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Modern bikes and space technology and marginal gains.


Trance Dance

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Posted

Uhmmmmm .... some interesting maths .... FOR SINGLE RIDERS ....

 

 

The game changes drastically when you introduce a peleton and constantly changing the lead rider .....

 

ONE out of nearly 200 takes the punch for a short while, gets back in line and recoups for the next stint ....

 

 

once IN the peleton the drag is almost negligible ....

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Posted

Uhmmmmm .... some interesting maths .... FOR SINGLE RIDERS ....

 

 

The game changes drastically when you introduce a peleton and constantly changing the lead rider .....

 

ONE out of nearly 200 takes the punch for a short while, gets back in line and recoups for the next stint ....

 

 

once IN the peleton the drag is almost negligible ....

 

Not sure if you've seen it already but there is a very recent thorough and interesting study on peloton aerodynamics here. It agrees  :thumbup:

Posted

1919 Tdf ave speed 24.056 km/h

2017 Tdf ave speed 40.210 km/h

 

You are not compairing apples to apples here.  If I remember there were hardly such a thing as team tactics in the beginning.  It was you and your bike and your own tools and spares to get to the finishlines.  Later teams, teams tactics and tech got involved.

 

What would the difference in avg be of the 1987 TDF to 2017 avg?

Posted

How much power is "lost" in the drive train?  I see some, Danish I think (Eldron?) ceramic bearing guys have come up with shaft solution to improve efficiency - 40% odd I recall. Nor commercially viable yet though.

Posted

How much power is "lost" in the drive train? I see some, Danish I think (Eldron?) ceramic bearing guys have come up with shaft solution to improve efficiency - 40% odd I recall. Nor commercially viable yet though.

If memory serves the Ceramic Speed direct drive takes mechanical efficiency from 98% to 99%.

 

I always thought mechanical and frictional resistance was 1% and wind resistance 99%...turns out I was wrong. 3-6% for mechanical and I can't find frictional numbers...yet...

 

Damn. There is a myriad of conflicting data out there. I don't have the energy :-(

Posted

OMG someone used data as plural correctly. Finally!

Oh jummy a maths debate.


Normalised data may be presented as non linear. I'd agree that the data should be at least 3Rd order

Posted

If memory serves the Ceramic Speed direct drive takes mechanical efficiency from 98% to 99%.

 

I always thought mechanical and frictional resistance was 1% and wind resistance 99%...turns out I was wrong. 3-6% for mechanical and I can't find frictional numbers...yet...

 

Damn. There is a myriad of conflicting data out there. I don't have the energy :-(

 

Nor the power! :ph34r:

Posted

Now that's a significant improvement!

 

But surely a race like that that would be influenced by training and nutrition to a greater extent than a once off hour sprint? Not to mention better drugs...

and tarmac!

Posted

And exactly why you need a car with 740kW to drive over 400km/hr, while one with 140kW can reach 200km/hr. Definitely not linear

That car used 50BHP to do 70mph.. scary. 

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