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PostPosted: Tue Jul 14, 2009 5:15 pm 
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ededwards wrote:
Nice little experiment but no real surprise at all that a modern top end bike beats a 26 year old top end bike.

Not really comparing like with like though is it - for a start the Lapierre has indexed gears so changes will be sharper and quicker with no need to move out of the aero position. Would have been interesting to compare them both with non indexed downtube shifting although that's just bringing up, yet again, a point I keep laboriously making.

In a related way, Ian Cammish is riding not dissimilar times nowadays to when he was at his peak and he puts it down to modern equipment.

But given the above, why we like older bikes is nothing to do with performance, is it? If I was racing I'd certainly have a modern bike but riding for fitness/enjoyment I'd much prefer an older bike - how much does passion weigh in any case?


Surely removing the 'technolgy' from the modern bike makes the comparison useless doesn't it? The whole point of the piece was to demonstrate that modern technology does actually make a faster, more comfortable bike and indexing is one of the key developments of the past couple of decades. I would rather have seen the old frame kitted out with a modern groupset and wheels as then you're purely testing the ride/performance of the frame itself.

Anyhow, you're quite right, that riding older bikes has nothing to do with performance, its about passion, nostalgia and a whole host of other individual stupid reasons.

My road bike is modern (1993) compared to most on here and I would love a 'new' bike but when it comes to the crunch, I always end up fixing my old girl rather than buy modern because I love her so much. I saw her sat next to an '09 Scott Speedster last week and she just looked nicer. Skinny steel vs big hydroformed aluminium... yeuuuuch!


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PostPosted: Fri Jul 17, 2009 10:21 pm 
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Iwasgoodonce wrote:
Right. Those who don't want to know the scores, look away......Now.

Timed Run Lapierre: 8-56 Pinarello: 9-15 (mins)

Output Lapierre: 317 Pinarello: 308 (Watts) Difference=Flex


Like the Big Cheese says:

Quote:
wonder what the two frames with identical groupset would have been like.


I'd say that flex is the least likely thing to have caused the power difference. Groupset and other component efficiency (I'd suspect flex in the wheels) is at least as likely, rider ergonomics and familiarity and placebo effect probably even more so.

There's a damn good analysis of frame flex on the web using Finite Element Analysis. The bottom line is that energy that goes into flex is returned, because bike frames are almost perfect springs. This isn't true of flex in a wheel.

Other physics to remember is that you have to take the cube root of relative power to get the effect on speed - ie big differences in power make VERY little difference to speed. This is because the force from air resistance goes up in an ever increasing curve with speed. So even the few seconds difference in speed looks too great to be explained by power - aero or some other factor seems more likely.

Oh - and thank you sooooo much for finding this! You are the man!


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PostPosted: Fri Jul 17, 2009 10:33 pm 
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ededwards wrote:
the Lapierre has indexed gears so changes will be sharper and quicker with no need to move out of the aero position. Would have been interesting to compare them both with non indexed downtube shifting although that's just bringing up, yet again, a point I keep laboriously making.


That's probably enough to account for the difference in speed and power - if shifts are taking longer then power output will be reduced through being in a non-optimal gear.

The truth is that it's damn hard to improve road bike performance by much, except more aero positions. The powertrain reached a high degree of efficiency a long time ago and the few improvements you can make get eaten up the cube law for air resistance - ie to travel twice as fast you need eight times (two cubed) the power.

The roadbike makers really don't like this mentioning much - it does make a nonsense of their propaganda about frame flex. Even if you accept that some loss takes place and increased stiffness is the way to minimize it (which it isn't - it would be better to optimize the amount of energy returned by a frame) once you understand the cube root law it's much harder to get excited.

Otoh it is reassuring to know that they've got comfort, which at least in the long pro races must be a key factor, right.


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PostPosted: Sat Jul 18, 2009 11:20 am 
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Climbing is a different matter though - aerodynamcis play a smaller part in the equation and weight and flex do matter.

Remember that carbon frames (or high end ones) are designed to be compliant in certain planes to give a more comfortable ride - it's the difference between the inherent characteristics of steel and a frame system specifically designed to give the bum an easier ride.

Flex does have an effect on cornering and steering at speed. Quite a noticeable one.

Finally - longetivity - steel frames for racing used to be finished after a season. That's why the teams gave them away. That's not true for carbon - though in top end use they'll only have probably two seasons use. A racing frame is not built with longetivity in mind.


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PostPosted: Sat Jul 18, 2009 12:46 pm 
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Quote:
steel frames for racing used to be finished after a season


I suppose bike companies have invented a steel which does not obey the laws of physics then :D


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PostPosted: Sat Jul 18, 2009 1:25 pm 
King of the Skip Monkeys
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Hmmm.... not so sure about longevity. Anything built correctly will last longer than most of us will be able to ride it. Theres a 35 year titanium frame on this forum and many 30+ year old super flexy Alans that are still in active use.

Any decent rider will/ should make the most of what he has whether its a brand new Felt or a 40 year old 531.


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PostPosted: Sat Jul 18, 2009 1:48 pm 
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Regarding steel frames being finished after one season, isn't it the case that they can normally just be realigned, then they ride as good as new?


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PostPosted: Sat Jul 18, 2009 2:05 pm 
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terryhfs wrote:
Climbing is a different matter though - aerodynamcis play a smaller part in the equation and weight and flex do matter.


Weight matters, but flex only matters if you believe that the frame is a damped spring. This is more likely to be true of a carbon frame than a steel one. See http://www.bikethink.com/Frameflex.htm

In fact, to the extent flex exists it might actually *help* deliver power:

http://www.kirkframeworks.com/Flex.htm

Quote:
Remember that carbon frames (or high end ones) are designed to be compliant in certain planes to give a more comfortable ride - it's the difference between the inherent characteristics of steel and a frame system specifically designed to give the bum an easier ride.


People over rate the inherent properties of material in frame design, although usually its the steel-forever crowd who do so. Modern carbon frames certainly can be comfortable, but isn't it comfort that keeps the boutique steel frame makers in business too?

Quote:
Flex does have an effect on cornering and steering at speed. Quite a noticeable one.


That is true!

Quote:
Finally - longetivity - steel frames for racing used to be finished after a season. That's why the teams gave them away. That's not true for carbon - though in top end use they'll only have probably two seasons use. A racing frame is not built with longetivity in mind.


Yes, racing frames aren't made for longevity, whatever material they are made of.

Back in the real world, however, steel is the longevity king. Why? Because it has a "soft" failure mode - i.e. it fails gradually, by bending. Alu and carbon otoh are prone to go "snap!" This matters a lot more with a secondhand bike, of course, because you don't know how it has been used.

I'm not anti-carbon by any means: I think it makes a lot of sense in a high end racer where it's worth paying big bucks for marginal performance increases. But some of the claims made to get club racers and commuters to pay extra to ride it are pure bunkum! (Excuse my language.)


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PostPosted: Sat Jul 18, 2009 2:14 pm 
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[quote="PurpleFrog"] Modern carbon frames certainly can be comfortable, but isn't it comfort that keeps the boutique steel frame makers in business too?[quote]

Sorry to pick up on just the one point but I think there's a whole range of reasons that keeps the real top end boutique steel frame builders such as Vanilla in business and perceived comfort is only one - exclusivity, pride of ownership, 'traditional values', customisation feature, among many others (and these can apply to carbon frames too of course).

Slightly at an angle, the comfort factor has always intrigued me - can't more comfort be found by having slightly softer, slightly wider tyres? Or having a less stiff wheel? Much more effective/economic ways of getting more comfort I'd have thought although comfort is overrated - whi cares when your legs are screaming, your lungs on fire and you're biting the handlebars?


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PostPosted: Sat Jul 18, 2009 4:11 pm 
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ededwards wrote:
PurpleFrog wrote:
Modern carbon frames certainly can be comfortable, but isn't it comfort that keeps the boutique steel frame makers in business too?


Sorry to pick up on just the one point but I think there's a whole range of reasons that keeps the real top end boutique steel frame builders such as Vanilla in business and perceived comfort is only one - exclusivity, pride of ownership, 'traditional values', customisation feature, among many others (and these can apply to carbon frames too of course).


Definitely. But don't Audax and Rando bikes tend to be steel? Although might be because of the age of their riders..

Quote:
Slightly at an angle, the comfort factor has always intrigued me - can't more comfort be found by having slightly softer, slightly wider tyres? Or having a less stiff wheel?


You should take a look at Rivendell's site. And Jobst Brandt's tests of tyre rolling resistance.

Quote:
Much more effective/economic ways of getting more comfort I'd have thought although comfort is overrated - whi cares when your legs are screaming, your lungs on fire and you're biting the handlebars?


I care! At least I care about the saddle - I'm never in too much pain to think about my ass feels. The modern saddle came out very badly, which doesn't surprise me...


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