2.The tendency to act in this way: "he was a man of impulse".
Synonyms:
impetus - impulsion - urge - stimulus - incentive - spur
Of course feel free to switch from common plain english to the language of physics whenever it suits you but from what I've read so far it's still not clear what the point of all this is other than arguing for argument's sake....
Still, for your information, during the time the impulse occurs whilst pedalling a force is apllied to an area of the pedal. At this area a pressure is then present and distributed over that area.
Since pedals, together with the handlebar and saddle, belong to the three areas that physically support the rider of the bike the pressure on the supporting areas is pretty much constant whereas the impulse to the pedals is only there during a short period of time.
Therefore it is not the impulse applied to the pedals that is the source of the problem even though it will inevitably contribute to it, it is in essence the pressure area that is the main concern.
Ciao,
fdegrove wrote:
Hi,
Exactly. The sides of the cleats don't exert pressure to the pedal.
Ciao,
Your definitions from the dictionary are terms open to interpretation. Give a physics/engineering statement as that language is not open to interpretation.
You brought up the term "Pressure" earlier. The physical meaning of "Pressure" involves "Surface Area". But you also agreed, and rightly so, "Area" plays no role in stability. So your statements are inherently contradictory.
Correct, Impulse at the pedals/drive only lasts "momentarily" but this is a separete discussion related to power transfer through the system.
Ciao
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