In other LeMans news: Porsche/Bike recored attempt

[William]

A Porsche 935 Was Once Used for a Bicycle Speed-Record Attempt

In 1979, Jean-Claude Rude wanted to go 150 mph on a bike. For that, needed a tow from a fast car.

https://www.roadandtrack.com/motorsp...-speed-record/


At 2:26 in the video...








William

[martl]

thanks for bringing up this interesting subject! It seems absolute speed records while drafting behind something fast is a theme through-out cycling history.

In 1899, a fella named Murphy did a mile in 57.8 seconds behind a locomotive on a wooden track between the rails:



Rompelberg used a top fuel dragster to reach 268km/h on the bonneville flats:



and, more recently, ex-TT racer and tv celebrity Guy Martin did a british record drafting a lorry



I wonder how many such attempts were made over the decades, and using which machines for draft?

[paredown]

The one that comes to mind immediately for me, was John Howard's attempt. He was probably the best US racer of his generation (Olympics, Pan Ams, numerous national US championships), competed (and won) one of the early Iron Man's, competed (and finished second) in the first RAM.

Then he got the idea of attempting the speed record. Maybe he was bored?

I think that is who is in your second picture:
http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm

Article in the LA Times:
http://articles.latimes.com/1985-09-...1_world-record

A close up shot of him on the bike while it is in a stand:

[oliver1850]

I remember one with a huge fairing behind a ('55 Chevy?). Chainring was huge, like 100 teeth.

[cadence90]

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[martl]

Originally Posted by paredown

I think that is who is in your second picture:
http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm

You're right - i blame google picture search

This is Rompelberg:



His bike was built by Dave Tesch, btw.
http://davesbikeblog.squarespace.com...the-world.html

I wonder what the "bigger wheels are faster" advocates have to say about the wheel sizes used?

Other finds:



(Marquet/FR behind a Cord)



(Jose Meiffret behind a Merc)

[Mark McM]

Originally Posted by martl

I wonder what the "bigger wheels are faster" advocates have to say about the wheel sizes used?

Bigger wheels are faster - when you have to supply all your own power, and aren't being sucked along in the eddy current behind a larger and more powerful vehicle. When you are being sucked along, smaller wheels may allow you to tuck in tighter the eddy current generator.

[m_sasso]

Anyone come across any power/watts numbers, curious as to how much work these cyclists are doing compared to how much they are actually being dragged along?

FRED ROMPELBERG
What
268.831 KILOMETRE(S) PER HOUR
Where
UNITED STATES (BONNEVILLE SALT FLATS)
When
03 OCTOBER 1995
The highest speed ever achieved on a bicycle is 268.831 km/h (166.944 mph) by Fred Rompelberg (Netherlands) behind a wind-shield fitted to a dragster car at Bonneville Salt Flats, Utah, USA on 3 October 1995.

[martl]

Originally Posted by Mark McM

Bigger wheels are faster - when you have to supply all your own power, and aren't being sucked along in the eddy current behind a larger and more powerful vehicle.
When you are being sucked along, smaller wheels may allow you to tuck in tighter the eddy current generator.

That, and at that kind of speed rotational forces on the tires are an issue. Hard to find a bicycle tire that is safe to use at 268km/h, and smaller=less rotational force.
(Still doubt very much there is a measurable difference between 26" MTB and 27.5" )