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Re: Graham Obree Speed Record Bike

Posted: Wed Sep 05, 2012 6:32 pm
by HammerTime2
And on a related front, perhaps this is one application where disc brakes would not be ideal.

Re: Graham Obree Speed Record Bike

Posted: Thu Sep 06, 2012 4:49 am
by jooo
Are there any photos of what the fairing may look like?

Re: Graham Obree Speed Record Bike

Posted: Thu Sep 06, 2012 4:49 am
by Weenie

Re: Graham Obree Speed Record Bike

Posted: Thu Sep 06, 2012 12:54 pm
by daj
I wish Grame Obree good luck in beating Jan Bos (Theo Bos's older brother and former speed skating world champion) and the Delft University of Technology team.
Image
The bike does have a different position for the rider (recumbent). But aerodynamics are key so I wonder what Graeme Obree comes up with.

Re: Graham Obree Speed Record Bike

Posted: Fri Sep 07, 2012 1:08 pm
by Epic-o
Image

Re: Graham Obree Speed Record Bike

Posted: Fri Sep 07, 2012 9:25 pm
by SolidSnake03
You can't help but love Obree and be just a little bit in awe of the things he does. The man is an innovator and a real thinker who seems to genuinely love doing the new/weird/odd-ball. Wish him the best of luck and that bike looks pretty awesome especially when you think that it is totally hand built.

Re: Graham Obree Speed Record Bike

Posted: Fri Sep 07, 2012 10:09 pm
by cmh
He's a mad scientist and I hope to hell he beats the record.

Re: Graham Obree Speed Record Bike

Posted: Sat Sep 08, 2012 3:14 pm
by Mike V
Here is a link to him riding the bike.

http://vimeo.com/45034602

Re: Graham Obree Speed Record Bike

Posted: Sun Sep 09, 2012 8:29 am
by ghisallo2003
He is indeed wonderfully innovative and eccentric and I wish him all success and more importantly, happiness.

Looking at the video the powering mechanism seems to resemble a go-cart, rather than conventional bicycle. It is hard to see clearly, but it does not look completely like a circular action. I wonder whether the aero advantage he is capturing in this way is outweighed by the potential for a loss of power.

What I love is that rather than endlessly model in the lab, he just gets on with it and finds out.

Re: Graham Obree Speed Record Bike

Posted: Sun Sep 09, 2012 11:01 am
by Rush
It looks like a stairmaster machine in terms of the drivetrain.

Re: Graham Obree Speed Record Bike

Posted: Mon Sep 10, 2012 12:50 am
by djconnel
I'll be pleased if he simply survives.

Re: Graham Obree Speed Record Bike

Posted: Tue Sep 11, 2012 12:27 pm
by Stolichnaya
Right on, DJ.

So far, from the video, stability and potential over-exertion just getting beastie up to speed seem to be challenging factors. A smooth circular pedal strong might help that... but I am no engineer and he is the mad tinkerer. This will be great to watch develop. Like NASCAR, entertaining high speed but really just waiting for the bone crushing impact to occur.

Re: Graham Obree Speed Record Bike

Posted: Tue Sep 11, 2012 7:44 pm
by Dozer
Obree is one of my all time favs. Any guy who can break the hour record on a bike he built himself is a bada$$ in my book.


However, I'm not so sure about this new bike. I see a couple of key design flaws:
- more driveline friction by using the stair stepper drive
- his frontal area is not small. It would be best to put the rider between the wheels so truly minimize the area
- breathing while laying on your chest has to be more difficult than when on your back. what's the power impact of that?
- seems very unstable. For a straighline top speed machine I'd use a very, very relaxed geometry so it practically goes straight by itself.


I really hope he proves me wrong and set the bar up a notch! :beerchug:

Re: Graham Obree Speed Record Bike

Posted: Tue Sep 11, 2012 7:59 pm
by stella-azzurra
When does the record need to be set?

Re: Graham Obree Speed Record Bike

Posted: Tue Sep 11, 2012 8:15 pm
by stella-azzurra
Link to Obree talking about it

http://vimeo.com/41906787

Re: Graham Obree Speed Record Bike

Posted: Tue Sep 11, 2012 8:15 pm
by Weenie

Re: Graham Obree Speed Record Bike

Posted: Wed Sep 12, 2012 9:51 am
by elviento
Thumbs up for innovation aside, that bike leaves SO much room for optimaization in terms of design. It can't be too low because you need some amount of height to maneuver the two-wheeler.

The front wheel seems perfectly ideal for a lefty type fork. The crank should simply be at the back to save so much additional leverage and energy loss and weight. That drive train is just nuts. Also needs a bit more trail to remain stable.

Waist needs to be tightly fastened to provide counteracting forces to the legs, otherwise, every pedal would move the body forward.

I imagine he is leaving at least 15-20% of efficiency out with that device.