CycleBanter.com

CycleBanter.com (http://www.cyclebanter.com/index.php)
-   Techniques (http://www.cyclebanter.com/forumdisplay.php?f=8)
-   -   29er "pedals easier" (http://www.cyclebanter.com/showthread.php?t=256117)

[email protected] July 15th 18 06:00 PM

29er "pedals easier"
 
I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?



AMuzi July 15th 18 07:34 PM

29er "pedals easier"
 
On 7/15/2018 12:00 PM, wrote:
I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?




Depends on the speeds and surface anomalies involved. For a
smooth board track a smaller wheel may well be more efficient:
http://www.tomsarazac.com/tom/opinions/wheelsize.html

But in typical riding conditions, a big fat 700x54 rolls
over depressions, rocks, debris, zombie bodies etc much
better than, say, a skateboard wheel:

https://www.youtube.com/watch?v=kdwROHgPask

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



Frank Krygowski[_4_] July 15th 18 09:00 PM

29er "pedals easier"
 
On 7/15/2018 1:00 PM, wrote:
I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?


I might point someone to the book _Bicycling Science_ by Wilson.

All things being equal, on typical road surfaces, a larger diameter
wheel should roll easier. But for slight differences in diameter, I'd
expect the differences in rolling resistance to be slight.

I'd expect tire choice to have a greater effect. That includes tire
width, as well as tire construction. Choice of pressure will also be
significant, and higher pressures do not always mean lower rolling
resistance on real roads.

Then there are the psychological effects to deal with. If he believes it
rolls easier, his 29er may indeed post faster times. Ditto if he paints
the bike red, if it has European cachet, if he replaces his steel water
bottle screws with titanium ones, if he buys more aerodynamic
sunglasses, etc.


--
- Frank Krygowski

John B. Slocomb July 15th 18 11:49 PM

29er "pedals easier"
 
On Sun, 15 Jul 2018 10:00:27 -0700 (PDT),
wrote:

I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?


Trek has an advertisement that says that the largr wheels roll easier.
My locak bike shop has one posted next to the door :-)

Andre Jute[_2_] July 16th 18 12:41 AM

29er "pedals easier"
 
On Sunday, July 15, 2018 at 6:00:30 PM UTC+1, wrote:
I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?


I wouldn't pay overmuch attention to the sneering of the usual clowns competing to be the most snide poster of the week.

I have a proper 29er, which means that it has 622x60 tyres mounted on rims at least 40% of tyre width, in this case 24mm across the bead retainers; all of the consideration I mention in this post are important primary parameters; if the makers skimp on them, the bicycle isn't a 29er and will not share in the benefits of a 29er. The tyres are furthermore inflated to very low pressures, in my case 2 bar or about 28-30psi to carry at least 135-150kg or bike, rider and extensive painting gear. (Despite what the usual morons will now tell you about my bike, about which they claim to know more than its makers or me, its frame is lighter than my two similar ali bikes; when you order custom tubes from Columbus, you get what you pay for.) My bike is very comfortable indeed without any other suspension than the air in the balloons, and light rolling too, and once it gets going, the momentum of those big tyres keeps it going, which also makes the pedaling easier.

Several distinguished European universities in recent years tested low inflation near-slick balloon tyres and found their rolling resistance less than narrow, high pressure, treaded tyres. That is a fact which continually comes as a surprise to a surprising number RBT posters, though it shouldn't: Jobst Brandt, the smartest engineer who ever posted here (not a high barrier, as most of those with punched tickets here have tenth-rate minds and are the products of third-rate colleges, and Jobst was a very thoroughly trained engineer -- his first job was with Porsche in Germany -- with brilliant insights) several times predicted these findings by a pure process of logic, which was also the logic behind his introduction of slick tyres for road bikes for an American firm he advised.

Andre Jute
Zero tolerance for pompous fools, less for lying clowns

Andre Jute[_2_] July 16th 18 12:45 AM

29er "pedals easier"
 
On Sunday, July 15, 2018 at 7:34:25 PM UTC+1, AMuzi wrote:

...a big fat 700x54 rolls
over .... zombie bodies etc much
better than, say, a skateboard wheel:
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


The 29er rider is prepared for all eventualities!

AJ
Heh-heh!


Oculus Lights[_2_] July 16th 18 01:09 AM

29er "pedals easier"
 
On Sunday, July 15, 2018 at 10:00:30 AM UTC-7, wrote:
I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?


Misusing the laws of physics to mislead the reader into a false conclusion.
A heavier rotating mass, or the same mass at a longer radius,
will need more energy to bring the linear velocity that the circumference is rotating at up to the same velocity.
That greater amount of momentum will require greater opposing force to slow it down. That's how the claim that a larger tire can roll easier is true..
But do we want a tire that rolls "easier" or that can be brought up to a desired rolling speed, easier?
This also leaves out aerodynamic drag. There's more drag on a taller tire and wheel of the same width. So you also have to overcome that drag. That drag on the tire and wheel is constant regardless of the bumps and surface resistance against the tire tread.
The aero part is easily seen by going back to when TT bikes were using smaller diameter front wheels till UCI banned that.
My MTB is still the same 26" rim brake wheels that its had since new in 2000. If it can't roll over the bumps and rocks and ruts and slop I want to roll over, then its the rider, and not the tire diameter that's the problem.

Jeff Liebermann July 16th 18 04:36 AM

29er "pedals easier"
 
On Sun, 15 Jul 2018 13:34:23 -0500, AMuzi wrote:

But in typical riding conditions, a big fat 700x54 rolls
over depressions, rocks, debris, zombie bodies etc much
better than, say, a skateboard wheel:

https://www.youtube.com/watch?v=kdwROHgPask


Ever notice that none of the numerous disaster movies show people
escaping on bicycles? The crowds are always running away from the
chaos either on foot or in various vehicles that eventually are
stomped flat by the monster or zapped by an alien flying machine.
Also, no motorcycles (except in "Meteor" and "Deep Impact"). I guess
the zombies know what they're doing by first destroying all the
bicycles.

"Bug Out Bike - Apocalypse Bicycle"
http://www.instructables.com/id/Bug-Out-Bike-Apocalypse-Bicycle/
I like the paint job. Unfortunately, I couldn't find any advice
suggesting that a 29" wheel was in any way superior to smaller wheels
for attacking or rolling over zombies. I suspect that the added
weight of the survivalist junk might ruin any benefits gained by a few
mm larger diameter tire. According to the movies, dead zombies will
bleed profusely, which will be too slippery to traverse on slick
tires. Instead, I recommend tires with some tread.

Or, just build your own 29" zombie crusher from plans:
http://www.atomiczombie.com


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[email protected] July 16th 18 05:57 AM

29er "pedals easier"
 
On Sunday, July 15, 2018 at 10:36:09 PM UTC-5, Jeff Liebermann wrote:
On Sun, 15 Jul 2018 13:34:23 -0500, AMuzi wrote:

But in typical riding conditions, a big fat 700x54 rolls
over depressions, rocks, debris, zombie bodies etc much
better than, say, a skateboard wheel:

https://www.youtube.com/watch?v=kdwROHgPask


Ever notice that none of the numerous disaster movies show people
escaping on bicycles? The crowds are always running away from the
chaos either on foot or in various vehicles that eventually are
stomped flat by the monster or zapped by an alien flying machine.
Also, no motorcycles (except in "Meteor" and "Deep Impact").



I think no motorcycles escaping the zombies is simply because motorcycles are really not very prevalent in the USA. And the screen writers are simply reflecting reality in their movie. On the road near my house, I hear about one or two motorcycles per day riding up the road. Compared to about 500 or more cars traversing the same road over 24 hours. 1/500th is about 0.2% I'd guess that is about the percentage of motorcycle ownership in the USA. No one I know owns a motorcycle. But I think they all own two or three or four cars apiece.





I guess
the zombies know what they're doing by first destroying all the
bicycles.

"Bug Out Bike - Apocalypse Bicycle"
http://www.instructables.com/id/Bug-Out-Bike-Apocalypse-Bicycle/
I like the paint job. Unfortunately, I couldn't find any advice
suggesting that a 29" wheel was in any way superior to smaller wheels
for attacking or rolling over zombies. I suspect that the added
weight of the survivalist junk might ruin any benefits gained by a few
mm larger diameter tire. According to the movies, dead zombies will
bleed profusely, which will be too slippery to traverse on slick
tires. Instead, I recommend tires with some tread.

Or, just build your own 29" zombie crusher from plans:
http://www.atomiczombie.com


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558



Jeff Liebermann July 16th 18 07:11 AM

29er "pedals easier"
 
On Sun, 15 Jul 2018 21:57:01 -0700 (PDT), "
wrote:

I think no motorcycles escaping the zombies is simply because motorcycles are really not very prevalent in the USA. And the screen writers are simply reflecting reality in their movie. On the road near my house, I hear about one or two motorcycles per day riding up the road. Compared to about 500 or more cars traversing the same road over 24 hours. 1/500th is about 0.2% I'd guess that is about the percentage of motorcycle ownership in the USA. No one I know owns a motorcycle. But I think they all own two or three or four cars apiece.


Estimates from various web pages:
8.4 million motorcycles registered in the US in 2017.
263.2 million vehicles overall registered in the US in 2017.
66.5 million bicycle riders in 2016.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


All times are GMT +1. The time now is 12:14 AM.
Home - Home - Home - Home - Home

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
CycleBanter.com