Interesting old crank design.

[Cicli]

Saw these PMP cranks in an old article. Interesting, even if they didnt work. Kind if cool though. Maybe they would have worked better if they were carbon.
There was the Z-Force also. These were earlier though.

[oliver1850]

They should have had a diagonal for extra stiffness.

[JStonebarger]

They look like they would work just fine. Or were they supposed to do something regular cranks don't?

[Pastashop]

^^^ Other than add unnecessary weight and reduce stiffness?..

[jumphigher]

Pics of these make forum rounds every few years it seems like. Cranks like that supposedly are more efficient than the regular type, and there have been several similar designs. Apparently though they didnt take the biking world by storm as their designers hoped.

[cmbicycles]

Originally Posted by oliver1850

They should have had a diagonal for extra stiffness.

I have a great idea. Why not use just the diagonal, it could revolutionize the radius of a pedaling circle.

[Louis]

Everyone knows that the shortest distance between two points is not necessarily a straight line.

Plus, that design gives you 7% more leverage for the same effort.

[regularguy412]

Originally Posted by Louis

Everyone knows that the shortest distance between two points is not necessarily a straight line.

Plus, that design gives you 7% more effort for the same leverage.

There. Fixed it for ya

Mike in AR

[cmbicycles]

Originally Posted by Louis

Everyone knows that the shortest distance between two points is not necessarily a straight line.

Plus, that design gives you 7% more leverage for the same effort.

The shortest distance between two points is almost always under construction.

[sales guy]

This isn't that old of a design. Actually if you check the books or the China/Taiwan bike shows and pavilions, they will have versions of this. There is also a couple other companies from Italy and I think Spain if I remember right that are making something similar too.

And actually, Caramba did their Double Barrel crank which had an offset pedal hole to BB bolt hole.

[CaptStash]

Clearly designed by someone who failed high school physics.

CaptStash....

[cachagua]

Right, but he ended up a marketing major, so... didn't matter.

[martl]

Originally Posted by jumphigher

Pics of these make forum rounds every few years it seems like. Cranks like that supposedly are more efficient than the regular type, and there have been several similar designs. Apparently though they didnt take the biking world by storm as their designers hoped.

on a sidenote, not too long ago, a design like this ("Z-torque") received a US patent. Apparently, the basics of mechanics and physics are no requirement for working at the patent office.

-> http://pardo.net/bike/pic/mobi/d.pmp-cranks/US5899119

http://pardo.net/bike/pic/mobi/d.pmp.../z-torque.html

[oliver1850]

The design puts me in mind of Popeye's arms.

[David Tollefson]

And then there is this...
http://www.velonews.com/2013/09/bike...rankset_301441

And this one that's a little difficult to see, but it didn't seem to slow her down much: