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  1. #26
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    Quote Originally Posted by kallee View Post
    I always thought I go harder on the steep sections because I suffer more.
    I also tend to save a little reserve for the hard sections. Not just to get them over with quickly, but because momentum helps get the bike over momentary obstacles like roots and rocks. Climbing steep-ish stuff on a mountain bike tends to be dynamic, and I'd pay attention to empirical results regardless of what a canned formula thinks the answer ought to be.

  2. #27
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    Back from the archives

    I love the search function on mtbr...
    Thanks for the previous posts, which had me thinking this morning as I pedaled my 30 pound cross bike with studded tires to work. I know the tires are heavier, but I think the rolling resistance was a bigger factor with regards to speed and power.
    I've been thinking about various bikes and the value of a lighter frame in particular. I was messing around with the calculator on the site you all mentioned and based on a 1.5kg change, with a rolling resistance of .04 (a high number, I think), the difference on a course that was 60 miles long would be about six minutes.
    Six minutes? That is it? It seems as though there are so many other variables that would have a bigger impact on overall performance (e.g., choice of tires, nutrition, sleep, appropriate bike for the course). For those of you who have done everything else to maximize your performance, weight seems like a great place to go. But if I pick a really stiff, well designed frame that is a bit more portly than the uber high-end frame, is it really going to make much of a difference?
    I ask in the spirit of learning.
    The great use of life is to spend it for something that will outlast it.
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  3. #28
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    Quote Originally Posted by Mr.Magura View Post
    Keep in mind, that the study makes some pretty rough assumptions.

    Pedaling efficiency for one, is not going to be equal on a noodle 2 lbs frame, and on a super rigid 4 lbs frame.
    The same could be said about many other components.

    Another assumption would be the loss of power due to the condition of the trail is not playing a part, which is also highly questionable.

    So if two bikes perform exactly equal, under the conditions of the trail and so forth, yes, the lighter bike is faster.

    To need a study to reach that conclusion, well, ahem, is pretty much a joke.

    So if we can have components and frames, that performs equal, but are lighter, all is good.
    If not, the 22 seconds mentioned above,and then some, are going to be lost real quick


    Magura
    I completely agree. the study is a study about putting an extra kilo of weight in a water bottle on an existing rig/rider. If they put the extra weight going into actual parts I'd say the speed that they lost in seconds could have been close to zero. Because you actually get something back I'd guess. better heavier brakes (talking off the shelf **** here not your airplane carbvon stuff ) and everyhting else would be able to perform better most likely.

    the way I see it is that these test can never be performed on equal bikes, since there is no equal. How would this be judged both lighter and he3avier.
    no one could ever define what an equal but 1kg heavier/lighter bike would be. But its still numbers. If anyone wants to make a 1kg heavier bike than another one and everything else calculated a littler bit stiffer, 1kg stiffer in total, good luck.

    How would equal performance of components be decieded? I can see at least 3-4-5 ways here. But I liked the study actually. Only if its only an approximation its still something. And thats better than nothing.
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  4. #29
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    I would also like to see the studies with regards to kinetic energy for the whole package, rider and bike, and lighter/heavier bike (not just weights in bottles) Speed increases kinetic energy squared and mass only linear.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.

    Quote Originally Posted by iheartbicycles View Post
    Specialized sucks ass.

  5. #30
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    There was also a test done with riders going up alpe d'huez, about 9 miles and 6800 ft of climbing. Adding 2000 grams of rotating weight resulted in about a minute slower times. Thats more climbing than most average rides, and a minute isnt much, especially when the weight is added to the fabled "rotating weight."

  6. #31
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    Quote Originally Posted by One Pivot View Post
    There was also a test done with riders going up alpe d'huez, about 9 miles and 6800 ft of climbing. Adding 2000 grams of rotating weight resulted in about a minute slower times. Thats more climbing than most average rides, and a minute isnt much, especially when the weight is added to the fabled "rotating weight."
    I sure agree, that 1 minute over 9 miles of heavy climbing, is not something us mere mortals would be able to feel.

    Having said that, when I make bike bits, I usually focus on not making compromises regarding stiffness or functionality, for the sake of saving weight.
    This philosophy is based on that the pi$$ poor engine my bike is supplied with, needs all the help it can get, so wasting power in a soft ultra light frame, VS. keeping as much power going to the ground through a super stiff frame, always means the latter choice to me.
    That some EPO munching pro looses 1 minute on a 9 mile climb due to weight, would make close to zero difference to me, as I am far from his EPO munching/fitness level, and have totally different issues to deal with.
    Just the fact that the cadence of the pro's is like 25% higher, allows them to have a softer frame than us mere mortals, without loosing as much energy.
    When mashing up a hill, on a super light soft frame, I loose so much energy in the frame, that 1kg of dead weight would be lost in the equation.

    The same holds true for brakes to me. The ones that spend 4 hours a day training, sure has much better technique, so the performance of their brakes is less important, as their technique makes up for lack of modulation and so forth.
    Back when I made the carbon brake, the biggest benefit besides immense amounts of power, was the very low static friction it offered. It actually made me quite a bit faster, as I can brake harder and later with confidence.
    Now it is going to be coupled with a 4 piston Shimano Zee brake, even though the Zee is pretty heavy.
    Why?
    Because the functionality saves me much more, than the weight penalty costs.

    I'd dare to claim that similar parallels, can be drawn for most components.


    Magura

  7. #32
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    Quote Originally Posted by Mr.Magura View Post
    I sure agree, that 1 minute over 9 miles of heavy climbing, is not something us mere mortals would be able to feel.

    Having said that, when I make bike bits, I usually focus on not making compromises regarding stiffness or functionality, for the sake of saving weight.
    This philosophy is based on that the pi$$ poor engine my bike is supplied with, needs all the help it can get, so wasting power in a soft ultra light frame, VS. keeping as much power going to the ground through a super stiff frame, always means the latter choice to me.
    That some EPO munching pro looses 1 minute on a 9 mile climb due to weight, would make close to zero difference to me, as I am far from his EPO munching/fitness level, and have totally different issues to deal with.
    Just the fact that the cadence of the pro's is like 25% higher, allows them to have a softer frame than us mere mortals, without loosing as much energy.
    When mashing up a hill, on a super light soft frame, I loose so much energy in the frame, that 1kg of dead weight would be lost in the equation.

    The same holds true for brakes to me. The ones that spend 4 hours a day training, sure has much better technique, so the performance of their brakes is less important, as their technique makes up for lack of modulation and so forth.
    Back when I made the carbon brake, the biggest benefit besides immense amounts of power, was the very low static friction it offered. It actually made me quite a bit faster, as I can brake harder and later with confidence.
    Now it is going to be coupled with a 4 piston Shimano Zee brake, even though the Zee is pretty heavy.
    Why?
    Because the functionality saves me much more, than the weight penalty costs.

    I'd dare to claim that similar parallels, can be drawn for most components.


    Magura
    I thought you'd use Magura brakes. Marta Mags rule.
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  8. #33
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    Quote Originally Posted by osokolo View Post
    I thought you'd use Magura brakes. Marta Mags rule.
    Naah, the Magura brakes have not impressed me, since they quit on 4 piston calipers.

    If they would make a 4 piston caliper, I'd most likely still stick with Shimano, as the levers are too hard to modify. The same goes for the 1 piece calipers.
    1 piece calipers, are great in theory, but makes no difference in reality.
    They are just a PITA to modify as well.

    So Magura is actually a Shimano brake guy.
    If I didn't intend to modify the brakes, and just needed out of the box performance, it would be a tie between them.
    The Magura brakes are very high quality, and their customer service is simply over the top.


    Magura

  9. #34
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    Quote Originally Posted by Mr.Magura View Post
    Naah, the Magura brakes have not impressed me, since they quit on 4 piston calipers.

    If they would make a 4 piston caliper, I'd most likely still stick with Shimano, as the levers are too hard to modify. The same goes for the 1 piece calipers.
    1 piece calipers, are great in theory, but makes no difference in reality.
    They are just a PITA to modify as well.

    So Magura is actually a Shimano brake guy.
    If I didn't intend to modify the brakes, and just needed out of the box performance, it would be a tie between them.
    The Magura brakes are very high quality, and their customer service is simply over the top.


    Magura
    Are you a spandex or a baggy? Why would you need more braking power than the Mags can offer?

    I am 195# on a good day and love braking late. Too late. Probably because I suck technically. But never needed more power for sure. Now, I ride mostly XC - so that may be the factor. You?

  10. #35
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    Quote Originally Posted by osokolo View Post
    Are you a spandex or a baggy? Why would you need more braking power than the Mags can offer?

    I am 195# on a good day and love braking late. Too late. Probably because I suck technically. But never needed more power for sure. Now, I ride mostly XC - so that may be the factor. You?
    I ride just about anything, depending where I am in the world at the time.
    Spandex is reserved for the road bikes though
    I'm just over the 200# mark as i recall.
    EDIT: 215# or so with gear.

    I would say that XC is a very small part of my riding though. It's mostly in the hard end of trail I guess, with a preference for pointing the front end downwards, and finding different means of transportation to get up.

    For XC, the Mags are plenty sufficient, but they are a far cry from the carbon brake, when it comes to being confidence inspiring, when braking hard.

    I guess the thing is that my bikes need to be pretty versatile, as i can't carry several bikes when traveling, so my priorities may differ quite a bit from yours.


    Magura

  11. #36
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    i didn't read the article, was this for a road bike?
    i think on a mountain bike where you have to throw the bike around more, weight has a greater effect on long term fatigue

  12. #37
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    Quote Originally Posted by Dan GSR View Post
    i didn't read the article, was this for a road bike?
    i think on a mountain bike where you have to throw the bike around more, weight has a greater effect on long term fatigue
    same here... that study about road cyclist climbing crap load of vertical feet is as relevant to MTB as global warming is.

    With the amount of acceleration out of corners, that an average MTB ride or race inevitably consists of, I can feel the difference between two sets of wheels - Roval SL and American Classic... the difference in weight is mere 200g - probably a bit more in rotational mass - but the seat of the pants feeling is pretty obvious to me... Carbon wheels accelerate easier - without any doubt and regardless of the terrain... I rotate them on the same frame - depending on conditions...

    I'll go as light as possible, without compromising reliability. This mostly applies to wheels - I pass on wheels that have 185# or even 210# weight limit... 240# is acceptable for me (195# riding weight). 200g difference in wheels has noticeable effect on overall speed/fatigue.... my opinion and experience - of course...

  13. #38
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    This is a great discussion - glad someone revived it from earlier this year.

    I don't think anyone touched on the added weight in the tests as a percentage of the "system" (rider + bike). A buddy of mine is 6ft 6in tall and well over 230 lbs with gear. (Sorry if you're reading this dude, but you're a big guy!)

    I suspect you could strap a small child to his hip and he wouldn't notice.

  14. #39
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    Quote Originally Posted by Mr.Magura View Post
    I ride just about anything, depending where I am in the world at the time.
    Spandex is reserved for the road bikes though
    I'm just over the 200# mark as i recall.
    EDIT: 215# or so with gear.

    I would say that XC is a very small part of my riding though. It's mostly in the hard end of trail I guess, with a preference for pointing the front end downwards, and finding different means of transportation to get up.

    For XC, the Mags are plenty sufficient, but they are a far cry from the carbon brake, when it comes to being confidence inspiring, when braking hard.

    I guess the thing is that my bikes need to be pretty versatile, as i can't carry several bikes when traveling, so my priorities may differ quite a bit from yours.


    Magura
    Interesting study on bike weight vs. performance-imageuploadedbytapatalk1355669622.583600.jpg

    Mmmkay. Yep. Versatile bike with Magura Raceline. Check.

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  15. #40
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    Quote Originally Posted by osokolo View Post
    Click image for larger version. 

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    Mmmkay. Yep. Versatile bike with Magura Raceline. Check.

    Versatile yes, but in the other end of the spectrum.

    Currently my preferred bikes are closer to DJ than XC.
    I think I would not have much fun riding street on your bike, let alone practice trial.
    I also doubt it would like the generally rough treatment in the long run.

    On the other hand, I'm fairly sure you'd find my preferred bikes pretty useless

    Right now I'm working on an on the fly adjustable head tube system, a bit like an Angleset, just without the hassle. That will hopefully allow me to really cross a DJ/street frame with a HT trail frame.

    Magura

  16. #41
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    Quote Originally Posted by Mr.Magura View Post
    Versatile yes, but in the other end of the spectrum.

    Currently my preferred bikes are closer to DJ than XC.
    I think I would not have much fun riding street on your bike, let alone practice trial.
    I also doubt it would like the generally rough treatment in the long run.

    On the other hand, I'm fairly sure you'd find my preferred bikes pretty useless

    Right now I'm working on an on the fly adjustable head tube system, a bit like an Angleset, just without the hassle. That will hopefully allow me to really cross a DJ/street frame with a HT trail frame.

    Magura
    different strokes for different folks... i am 90% XC lactic acid junkie type of rider. the rest of 10% goes to AM. road is intertwined - but insignificant...

    DJ and street don't really interest me. DH is fun, but requires career change... also, i prefer to ride up before i go down... having fun with both...

    in XC - weight is very important. i find tests and statistics compiled on the road - completely useless and not applicable to MTB - weight wise.

    yep, sometimes i can piss more than i can shave off the bike - but 200 grams in rotational weight is something that even we - mere mortals will feel easily and without any doubt...


  17. #42
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    Quote Originally Posted by osokolo View Post
    different strokes for different folks... i am 90% XC lactic acid junkie type of rider. the rest of 10% goes to AM. road is intertwined - but insignificant...

    DJ and street don't really interest me. DH is fun, but requires career change... also, i prefer to ride up before i go down... having fun with both...

    in XC - weight is very important. i find tests and statistics compiled on the road - completely useless and not applicable to MTB - weight wise.

    yep, sometimes i can piss more than i can shave off the bike - but 200 grams in rotational weight is something that even we - mere mortals will feel easily and without any doubt...

    We sure are in opposing ends of the scale.

    I sure agree that weight matters, that is simple math. Where I strongly disagree, is when weight saving is done at the cost of function.
    Especially for frames, the weight is of much lesser importance (again to mere mortals like us), than the energy loss from a soft and flexible frame.

    Another place I've wondered why people don't look for function, is some of the super light carbon bars. Some of them are like having rubber bands between the grips and the fork.

    Again I'd like to point out though, that these priorities sure changes, if you ride pro level, but I for one feel I need all the help I can get.
    I think much of this is related to, that many people think they need pro equipment. Unfortunately most riders are like you and me (ok, like me, as you obviously are in pretty good shape), and that does not go hand in hand with the compromises of much of the pro stuff.

    Magura

  18. #43
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    Quote Originally Posted by Mr.Magura View Post
    I sure agree that weight matters, that is simple math. Where I strongly disagree, is when weight saving is done at the cost of function.
    Magura
    This. Couldn't agree more.

  19. #44
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    The ultimate weight reduction for the $$$ is colon blow. You can drop 2 pounds in no time and once the fury subsides feel better afterwards. Food for thought!
    The Truth will set you free.

  20. #45
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    I think most everyone would agree that weight has an impact. I guess the question for me is the effect size. Just because it makes a difference doesn't mean it makes a 'meaningful' difference. This is certainly subjective, since the individual gets to choose what they value. That being said, I wonder how researchers might further identify the actual change. What about using a power meter? If, for example, one compared a bike model that had an aluminum frame and a carbon frame, with identical components, and examined both time and power over a specific course, and used a couple different tires that had differences in rolling resistance. Like so:

    aluminum bike, tire type a (low rolling resistance) vs. carbon bike, tire type a

    then

    aluminum bike, tire type b (high rolling resistance) vs. carbon bike, tire type b.

    I realize that the stiffness of the frames could make a difference, but that is a confound that might be controlled with a covariate analysis. Or, we just accept the difference and see how it plays out.

    What do you think? Where are the flaws in this sort of design?

    Josh

    Quote Originally Posted by Mr.Magura View Post
    We sure are in opposing ends of the scale.

    I sure agree that weight matters, that is simple math. Where I strongly disagree, is when weight saving is done at the cost of function.
    Especially for frames, the weight is of much lesser importance (again to mere mortals like us), than the energy loss from a soft and flexible frame.

    Another place I've wondered why people don't look for function, is some of the super light carbon bars. Some of them are like having rubber bands between the grips and the fork.

    Again I'd like to point out though, that these priorities sure changes, if you ride pro level, but I for one feel I need all the help I can get.
    I think much of this is related to, that many people think they need pro equipment. Unfortunately most riders are like you and me (ok, like me, as you obviously are in pretty good shape), and that does not go hand in hand with the compromises of much of the pro stuff.

    Magura
    The great use of life is to spend it for something that will outlast it.
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