Curved cranks boost torque by 30%

[Si]

You can gloat all you want, but I bet that C+  give it 9/10 in their next crank test.  (obviously it would have got 10/10 but it isn't carbon and costs under £500).

Anyway, everyone knows that rotational force is better than straight line force - that's why Obree made his bike out of a washing machine.

[Greenbank]

You can gloat all you want, but I bet that C+  give it 9/10 in their next crank test.

At 1.2kg it'll be pretty damn stiff too!

[clarion]

You can gloat all you want, but I bet that C+  give it 9/10 in their next crank test.  (obviously it would have got 10/10 but it isn't carbon and costs under £500).

Well, yes, except they'll need a much flashier press release than that to get such a high score...

[chris]

I wonder if they do a tandem cross over version. If they do we could increase our torque by 60% If they do my stoker would do her fair share of the work 

[clarion]

Don't you know anything?  One set of cranks increases by 30%, the other by 30%, so the overall increase is 30% of 30%, which is 9%...

No, hold on.  That's not right.  Ah.  The first is increased by 30%, which makes it 130%, then the other is increased by 30%, and all the power passes through the stoker's chainset, so that would be an increase of 130% x 130% = 16,900%

Er, maybe that's a bit high.  I'll have another go.

Ah.  Simple.  Just multiply them together, giving 30x30 = 900% improvement.  That would be worthwhile.

[chris]

Don't you know anything?  One set of cranks increases by 30%, the other by 30%, so the overall increase is 30% of 30%, which is 9%...

No, hold on.  That's not right.  Ah.  The first is increased by 30%, which makes it 130%, then the other is increased by 30%, and all the power passes through the stoker's chainset, so that would be an increase of 130% x 130% = 16,900%

Er, maybe that's a bit high.  I'll have another go.

Ah.  Simple.  Just multiply them together, giving 30x30 = 900% improvement.  That would be worthwhile.

how would that work for the Triplet?

[clarion]

I think the forces would probably be excessive. 

[anth]

1.21 jigowatts!!!! 

[clarion]

You should be achieving speeds in excess of R17 at that.

[Si]

Given that the directional curve increases power to the BB, does that mean that when fitted to a fixed-wheel bike trying to leg brake will result in the cranks ripping your legs off as the force from the back wheel is directed through the cranks back to your legs?

I fear that there could be important safety considerations here!

[clarion]

It's a consideration.  Perhaps you should email them to let them know they need a safety notice?

[Zoidburg]

They have slight wing profile, if you pedal fast enough do they push you sideways?

[chris]

A big problem with these is once you've discovered that they are no good you can not throw them away as they keep coming back

[clarion]

A big problem with these is once you've discovered that they are no good you can not throw them away as they keep coming back

But with added power!

[LEE]

I think I may have cracked the problem using my Orbit as a test-bed.  It's a more traditional solution but torque is definitely increased.

I've not ridden it yet but I don't foresee any issues.  I can't think why nobody thought of it before.

[clarion]

That looks great.  Do let us know how you get on.  The Patientline access to the Internet is a bit poor, though...

[tonycollinet]

I think I may have cracked the problem using my Orbit as a test-bed.  It's a more traditional solution but torque is definitely increased.

I've not ridden it yet but I don't foresee any issues.  I can't think why nobody thought of it before.

. I've got a wonderful picture of you astride, with one foot in each pedal - and the saddle disappearing somewhere *up* 

[gordon taylor]

LEE, that won't work because the pedal will hit the ground. DOH! I can sell you some elliptical wheels which will raise the whole bike up at just the point where the pedal nears the ground. They are 44.34568% more efficient than something else. 

[tonycollinet]

That won't work, cos the elliptical wheels won't clear the frame.

No - what you need is a wavy road. Wavelength = distance between wheels. Timed so that the pedals go into the valleys, as the wheels are on the peaks. You will need to get the exact right gear ratio though, or you'll drift out of phase, and it'll all go horribly wrong.

I can guarantee that it will be some percentage more efficient than the thing that is less efficient.

[clarion]

There are plenty of deeply rutted 'wavy' roads in the Merton area.  Could I suggest a route?

[chris]

There are plenty of deeply rutted 'wavy' roads in the Merton area.  Could I suggest a route?

LEE, that won't work because the pedal will hit the ground. DOH! I can sell you some elliptical wheels which will raise the whole bike up at just the point where the pedal nears the ground. They are 44.34568% more efficient than something else. 

That won't work, cos the elliptical wheels won't clear the frame.

No - what you need is a wavy road. Wavelength = distance between wheels. Timed so that the pedals go into the valleys, as the wheels are on the peaks. You will need to get the exact right gear ratio though, or you'll drift out of phase, and it'll all go horribly wrong.

I can guarantee that it will be some percentage more efficient than the thing that is less efficient.

There is a much easier way of testing it -



Chain's a bit .....

[Regulator]

There is a much easier way of testing it -



Chain's a bit .....

Is that the Duchess of Cornwall pedalling the bike?!?  


 

[Greenbank]

Is that the Duchess of Cornwall peddaling the bike?!? 

Dunno, what does the verb "to peddal" mean?

[Zipperhead]

In all seriousness, a question that has been at the back of my mind since seeing the curved cranks.  If they were some form of mild sprung metal then when you put the power down (on the downstroke, or pull up against the cleats) then you could add tension* to the crank.  At the dead spots this tension would be trying to unload against your foot, thus pushing your foot through the dead spots.

Could this be the secret to this new design?  Rather than the old L shaped or straight cranks, is this curvey thing a real spring?

The current issue of Velovision has a short review of a hub which contains a spring to do just that.

[Regulator]

Is that the Duchess of Cornwall peddaling the bike?!? 

Dunno, what does the verb "to peddal" mean?