Energy saving device - better than oval chainrings?

[Teamfixed]

Ha I had those L shaped cranks on a rather nice Columbus Viner frame in the early 80's with gold anodised Modolo brakes. Wish I had kept it.

 

[cyberknight]

Is that wet snake oil or dry snake oil??

your behind the times , its snake wax baths now

 

[presta]

Most likely total rubbish but it does change the biomechanics of the crank in a subtle way; effectively reducing crank length at TDC and BDC so I guess works like oval chainrings. Which the jury remains resolutely out on despite them having been around for ages..

If the pedal force is always downwards then the locus of the pedal is still a circle of the same diameter, but displaced downwards. If the direction of the pedal force varies, you'll end up with an irregular locus that could be any shape, but whatever you do, it can't increase the torque you're applying to the crank. It's interesting that the lower pedal position increases the chance of it grounding on a corner, but if it does ground it'll swivel out of the way and prevent damage.

 

[Drago]

Can you give us the date when everything worthwhile was invented ?

1939. Or 1941 in the American calendar.

 

[fossyant]

your behind the times , its snake wax baths now

In a slow cooker !

 

[fossyant]

But but but
surely different types of lube need to be checked out and improved????

Oh, and when Finish Line invented Ceramic Wet.

 

[ColinJ]

It's interesting that the lower pedal position increases the chance of it grounding on a corner, but if it does ground it'll swivel out of the way and prevent damage.

Hmm... There must be at least one of us who has crashed as a result of grounding a pedal on a bend! Anybody care to tell us about it?

 

[wafter]

If the pedal force is always downwards then the locus of the pedal is still a circle of the same diameter, but displaced downwards. If the direction of the pedal force varies, you'll end up with an irregular locus that could be any shape, but whatever you do, it can't increase the torque you're applying to the crank. It's interesting that the lower pedal position increases the chance of it grounding on a corner, but if it does ground it'll swivel out of the way and prevent damage.

Yes, I guess it depends on which direction the force is being applied to the pedal on the power stroke. It did get me thinking if there would be any benefit to some sort of linkage that effectively shortened the crank length at the top and bottom of the stroke - could give the biomechanical benefits of shorter cranks whilst maximising the torque they can supply under power..

 

[Fastpedaller]

ISTR seeing an old patent with gearing that changed the crank length during rotation - as with just about anything which isn't simple, the losses become greater than the gains!

 

[presta]

some sort of linkage that effectively shortened the crank length at the top and bottom of the stroke

It's lengthening the crank at the bottom.

Hmm... There must be at least one of us who has crashed as a result of grounding a pedal on a bend! Anybody care to tell us about it?

Me for one, but I don't think I'd be trying those out, they look annoying to use, and for no other benefit.

 

[Specialeyes]

4 available, 18 sold! Come on, own up... who was it?

I've mentioned before, I did have a set of PMP L-shaped cranks on my Kirk Precision (along with ergo bars and a Campagnolo Biodinamica bottle that was the size of a fire extinguisher and held about a cupful of liquid). It was the pinnacle of everything that was dodgy about the 80s


Edit - thar she blows, outside the old Kirk offices in Basildon, just to complete the set of things that were dodgy about the 80s!

 

[Gillstay]

Hmm... There must be at least one of us who has crashed as a result of grounding a pedal on a bend! Anybody care to tell us about it?

Yes, but on a Puch moped and crashed again on the way home and took off the other pedal. I was a slow learner that day.

 

[silva]

If you put voltage on such crank you can play that game, how is it called, when having to remove the chainring :P