29 vs 26

Mountainbiking central

29 vs 26

Postby paul33 » Tue Apr 03, 2012 7:30 am

Does anybody know with the same gearing what is the speed or rolling distance between a 26 and 29 wheels. I am involved in a local bike race (Barrow Island)with different size wheel sizes involved and it would be nice to be able to equaise the time results.
BMC SLX01 2010
BMC Road Racer SL01 2008
User avatar
paul33
 
Posts: 230
Joined: Sun Jan 25, 2009 7:56 pm
Location: Victoria Park

by BNA » Tue Apr 03, 2012 8:12 am

BNA
 

Re: 29 vs 26

Postby mitzikatzi » Tue Apr 03, 2012 8:12 am

Not sure what youare asking. maybe

or

Circumference

A fast rider on a 26er will beat a slow rider on a 29er and vise versa.

Same rider different bikes. Depends on the terrain or the quality of the bike.

With a 29er you use a rear sprocket with 1 or 2 teeth bigger (use the gear calculator) than with a 26 inch bike for the same gearing.

ratio disscussion in this thread
Building a bike around a Niner One frame
Xplora wrote: Do not get cheap SPDs, your body will hurt you.

trailgumby wrote:29ers are awesome.
User avatar
mitzikatzi
 
Posts: 1730
Joined: Mon Jan 21, 2008 10:21 am
Location: Perth

Re: 29 vs 26

Postby trailgumby » Tue Apr 03, 2012 11:28 am

I'm a little confused about what you're asking too. So I'm just going to throw the physics considerations at you and hope some of it sticks. :P :lol:

Gearing and Speed
With the bigger wheel size you'd just select a different gear, until you run out of gears at the low end. 29er wheels are roughly 11% bigger, which equates more or less to the difference between a 34T granny gear and 30T second gear on a 9-speed cassette. So unless you really need that granny gear (I did on the weekend) then there's no "conversion" to be done for speed on wheel size. Bigger wheel does not mean faster necessarily: read on!

So what difference does a bigger wheel make?
29ers lose less energy over rough terrain than the smaller wheels. This is due to the bigger hoops meaning you don't drop as far into the ruts in choppy surfaces and then waste energy coming back up. The reduced angle of attack over bumps means less of your kinetic energy is spent moving your mass up and down and it is instead preserved in forward motion. If you slip on a loose surface say while pedalling uphill out of the saddle, I've found they tend to regain traction more often.

However, on smooth terrain the momentum conservation advantage is neutralised, and if the track gets tight and twisty necessitating you getting on the brakes a lot to negotiate corners, the extra rotating mass in the big hoops and tyres becomes a disadvantage as you have to accelerate back up to cruising speed. Further, the taller front end usually means a higher centre of gravity, which slows steering response and requires more body english from the rider - even if you don't have to get on the brakes.

Conclusion
So whether a 29er is faster is terrain specific. After seeing my mate shave nearly 10 minutes off his best lap time by swapping to a 26er for his last lap of the Mont 24hr a couple of weekends ago, my views are now more fluid than they were and I'm questioning whether my next bike will still be a 29er.
User avatar
trailgumby
 
Posts: 10365
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: 29 vs 26

Postby Mugglechops » Tue Apr 03, 2012 1:03 pm

trailgumby wrote: Conclusion
So whether a 29er is faster is terrain specific. After seeing my mate shave nearly 10 minutes off his best lap time by swapping to a 26er for his last lap of the Mont 24hr a couple of weekends ago, my views are now more fluid than they were and I'm questioning whether my next bike will still be a 29er.



How many people were on the track when he did his last lap. Two of my mates both shaved 5-6 minutes off their last laps at the Mont. One was on a 29er the other a 26er. From my experience at the Mont since 2003 the number of people on track holding you up has a far greater impact than what wheel size you are riding.

I think somwhere on the net there is a comparison with power meters that shows the 26er uses less power for the same speed. Therefore it should be faster. In saying that I still love my HT 29er and my 6in Dually 26er. I just need to start riding the 29er more like a hardtail and not like a dually to go faster.
User avatar
Mugglechops
 
Posts: 2367
Joined: Mon Jan 10, 2011 5:51 pm
Location: Shoalhaven

Re: 29 vs 26

Postby paul33 » Tue Apr 03, 2012 4:25 pm

The reason I asked this question is that I ride with other riders of the same abillity, but they always seem to just keep moving ahead now . A 11% difference between the size of the wheels is a bloody good excuse for me and so I can order a new 29 er with confidence

Thanks :D
BMC SLX01 2010
BMC Road Racer SL01 2008
User avatar
paul33
 
Posts: 230
Joined: Sun Jan 25, 2009 7:56 pm
Location: Victoria Park

Re: 29 vs 26

Postby toolonglegs » Tue Apr 03, 2012 4:29 pm

Your next bike might be a 27.5 Gumby :P .
Image
User avatar
toolonglegs
 
Posts: 14476
Joined: Fri Jun 29, 2007 7:49 pm
Location: Somewhere with padded walls and really big hills!

Re: 29 vs 26

Postby RonK » Tue Apr 03, 2012 4:47 pm

paul33 wrote:The reason I asked this question is that I ride with other riders of the same abillity, but they always seem to just keep moving ahead now . A 11% difference between the size of the wheels is a bloody good excuse for me and so I can order a new 29 er with confidence

Thanks :D

Don't see how it makes any difference. :roll:

44x13T 54 - 599 (26 x 2.0) at 90 rpm = 38.3 kph
and
44x13T 50 - 622 (29 x 2.0) at 90 rpm = 41.5 kph
but
44x12T 54 - 599 (26 x 2.0) at 90 rpm = 41.5 kph

So change gear!

Buying a 29er will not make you faster.
Cycle touring blog and tour journals: whispering wheels...
User avatar
RonK
 
Posts: 5470
Joined: Mon Aug 24, 2009 2:08 pm
Location: Brisbane, Queensland

Re: 29 vs 26

Postby mitzikatzi » Tue Apr 03, 2012 5:00 pm

What RonK said. Change gear :shock:
Xplora wrote: Do not get cheap SPDs, your body will hurt you.

trailgumby wrote:29ers are awesome.
User avatar
mitzikatzi
 
Posts: 1730
Joined: Mon Jan 21, 2008 10:21 am
Location: Perth

Re: 29 vs 26

Postby toolonglegs » Tue Apr 03, 2012 5:14 pm

29'er will be quicker on certain terrain compared to 26'er... always going to be a compromise... hence some pro riders with big budgets are experimenting with the 27.5'ers.
11%?... no.
Image
User avatar
toolonglegs
 
Posts: 14476
Joined: Fri Jun 29, 2007 7:49 pm
Location: Somewhere with padded walls and really big hills!

Re: 29 vs 26

Postby Mulger bill » Tue Apr 03, 2012 8:35 pm

Wouldn't the greater rotating mass make a 29er slower to accelerate?
Whether that's a disadvantage or not would depend on the trails of course...
...whatever the road rules, self-preservation is the absolute priority for a cyclist when mixing it with motorised traffic.
London Boy 29/12/2011
User avatar
Mulger bill
Super Mod
Super Mod
 
Posts: 26034
Joined: Sun Sep 24, 2006 2:41 pm
Location: Sunbury Vic

Re: 29 vs 26

Postby trailgumby » Tue Apr 03, 2012 8:51 pm

Mulger bill wrote:Wouldn't the greater rotating mass make a 29er slower to accelerate?
Whether that's a disadvantage or not would depend on the trails of course...

Yes, and yes.
toolonglegs wrote:29'er will be quicker on certain terrain compared to 26'er... always going to be a compromise... hence some pro riders with big budgets are experimenting with the 27.5'ers.
11%?... no.

Ah, yes. 650B. :lol:

From what I hear it's the riders who are on the smaller side who are going for this option, because of the difficulties in getting their position on the bike sorted to their liking with a 29er. Usually it's because the bars are too high compared to the seat. From my limited experience with a 29er this made me feel like I was trying to negotiate a technical trail on clown stilts. Lowering the bars made a huge difference.

:idea: Maybe someone should bring out upside-down riser bars for 29ers?
User avatar
trailgumby
 
Posts: 10365
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: 29 vs 26

Postby mitzikatzi » Tue Apr 03, 2012 9:05 pm

trailgumby wrote:...snip...

:idea: Maybe someone should bring out upside-down riser bars for 29ers?


Just mount your current "riser" bars upside down? :shock:

What Emily has to do to make a 29er "fit". here sometimes a 650c or a 26er makes more sense.
Xplora wrote: Do not get cheap SPDs, your body will hurt you.

trailgumby wrote:29ers are awesome.
User avatar
mitzikatzi
 
Posts: 1730
Joined: Mon Jan 21, 2008 10:21 am
Location: Perth

Re: 29 vs 26

Postby trailgumby » Tue Apr 03, 2012 9:15 pm

mitzikatzi wrote:
trailgumby wrote:...snip...

:idea: Maybe someone should bring out upside-down riser bars for 29ers?


Just mount your current "riser" bars upside down? :shock:

Ends where the grips are still need to be angled up to be wrist-friendly.
User avatar
trailgumby
 
Posts: 10365
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: 29 vs 26

Postby Mulger bill » Tue Apr 03, 2012 9:18 pm

Hmmm, I looked at the Anthem 29er when I went to a dually but there was no way ol' stumpylegs would ever get comfotable without a leaning backwards position. 650B might be worth a hardtail look.
...whatever the road rules, self-preservation is the absolute priority for a cyclist when mixing it with motorised traffic.
London Boy 29/12/2011
User avatar
Mulger bill
Super Mod
Super Mod
 
Posts: 26034
Joined: Sun Sep 24, 2006 2:41 pm
Location: Sunbury Vic

Re: 29 vs 26

Postby mitzikatzi » Tue Apr 03, 2012 9:31 pm

trailgumby wrote:
mitzikatzi wrote:
trailgumby wrote:...snip...

:idea: Maybe someone should bring out upside-down riser bars for 29ers?


Just mount your current "riser" bars upside down? :shock:

Ends where the grips are still need to be angled up to be wrist-friendly.


:| I should have known it was not that simple. I thought I have read of short people mounting bars upside down to make 29ers fit maybe it was just the stem.

There are a couple of 650s dual suspension bikes. A big 650c thread on mtbr.
Xplora wrote: Do not get cheap SPDs, your body will hurt you.

trailgumby wrote:29ers are awesome.
User avatar
mitzikatzi
 
Posts: 1730
Joined: Mon Jan 21, 2008 10:21 am
Location: Perth

Re: 29 vs 26

Postby paul33 » Thu Apr 05, 2012 7:49 am

The cycling here on Barrow Island is a combination of road and dirt road riding, we are not allowed to go off road as its an A class reserve. Parts of the road are corrigated and the "huge mountains" here are a maximum of 60m above sea level.
With this conversation I think I have 2 main problems 1. Falling into the corrigations will slow the wheels down and 2. like all cyclist not enough legs

Thanks for all your help :D
BMC SLX01 2010
BMC Road Racer SL01 2008
User avatar
paul33
 
Posts: 230
Joined: Sun Jan 25, 2009 7:56 pm
Location: Victoria Park

Re: 29 vs 26

Postby drubie » Fri Apr 06, 2012 12:51 pm

paul33 wrote:1. Falling into the corrigations will slow the wheels down and 2. like all cyclist not enough legs

Thanks for all your help :D


Sounds like 29er country to me - bigger wheels = bigger holes you can roll over, no climbing means no worries about acceleration. If you only have room for a single MTB then I still think a 26er is more versatile - the 29ers to me feel just a bit too unwieldy in the sketchy/tight/jumpy stuff but I am a complete MTB gumby. Just after I finished building up a (smaller) blue Apollo 26er hardtail I was amazed at just how alive that bike was compared to my usual ride...and I liked it a lot. There's a lot to be said for smaller, more agile mountain bikes.
So we get the leaders we deserve and we elect, we get the companies and the products that we ask for, right? And we have to ask for different things. – Paul Gilding
but really, that's rubbish. We get none of it because the choices are illusory.
User avatar
drubie
 
Posts: 4617
Joined: Wed Oct 22, 2008 10:12 am
Location: New England

Re: 29 vs 26

Postby trailgumby » Fri Apr 06, 2012 4:33 pm

drubie wrote:There's a lot to be said for smaller, more agile mountain bikes.

Some of the more gravity oriented guys in my area tend to opt for smaller frames deliberately for this reason, they're a lot easier and more nimble to handle on techy descents.
User avatar
trailgumby
 
Posts: 10365
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: 29 vs 26

Postby jules21 » Sat Apr 07, 2012 11:31 am

i have a 26er HT and a 29er duallie and they are like chaulk and cheese. i haven't gotten used to flicking the 29er into corners - keep running wide, not just as it steers slower, but as the bigger wheels seem to push out wider as you lean in around your CoG.

however, out at the You Yangs yesterday, i was really impressed with the 29er coming down black diamond runs over rocky descents - just ate them up, whereas i know my 26er (HT) would be trying to kill me. partly that's probably the dual suspension helping - but the big wheels certainly eat up rocks and other obstacles.
Image
User avatar
jules21
 
Posts: 8815
Joined: Thu Apr 02, 2009 10:14 pm
Location: deep in the pain cave

Re: 29 vs 26

Postby trailgumby » Sat Apr 07, 2012 1:35 pm

@jules: have you tried getting the bars as low as possible on the 29er? Makes a big difference I've found.
User avatar
trailgumby
 
Posts: 10365
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: 29 vs 26

Postby lucifuge » Wed Apr 11, 2012 11:44 am

To the OP, another angle that I don't think has been raised.

Power output: To a large extent your power output will be static. So the gear ratio/cadence you have use on your 26er, will be different combo on your 29er, BUT on average your overall speed would be comparable.
lucifuge
 
Posts: 66
Joined: Mon Apr 25, 2011 7:43 pm

Re: 29 vs 26

Postby Gordo » Fri Apr 20, 2012 2:38 pm

anything designed for XC with 100mm of travel, 29er all the way. Epics and stumpy HTs maneuver so well i reckon. very little diff between a 26er. the more travel the more inclined i would be to to go 26 just to get a bit more maneuverability. not sold on camber and stumpjumper fsr 29ers...or for that matter anthem X due to its apparent longer chainstays, but will test ride one in a month.
Gordo
 
Posts: 124
Joined: Wed Jan 26, 2011 9:18 am

Re: 29 vs 26

Postby Marx » Fri Apr 20, 2012 3:14 pm

29ers don’t. Just a fad. Don’t ask anyone who owns one because their opinion of their own bike over something someone else is riding would be obvious. They’re now preferred by taller riders because the compromise in frame geometry to fit the larger wheels don’t adversely affect handling as much in the larger frames as it does in the smaller frame sizes XS~M, but that’s like saying gonorrhoea is the best of all the sexually transmitted diseases.

29ers are good for those who upgrade often, as it will fit in nicely when in 2013~14 the US brands trot out something new.

But please, Don’t hate me for my opinion.
-----------------------
A bike and a place to ride.
User avatar
Marx
 
Posts: 213
Joined: Mon Jun 15, 2009 12:36 pm
Location: Kensington Melbourne Australia

29 vs 26

Postby toolonglegs » Fri Apr 20, 2012 3:29 pm

Hence 650 / 27.5 is on the way ;-)
Image
User avatar
toolonglegs
 
Posts: 14476
Joined: Fri Jun 29, 2007 7:49 pm
Location: Somewhere with padded walls and really big hills!

Re: 29 vs 26

Postby antipodean » Fri Apr 20, 2012 9:41 pm

Marx wrote:29ers don’t. Just a fad. Don’t ask anyone who owns one because their opinion of their own bike over something someone else is riding would be obvious. They’re now preferred by taller riders because the compromise in frame geometry to fit the larger wheels don’t adversely affect handling as much in the larger frames as it does in the smaller frame sizes XS~M, but that’s like saying gonorrhoea is the best of all the sexually transmitted diseases.

29ers are good for those who upgrade often, as it will fit in nicely when in 2013~14 the US brands trot out something new.

But please, Don’t hate me for my opinion.


Thats right, don't ask for an opinion on a bike from someone who actually owns one, instead ask someone who thinks they know
what they are talking about but clearly have no idea.
2013 Oppy SL
2013 Boardman CX Pro
2012 KHS Yuma 29er
antipodean
 
Posts: 963
Joined: Sun Aug 10, 2008 4:48 pm

Next

Return to MTB

Who is online

Users browsing this forum: No registered users



Popular Bike Shops
Torpedo 7 Torpedo7 AU
Ground Effect Ground Effect NZ
Chain Reaction Cycles CRC UK
Wiggle Wiggle UK
Ebay Ebay AU

“Bicycles BNA Twitter
“Bicycles BNA Facebook
“Google+ BNA Google+
“Bicycles BNA Newsletter

> FREE BNA Stickers
> BNA Cycling Kit