Bike test: old vs new, on a climb, with SRM

Pro Cycling mag tested a 9.6kg 1983 Pinarello and a new, 7.1kg Lapierre on a 7.2%, 3km climb using an SRM. I think the riders are neo pros

On average, the lighter bike cut 19 seconds off the 9min15s climb, and the riders generated 317.6w on the Lapierre vs 308.1w on the steel Pinarello, with virtually the same heart rate!

http://www.fredericgrappe.com/media/.../manipvelo.pdf

Non PDF version, without pics:

old vs new old vs new


What's up with this bit? What happened to the old "bike flex doesn't lose power" stuff?

"The key finding comes from comparing power output on each bike. "Because of the stiffness of the Lapierre, the riders were capable of providing 10 watts more in an intense time trial type effort,” Grappe tells us. “Being less rigid, the Pinarello absorbed 3.1 per cent of the riders’ energy whichcouldn’t be used to propel the bike forward. This translates as a gain of 0.7kph on a climb and resulted in an average 18 second difference between the bikes.”

Same heart rate means nothing in this test -- it's just noise. Lighter total weight and higher power output means faster climb, so the result is predictable.

Bike flex reduces power input, and could definitely be a factor.... but they didn't test for that (despite their efforts in measuring HR).

Interesting, though. I'll look at it more when I get some time.

Yep but after a 4 hour ride on the Lapierre, the rider couldn't walk and all his fillings were loose, causing him to lose a day of training because he had to go to the dentist.

Ugh... upon further review this is more of the same bike mag crap which perpetuates cycling myths in the interest of selling products.

The ~3% increase in speed is completely explained by the ~3% increase in output power by the riders, who were riding by feel only. That's before even considering that the Lapierre is 2.5kg lighter, which should have given it another 3% advantage when totalled with the rider weights (ranged from 57-82kg).

The statement that the riders got an extra 10w output from the Lapierre due to its stiffness is purely speculation, since feel and HR were the only metrics measured. A 3% difference in output over ~9min is pretty dang small to try to control by feel, and forget about seeing it on an HRM (although the riders HR were actually higher on the Lapierre, too).

Yeah, comments about the bikes handling and feel are interesting, but not much in the way of a controlled experiment took place. EG, what about the gear ratios, ie, cadence, and the effect of the downtube shifters with riders not experienced on them? If someone really wanted to get closer to evaluating the effects of frame stiffness on climbing, gearing could be made equivalent (with no shifting allowed) and 2.5 weight could be added to the new frame.

But the results are a bit surprising. Let's see.....riders generate an average of 3.1% more power, with bike/rider avg weights which are 3.2% lighter, yet only climb 3.4% faster? At speeds of 12 mph, there is some small wind resistance, but I would have predicted a bigger advantage than this test got.....6% (33 seconds) would be more like it. Seems to me the old flexie-flyer bike was more efficient on the climb, not less. Bottom line to me is that these trials shoot a big hole in the "stiffer is better" for climbing performance arguement

frenchyge, you beat me to it this morning....took a bit longer for my coffee to kick in. Agree that this is just more BS from a bike mag. The comments about the downhill handling are interesting though....to me, that's the prime reason to have a solid frame/fork.

Are we supposed to consider this a credible study? Is it actually considered proof of something?

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Don't know what it was supposed to prove, but to me it's proof that most elite cyclists don't have a good background in math or physics, or didn't get to experience a "Design of Experiments" class in college.

But it is interesting that the new stiff CF wonderbike was slower than one would expect. Perhaps you have a theory....only thing I can propose is that flexy really is better

After reading the "study" twice, I can safely say that didn't earn the right to be called an experiment, test, or anything else that might relate to objectivity.

Some of the things that were wrong:

• Having riders gauge their own power output.
• Letting the riders know what bikes they were on.
• Not factoring rider weight
• Not factoring differing aero drag coefficients (different sized riders)
• Not controlling rolling resistance (which can vary with different paths on the macadam)
• Not considering meteorological changes (primarly winds speed and direction)
• Not accounting for tire pressures (rolling resistance again)
• I'm already bored, so I won't go on.

So, what are the real results?

1. Perceptions can vary and might be influenced by the bike.
2. Perceptions are far from factual

__________________
Sex is horrid
Pain is Fun
I cut my fingers off
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lol:d

Actually, considering the 2.5 kg difference in weight, and the substantial increase in price of the lighter bike, I think the results support the conclusion that the bike is not all that important and its better to spend your $ elsewhere...doesn't support the "lighter is better" argument all that much.

What disappointed me was that they dedicated only a tiny amount of the article talking about the results.

That's because they didn't have any results worth talking about. Every iota of result was a product, either primarily or secondarily, of rider perception. In no way did the people conducting this travesty of objectivity even try to minimize or null bias in the experiment. I'll bet every rider decided in their minds beforehand that steel was going to climb worse.

There are more credible results in an astrology column in the paper.

__________________
Sex is horrid
Pain is Fun
I cut my fingers off
One by one

3. Buy this sexy new bike, because feeling faster is worth 3% more power output.

Typical cycling rag garbage.

There wasn't a lot of space left after writing about the credentials of the physiologist, the rider bios, scoring rider perceptions during the 30 min ride around, detailed photos and descriptions the components, etc. All was designed to make the reader believe in the 'test', although it was nothing more than a review.

The writer already knew which would win because years in the profession have left him proficient in matching the company name on his paycheck with the brand name on one of the given test bikes. That's the easiest type of 'experiment' to run. Even better since he used a 1983 bike as Brand X, so he doesn't even have to piss off the company whose bike didn't win. Next month there'll probably be a new Pinarello that'll make us the hottest thing on 2 wheels.