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It's official - 27.5" is the slowest of the 3 wheels sizes

kitttheknightrider's picture

Surely you ride for fun and we all know that is where the 'tweeners win hands down, just like we all know that clown wheels are the fastest and easiest to ride which is why most people race xc on them and that kiddy wheels are just for the dinosaurs that refuse to progress.

Going to the kitchen to get my popcorn now.

Rob's picture

+1 for kitttheknightrider

Speed is only part of the story. MTB is fun. Good handling is fun. Speed is kindof fun, but think I'd rather have something nimble.

*Not that I have watched this yet... if they say one size is fastest and the most manoeuvrable would be very surprised.

hawkeye's picture

just maybe... you should have watched the videos before commenting. Eye-wink

Some very interesting nuances in their findings, but I also found part 1 on what and how they measured effort just as interesting. Hint: it's not just about the legs.

While the overall finding was that 27.5 was the slowest, it's not as simple as the headline (which achieved its aim of windimg up kit Evil Eye-wink ) makes out.

Watch and enjoy - I think it's awesome seeing a bit of science being applied to our sport. It gives some clarity amid the overload of marketing spin.

And I'll admit to some schadenfreude seeing Giants marketing claims about their new favourite wheel size getting speared. Smiling

Rob's picture

I don't have time to watch 17 minutes of video on wheel sizes. What's the management summary? Eye-wink

And more to the point... is the fastest also the most manoeuvrable? Sticking out tongue

badchef's picture

well i watched most of the first vid, blah blah blah, i thought experiments worked around a control or standard, if you have 3 different bikes with different wheel sizes would the geometry, sizing and travel be different, and the leverage ratios of the rear suspension?also if the riders chosen would have a natural preference towards one wheel size anyway because thats what they are used to, dunno im sceptical, perhaps mythbusters can have a crack, didnt that nino bloke smoke everyone on a 27.5 bike?

hawkeye's picture

"Watch the video"

or don't. Smiling

It's not perfect but it's a lot better than a lot of other comparisons I've seen. To get a full understanding of how they controlled for variables you'd have to read whatever paper was published from the study. Eye-wink

Fatboy's picture

Interesting. I'm sure this study will be peer reviewed then accepted as fact based on the sample size of 1 of each size bike being ridden by 3 riders in total. Then we will see the death of 27.5?

hawkeye's picture

Yeah, probably. Smiling

Sheesh guys it's just a bit if infotainment in the vein of mythbusters. Lighten up!

Fatboy's picture

Hey @hawkeye - I was tongue in cheek but don't know how to do those little pictures of someone winking...

badchef's picture

;} ;} ;}

hawkeye's picture

@fatboy All good Smiling

Jonathan's picture

Maybe you guys should wait till the kids on the 24" wheels come flying past or you can go classic and have a 5" on the rear and a 36" up front or the likes Sticking out tongue:P

Seriously thou, I really don't no anymore. I still have a 26" and i still love it! Too me, its all about feel and as you guys have also been saying fun, and science certainly cant tell you how much fun a bike is. Especially when fun is so subjective apparently.

What i will say is that i think gone are the days where 29ers are cumbersome and slow in the tight stuff. Ive ridden a few and didn't really notice any issues in tight switchbacks or tight technical stuff, the only thing i did notice is just how bloody quick they were and how much grip there was on tap compared to any other 26 i've ridden (including my slack 150mm 26"). What i did notice is how the trail and terrain makes very little difference and ur not really working the trails as much as you would on a 26er.

Im starting to think i should maybe buy a 29er just too see what im missing out on (or not)...


spindog's picture

always a bit suss when the research is 'sponsored' by companies with skin in the game.
Santa Cruz must be a bit pissed with the outcome of this "evidence based research" (or is it pseudo-science?) given that most of their range are 27.5inch bikes?
would like to read the paper since the researchers comments seemed a little contradictory at times Eye-wink

[Mod. slight adjustment to the title]

kitttheknightrider's picture

They are a bike company, not a marketing company and as such sell bikes that are fun to ride, not just fast to ride (and move off overly priced showroom floors.)

That's the part grumpy old Alf "Hawkeye" Stuart can't comprehend. Besides, "science"? Was it done by Dr Karl in a lab? No I didn't think so.

John, just go and talk some manufacturer into giving you another fast 29er to write some quick review on to help push sales while the rest of us go and grab our bike from the stable that will put the biggest smile on our face for the particular trail we are heading to.

Now where is that Pete bloke to come and give his 2c worth, that's always interesting.

(removing tongue from cheek to put in more popcorn. Eye-wink )

kitttheknightrider's picture

Scientific, pfft. It was done by a bloody university lecturer and we all know they are just people that aren't good enough to cut it in the real world in their chosen profession. Just look at him, he wants to measure and analyse gas output, he didn't even put the gas mask on the right end.

pharmaboy's picture

With their equipment, they could actually do something useful - say how much difference does one kilo make to a time, or a tyre comparo

Must admit though, on a group ride I've never once seen the last guy coming up the hill on the 26er with a smile on his face - so not sure where all this fun they are having is at...... Eye-wink

Callum Hunter's picture

im at LEAST 2 minutes faster around marrinup (my local trail) on my 27.5 than i was on my 26er. all depends on the rider n their style

fairy1's picture

26" king of the downs yeew! I still think different wheel sizes should be in different race categories just like BMX. You will have to pry my 650b with 26" wheels from my cold dead dinosaur hands, hahaha!

If you win races, you picked the right bike, if you enjoy the shit outta your rides you picked the right bike. The average schmuck could find 12 seconds a lap in fitness and skill easily so wheel size really shouldn't matter, geo and componentry is way more important.

Oldernslower's picture

Being an ex-university lecturer - I get rather sick of arrogant, ignorant, uncomprehending, uneducated, know alls denigrating those who have the brains to undertake research while they sit back and reap the benefits in utter ignorance. Maybe some should look at everything they use that is the product of university based science research, that includes your MTB by the way, and maybe how you train. Also maybe a look at other work that Dr Hurst does, e.g. and the links at end of post before you denigrate him.

There is a lot wrong with that flawed 'test' which is common with sports research - but it is an indicator and the result is consistent with the hypothesis that 29r's are faster - like most research it supports a hypothesis, and does not prove it. Not racing anymore so I don't really care which is faster.

You can have fun on most bikes - but if there is an argument as to which is faster then isn't it legitimate to try and find out under slightly controlled conditions and add it to the evidence?

There is a difference between statistical significance and practical significance - pity some haven't understood this - or are just too effing ignorant to find out the difference or understand the difference.

Kitthenightrider - re read your posts - do you understand how ignorant they make you look? I take it you are a product of the University of Wanker'shire, maybe you need to change hands occasionally.

Pharmaboy - What is the difference of one Kilo on performance? - its been done years ago - do a web search! They got it down to indicating what the effect a water bottle has due to wind resistance.

Callum Hunter - list all the factors that could make you faster over time around Marrinup - on the same bike! Whats the steepest climb/downhill at Marrinup, and at the Goat Farm? What would the results of that flawed study suggest as to which is faster at the Goat Farm? Didn't Dr Hurst state there may be a reason the 27.5 was slower in this test? What was it?

Fairy1: The riders had a minimum of 18 months racing - so were fit. And would you be faster on one of the different bikes with your current level of fitness? And does the info that the evidence supports a 29r being faster + the subjective experience of elite riders that 29rs are faster, help you to choose a MTB bike for racing - or would you just ignore the evidence? (Influence of course type on upper body muscle activity in elite Cross-Country and Downhill mountain bikers during off Road Downhill Cycling)

kitttheknightrider's picture

has taken one word of what I have previously posted on this thread as being said seriously then it is probably a good thing they are no longer educating our future scientists / researchers.

Simon's picture

Well said.

Aussie culture sux when it comes to the BS around academic work.

If some things were said in tongue and cheek I missed it too.

I regularly come up against this prejudice in the work place now I'm out in private sector. Even though I have been for the last 12 years.

Ignorant people keep assuming since I have a PhD I won't be able to deliver anything practical. I soon prove them wrong and try not to make them look to stupid.

I'm often told the research they have looked at was to 'theoretical to be practical'. This nearly always translates as 'it was beyond them and they didn't understand it and couldn't use it'. I have always been able to add something and create a better product. Usually my ideas have been the paradigm shift a company has needed to get beyond trial and error product development and what they have been doing for the last 30 years.

My doctorate increased export sales by $2million per year. My doctorate like many was government sponsored on the basis it has potential to generate additional export earnings for a company.

Other research also resolved an issue that allowed a start up wind turbine manufacturer to begin operation of its prototype which led to a publically listed company and export earnings, not to mention a unique product making wind farms viable on what had been marginal sites.

I have developed many building products, many for startup companies, all of whom export.

I have allowed another startup to deliver an export order worth $150million and with further development another $48million. They held a BBQ to thank me where people said 'thanks for saving our jobs and the company of 110 staff'.

I have used my credentials to impress green groups and government for trail advocacy.

I now write policy for the State Government to improve how tax payer money is spent.

At each one of these stages, other than trail advocacy, I have come up against prejudiced attitudes from individuals regarding my qualifications.

This is obviously a bit off topic from wheel sizes. These sorts of comments frustrate me. Whether in tongue and cheek or not they reinforce a stereotype that is far from reality.

pharmaboy's picture


Ok, please find the kilo study for me - searched plenty for it, and not found it. Lots of stuff on road bikes, analytic cycling can do the climbing part, but there are lots of assumptions on rolling resistance. Real world Mtb is required because of the large amount of braking, and the increase in rolling resistance due to weight.

Genuine request

GAZZA's picture

Wheel size again,
I've been riding my bike.
Step away from the computer and ride what you bought!
I'm sure you'll enjoy whatever wheel size you have?
Just sayin!

C3PO's picture

Well played Hawkeye.

fairy1's picture

Olderandslower, I know those guys are fit and probably skillful but not every person that walks in to a shop is. A lot of the time people will pick X size wheel just because they heard it was the hot shit.

I raced DH(on a pretty easy track) on a hardtail and people kept telling me I'd probably go ok on a dually so I bought one(two actually)and I took some seconds off my time but hated the magic carpet type ride and racing got boring. I much preferred the handicap of riding a hardtail and if I go back to racing it would still be on a 26" or 650b hardtail, screw the times, it's more fun.

kitttheknightrider's picture

miss this?

"(removing tongue from cheek to put in more popcorn. Eye-wink )"

Maybe if people lightened up a little and actually took the time to comprehend what was typed there wouldn't be so much angst.

It's been my experience, and the studies I have conducted over the last 40 years as a classicaly trained smart arse back this up, that when people get their backs up about things that are clearly said in jest it is usually because they acknowledge an element of truth in the statement. Take that as you will.

[Mod. slight adjustment to title]

Simon's picture

Easy to miss as there are plenty of ignorant dickheads that honestly believe what you said in jest.

I have had to manage my way around plenty of them so a company can move forward. This has included creating projects for them to keep them busy and out of the way.

Sometimes they get themselves managed this way into redundancy.

Being upset because there is some truth in it? Get over yourself. You've already offended people, saying its their problem now? Well done.

We're ready for your apology.

kitttheknightrider's picture

I will respond, but only so that you don't think I have shirked away from what I have said.

Please don't hold your breath too long waiting for an apology from me for anything I have typed here as you will be cold and blue long before it comes. I am responsible for what I have typed, I am NOT responsible for what people read nor how they chose to comprehend it.

As I have said, maybe if people actually took the time to to read what is written before they jump to their keyboards to respond to it, they might be better equiped at understanding the tone in which it is written.

Have a nice day.

StanTheMan's picture

You boys take a chill pill.

everyone has to navigate around idiots in what ever field they work in. No one is immune.

ohhh that's too exciting. Ive always wanted to upgrade to a 29er. But Now I have scientific evidence to give to the director of war & finance,. whoooohoooo!

staffe's picture

thread on nobmob ever, just when you though all the heated discussions around wheel sizes were over and all the weird and wonderful theories why one should stick to the 26er were all gone comes this - Bang! Best thread ever. The passion - wow! Simon is my new hero!

spindog's picture

as any decent rider knows and will tell you the critical enabler in this equation is not wheel size, it’s the much maligned and misunderstood dropper post.

as Prof Bruce Cockington as his team at the critically acclaimed C.A.O.B. Labs* have so convincingly demonstrated in their seminal work titled “modal efficiency and cadence optimisation of the dropper enhanced velo"

it’s now generally recognized by all but a small group of deniers that the dropper post has opened the door to previously untapped performance benefits well beyond any discernible advantages by virtue of wheel size.

*C.A.O.B. (Cocking About On Bikes) Labs University of Woolloomoolloo - proudly sponsored by the Dirtbar bike stop and microbrewery

Pete B's picture

 photo 37868dbd1917999a7d60d0088e2d68c719e1b938fe492e8e57d925ec04e2d968_zps5xkrvyji.jpg

Simon's picture

You are responsible for the clarity of your writing. People have misinterpreted it.

You then chose to have a personal go saying we must have personal issues to have misread it. Unacceptable.

Your poor attempt at humour that maintains inaccurate stereotypes doesn't help anyone.

Lach's picture we can easily and cheaply throw our support behind one view or another in these discussions without having to commit to any real thinking or explanations. Smiling

pharmaboy's picture

Look you bunch of asshats, , everyone knows it can't be a scientific test unless there are background shots of bespectacled men in white coats and preferably an important looking front of building shot with Ponds Institute written on it.

spindog's picture

so my research may lack a little scientific rigour however some observations.

I’ve had and continue to have heaps fun on 26” bikes, especially the last one which is by far the best (all carbon/full xtr) I’m reluctant to part with it. when 29ers were being heavily promoted as the way forward I test rode a few and bought one. the 29er’s a great bike for open fast trails however in the tighter technical stuff it’s a bit like driving a bus. I admit that maybe not all 29ers might feel this way although I think mine’s fairly representative of the current crop in terms of geometry, etc. 29ers are v.good at rolling over/up/down stuff and definitely don’t require as much skill to punt at trail obstacles. they’re probably a good option for newer riders to get started.

however my 26er is much, much more fun! it’s lighter, around 2.5kgs from memory and therefore much more easily popped.

having answered the questions about 29ers I was ready to sell it and take the next step however the results of this research have given me cause to reconsider - so what conclusions can you draw?

most manufacturers have been quick to talk up the benefits of tweeners and it’s reasonable to assume you are getting all the benefits of a 26er and 29er combined in the one bike however what this seems to indicate instead is that tweeners are just a critically flawed compromise, they miss the agility/fun factor of a 26er and don’t quite have the outright speed of a 29er.

Like I said I was planning to sell my 29er and replace it with a tweener, now I’m not so sure..

kitttheknightrider's picture

I know I am not an academic, I'm just a poor simpleton, but please quote where I have had a personal go at anybody on this forum.

Edit: Just remembered I had a personal dig at John very early on. I am confident that he knows me well enough to have taken it exactly as it was intended and I did PM him several hours ago to make sure. So if that is the personal attack you refer to then ok but otherwise please quote away.

Rob's picture

Could someone please post a management summary of this thread for the time poor?

Thanks Smiling

kitttheknightrider's picture

It is a flawed study, but it is done by a "lecturer" using !00,000 pounds worth of equipment, so it must be accurate.

They use the same frame, a superfly, which I believe was designed around the 26' wheel then redesigned for the 29er platform but I could be wrong.

They use the same tyre on each wheel, presumably the same compound, all at the same pressure.

They use three "riders" with at least 18 months experience in racing. They each do one lap on each wheel size with a 1hr rest between laps.

The data is then analysed. There is no scientific difference between any of the bikes. There is a practical benefit of 18sec per lap to the 29er. The 26" is marginally quicker than the 27.5"

The 29" is quicker up hills.

The 26" is quicker down hills.

The 29" requires less effort.

I don't recall if they actually changed the gearing or not to suit or if they used the same cluster.

People don't take the time to read things and then get shitty when they misunderstand what has been written.

Others don't back down.

I think that about covers it.

fairy1's picture

Haha, possibly the only funny thread I have seen on here, keep at it gents.

I could post pics in the old forum, stuffed if I can work out how on here.

pmbc.crash's picture

Bastards! my last excuse for being slower downhill than my mates as been taken from me.

Simon's picture

The paragraph where you seem to be proud of 40 years as a smart arse is where you passively went on attack. Then again at the end with your summary to Rob. Again if this was not your intention your writing could be clearer.

You may even make sense in your summary for Rob regarding the study.

The issue is with your other inappropriate comments.

All I took out of the study was the variability in the results between bikes and riders was too great to draw rigorous conclusions (ie results were statistically insignificant). However some differences were observed in their data set. This is common in initial testing. With further work they should investigate the causes of variability and either reduce it or increase the number of samples. Some of the points you mention are likely sources of variability.

Carlosdjakal's picture

sorry can't get the pic

DudeistPriest's picture


spindog's picture

it's going to be a long year and this is a great distraction from the real idiots, the ones in Can'bra!

badchef's picture

i cant believe everyone is at it again, although this thread is piss funny, peeps shouldnt take it so seriously, its the same shit as always, smart people telling us how smart they are and dumb people{like me} proving how dumb they are,now before i fall off my soap
box where the bloody hell did i put me popcorn??? hey kit you got any extra?? oh yer who was the fastest in 2014 uci xc and what bike did they ride???

badchef's picture

was it a bmc 29er hardtail? if im correct then ditch the full sussers people, we've all been lied to, quick back on the hardtails everyone, i guss fairy1 was right after all

kitttheknightrider's picture

always plenty of popcorn in my house

Sorry, but I am going to be the bad chef here because it's only the microwave kind. Hang around long enough and you'll soon learn you need to be able to make it quickly when I'm involved.

Now back to your question hardtail is correct which is a problem for me because I'm the only one in my group to regularly ride a hardtail so I should be the quickest but I'm normally at the other end. The good news is that its a 'tweener so thanks to hawkeye for bringing this valuable study to light, I now have an excuse for being the slowest.

Oh, and did someone say hardtail 'tweeners are fun to ride? Bet your bloody ar$e they are, even more so if it's the long travel version, but long travel / short travel is for another discussion.

I feel what should be discussed further here is whether or not they were using 650B+ rubber on that wheel because when you do swap out your regular 650B tyres for the extra width / volume of the new 650B+ you get so much more grip and also run so much faster. From memory that scientific lecturer said they were the same width tyres and given that 29ers and 26ers are hampered by not being offered the "+" option (it's only available for B's and fats) he must have used those silly skinny rubber that was so 2014.

obmal's picture

Why don't we settle this with a good olde ride, you guys can hug it out all sweaty muddy MTB style...

I have all three wheel sizes and all I know is somedays the internet says I'm slow and somedays it says I'm fast.. even on the same bike!

I could try and tell you how smart and important I think I am, but my cat just said the dog needs to use the computer now Sad

badchef's picture

since its been proven that 29ers are fastest, followed by 26ers then 27.5ers, could we perhaps mix it up and put the fastest riders onto 27.5 bikes and the slowest riders on 29ers bikes and the boys with 26ers can stay on them and have the most fun,now in theory the slowest riders should win because they have the fastest bike , the fastest riders should come second on the 27.5 and the 26ers wont care where they come because they are having the most fun!! or maybe the fastest riders will win due to their superior fitness regardless of which bike???

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