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Re: Retro TT stuff [dave_w] [ In reply to ]
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oops...you're right there :)


Graeme Obree

These aero bars are completely custom - they took Obree three months to whittle down from a solid piece of aluminium




massive drilled out 67 tooth chainring ,




shaved down mtb pedals ( were double sided before)

drilled out derailleur wheels


Last edited by: lacticturkey: Feb 10, 10 10:18
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Re: Retro TT stuff [BrianLizard] [ In reply to ]
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did you turn a 650 zipp into a 700c? Those dropouts are loooooong.


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My training
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Re: Retro TT stuff [stal] [ In reply to ]
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In Reply To:
did you turn a 650 zipp into a 700c? Those dropouts are loooooong.

Yup. But only 3cm longer than the factory 650 drops. It's 1/4 Aluminum and still pretty ridged. There is still more flex in the frame than the rear.

____________________________________________
I only believe what I read when I agree with it...
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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Not sure how "retro" the Graeme Obree bike is. As I recall he crafted those handlebars out of a solid chunck of Al just last spring. Pretty cool, nonetheless.

Suffer Well.
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Re: Retro TT stuff [BrianLizard] [ In reply to ]
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very cool. Did you get a custom fork made to get your desired geometry....or are you just riding it with an off the shelf 700c fork and it's working out?


----------------------------------------------------------------

My training
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Re: Retro TT stuff [vikingstumps] [ In reply to ]
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The Human Lung
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Re: Retro TT stuff [vikingstumps] [ In reply to ]
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The pic isn't very "retro".... but, the h-bar idea has some retro-roots
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Re: Retro TT stuff [stal] [ In reply to ]
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In Reply To:
very cool. Did you get a custom fork made to get your desired geometry....or are you just riding it with an off the shelf 700c fork and it's working out?

Just added a 700c fork (from my Softride). The geometry actually improved.

It was a pretty twitchy ride as 650c. When it was a 650, I dropped the beam so the wife could ride it. She went on one ride and if I remember correctly when I asked her if she wanted to race it... Her answer was "F' no!"

____________________________________________
I only believe what I read when I agree with it...
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Re: Retro TT stuff [vikingstumps] [ In reply to ]
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Re: Retro TT stuff [vikingstumps] [ In reply to ]
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German track bike for Barcelona games 92
other model
Last edited by: lacticturkey: Feb 10, 10 10:53
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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That Pinarello is one of my favorite bikes of all time. I would love to see it in person. Speaking of seeing things in person, I wasn't into cycling or triathlon in 1996 when the Games were in Atlanta. I live in Georgia about three hours south of Atlanta. Knowing what I know now, I can't believe I didn't get up there and watch any of the Olympics. My parents went, as did my sister (she was living up there at the time). She was in the park when the bomb went off.
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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I don't think they put much time into the brake set-up. Why bother with a longer cable anyway? Rear cable won't reach, no problem...
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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3rensho aero bars on pursuit bike circa 80s
Last edited by: lacticturkey: Feb 10, 10 19:38
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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My TT bike:



Waiting for a Shamal HPW 12 on the front, and some Scott 100K bars. On my way to a 27´25" 20km TT last spring:



Finally here are my ´ghetto Rotor rings´, take an old set of Biopace cranks and rotate the chainrings anticlockwise 2 stops (144 degs). I get at least 10% more power with these cranks*



* I might have made that last bit up.

-------------------------------
´Get the most aero and light bike you can get. With the aero advantage you can be saving minutes and with the weight advantage you can be saving seconds. In a race against the clock both matter.´

BMANX
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Re: Retro TT stuff [Barchettaman] [ In reply to ]
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nice ! What's the theory behind rotating the BP rings ? by changing the phase wouldnt that reverse the intended effect ?
ie- increase torque during the weaker part of the stroke and lower torque on the strong part ?


Last edited by: lacticturkey: Feb 11, 10 6:33
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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From Sheldon Brown´s site:

To a casual glance they resemble elliptical chainwheels, but on closer examination they turn out to be the exact opposite of the classical elliptical design. The product of extensive research and computer-aided design, Biopace chainwheels have the small radius engaged when the cranks are horizontal, the large when they are vertical. This is because the Biopace design is based on a dynamic analysis of the motion and momentum of moving cranks and legs, unlike the static, geometric analysis that produced classical ellipticals.
The theory is that during the power stroke, when the cranks are more or less horizontal, you are using the power of your legs to accelerate your feet, which get going quite fast in the lower gear provided for that part of the stroke. The momentum of your feet then carries the pedals through the "dead spot" when the cranks are near vertical. Since the rider doesn't push as hard during the power phase of the stroke, and motion is slower when the leg is changing direction, the Biopace design is gentler on the knees than even round chainwheels. So by moving them 2 positions anticlockwise on the crank, you get something similar to a Rotor or Q-ring. Works best with the older Biopace rings as they have a more pronounced elliptical shape.

Hope this makes sense, kind of.

Normal:



Ghetto Rotor ring slowtwitch special:



Q rings:



-------------------------------
´Get the most aero and light bike you can get. With the aero advantage you can be saving minutes and with the weight advantage you can be saving seconds. In a race against the clock both matter.´

BMANX
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Re: Retro TT stuff [Barchettaman] [ In reply to ]
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Nice ride. Needs a nice quill stem to stay with the retro vibe but it looks like you have a great position.
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Re: Retro TT stuff [Barchettaman] [ In reply to ]
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sounds like a obree homebrew innovation ... nice !


this one has kind of a retro look to it
was put together for Micheal Secrest in 1996 who rode 1256 Miles in 24 hours at Phoenix International Raceway (WR)
(you can see the truck he was drating in the pic on the newspaper on the wall)
92 tooth chain ring, negative rake forks and an elevated right chain stay
Last edited by: lacticturkey: Feb 11, 10 7:29
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Re: Retro TT stuff [Johnny99] [ In reply to ]
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Thanks. The Ritchey Probiscus tri bars are integrated to the stem, so I had to get a threaded/threadless adaptor with a 1/8" shim. Works beautifully though.

I can´t claim any credit for the idea of moving the chainrings round on a Biopace crank. It was mentioned over on Bikeforums. I definitely think someone should test them v. Q-rings and Rotors as a budget option though, certainly in the spirit of this site.

-------------------------------
´Get the most aero and light bike you can get. With the aero advantage you can be saving minutes and with the weight advantage you can be saving seconds. In a race against the clock both matter.´

BMANX
Last edited by: Barchettaman: Feb 11, 10 8:58
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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Where is the Huffy TT bike hanging?
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Re: Retro TT stuff [toolguy] [ In reply to ]
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Not sure if it qualifies as retro, but it's close enough. Components of interest: Hooker SL front brake, grip shift bar-end 8 speed shifters and even Zipp Ballistic hubs.





" Aerodynamics are for people who can't build engines. - Enzo Ferrari "
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Re: Retro TT stuff [Smoiniye] [ In reply to ]
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Re: Retro TT stuff [jeremyb] [ In reply to ]
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Re: Retro TT stuff [gregclimbs] [ In reply to ]
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In Reply To:
One for the record books:

http://wattagetraining.com/...ic.php?f=2&t=258

:D

g


Woah...look at the fork on that thing! Did he run a Zipp trispoke?

http://bikeblather.blogspot.com/
Last edited by: Tom A.: Feb 11, 10 15:29
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Re: Retro TT stuff [lacticturkey] [ In reply to ]
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Holy Pedal Power Batman!
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