One for the bicycle geeks

[Mich the Tester]

100mph on a bike made in the kitchen. If anyone can do that it's Graeme Obree.


Graeme Obree reveals thinking behind design of bicycle for attempt at human-powered land speed record - Telegraph

The 100mph bike – designed in the bath and made from an old saucepan - Telegraph

[TimberWolf]

If it's accomplished by slip-streaming behind a vehicle I'm not interested.

Why is he adopting a bent-over arse-upward recumbent position? Graeme Obree, former world pursuit champion and hour record holder, reveals he is homosexual - Telegraph

[Mich the Tester]

If it's accomplished by slip-streaming behind a vehicle I'm not interested.

It isn't. This is the existing world record at 82 mph;

[gingerjedi]

I've got my eye on one of these: Lovely Bicycle!: The Pashley Guv'nor: A Retrogrouch's Dream



Beautiful.

[Mich the Tester]

Aside from the obvious jokes about his sexuality, he's put a lot of thought into this and believes that he can produce more power lying on his front than on his back. If you train in a gym and do leg presses, that's similar to a recumbent position on a bike; a well trained athlete can produce a lot of power that way as the gluteus, hamstrings and quadriceps are used very effectively. But Obree's position is more akin to a second row forward in a rugby scrum; if you've ever pushed against an electronic scrum machine that measures power output, you'll know that you can actually produce even more power that way, perhaps because the gluteus muscles are recruited even more effectively than in a recumbent position, and they're the biggest, most powerful skeletal muscles in the body.

Anyway, I've always admired this guy, even well before I really got into cycling, because he's one of those slightly eccentric individualists who does things his own way and sees them through to success. It'd be good to see what Sir Chris Hoy could do on that bike though.

[Mich the Tester]

I've got my eye on one of these: Lovely Bicycle!: The Pashley Guv'nor: A Retrogrouch's Dream



Beautiful.

Very nice

I've got one of these, having dumped a batavus after a couple of months because the frame kept bending.



and I've just ordered one of these for the track;

[TimberWolf]

Aside from the obvious jokes about his sexuality, he's put a lot of thought into this and believes that he can produce more power lying on his front than on his back. If you train in a gym and do leg presses, that's similar to a recumbent position on a bike; a well trained athlete can produce a lot of power that way as the gluteus, hamstrings and quadriceps are used very effectively. But Obree's position is more akin to a second row forward in a rugby scrum; if you've ever pushed against an electronic scrum machine that measures power output, you'll know that you can actually produce even more power that way, perhaps because the gluteus muscles are recruited more effectively than in a recumbent position, and they're the biggest, most powerful skeletal muscles in the body.

Anyway, I've always admired this guy, even well before I really got into cycling, because he's one of those slightly eccentric individualists who does things his own way and sees them through to success. It'd be good to see what Sir Chris Hoy could do on that bike though.

Yes, he has a background of developing his own Heath-Robinson record breaking bikes. I was disappointed to learn that his last innovation was banned. If I were going for a record I'd imagine that shape to be the better than recumbent too, if only for psychological reasons. It seems to attack the road aggressively. It's important to minimise frontal surface area and have a nice streamlined shape (hard to say what difference from the classic recumbent style would be), which is where most of the power losses would occur:

power = weight * velocity * friction (tires, bearings, chain) + aeroDrag * velocity^3

At that speed this boils down to aerodrag * the cube of the velocity,

where aerodrag = 0.5 * airDensity * CoEffAirResistence * frontalArea

where CoEffAirResistence will be measured in a wind tunnel.

So he wants a nice slippery shape (long is usually good) and minimising frontal area, and secondary considerations being weight and frictional losses.

[Lockhouse]

He's forgotten the chain. Back to the drawing board.

[Mich the Tester]

Yes, he has a background of developing his own Heath-Robinson record breaking bikes. I was disappointed to learn that his last innovation was banned.

Yep, the UCI are currently trying to take cycling back to the 19th century.

[TimberWolf]

He's forgotten the chain. Back to the drawing board.

And from past experience, no chain = sudden agonising pain in the goolies/coccyx. And the pain is probably even worse when you have no pedals either.