[Closed] 29er v 27.5 over distance

A bit.

As above really. I’ve owned both in various guises and honestly don’t think there’s that much in it.

Have done 75 miles on both and can agree with the above, don't really notice much difference to be honest.

You will feel more on the tyre you choose to run that the size, summer tyres for summer etc

James

I have two 29ers in full sus and hardtail and I think they both roll better than my old 27.5 only drawback not so nimble on very tight singletrack but still better for most of my riding which varies from fireroads and gravel to flowing singletrack and a small amount of gnarly downhills

No, you won't notice the difference due to the wheels. The tyre choice will make much more difference and, if they're on different bikes, geometry will be next.

Thanks for the replies. I have always ridden a 29er Giant Anthem. We're planning on attempting The Badger Divide later this year. Last year on the same ride I was slowly falling back on my two friends on 29er hartails. I'm considering changing bikes to a 27.5 hardtail (6;2ft). On the list potentially are some of the Ragley bikes, Sonder transmitter and Vitus. I would be running the 27.5 on a 2.3 or 2.4 inch tyre maximum.

I have a 27.5 anthem and a 29 anthem.
Strava says that the 27.5 is quicker but that can be due to a walker being in the way or not.
All I know is that at the end of a ride I’m more likely to chase roadies on the 29 than the 27.5. I prefer the 29.

Anthems are fast bikes; put quick tyres on the and it won't be the bike slowing you down.

My regular practice loop starts with a tarmac/gravel road climb of about 250 m elevation. My fastest time was 15:30 on a 27.5 hardtail. I've done it in under 16:00 several times on an old 26" Anthem, but I'd say the 27.5 hardtail is generally about 15 seconds faster. I also have an old 29er hardtail as a hack. That seems to be about as fast as the Anthem on the climb. Tyres make a huge difference, the wheel size doesn't seem to. Being tired makes a bigger difference again. The Anthem is a little bit quicker on the off-road descent, it's easier to ride and more stable. The 29er is slowest on the descent by a long way, it has 80 mm Rebas versus 130 mm forks for the other two. On an all day ride, I'd take the suspension bike every time, much less fatiguing so you're much fresher at the end. Putting a fast rolling XC tyre such as a Racing Ralph on the back, with something a little bit grippier on the front will make a massive difference.

It had 2.25 racing ralphs on it and the rear shock pumped to 200psi. I found on the longer climbs and road sections it was not as efficient as the hardtails. The Badger Divide is a punishing ride with +8hr in the saddle each day.

Didn't the entire MTB world spend about 5 years arguing over this?

It's been a while since I've entered an XC race, but last time I did, everyone was on a 29er. There's a reason for that.

When taking part in an utramarathon, and a couple of guys ease away from me in the last few miles, it's bugger all to do with my choice of running shoe.

Is it really the bike or were the other 2 guys just a bit fitter on the longer climbs (not to be rude)?

If your fs was pumped up really hard and had similar tyres then there’s only extra weight really at play (plus geometry). The Anthem is meant to be fast xc anyway so maybe there’s a few lbs of weight difference?

If you do swap wouldn’t it make sense to go 29er hardtail so most of the stuff from the Anthem swaps over? To get real benefit you’re going to have to go full xc hardtail Carbon or something trail but leaning towards xc. I don’t think the bikes mentioned really do that. Bikes like the Trek Procalibre or Specialized epic would need to be on the list I’d have thought.

Sorry to be a bringer of bad news but it would seem that you do not have as good endurance fitness as your pals. Can't see the bike being such a huge difference (your bike sounds ideal for distance riding) unless the terrain is particularly punishing which I believe the badger divide isn't very from my understanding of it. Don't most folk do it on gravel/tourer type bikes?

I find when I have done multiple day rides with some friends (who I'm a lot faster over a couple of hours) they really come into their element when in the latter stages of the ride. Seems some folks are better at short distances (me) and some are better at long distances, who'd have thought it?

One thing I have noticed recently (due to riding the same local trails dailly on 3 different bike with 3 different wheel & tyre sizes) is that my pedal speed and timing (over bumps and around rocks, roots etc) is different on each bike. I find that spinning in easier gears on my 26" bike really doesn't work as well as riding with a slower cadence in a bigger gear and vice versa with my 29" (spinning seems to be the key with this bike). My 27.5+ bike seems to be somewhere in the middle.

I think it's to do with the acceleration and deceleration of the wheels (more noticeable on bumpy climbs), smaller wheels accelerate quicker but decelerate quicker compared to bigger wheels which accelerate slower but hold their speed better.
Could also be exacerbated by the pedal rotation matching up to the wheels rotation on the 26" bike (tend to climb on the steeper sections in 32/32) as the gears are 1 to 1. This doesn't seem to happen on the 29er as it's essentially geared up due to the bigger gear.

I'm no expert so I might be gibbering sh$$e but just thought I share my musings.

I think you’d be mad to swap from 29” to 27.5” considering the bikes that are used for long distance races like The Tour Divide:

https://bikepacking.com/bikes/tour-divide-rigs-2019/

I have always ridden a 29er Giant Anthem. We’re planning on attempting The Badger Divide later this year. Last year on the same ride I was slowly falling back on my two friends on 29er hartails. I’m considering changing bikes to a 27.5 hardtail (6;2ft).

The choice is also hardtail vs FS and the other question is whether any of it will account for the probable difference in fitness.
All in all and all other things the same a 29er rolls more easily and more comfortably over longer distances. It could be seen as similar to the level of difference between a hardtail and a good XC FS bike on a smooth climb, it's just happening all the time your wheels are rolling off-road.
So on balance it might not make any difference on day 1, yet by day 3 you'll likely to be less comfy/more beat up on the 27.5 hardtail (I don't think it's a particularly rough route though?).

Big wheels don't roll faster in general, they roll faster over rocky and bumpy stuff. This is very noticeable on Peak District or South Wales rocky trails, but far les of an issue on dirt trails or gravel. But if I were buying a new bike for XC it'd be 29 every time. In fact you'd struggle to find a 27.5 bike with an XC theme I reckon.

Big wheels don’t roll faster in general, they roll faster over rocky and bumpy stuff. This is very noticeable on Peak District or South Wales rocky trails, but far les of an issue on dirt trails or gravel

I know what you mean, though I don't think it needs to get particularly rough on a 'gravel' track eg Scottish estate road for a 29er OD to have an advantage ime, particularly as the av speed goes up or you're loading the bike. It's a small advantage over a lot of small bumps on a longer day, less noticeable in a way but it adds up.

Didn’t the entire MTB world spend about 5 years arguing over this?

We're probably about to go back to it all with gravel bikes too.

Unfashionable view, I know, but I am convinced wheel size is more about rider height than anything. I have a 26er, and 27.5er and a 29er.
I am 6ft 3 inches tall. The 29er is the first bike that feels it actually fits - and doesn’t make me look like a gorilla humping a football.
If you are small the. Just on shear Proportions 26 inch wheels will work better....

As for which is fastest ... not really that bothered

Mullet bike, 29 front with 27.5 rear....best of both worlds.

I'm planning to do the Badger Divide later this year too, we were supposed to be doing it next weekend, ho hum.
I'll be doing it on my Sonder Camino with 700x40mm or my 29er Sherpa, I think the Camino will be the one though with the faster tyres.

Sonder Camino with 700x40mm or my 29er Sherpa

I have ridden the whole route before, anyone attempting this on a gravel bike is in for a lot of pushing the bike on day two (we did 3 days from Glasgow to Inverness). IMO it's not a route for a gravel bike, theres some very rocky sections from Loch Ossian onwards until Fort Augustus. Take the Sherpa.

My other tip is to push further north of Killin on day one. We stopped at Killin and it made day two a really tough one (around 82 miles with lots of climbing and some tough terrain)

I was thinking of doing it from Inverness and then head home once I got to the Forth & Clyde canal. 🤔

I've seen / read every study I could find into this (some scientific, some not). To summarise the results in one sentence; there's a tiny bit of difference in favour of the 29er for competitive elite level XC racing regarding lap times and power per watt.

For general riding, I wouldn't worry about it. I ride mainly XC and have a 27.5 Anthem and it doesn't slow me down in any way. Having said that, neither did my old 26 inch Specialized Epic.