29 inch study is a myth.

Printable View

  • 03-05-2006
    dr.dirt
    29 inch study is a myth.
    If someone can get me something more than this poster presentation I would be way appreciative. From what I can gather;
    1)this study was never published . it was presented as a poster in 2003 at South West Conference of American Colllege of Sports Medicine along with such landmarks as; "THE EFFECT OF AN ERGONOMICALLY DESIGNED GARDEN HAND TOOL ON FOREARM MUSCLE ACTIVITY."
    2) The principle investigator a J.T Herr, was from all I can gather an undergrad. MacRae the second author is a full prof. and directs the undergrad sports medicine program at pepperdine.
    3)It's kinda hard to interpret the results as they are kinda cryptic from the poster presentation, but the p values were good where they measured it. meaning they were statistically significant. There were 5 riders who did a uphill and a xc course. The heart rates (avg and max) were pretty equiv. The 29 inch was faster on both uphill 6.33 vs. 6.68 min and the XC course 13.62 vs. 14.0. I am a bit confused as they report no diff in power but the numbers say diff; 45W(26inch) vs. 47W (29inch)for the uphill, and 50W (26inch)vs. 56W (29inch) for XC....eh? This says although the 29inch was faster it also took more power. ahhh....so you pedaled harder and went faster basically.
    4)I have no idea how they standardized their bikes and riders. Differences in tires, suspension etc...are not accounted for. But beyond that they basically try and pull a fast one. The 29 inch took more power. Thats prob one of the reasons this never got published.
    Sorry.





    THE EFFECTS OF MOUNTAIN BIKE WHEEL SIZE ON PERFORMANCE IN UPHILL AND CROSS-COUNTRY CYCLING.
    J.T. Herr and H.S-H. MacRae. Dept. of Sports Medicine, Pepperdine University, Malibu, CA 90263.
    Purpose: Since mountain bike cycling performance is affected by bicycle design, the purpose of this study was to assess the effect of wheel circumference on mountain bike performance during uphill (UP) and cross-country (XC) cycling. Methods: Five sub-elite cyclists (34 ( 1.9 yr, 63.5 ( 6.3 ml.kg-1.min-1, 6.14 ( 0.5 W.kg-1 peak power) completed an UP course (1.38 km, 123 m elevation gain) and XC loop course (3.63 km, 158 m elevation gain) on mountain bikes equipped with either standard 26” (STA) or big 29” (BIG) circumference wheels. During these field trials, expired gases were continuously measured with a portable metabolic system (VO2000, Medical Graphics), and cycling performance (as measured by time to complete the courses (T), power output (P), cadence (C), speed (S), and heart rate (HR)), with an SRM Training System. Results: The gas exchange data are not reported here. Mean HR’s were not different between STA and BIG during UP (170 ( 9.4 vs. 172 ( 5.9 bpm), or during XC (168 ( 7.9 vs. 168 ( 8.5 bpm). Mean HR’s during UP were ~ 94% HRmax, and ~ 93% HRmax during XC. The time to complete the UP course was faster on the BIG wheel bicycle (6.33 ( 0.3 vs. 6.68 ( 0.4 min on STA, p = 0.03), and the XC course completion time was also faster on the BIG equipped bicycle (13.62 ( 0.5 vs. 14.0 ( 0.4 min on STA, p = 0.02). Absolute P (uncorrected for bicycle mass) was not different during the UP trials between STA and BIG (average P was 267 ( 45 vs. 300 ( 47 W), or during XC (average P was 200 ( 50 vs. 207 ( 56 W). Conclusion: Larger circumference wheels improve mountain bike performance during climbing and cross-country riding, with no detrimental effect on cardiovascular (HR) or muscle (P) function.
  • 03-05-2006
    Go Kart Motzart
    Uhh, OK. Don't buy one. You not having one will be a huge loss for the 29" wheel community, but we will make it. No really, we will.

    Maybe it's not "faster". Maybe "faster" is not the reason I ride one. Maybe I'm not concerned about the study. Maybe I wasn't even aware of the study. Maybe I don't like studies. Maybe I choose my equipment based on my own experiences, not studies. Maybe it's all a scam and I replaced all my 26" wheel bike for no reason. Maybe the government is behind all this. Maybe I'll go to bed.
  • 03-05-2006
    ozlongboarder
    I think its time we get a "anti" 29er forum. We all know they suck anyway. Mine sucks bigtime, I only ride to be cool and fit in with the "in" crowd. The wheels virtually taco when I look at them and they are so SLOW the recumbent riders can beat me.







    :rolleyes:
  • 03-05-2006
    lidarman
    I wish you did have the results to present! Bummer.

    This is exactly what my beef is with 29ers. If no one has done a study, then why would anyone have a basis that 29" is better than anything else? Why not 32" wheels if bigger is better? My 5' 0" wife would not appreciate a 29" bike since she can barely deal with the 26" wheels she has now! It's gotta be more about fit to a particular rider than some absolute number anyhow! That is why I say it's all BS.




  • 03-05-2006
    dr.dirt
    Sizing
    Quote:

    Originally Posted by lidarman
    I wish you did have the results to present! Bummer.

    This is exactly what my beef is with 29ers. If no one has done a study, then why would anyone have a basis that 29" is better than anything else? Why not 32" wheels if bigger is better? My 5' 0" wife would not appreciate a 29" bike since she can barely deal with the 26" wheels she has now! It's gotta be more about fit to a particular rider than some absolute number anyhow! That is why I say it's all BS.

    I really liked the 29 inch idea esp as I am over 6ft. I have all the order forms for getting measured for a custom 29inch Ti frame. As I am currently riding a Ti 26 HT I was going to be dropping a lot of coin on a concept. As popular as the 29 is, it was a big gamble. Hence I tried to find the original study. It's really a remarkably bad work. Not that I would have done much better as an undergrad.
    While Motzart may not be interested in studies or speed (odd then that he took the time to read and reply to my post) it was such a common thing quoted on the 29 forum it seems part of the bible.
    Not that you need studies to prove these things. Suspension forks never needed a study, Greg Herbold eviserated the entire field on a pair of the first Rock Shox. After that it seemed pretty obvious.
    I'll give it a shot. Someday drop a couple bills on a Karate Monkey. See what the hub-bub is about. Didn't know I would need to be part of a different community. Where do I pick up the membership card...is there a secret handshake?
  • 03-05-2006
    DeeZee
    With ya!
    Quote:

    Originally Posted by lidarman
    I wish you did have the results to present! Bummer.

    This is exactly what my beef is with 29ers. If no one has done a study, then why would anyone have a basis that 29" is better than anything else? Why not 32" wheels if bigger is better? My 5' 0" wife would not appreciate a 29" bike since she can barely deal with the 26" wheels she has now! It's gotta be more about fit to a particular rider than some absolute number anyhow! That is why I say it's all BS.

    It's gotta be more about fit to a particular rider than some absolute number anyhow!

    26,27,28,29,30,30.5,30.6,30.7...... :rolleyes: who knows what the magic number is :confused: There is not one

    The fact is that the bigger the rider the bigger the wheels. The wheel size should not stop at 26" because that was the only tire available for the M-Bike forefathers to use. :eek:
  • 03-05-2006
    fsp
    There is quite a bit of hubbub over it yet, even in the 29er forum:

    http://forums.mtbr.com/showthread.php?t=170411
    http://forums.mtbr.com/showthread.php?t=170061
  • 03-06-2006
    sportsman
    Do you always wait until an manuscript is published in a peer-reviewed journal before making a bicyling purchase?
  • 03-06-2006
    richwolf
    Well,

    I think it cost more than a few hundred to get into a 29 inch bike. Frame, fork, rims and tires at the minumum. Probably a different front derailluer too.

    Here are my thoughts:

    1. They will not climb as fast, due to heavier wheels nor will they accelerate as fast. This is assuming similar builds and tires.

    2. Big riders will probably be better off on them than small riders. What would Paul Bunyon ride??

    3. They should roll through bumpy stuff better and perhaps offer better absolute traction given similar tires.

    Now I did put my money where my mouth is and I just finished building up my Voodoo Dambala with exiwolfs. First ride today. Now I am vertically challenged but my curiousity got the best of me. Should beinteresting going back to a hardtail and rigid front fork. Softride stem and suspension seatpost. The wheels look huge!!
  • 03-06-2006
    tallboy69
    Whatcha got against Universities? Guys have to do studies on something to keep the grant :)

    Really, The MTB house has many mansions. SS, DH, FS, Rigid, etc. The evangelism surrounding 29ers puts some off, but many of us are better off with 29ers. Anything that gets people off the couch and out of a car is good.

    BTW, I'd like to see the research that proves 29er don't climb as fast.
  • 03-06-2006
    BontyRider
    Since so many other parts of a bicycle are tuned to the specific rider to achieve proper fit (Frame geometry, crank length, handlebar width, stem rise & length...), why not wheel diameter too?

    I would imagine that wheel diameter should be part of the calculus, but it's too impractical for the industry and for consumers, which might explain why there are two wheel sizes and not ten. So perhaps 29" wheels are best for some, 26" wheels are best for others, and everyone else just kind of picks one or the other...
  • 03-06-2006
    dr.dirt
    please read before you post...don't trust the man
    Quote:

    Originally Posted by sportsman
    Do you always wait until an manuscript is published in a peer-reviewed journal before making a bicyling purchase?

    "Not that you need studies to prove these things. Suspension forks never needed a study, Greg Herbold eviserated the entire field on a pair of the first Rock Shox. After that it seemed pretty obvious."
    When somebody tells me a study says something I look at the study and see if they had a valid conclusion. Interestingly enough this is often not the case. Everyone in the sciences should do this. The public often gets taken for a ride as they are a bit less familiar with evaluating data. In this case the famous pepperdine study which I found on quite a number or 29inch manufact sites, and mentioned ad nauseum here, was a joke. Sure there was a 4% drop in time, but there was a 12% increase in how much power the 29 incher used.
    There are a few places other places I've seen bike related manufacturers making false claims and referencing "scientific studies." Another example was Accelerade which if you've read their claims would seem to be the wonder elixir of the cycling gods. Turns out their "studies" were internally generated and fundamentally flawed. And there was real scientific data that said there was no diff between sports drinks (thread was sometime in may 04)
    What I am doing is watching your back. Industry (including the bike industry) throws a lot of ads around quoting "scientific studies." I'll tell you when they are full of [email protected] No charge.
  • 03-06-2006
    OneGearGuy
    Quote:

    Originally Posted by dr.dirt
    "Not that you need studies to prove these things. Suspension forks never needed a study, Greg Herbold eviserated the entire field on a pair of the first Rock Shox. After that it seemed pretty obvious."

    Yeah, I guess the fact that H-ball was the most talented descender at the time had no relevance... ;)

    Ride what you want. We who embrace the niner experience don't expect (or want) every rider to drop 26" wheels. We merely want a large enough community in which to share our joy and to warrant enough manufacturers to step up and provide viable product choices for the bigger wheels. It seems pointless to argue who will be better off with each size wheel; similar to full suspension vs. hartail; disc vs. rim brakes, etc. etc...
    I have female friends who are 5' tall happily riding the big wheels and 6'4" giants who are equally happy. Don't give up your Trek Fuel just to win me over, heheh! :p

    OGG
  • 03-06-2006
    RobW
    Quote:

    Originally Posted by richwolf
    1. They will not climb as fast, due to heavier wheels nor will they accelerate as fast. This is assuming similar builds and tires.

    Now I did put my money where my mouth is and I just finished building up my Voodoo Dambala with exiwolfs. First ride today. Now I am vertically challenged but my curiousity got the best of me. Should beinteresting going back to a hardtail and rigid front fork. Softride stem and suspension seatpost. The wheels look huge!!

    Number 1 (climbing) is wrong in most circumstances, as you will soon find. Grab a Nano for the rear, much faster...