Cerdan Crankset

[Doug H.]

https://www.designboom.com/technology/cerdan-crankset-increases-pedaling-power-06-30-2021/

See above link:

I find this design fascinating so thought I'd share it with the Group. This isn't electronic shifting or carbon but good ole mechanical and metal. Could this innovation become accepted in the mainstream cycling world?

Doug

[Peter Adler]

"if you’re a keen cyclist, you probably know the difficulty of the so-called ‘dead zone’ when pedaling."

So, yet another iteration of the "I don't feel like I'm getting the same amount of power at every degree in the rotation"  fetish. Has everybody exhausted their pile of discarded Biopace etc. chainrings already?

It's hard to make the argument that the "dead zone" is a problem, when your advertising test dummy's feet aren't actually attached to the pedals. Wouldn't slippage on the pedals account for more power variation than a theoretical "dead zone"? In my mind, it certainly calls the designer's quasi-scientific assertions into question. And does the improvement, whatever it is, outweigh the liabilities of additional weight and the extra set of single-manufacturer components to wear out?

This reeks of a non-cyclist engineer trying to fix a non-problem for the benefit of his own ego/profit. If you're actually a "keen cyclist", you've long since adjusted your pedaling style to accommodate any sense of a "dead zone" you may happen to feel. Why wouldn't you? It's not as if every bicycle you've ever pedaled doesn't pedal the same way.

Peter "surprised to discover how mad this seems to make me" Adler

pedaling normal cranks on normal bikes in normal ways, just like everybody else in

Berkeley, CA/USA

[Peter Adler]

And hey: Doesn't this design pretty much demand a 1x(X) chainring setup? What about the hundreds of millions of cyclists who ride multi-chainring bikes, Monsieur Engineer Guy?

Peter "like I said" Adler

Berkeley, CA/USA

[Garth]

I doubt it.

It's highly proprietary, the rings(1,2,3 ?) would have to be specific to it. No mention of the bottom bracket.

Proprietary = boat anchor on land.

Some cycling geeks would buy/try it, but never the mainstream.

[Michael Morrissey]

Wow that is really interesting. I would love to try it! My 30 second search of the internet shows none for sale though. Thanks for posting this.

On Thursday, July 1, 2021 at 2:06:07 PM UTC-4 Doug H. wrote:

[ascpgh]

Well, "the dead zone" also has more distinct margins on stiffer frames. Maybe if M. Cerdan had a more supple frame he would find that its recoil from deflection during his input power zone there would be less of a "dead zone" if any. 

Instead of inventing something without measure of an existing need, I just saved and bought a frame and fork that fit me well and complimented my riding. No risk, comparatively, but lacks the opportunities for preening and self adulation.

The video of the functioning prototype (no leads or links for buying) has a rider on a large diameter aluminum MTB on road tires with an aero clip on handlebar handle. If trying to focus on your improvement to cycling, perhaps optimize all the other cheaper things to improve the experience. 

Andy Cheatham

Pittsburgh

[Doug H.]

How many inventions went through iterations until something new and improved was accepted by the masses though? This particular design may not be accepted or even particularly functional but I like the ingenuity of the inventor. The process of invention is more like evolution than creation in many cases.

Doug

[Jay]

I would love to test this against an oval chainring.

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[Cyclofiend Jim]

This idea has been around a long time. If you go back into The Data Book, you'll see early drawings of spring-loaded cranksets. There was "BikeDrive" a few years ago, and there have been more throughout the decades. They have not caught on yet, which I don't think is a bad thing. It complicates an otherwise simple and direct power mechanism which works fine. 

- J

On Thursday, July 1, 2021 at 11:06:07 AM UTC-7 Doug H. wrote: