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Science or Psuedo-Science 9 LB heavier bike climbs same speed as lighter bike?
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The problem is people rarely consider the combined weight of the rider AND the bike. When put in that perspective, a 150lb rider + a 15 pound bike versus a 150lb rider + a 20lb bike, the difference is marginal at best.
Also, as the article mentions very briefly, we are rarely climbing a hill at our max wattage and effort. So we automatically will increase our power slightly to compensate for the weight difference without realizing it.
Just goes to show that if you want a steel bike, get one. No need to put aside considerations for a steel frame because carbon is a pound lighter.
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dont see a lot of science there -- plenty of opinion tho. Still food for thought tho.
I would say the whole blog is unabashedly heavily retro - ie steel bike - slanted. Which is fine. Still I'll take the lighter bike up the hill, thanks.
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Jan Heine is known for having a lot more than just a "slant" towards retro steel. To each their own, but I do think there are too many people who focus on maximizing their speed when they really should maximize the enjoyability of cycling. Why would you want to get to your destination sooner if the point is to enjoy the time ON the bike?
Tai
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i believe static weight is less of a factor than rotating weight, so if the 9 lbs are in the frame that's better than in the wheels, crank arms, etc.
however, law of physics is such that all things being equal it will take more energy to move a heavier object up a given hill than a lighter object.
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How about no science. As if an elementary student wrote an essay without doing the actual work.
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The slant of the piece is more on frame stiffness/power transfer than weight. But yes, pseudo-science is a stretch.
The wise man said follow me...and he walked behind. -
I would be more than happy to test this theory anytime someone wants to pay my way to the test mountain and give me a high-end low weight bike.
Life is too short to be small. - Disraeli
So, why not be petty? - The Short White Guy™ -
nightfend, most carbon frames are 2-2.5 lbs and a light steel frame is 5-5.5 lbs. Also the 2.5 lb carbon is stiffer (BB, HT, etc.) than a 5.5 steel and likely rides just as well. My first bikes were steel and I still have that romantic memory of them but reality and romance are as different with bikes as they are with woman.
How much does EPO weigh? That extra weight will make you go faster up hill!
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nightfend, most carbon frames are 2-2.5 lbs and a light steel frame is 5-5.5 lbs. Also the 2.5 lb carbon is stiffer (BB, HT, etc.) than a 5.5 steel and likely rides just as well. My first bikes were steel and I still have that romantic memory of them but reality and romance are as different with bikes as they are with woman.
How much does EPO weigh? That extra weight will make you go faster up hill!
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OK, say a 150 pound rider, 3 pounds of clothes and shoes, 15 pound bike plus pounds of tools, WBs and cages and pedals. 170 pounds. Nine pounds heavier bike = 179 pounds. (Actually the heavier bike weight will, almost certainly INCLUDE pedals already so the difference might well be smaller by the weight of the light bikes pedals.)
Say Mr. 15 pounder does a 10 miles climb at 15 mph. 40 minutes. Or 170 pounds X feet climbed/40 minutes = power (in some arbitrary unit). If Mr Heavy puts out the same power = 179h/x minutes, we can solve for x, the time the heavier bike will take.
170h/40 = 179h/x or x = 179h/170h X 40. The h's cancel and x = 42.1 minutes or 127 seconds back on a 40 minute climb.
This analyses uses constant power output. If we put the speeds the same, we can see that the power difference for the heavy bike to keep pace with the light bike would be 179/170 = 1.053 or 5.3%. Not much. Matters of fit or stiffness affecting the effective power output of the riders could have more effect on speed. Looking at the photo in the article, the heavy bike rider looks much more relaxed, in a much better place to sustain a long hard effort. I can't tell how much of that is the bike and how much is the rider, but when switching bikes doesn't change the result, it suggests the light bike is a bit of a dog.
Ben
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What goes up must come down. How well does a flexible steel or titanium bike ride coming down a twisty road? I had an aluminum Santacruz Blur Long Travel that I swapped for the carbon version. All parts the same except the fork which was the same Fox Float 32 150 except the steer tube was the tapered variety. That bike descended much better. Went straighter, deflected less when riding rough trails. Accelerated a bit better too but I didn't notice that aspect as much as the descending improvement.
I descend better on my carbon road bike than any metal bike I ever owned too. That may partly be frame geometry and how accurately the frame was constructed too.
I think the weight thing is true though. A little extra weight is no big deal. But when I put heavier tires on my mountainbike I can always tell and climbing is slower. In fact I know some climbs that I can't get up if I have say DH tires on which are massive at 1200 grams each. I say weight does make a difference, the question is how much.
9 pounds heavier climbing the same? Bull crap.
Lance who?? -
It'd be interesting to include the average grade of their test hill. I agree bike weight is less important on flat routes but I think bike weight is somewhat important on medium distance and medium grade climbs. However, I think bike weight is more important when the grade exceeds, say, 10%. I slap fenders on my cross bike and ride it throughout the year when I'm at work. It is pretty heavy and although the geometry is pretty close to my regular road bike, I feel like I'm working harder to go the same speed up the steep hills.
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You don't have to convince me about carbon. I don't actually own any metal road bikes having crashed my supersix last year. Just carbon race bikes now.
But there are plenty of teammates of mine that comment how nice a custom Independent Fabrications or Strong frame would be, but that they just think they would be too slow if they were to ride a bike that was 19lbs. I just shake my head.
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Why does everyone assume that modern steel and Ti bikes are much less stiff than carbon? This is really not a statement that is supported by evidence. It is not the material, it is the design. Also, the difference between a modern steel frame and carbon is around 1kg or 2lbs (less for Ti and Al). This as a percentage of the bike rider combo is very small and adds very little to the time needed to climb at equal wattage. A lot of people have had a good long drink of the Carbon Kool-Aid. For the record I have or had Steel, Ti, and Carbon.
Cheers...Daryl LeBlanc
-Life is too important to be taken seriously- Oscar Wilde -
meh. I ride with friends that are on crabon bikes, aluminum, aluminum + crabon, and my mixed steel and crabon frame. We all are about the same ability. We like to ride fast until we can't, then we just ride and when we're done, we have a few beers and enjoy our time on the group rides. I"m not racing so really I"m just riding against my friends, some days one of us does better than the other, but when it comes to hills, I still ride the others off my wheel unless I cooked myself early. I also weigh about 15 lbs less than they do. Does that mean my steel & crabon bike is "better" than my friend's all-crabon Time frame? Not really. It's just that the engine weighs about 20lbs less.
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black dog, A cro-mo frame with the design to equal a 2.5 lb carbon stiffness would be ~6 lbs. You are correct that even at 3.5 lbs, that's not much in the total weight. I do enjoy listening to a guy talk about his 18 lb bike while he rubs his 50 lb belly hung on his 225 lb body (note: my weight references are for dirt rigs and fat dudes). I have a 22 lb bike and a 150 lb body...my bike is faster! ;}
I had two identical bikes but one was a carbon frame and the other AL. Without giving the 10 page report, the carbon bike was better. If that is carbon kool aid, poor me some more! ;}
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Ok. I'm calling BS on your 225lb guy bragging about his 18lb bike with a 50 lb belly.
That just DOES NOT happen.
225lb people just DON'T brag about weight. I'm 225, ride a 18lb road bike (CAAD10 w/DuraAce 10spd), do NOT have a 50lb belly (as in there is no way I could weigh 175lbs), do NOT brag about the weight of my bike, and RARELY have to catch up to people on hills - even those who weigh 150 lbs.
BULL$HIT.
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JM- My Singular Swift mtb with a Phil Wood machined steel ebb weighs less than 5.5 pounds. My Surly KM weighs 5.25 pounds. The heaviest chromoly road bike frame I've ever owned was a Univega made with Columbus Thron @ 4.4 pounds.
The guys at the shop don't ride carbon for the weight savings they ride it for the stiffness (Santa Cruz Nomads and Tallboys).
Jam Econo -
Hey JMDirt...What are you picking on me for? I thought we were friends! Besides, my bike is 16lbs, not 18, and I rarely actually rub the Buddha, at least in public!
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"meh. I ride with friends that are on crabon bikes, aluminum, aluminum + crabon, and my mixed steel and crabon frame. We all are about the same ability. We like to ride fast until we can't, then we just ride and when we're done, we have a few beers and enjoy our time on the group rides. I"m not racing so really I"m just riding against my friends, some days one of us does better than the other, but when it comes to hills, I still ride the others off my wheel unless I cooked myself early. I also weigh about 15 lbs less than they do. Does that mean my steel & crabon bike is "better" than my friend's all-crabon Time frame? Not really. It's just that the engine weighs about 20lbs less. "
iamus72 -- This post describes me as well. Been riding 35 yrs, since I was 15. Raced on steel, Al, Al + carbon, steel + carbon, Ti, Ti + carbon, carbon, and unobtanium + carbon. The weight really doesn't matter much - none of my bikes since ~1990 have been "heavy". It's about how you FEEL on them, whether you feel fast, and inspired. Do they ENABLE you or HINDER you at your present fitness level.
Granted, my carbon frames are sub $2500 frames, but I have yet to ride one that I find as comfortable as my Ti frame or the (high-end) steel frames I've owned. I'm probably not strong enough to feel the added stiffness of a $5000 Pinarello with a BBmondo crankset standard. I also feel that these uber-stiff frames are actually potentially more sketchy on bumpy downhills. Instead of absorbing irregularities in the pavement while leaning into a corner, the stiffness induces more wheel hop, so you really have to pay attention. -
It's funny, I replaced my SuperSix late last year with a Ridley Helium with Sram Red. The thing weighs 15lbs, which is the lightest bike I've ever owned. It also happens to be the stiffest bike I have owned and is not exactly the most comfortable bike. But, after a few months, I have really begun to love the bike. Especially on hilly rides. So while carbon is great at saving weight, its biggest plus is just how stiff the frame can be.
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Stiffness. I rode Klein #2 in my racing days, when I was close to as strong as I'd ever be. Way, way too stiff! The Fuji Pro I was riding at the time had sweet fit and the moderate stiffness (for classic steel) felt as stiff as I would ever need.
A few years later, there was this Pro rider, Sean Kelly, who was a very successful road sprinter. Won a lot field sprints. It has always puzzled me how that could be done on the very flexible Vitus he rode if stiffness was really that important.
I was taught and still believe that stiffness is needed for a small, select group of really strong riders and those who have never learned to pedal good "circles". Granted, in the old days of skinny tubed steel, stiffness was an issue for large frames. But now, adequate stiffness is easy to get in almost any material. But "adequate stiffness" for our bodies and "adequate stiffness" for our egos tend to be different numbers. At least that is my opinion.
Ben
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I agree with Entheo: static vs. rotational mass. Put some lightweight carbon rims on just about any frame and it will make a difference in climbing more than adding or subtracting a pound or two from the main frame itself i strongly believe. Basically if it rotates around an axis (and I think the further from the axis, the greater the impact) , then lightening it will make a difference. wheels (rims mostly), shoes, pedals, cranks, chain, chainrings, cassettes, etc.
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Even those differences are only really apparent when accelerating. When riding at a steady state, weight differences are not that important until the differences get very large.
The reason racers need light bikes, and especially rotating mass, is to respond to and make the repeated accelerations that are so important to bike racing. But settling in and tapping out the tempo...bike weight is just not that big a deal.
It is his word versus ours. We like our word. We like where we stand and we like our credibility."--Lance Armstrong.
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