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  1. #1
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    26er vs 29er experiment at the 24 hours of Old Pueblo

    26er or 29er – Which was Faster at the 24 Hours in the Old Pueblo? | Mountain Bike Review

    Gotta get in there and mix it up! If you're trapped indoors today that is.

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    In 2011 I had an 'old school' mid 1990's chrome moly framed 26" with v-brakes that weighed 24lbs.

    2012 I bought a Trek Superfly AL Elite 29" w/ custom wheels, etc. got it down to 22.5lbs

    I Live and race in midwest - 29er fork and brakes are light years better - I realize article was on single speed - but otherwise I am not really surprised by results.

    I thought it was cool having about the only bike with rim brakes and then winning/podium finishes against carbon 29ers

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    awesome find

    thank you

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    Yawn....!

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    Quote Originally Posted by BruceBrown View Post
    Yawn....!
    No kidding. Horribly unscientific comparison.

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    I think its a very interesting test.
    Probably not very scientific, but it agrees with other more scientific approaches(different riders, powermeters, and so) in which 26er was more efficient than the 29er.
    Not trying to set the thread in flames, but, there's a really scientific test proving that 29ers are really better?

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    Quote Originally Posted by Puxa! View Post
    I think its a very interesting test.
    Probably not very scientific, but it agrees with other more scientific approaches(different riders, powermeters, and so) in which 26er was more efficient than the 29er.
    Not trying to set the thread in flames, but, there's a really scientific test proving that 29ers are really better?
    hmmm, I must've missed the memo. I've never seen a "scientific test" that said 26" bikes were more efficient. For that matter, I've also never seen one that showed that 29ers were significantly more efficient.

    The only remotely valid comparison I've seen was published in Mountain Flyer Magazine (Jan or Feb, 2012, can't find it online to verify).

    The author took two very similarly set up bikes, a 26 and 29, and over a number of weeks rode them over multiple courses. Some were clearly suited for the 26, others for the 29. To keep it fair, he measured time and power over each course on each bike. He noted not only the speed differences and power differences, but also how they "felt".

    Turns out that there isn't a nickel's difference between the two wheel choices until you factor the feel that you as the rider like and your skill level. The skill level comes in when you consider the additional stability with the 29er wheel.

    The only truly meaningful differences in times between the two bikes were on courses that were so clearly favoring one bike over the other that the result wasn't a shock. In essence, in a really, really twisty (really, really!) course, the 26" was a little faster. On an almost pure fire-road course, the 29er was a little faster. On all other courses, the differences between the bikes in terms of elapsed times and power output required to achieve the times were well within statistically insignificant limits, almost wholly attributable to 'noise'.

    For most of us, it boils down to what we like. For the pros, it boils down to what the sponsor is trying to push on the marketplace. The riders don't revolt when they're asked to ride one size or the other, as they know (or should know) it won't matter.

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    I'm sorry I can't post links with my phone(at least I don't know how to), but there was a guy with a blog who did two tests, with power meter and things like that, in different terrains, and the results were that both sizes were very close, with a slight advantage to the small one. And there was a magazine test, with different riders, equivalent bikes, different courses in different days, lots of measuring devices, and the result was slight advantage to the 26er.
    I agree with you in your final statement, If i was paid to ride, I'd ride what the sponsor would give me, but as most of us pay to ride, we ride what we like.

    However, what I find interesting is that the big brands that are pusing the 29er is better movement, and have all necesssary resources to make a definite test to prove them right or wrong, did not do it(or at least, did not share the results)
    I've tried HT and FS 29ers and did not enjoy them as I was told I would, and so I started questioning wether all this info was good or not.


    Oh, I just remembered a "test" from Specialized. Christoph Sauser, two laps, one with each wheelsize, and the 29er was some little seconds faster, with a higher heart rate...Now that was a good test

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    So in other words different wheel sizes have different advantages and disadvantages. No real shocker there.

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    Quote Originally Posted by mudge View Post
    For the pros, it boils down to what the sponsor is trying to push on the marketplace. The riders don't revolt when they're asked to ride one size or the other, as they know (or should know) it won't matter.
    I agree

    When the manufacturer comes out with a new product, the pros ride it and it is pushed into the market place and we are made to think if we do not buy it, we will be at a disadvantage...

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    Quote Originally Posted by zrm View Post
    So in other words different wheel sizes have different advantages and disadvantages. No real shocker there.
    The real surprise is how small the measurable differences are.

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    I think wheel size is more relative to frame and rider size. I'm 6'3" and 29er wheels are a no brainer compared to 26". My prediction: 650b will dominate the market in 5 years; reason being, average male height is 5'10". 26ers were too small, 29ers are too big, but 650b will be just right because that's where the majority of riders will fall in line.
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    Quote Originally Posted by mudge View Post
    The real surprise is how small the measurable differences are.
    1-2 minutes in a hour is a big difference for just changing equipment if you think about it.

    If lap average was 15mph for 1 hour lap: 1 minutes = 1,320 ft

    Or about a 5 watt difference - 5 watts may not sound like a lot but with the the authors experience (seasoned rider) it may take a year of training to make up that difference on conditioning alone

    The faster bike is over 4 football fields in front of you

    My disclaimer: I hope I got that right....
    Last edited by scottz123; 03-06-2013 at 03:47 AM.

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    I totally agree it would take a lot of training to go 2 min/hr faster....if all a guy has to do is go back to the smaller wheel I'd certainly do it. And I'm 6' 4".




    Quote Originally Posted by scottz123 View Post
    1-2 minutes in a hour is a big difference for just changing equipment if you think about it.

    If lap average was 15mph for 1 hour lap: 1 minutes = 1,320 ft

    Or about a 5 watt difference - 5 watts may not sound like a lot but with the the authors experience (seasoned rider) it may take a year of training to make up that difference on conditioning alone

    The faster bike is over 4 football fields in front of you

    My disclaimer: I hope I got that right....

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    Quote Originally Posted by scottz123 View Post
    1-2 minutes in a hour is a big difference for just changing equipment if you think about it.

    If lap average was 15mph for 1 hour lap: 1 minutes = 1,320 ft

    Or about a 5 watt difference - 5 watts may not sound like a lot but with the the authors experience (seasoned rider) it may take a year of training to make up that difference on conditioning alone

    The faster bike is over 4 football fields in front of you

    My disclaimer: I hope I got that right....
    The circumstances under which that "test" was done are so freakishly unscientific as to yield no legit conclusions.

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    The problem I have with this "test" is those time differences from lap to lap were similar to the lap time differences I had at 24 hrs of Moab when I did it and I was on one bike. Most people's lap times get progressively slower and then the last lap in the day time is faster than your lap times at night as the body's circadian clock kicks in and you have daylight to see better.

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    Quote Originally Posted by mudge View Post
    The circumstances under which that "test" was done are so freakishly unscientific as to yield no legit conclusions.
    I'm sorry...I thought you said "The real surprise is how small the measurable differences are".

    Nobody wants to hear their 29er wonder bike - may be slower....

    Me included!

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    Quote Originally Posted by scottz123 View Post
    I'm sorry...I thought you said "The real surprise is how small the measurable differences are".

    Nobody wants to hear their 29er wonder bike - may be slower....

    Me included!
    The earlier comment about minimal differences was not referring to this specific comparison, but rather merely a comment on the lack of surprise that there are advantages/disadvantages.

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    Hmmm, I suppose if wheel size really mattered (which it doesn't) then why not simply go back to 24 inch wheels? Cannondale (and others) tried this in the early 1990's. If smaller wheels really made you faster then why aren't there any 24 inch wheel bikes out there at the races?

    Bottom line: 29er vs 26er = No difference at all. What matters is how the bike feels. If 29er feels nice then ride it. If you like 26er better then ride it.

    The point is: just go ride your bike and enjoy it.

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    Quote Originally Posted by wjphillips View Post
    Bottom line: 29er vs 26er = No difference at all.
    I thought one had 26" wheels and the other 29" wheels?

    Posters with comments - what are you guys riding?

    I am on Trek Superfly AL elite last season - first season on modern bike - weighs a little over 22lbs. With the longer wheelbase compared to 26" 24lb bike I came off of am not that impressed. Brakes and forks way better on Trek, though.

    I live in midwest with rolling terrain.

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    I'm a bit confused about the comments that say "it doesn't matter, ride what you like". Guys, it's the XC racing board so it's all about going faster. I like riding my Moonlander but I'm not going to spend time and money traveling to races with that bike, right? It's hard to tell if a bike is a minute faster per hour but that is a hard-fought minute and it's worth the discussion.

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    The only thing that is certain here is that there has to be a difference in performance between 26" and 29" wheels. They're different sizes, so they'll perform differently. The "no difference" contention really is the only empirically wrong piece here.

    The funny part is that all of us KNOW what the differences are. We've read about, talked about and experienced these. It's not rocket surgery. 29" wheels accelerate (climb) and turn slower. But 29" wheels roll over roots, rocks easier (faster) - which can translate to lower fatigue, higher speeds - depending on conditions (picture those last three words bolded).

    So, the obvious part that we've all known... each bike has its strengths and weaknesses relative to the other. In a perfect world, your sponsor would provide one of each and not dictate which to ride where and when.
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    Quote Originally Posted by scottz123 View Post
    I'm sorry...I thought you said "The real surprise is how small the measurable differences are".

    Nobody wants to hear their 29er wonder bike - may be slower....

    Me included!
    Reading that article leads me to believe that any gains on 29er vs 26 are minimal. There is more variation in riding than there is on the bike. Remember also that since we ride dirt trails conditions change all the time. I also road bike and I have 7 mile loop that shows 20 rides with in 30 seconds, but on dirt the conditions change. Rocks move winds shift dirt gets harder or softer.

    So what I take away from this test is that differences are small and each wheel size has its advantage and dis-advantages. I ride a 26" hardtail and I know a weakness of my talent is very tight switchbacks. So given that moving to a 29er probably would make that worse and make my riding less enjoyable as I like to ride a lot of tight twisting rocky trails and do the occasional race. The rockiness may favor the 29, but I need and like a tighter handling more maneuverable bike. Plus at 5'7" I am not very tall. Am I giving up speed on race course with a 26" hardtail? Possibly depending on the course, but probably a lot less than that what can be corrected with little smarter training and skill development.


    Now if you are looking to win races and have skill and fitness to do it here is what you do.

    You bring 29HT, 26HT, 26FS, and now even 27.5 HT. Pre ride the course with all bike and select the one that gives you the best lap time for that course. In the end it may provide the 30 seconds you need to take the win. For those of us who cannot train to ensure 100% peak fitness at race time it probably won't make a difference.
    Joe
    '12 Santa Cruz Highball 29", '13 Santa Cruz Solo 27.5",Vassago Verhauen SS 29" XC, AM, blah blah blah.. I just ride.

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    The author of the article never attempted to make this his masters thesis. The lack of scientific control is a given. This article is an opinion piece, not a scientific article.
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    Exactly and it was really a wash. Even if you could get very accurate numbers in time trail format things change when introduce traffic and variable conditions. Some place may suit a certain bike type for a certain rider skill set and then 1 mile later it all changes. The big question is does the time gained where a certain wheel size is stronger counter any time lost where that same wheel is weaker? Beyond that some riders fitness and skill level may be accentuate or minimized by a certain wheel size.

    Even we you get very scientific I think the real issue is that the differences are still so small as to be overshadowed by other harder to control factors. All you are left with is opinion and "feel".
    Joe
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    [QUOTE=OldZaskar;10234571]The only thing that is certain here is that there has to be a difference in performance between 26" and 29" wheels. QUOTE]

    I disagree. It depends how you are measuring performace. Since we are talking about bike races I assume that performance means lap times. The only thing that seems near certain in the article is that wheel size is far less important then other variables. Darkness, Mechanicals, Riders not being ready for thier next lap, all had a much bigger influence on lap times then wheel size. Compared to those things one might be able to conclude that wheel size does not matter at all.
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    Really, this whole arguments like saying what is more efficient, a 26 inch penis, or a 29 inch penis ?

    LOL, both pretty efficient i would think.........
    Dont ever let the truth get in the way of a funny story....

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    Quote Originally Posted by JoePAz View Post
    ... things change when introduce traffic and variable conditions...
    This is an interesting point and a good observation. I experienced this 3 weeks ago - on my second ride (first race) on a 29er. It was a huge (150+) mass start which led to lots of traffic. For the first lap, I spent an inordinate amount of effort getting passed slower riders - you know the drill, e.g. quick accelerations past 1, 2 or 3 guys. By the 2nd 1/2 of that lap - and all subsequent, things smoothed out.

    I thought about the 29" wheels each time I had to accelerate like that - mostly because I was so new to the bike - and wondered if I was burning more matches than if I were on my 26" wheels.

    32 miles and a #*$& ton of roots and rocks later, as I stepped off the podium (no ****), I attributed that placing to the bike. I was absolutely convinced I was able to keep hammering because of the bike. Okay, it's my first FS too. That may have helped with the rocks and root. ;-)

    But I do think what I gave up accelerating/climbing with the bigger wheels, I made up because of the conditions on THAT course, THAT day.
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  29. #29
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    Do you think wheel size matters more than 2#'s on your race bike? More than XTR vs. SLX? I think wheel size matters more than that....the problem is which is faster?

    It is true that bike racing is more of a competition between men than between machines....but I doubt many racing enthusiasts are racing 27# hard tails so our wallets say that the bike matters.

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    Quote Originally Posted by OldZaskar View Post
    It was a huge (150+) mass start
    The races I do that are mass start, are over 1,000 people. My age group is usually half of your mass start race! Not bashing you, just thought 150 people being huge was funny!

    Quote Originally Posted by Fastskiguy View Post
    but I doubt many racing enthusiasts are racing 27# hard tails so our wallets say that the bike matters.
    the bike shops also say the bike matters! My problem was I liked my 26er better, but the races I do cater to the characteristics of the 29er. So, I'm on a 29er now. Maybe 650b is the ticket!

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    Quote Originally Posted by Fakie1999 View Post
    The races I do that are mass start, are over 1,000 people. My age group is usually half of your mass start race! Not bashing you, just thought 150 people being huge was funny!
    Really? Wow. I'm a Cat-2, 40-44 (usually the biggest class) and in a regular XC race here in GA, there are usually under 40 guys. There maybe a couple hundred racing that day, but they let the off in 30 second intervals. So, the hole-shot is usually a battle between 8-10 guys. The race I referenced was the a 6-hour and they let everyone off at the same time. And yeah - 150 seemed huge ;-)
    Mountain bikers who don't road ride are usually slow.
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    1,000 people mass start, that's crazy. What is the name of that race?
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  33. #33
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    Just to throw it out there, the guy's whole claim was this:

    The lower inertia and rotating mass of the 26er wheel vs 29er allowed him to expend less energy accelerating when passing others. He claimed he was needing to acclerate and pass 50 riders or so a lap. Less energy spent passing meant he could carry more speed overall.

    This is actually a pretty good argument.

    'nuff said.
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    Quote Originally Posted by dru View Post
    Just to throw it out there, the guy's whole claim was this:

    The lower inertia and rotating mass of the 26er wheel vs 29er allowed him to expend less energy accelerating when passing others. He claimed he was needing to acclerate and pass 50 riders or so a lap. Less energy spent passing meant he could carry more speed overall.

    This is actually a pretty good argument.

    'nuff said.
    'nuff said?? Srsly? The difference in wattage required to accelerate a 26 vs 29 inch wheel from a standing start to top speed is pretty small, and once you're rolling and only speeding up a few mph, it's barely measurable. It may "feel" harder to accelerate the larger wheel, but the explanation re: accelerating to pass numerous riders accounting for the difference he noticed between the two bikes is not a pretty good argument.

  35. #35
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    Quote Originally Posted by mudge View Post
    'nuff said?? Srsly? The difference in wattage required to accelerate a 26 vs 29 inch wheel from a standing start to top speed is pretty small, and once you're rolling and only speeding up a few mph, it's barely measurable. It may "feel" harder to accelerate the larger wheel, but the explanation re: accelerating to pass numerous riders accounting for the difference he noticed between the two bikes is not a pretty good argument.
    I'm working right now to see how easy it is to calculate the difference in wattage between the two sizes. I doubt very much it is 'pretty small' since it would be a safe bet that the bigger wheels have a weight penalty of 200g minimum, and that weight is 31.5 mm further outward. This stuff is highschool/1st year university physics and I suck at math, so bear with me.
    occasional cyclist

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    Quote Originally Posted by dru View Post
    I'm working right now to see how easy it is to calculate the difference in wattage between the two sizes. I doubt very much it is 'pretty small' since it would be a safe bet that the bigger wheels have a weight penalty of 200g minimum, and that weight is 31.5 mm further outward. This stuff is highschool/1st year university physics and I suck at math, so bear with me.
    Don't forget to factor in rolling resistance differences. Most formulas for calculating acceleration power requirements don't.

  37. #37
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    So far, digging up horrible things like radians, I've come up with the following, assuming 700 g 29er tires, and 500 g 26er tires.

    I haven't got the energy expended yet.

    for accelerations from 20 km/h to 25 km/h

    the 29er tire has 1.433 kgm2/s2 of angular momentum going up to 1.788

    the 26er tire has .9158 rising to 1.145...

    bear with me, more coming.

    Drew

    the 29er tire needs .355 watts each time it is sped up

    the 26er tire needs .229 watts each time it is sped up

    the rims would be a bit less of course..

    I'm curious about how much more I can do....
    Last edited by dru; 03-24-2013 at 03:43 PM. Reason: more maths
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    Quote Originally Posted by dru View Post
    So far, digging up horrible things like radians, I've come up with the following, assuming 700 g 29er tires, and 500 g 26er tires.

    I haven't got the energy expended yet.

    for accelerations from 20 km/h to 25 km/h

    the 29er tire has 1.433 kgm2/s2 of angular momentum going up to 1.788

    the 26er tire has .9158 rising to 1.145...

    bear with me, more coming.

    Drew
    Drew, not wanting to dissuade you from your pursuit, but this sort of thing has been addressed ad infinitum by folks who are engineers. The numbers you come up with will be small, and without factoring in the lower rolling resistance of the larger wheel, will be indecisive.

    IIRC, it was Lennard Zinn who said that cyclists accelerate so slowly that engineers don't even describe what we do as accelerating. He was talking about pro roadies, btw. We don't accelerate, we just don't go quite as slowly for a few moments.

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    Yeah, the numbers I've just added are pretty tiny. Still, I haven't heard anyone say that nice light race wheels dont feel night and day better than heavy ones. It has to affect something otherwise you guys would all be riding bikes like I ride.

    It is painful doing these maths I have to admit!

    Drew
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    Quote Originally Posted by dru View Post
    Yeah, the numbers I've just added are pretty tiny. Still, I haven't heard anyone say that nice light race wheels dont feel night and day better than heavy ones. It has to affect something otherwise you guys would all be riding bikes like I ride.

    It is painful doing these maths I have to admit!

    Drew
    Key word: feel

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    I wonder which is a bigger factor.....heavier rims and tires or a greater circumference. I'd bet the bigger circumference. I'm looking forward to the results of the calculations.

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    I think the best approach is to require all riders to give specific details about their phyique and bike setup at every sponsored event (small or large)

    Then all this data should be collected into a database where random samples can be taken and a statistical trend can be developed.

  43. #43
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    afaik bigger circumference and slower rotation speed (29er wheels dont rotate as fast as 26 to go the same speed) cancels each other's effect, the only real difference is weight, and to accelerate 100g even as rotating mass from 20 to 25 km/h takes like no energy at all
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    Quote Originally Posted by nya View Post
    the only real difference is weight, and to accelerate 100g even as rotating mass from 20 to 25 km/h takes like no energy at all
    But then why is there such a big market for lightweight wheels? Why does conventional wisdom say you look to save weight in the wheels first? We can say a lot of things about the big wheels but we can't say the weight isn't much of a factor.

    Or...or can we? There was an article in Bicycle Quarterly that argued that extra wheel weight made very very little difference.

    I'll be honest, I don't know but the big wheels "feel" more sluggish FWIW

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    Quote Originally Posted by dru View Post
    Just to throw it out there, the guy's whole claim was this:

    The lower inertia and rotating mass of the 26er wheel vs 29er allowed him to expend less energy accelerating when passing others. He claimed he was needing to acclerate and pass 50 riders or so a lap. Less energy spent passing meant he could carry more speed overall.

    This is actually a pretty good argument.

    'nuff said.
    Close. You missed the true key factor. He passed ~50 riders/lap. If he had to speed up to pass them, that means he had to slow down. WHERE he had to slow down can be just as important as how often, and how LONG he slowed down can be hard to track. He needs to go back and do 4 laps, 2 on each bike, without anyone else out there to slow him or motivate him to kick it to catch and pass. Or do this with a power meter. Anyway, pretty sure 2008 wants it's argument back.

  46. #46
    nya
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    I would say that its for the placebo effect, I went for lightweight ones also
    but it would be stupid to say it has no effect what so ever, but i would say the "speed" effect is only small part of the overall lightweightness advantage...handling is definitely the other one, lighter wheel is easier to turn and do other stuff, etc

    but stiffness is probably more important than weight imo, and tons of other stuff

    and why is there market for that, why is market for lightweight titan screws with even less effect, or expansive carbon bottle cages etc etc...because people buy them
    XCO results, races, riders etc http://mtbcrosscountry.com

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