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• #87052
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• #87053
Yes, but there are still some alloys that are stiffer than others.
No, not among aluminium alloys* suitable for bicycle manufacture, to any extent worth considering. There is about 5% difference in elastic modulus between the stiffest and least stiff, but nobody picks their alloy based on that, it's strength which comes first since all the vaguely useful alloys are adequately stiff once your component has been designed strong enough, so designers tend to look for stronger alloys in order to use less material.
*and even less so among alloy steels
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• #87054
Yes, but there are very stiff steel frames and not very stiff steel frames.
From the outside and from the inside there's not much difference in the way they look,
So where does the stiffness come from? -
• #87055
Yes, but there are very stiff steel frames and not very stiff steel frames.
From the outside and from the inside there's not much difference in the way they look,
So where does the stiffness come from?1% small differences in section/butting
1% small differences in geometry
1% small differences in lug form (in particular, the BB shell transfers some high stresses from tube to tube, a small deflection there is highly magnified at the other end of the tube)
97% in the imagination of people riding the bike rather than actually measuring its properties. -
• #87056
So a lighter and stronger steel alloy doesn't necessarily make any difference in stiffness?
It's possible to use thicker tubes from a lighter steel alloy and have the same weight, but cause the tubes are the same diameter, there won't be much difference in stiffness? -
• #87057
For practical cycling purposes, all steels have the same density too, so there are no 'lighter' steels.
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• #87058
At the extremes, you can just about make a useful ductile iron at 7g/cm³ and a stainless steel (which will be verging on a sueralloy) at 9g/cm³, but all the steels useful for frame tubes come in very close (±2%) to 8g/cm³
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• #87059
Srsly?
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• #87060
A little bit.
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• #87061
So much totally not.
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• #87062
don walker ?
if so, uh oh, pistis back on the forum
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• #87063
don ?
No, Harry & Brian, noted Geordie testers now making SPNK wheels.
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• #87064
Don't be stupid, Tester. It clearly says on the forks that it was made by Dan and Ed
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• #87065
Part of the story is here, 1994 Commonwealth Games where Shaun Wallace rode it to a silver medal behind a young Brad McGee, obviously before Von Wanker adopted his current typeface.
IIRC, one or both Walker brothers rode a similar design, but with the Obree 'tuck' position in domestic TTs before the RTTC banned it.
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• #87067
lights, pedals, tyres... sledthread >>>
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• #87068
Not sure where else to post...
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• #87069
Maybe better in Polo or West Drinks.
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• #87070
or start a thread for steam punk circulatory gyrating hoops*
*the cam shaft driven ones obviously
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• #87071
definitely would subscribe to that ^
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• #87072
how do you stop that thing?
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• #87073
I think the same way you stair that thing.
With faith
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• #87074
with punk steam obvsly
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• #87075
Never thought about braking, unless they carried an anchor in the cradle and dropped it for a very sudden stop they must had used some kind of hub or rim brake.
The best thing about this is that whenever you applied the brakes the cradle would rotate backwards to take away some of the wheels momentum. Locking the brakes would mean the cradle would be locked to the wheel for a 'washing machine' experience, the original fixie?
On a technical mountain descent in a race of these machines a skilled descender would use just enough brake to get the cradle to 90 degrees for optimal deceleration, bringing thier bodies parallel to the road.
That image is from 1835 BTW, 19th century bikes thread?
not cheap either...
https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=campagnolo+record+bottle+cage&safe=off&tbm=shop