rbrides

Hello mountain bikers,
I don't own a MTB but have done a fair amount of bikepacking with my gravel bike, approximately 1500 miles. So I can explore more single track BP routes I'm considering buying a MTB. It seems 29 inch wheels are the best way to go but manuafacturers as still making and selling a lot 27.5. All my gravel bike trips have been on 700c wheels (same size as 29s) but of course the MTB tires on 29s will be bigger/wider/different.

What are the pros and cons of 27.5 MTB wheels in general and when bikepacking specifically?

Thank you in advance for your helpful comments and replies.

Moisture

You might want to take a look into something such as the Salsa Fargo or Cutthroat - fantastic options for what you are looking for.

I have a 650b gravel bike and a 29er MTB.

The 29er will take a bit more effort to get up to speed, or to slow down. it doesnt feel as tossable, purely from a wheel size perspective. Generally speaking, 29er motivates you to stick to a desired speed, and hold that speed over a variety of conditions, as efficiently as possible. once holding, it will navigate over most obstacles your way with very little penalty in momentum.

I would prefer 27.5" on my MTB because I would prefer the extra acceleration/braking response with a slightly more tossable nature.

prj71

You've got it backwards. 27.5 is starting to fade away. The Salsa bikes mentioned above are a good option.

You might like this as well...

https://www.trekbikes.com/us/en_US/b.../1120/p/33304/

Moisture

whatever trends the market tries to push onto us is 99% irrelevant to me. I prefer 27.5ers and couldn't possible care less whether the market tries to move away from them or not. They exist. You can run them on 29ers. It will sometimes make sense to .

prj71

I wouldn't call it a trend. 29 rolls over uneven terrain better and is a bit more comfortable.

The bike manufactures have slowly been phasing out their 27.5 offerings the past 2 years.

mtnbud

Comparing a 29+ to 26, the 29+ can't corner as sharp but it rolls over everything. In some ways the 29+ feels more efficient than the 26. With bigger tires, I have way more clearance for bikepacking bags. I'm not sure if there's much difference in clearance between 27.5 and 29, but space for bags might be something to consider.

From talking to others, your height might come into consideration. Some shorter people I have talked with said 27.5 bikes fit them better than 29.

Moisture

I am 190cm tall and I feel like 27.5/650b still fits me better, I am not exactly short.

Again, I have both, love both. The bikes are very different in geometry, intended use/feel and are each designed to take full advantage of their respective tire sizes.

agree that 29" wheels are simply more efficient when rolling and focusing on the maintenance of moment. Around tight turns and tight courses which involve lots of acceleration/braking, 27.5 would be the way to go.

Interesting comparison between me and a friend ripping some doubletrack (he was on a 26" GT rigid alum hardtail, I was on my 29" carbon hardtail w/ front air fork...)

The 26" bike clearly had superior responses during acceleration/braking which didn't seem to involve much penalty while holding that momentum. 29er obviously tackles rough terrain a bit smoother but hard to say how much better since the bike was rigid vs air fork. 26" geometry liked to change direction faster. Otherwise both bikes seemed about equal in outright speed with the 29er air fork possessing clear advantages over the nasty terrain.

rbrides

Great feedback y'all!

Steve B.

I would think a bike without F suspension is more an ideal for bikepacking, thus some comfort can be gained with larger tires, which then drives the choice towards a 27.5 ?. I saw BicycleTouringPro's video with a bikepacking dedicated bike, in his case a Chumba Ursa 29+, using 3" tires, seemed like a good way to go.

Kapusta

For bikepacking... especially if this will be a hardtail or rigid, 29er for sure. 27.5 serves a few specific purposes well, but they are largely not relevant for bike packing. Heck for bikepacking I'd even be looking at 29+.

rbrides

29+!!

Thanks for the input.

2old

I think it's different strokes...... My wife is 5'5" and it always seemed that 27.5 would be ideal for her, but she took to a FS 29er like the proverbial duck to water. She feels out of sorts on any other size now. Agree with Mr K above; maybe + would be even better.

c_m_shooter

I have bikes with all three sizes of wheels. The diameter doesn't matter. Width does....

Kapusta

Huh, different strokes…

In my experience they both make a huge difference on a HT, just in different ways.

veganbikes

+1 on Chumba, those folks are awesome. I got to tour their facilities and chat with everyone and I was really impressed, they are also going to start doing Ti in house and their first frame was awesome. I am super excited to see where they end up but it is only going to get better and better.

Kapusta

Have they changed ownership in recent years?

Moisture

I would say, 99% wrong.

Moisture

Diameter makes a difference, just like width does. The bike industry would have largely relied on just one diameter of wheel if this were the case.

Maybe 26" will be the best choice for you. or 27.5". or 29". Leaving one tire size or another out of the equation, or leaning towards another is a mistake unless you've thoroughly tried out different takes on frame geometries with ideally all three being put to the test.

I've used all three, love all three, aim to split the difference with a 27.5, but will lean towards 26 or 29" depending on how wide or thin i need my tires to be.

This is IRRESPECTIVE on how common one size of wheel manufacturers will lean toward when designing a frame. Anyone can make good use of all three wheel diameters with any combination of tire width under a variety of purposes. how would you know which is best without an apples to apples comparison regarding frame design?

veganbikes

I think they did somewhat but I cannot fully remember there were just so many pretty bikes and info so I don't quite remember the full history.

@Drippy: yeah width is quite a bit more important than diameter I would much rather have a wider smaller tire than a skinny larger tire.

2old

AFAIK, the original Chumba, which seemed to focus on FS, was sold lock, stock and barrel.

Kapusta

That’s good to hear. I’ll take them off my “Don’t Go Anywhere Near” list.

With the reputation the owner made for himself on MTBR, i’m surprised anyone wanted to buy the brand.

He was right up there with Tony Ellsworth.

veganbikes

I would support them the new folks doing Chumba are good folks certainly didn't seem like a-holes or anything like that just down to earth bike nerds who make some sexy stuff or design sexy stuff (as their ti frames at the time were coming from Lynskey, which is not a bad thing). I felt nothing but love and warmth going in there (and not just because I was in Texas and Texas is usually warm or hot as well)

prj71

You do realize that a 27.5 x 2.8 or 3.0 tire is roughly the same outside diameter as 29 x 2.4 tire correct?

prj71

Friend of mine just dropped $10k on a Chumba Ti bike. It's really nice.

https://www.chumbausa.com/sendero-ti...tain-bike-29er

c_m_shooter

Yes.....It is fairly obvious.