[Closed] Are 'trail' bike wheel sizes finally going to converge to somewhere around 29"?

The only time I'm bothered about what size my tyres are is when I need a new tyre.

If you want/need a new bike though tyre/wheel size is a bit more of a consideration!

In what way? Do you buy new ones the same as your old ones, or do you make sure you have a selection of tyres in every size available at all times?

I've converged on 29in for trail bikes, but I don't think everyone will for a fair while yet.

Interesting question though, if you think in terms of 20 years' time or whatever.

Personally I'd say 27.5.

Caveat on that would be 'it depends on your trails'. I've ridden a 29 around my local trails and it's just not nimble enough when it comes to changes of direction. I can totally see the strengths of 29 though.

When it comes to upgrading my 26 (not any time soon) I'll be going 27.5.

no.

not wanting to make the obvious u-turn from 29 back to 26, we have been presented the way forward 650b/27.5

most folk will tolerate that as its as close to 26 as seems likely to exist in the new standards/near future

+ is all the hype of fat, but which you can put on your 275 wheels, in a 29 frame

28.25" is where the cool cats are headed.

[img] [/img]

Personally I'd say 27.5.

not wanting to make the obvious u-turn from 29 back to 26, we have been presented the way forward 650b/27.5

The thing I am trying to get at is 27.5" seems to be increasing in tyre size, and may merge with 'plus'.

The future is looking like it will be 27.5" with fatter tyres or 29" with skinnier tyres both in the same or very similar sized frames

to see perhaps a stabilizing standard look at this 2017 trail bike from the World's largest bike manufacturer: 27.5+ and 29'er compatible in one frame set.

They offer the 27.5+ models and 29'er models on same frame set with change of wheels/fork

[img] [/img]

they never made a "fat bike" as they don't rush to market to satisfy niche trends

[s]Didn't Giant have a thing about sticking to 27.5" only? [/s]:-)

Edit: Actually ignore that it's not really helpful to the discussion

I still think 29" wheels are a bit much on very small full suspension frames - especially if you think a "trail" bike has 130-150mm of rear suspension and you want a dropper post. It does therefore make some sense to have different wheel sizes for rider height. On a hardtail it's less of an issue.

I still think wheel size shouldn't be categorised at all by genre. It should be a choice proportional to rider size, like bar width, stem length, frame size, seat post height and crank size.

I still think 29" wheels are a bit much on very small full suspension frames

Yes, but you could get around that by using skinnier tyres on 27.5" rims or fatter tyres on 26". I don't think 27.5 or 26 for that matter are going to disappear completely.

I'm only 5'7" and much prefer a 29er as a long distance hardtail, 27.5 for messing about in the woods. Purpose is important.

I still think wheel size shouldn't be categorised at all by genre. It should be a choice proportional to rider size, like bar width, stem length, frame size, seat post height and crank size.

That does make sense, but looking at the genre of trail bikes for the averaged sized rider, wheel size seems to be converging in the way I stated at the start of the thread.

the creeping to fat tyres on 275 and using a 29 frame wont last (IMO)with already significant kick back.
grippy or draggy, paper thin sidewalls or heavy as an anvil...... there doesnt seem a compromise, that cant already be achieved sub 2.4"

the fat fad will fade and then folk will want tighter tolerances again, not tight like the yanks like, but uk-mud-tolerable clearances

the magazines tried to push plus sized modals, but anorexia is still a problem

I've got a 29er trail bike. I like it. I can't think of any way it'd be made better with smaller wheels. I've never ever found myself not able to turn the bike quick enough.

I can see for shorter riders it would be getting towards a pretty high front end with a 29er though, and for them I can see a 27 or 26er might work better - similarly at the rear end for chainstay length/accommodating suspension/constantly sitting on the rear tyre reasons the same applies.

if you subscribe to the "long means long chainstays as well" variant of long low slack geometry then maybe there is room for an extra inch or two of tyre diameter within a basic safety bicycle setup. 31"?

dmorts - Member 
I don't think 27.5 or 26 for that matter are going to disappear completely.

Industry is trying hard to kill 26. Still old stock about, especially second hand, but it's getting increasingly harder to get new 26 wheels/rims. Not impossible, but the selection is often far lower than for 27.5 and 29.

Still, I'm determined to get a bit more out of my 26er Nomad. One more set of wheels on order and will run it for another year or so.

I was open to a 650 after only haveing ridden 29er for a few years. Test rode a few bikes but I prefferred the stability of the 29er.

I'm 180 cm tall and i struggle with front end height: I have -17 stem on my hardtail. Some of my mates are much shorter, I can't see them fitting 29" full sus bikes. Probably not even hardtails.

After owning a fatbike, I'm not interested in riding a skinny bike on rough trails. Gravel, maybe.

However for most of the year 4 - 5" is excessive unless you are riding fatbike specific territory like peat bogs etc.

I like the way 29er+ rolls, but the dimensions of the wheels makes for a too stretched out bike for me, or toe overlap.

So this recent trend to 650b+ is encouraging, a bit more volume, and the same diameter as an ordinary 29er is going to make for a better trail bike.

Even better is the ability to run 29er or 650b+ on the same frame. There's your gravel bike and mtb in one package. 🙂

I'll be making the move, and it's a shame Giant don't sell this model in the UK.

[img] ?height=600&quality=90&mode=none&bgcolor=white[/img]

I'm happy to have the choice now, tbh. As long as I can still get 26" tires. I am wondering though, I might have enough clearance on my 26er FS with a slight mod to the frame to fit 27.5. Might be fun to try.

Some of my mates are much shorter, I can't see them fitting 29" full sus bikes. Probably not even hardtails.

If they ride medium frames normally then they might be ok on a 29er according to Norco

[url= http://singletrackworld.com/wp-content/uploads/2017/01/the-2017-norco-sight/ ]http://singletrackworld.com/wp-content/uploads/2017/01/the-2017-norco-sight/[/url]

That's about the new Norco Sight in 27.5" and 29" flavour. To quote Norco (indirectly)

The two bikes are almost identical in fit. While the 29er has 10mm less travel, both frames feature the same rear centre lengths (that’s chainstay length).

Note: no small or xsmall in 29" (which makes sense).

EDIT: I have seen this elsewhere when looking at 29 and 27.5 versions of bikes, very similar geo. with the 27.5 version just having longer travel. My wife's Orange Diva for example was 29 one year then 27.5 the next with the stack height remaining the same. The 29 had 100mm travel and the 27.5 had 120mm

I'm only 5'7" and much prefer a 29er as a long distance hardtail, 27.5 for messing about in the woods. Purpose is important.

I'm also 5'7.. and think similar..

I'd go so far as saying my ideal quiver would be 29er HT, 27.5 FS. But I'd rather just one bike.. so 27.5 FS it will be when I can upgrade. (Not much wrong with my 26er IMO.. )

quiver

Mate, you are not allowed to say 'quiver' on here.

That SS giant looks cool.

I've largely concluded that 29" wheels are better at any riding niche that isn't done in skinny jeans. The caveat to that is that 29" wheels don't fit into a lot of frame designs (and people sizes). so a lot of longer travel bikes will stick with 650b because even if you package the wheel in the chainstay (easy enough), you can't get the suspension travel without hitting the seatube or having a very rearward axle path.

OTOH, maybe we're due for the next instalment in the seven year cycle of elevated pivot, idler pulley suspension designs.

I'd go so far as saying my ideal [s]quiver[/s]* bikes would be 29er HT, 27.5 FS. But I'd rather just one bike.. so 27.5 FS it will be when I can upgrade.

I used to think this, then 27.5+ came about... and now slack and fast looking 29er full suss bikes too... hence me starting this thread!

e.g.
[img] [/img]

*FTFY

I'm still really hoping 26+ becomes a thing.

now slack and fast looking 29er full suss bikes too...

They've been around a little while- my meta 29er is pretty close to some of the current crop if I recall the angles correctly and it wasn't a new model when i bought it three years ago. 2012 I think it was released. Trek remedy i think was another about the same time. 650b just came along and got in the way!

The idea of a HT frame that accommodates 27+ and a sensible sized 29" tyre is starting to make more sense to me...

Obviously sense will more than likely prevail and it would just become a 29er with plenty of mud clearance, but it's nice to think you [i]could[/i] change wheels based on seasons if you wanted...

colournoise - Member
I'm still really hoping 26+ becomes a thing.

Surly 1x1s have been able to take 3" tyres since then. The problem being that the choice was small because the "experts" thought 2" was big enough. Since Surly started distributing their own tyres (Dirt Wizards) it's gaining a little momentum.

[url= https://c1.staticflickr.com/6/5561/13983876478_91f38a10c3_o.jp g" target="_blank">https://c1.staticflickr.com/6/5561/13983876478_91f38a10c3_o.jp g"/> [/img][/url]

28.25" is where the cool cats are headed.

While I am sure said in jest, this is actually the truth. Within maybe [edit] 24 months I would say most bikes will be either 29.5 (but still called 29ers) or 28.25 (but still called 27.5).

Can you elaborate further on that?

First "29er" tyres came up at ~ 28.5" actual diameter, Gary Fisher decided to brand fat (in the old-fashioned sense) tyre + 700c rim diameter as "29er" because it sounded cooler than "28 and a halfer". The early 29er tyres (eg the Bontrager Jones) were not very high, I read somewhere that it was in order to fit into the then current tyre moulding machinery.

29" is a size designation not an actual size.

He means that the trend for tyres is getting wider. The '29' and '27.5' sizes are based on a ISO rim diameter with a 2" tyre so he's saying that 29ers will trend towards 2.5" tyres while 27.5s will trend towards 2.8"

he's saying that 29ers will trend towards 2.5" tyres while 27.5s will trend towards 2.8"

In that case there's a 1.25" difference between the wheel sizes (including tyres). That pretty much sums up what I was trying to get at. Following the trend, it looks like one frame (possibly needing very slight geometry tweaks) will work for both wheel sizes.

dmorts - Member
..Following the trend, it looks like one frame (possibly needing very slight geometry tweaks) will work for both wheel sizes.

Assuming that the 29er size was for road and gravel use, you'd be using a tyre slightly bigger than 2", so let's pick 2.15" as a medium choice.

That gets you roughly 622mm + 55mm + 55mm = 732mm overall diameter

Then for trail riding you use the 650b+ size with say a 3" Nobby Nic

Which is roughly 584mm + 75mm + 75mm = 734mm.

So theoretically bugger all difference in diameter and no geometry changes needed.

I've recently acquired a mk2 Solaris, having gone cheap full sus (2nd hadn zesty) for a laugh/experiment on my 26" wheels, and sold my Scandal as I didn't like the steep angles(by modern standards)on the downhill.

I've set the Solaris up as an xc bike still though, large frame, I'm 6ft, long arms, 70mm stem, 100mm forks. Does that really well, but I reckon with some B+(ish) tyres and a 120mm fork with a shorter stem it'd be bags of fun, even on the techy and tight, twisty stuff, I mean it's not bad at that how it's set up now. Maybe not quite as agile as a good 26" hardtail in the really tight stuff between the trees, but overall covers ground brillianty for general xc and 'trail' riding.

There is something about the directness of a hardtail that's hard to beat, I like full suss for rocky, chattery, tiring stuff but on smooth, loamy local trails a hardtail is all I need.

If I had to have only one bike right now I think it'd be a 650b light (for steel) steel hardtail with a 130mm fork and a dropper. PP Oka I suspect.

I wonder if the bike industry itself will get tired of all the differing standards and having to manufacture all these products in a range of sizes?

core - Member
...I wonder if the bike industry itself will get tired of all the differing standards and having to manufacture all these products in a range of sizes?

This conversation has been going on for over a century. 🙂

I have bikes with the following sizes of 26" wheels
ERD
559 Usual mtb size
584 26x1½" aka 650b
590 26x1?" the smaller British roadster size.
597 26x1¼" sporty British bikes - especially prewar

Don't have all the full variations, there's also 571 or 599* 26" wheels 🙂

The British bike industry missed an opportunity to pioneer the mtb over 70 years ago. They were selling bikes to the colonies with 2" tyres (I think 599mm) that looked very similar to the later Raleigh Bomber but with more conservative bars.

I have bikes with the following sizes of 26" wheels

Arent yours are on different bikes though?

Might we see more of the same bike offered with different rim sizes, but roughly the same overall rim + tyre diameter?

I have bikes with the following sizes of 26" wheels

Aren't yours are on different bikes though and different types of bikes too?

Instead, might we see more of the same bike offered with different rim sizes, but roughly the same overall rim + tyre diameter?

epicyclo - Member

I think so. It's an ideal way to have a general purpose bike.

Assuming that the 29er size was for road and gravel use, you'd be using a tyre slightly bigger than 2", so let's pick 2.15" as a medium choice.

<snip>

Then for trail riding you use the 650b+ size with say a 3" Nobby Nic

<snip>

So theoretically bugger all difference in diameter and no geometry changes needed.

And all you have to do is give up a load of flexibility and capability, for no reason. No idea why anyone would accept a 29er that can only run skinny tyres in 2017. (OK, you could run bigger tyres, at the cost of a higher BB... but that's daft)

TBF adjustable geometry isn't just the right way to do it, it's the only good way. It's easy to do, and has no significant downside. The entire point of a transformable bike is choice so why do it in a way that reduces it?

We can have bikes that do both jobs as well as a "29er specific" or "b+ specific", in fact it's not even hard. Why settle?

Northwind - Member
And all you have to do is give up a load of flexibility and capability, for no reason...

I don't follow your reasoning. Why would you need adjustable geometry if it comes out the same with both wheelsets?

I would like adjustable geometry, but I don't see it as being needed or adding anything in this situation.

Realistically most people would expect to be able to run a 29x2.3 (739mm OD) and plenty would be keen on a 29x2.5 (749mm)

Let's say you really want to run that on trend "27.5x3" wide tyre too (736mm), compared with the 29x2.5" there's 12.5mm in it diametrically, radially it's 1/4", let's be generous and say you're going to need to find an extra ~7mm of extra radial clearance to accommodate biggish 29" tyres, it van be done on a 420-430mm chainstay...
And a minimum of say 82mm between the stays, it's really not that much of a logical leap to make and sell frames that can clear a reasonable sized 29" tyre and a clownish "27+" and have some broad market appeal from a single set of tooling...

I'd buy that (for the right price), and probably only ever fit 29x2.2-2.5 tyres (who really wants to bother swapping wheels?), but [i]choice[/i] is apparently what the people always want, so give it to them...

an you elaborate further on that?

Sure. As mentioned tyre sizing is nominal not fixed, in summary right now:

26 tyre = 26.5" diameter
27.5 = 27.5"
29 = 29.5"

27+ varies between around 28.25 and 29.

However the sustainable trend seems to be for 27.5 to get bigger, maybe settling in the 2.5/2.6 region in the long term width wise. Wider tyres are taller, a 2.5 Maxxis WT measuring just shy of 28.25 diameter, a 2.6 would definitely get there. So I predict that plus will fade, replaced by 2.5/2.6 tyres on 27.5, and dying off pretty much as a 29+ format.

That would leave us with 27.5 measuring up at an average of about 28.25, and 29 going more towards the XC market again at 29.5.

This trend actually makes the 27.5 tyre the legit tweener size it was always claimed to be, rather than closer to 26.

epicyclo - Member

I don't follow your reasoning. Why would you need adjustable geometry if it comes out the same with both wheelsets?

It doesn't come out the same, except with small 29er tyres. So basically you're making a bike that's a good plus bike and a compromised 29er. And the important thing is, there absolutely no reason it can't be equally as good with both.

cookeaa- your logic is sound. My Pact is basically what you've described.

A set of 27.5x3 and a set of 29x2.2 are easily interchangeable and I find the difference in geometry (BB height) to have no affect on handling.

The SS giant in a previous post is again the same frameset. It uses a sliding dropout to support both wheel sizes and gears or SS. You can get the geared model in the UK, and SS easily 🙂

esher shore - Member
The SS giant in a previous post is again the same frameset. It uses a sliding dropout to support both wheel sizes and gears or SS. You can get the geared model in the UK, and SS easily

That's good to know. I wonder how available the requisite dropouts are, or frames for that matter.

That would leave us with 27.5 measuring up at an average of about 28.25, and 29 going more towards the XC market again at 29.5.

benpinnick, I broadly agree although 29" seems to be gaining traction for "enduro" bikes and shorter travel 29er trail bikes are getting more common.

Orange Bikes launched today, [url= http://singletrackworld.com/wp-content/uploads/2017/01/orange-bikes-launches-stage-5-and-stage-6-bikes/ ]the Stage 5 and Stage 6[/url] are both 29" trail and enduro bikes respectively. They already have the [url= https://www.orangebikes.co.uk/bikes/segment-pro/ ]Segment[/url] as a short travel trail bike 29" option.... no plus bikes though

I'm still really hoping 26+ becomes a thing.

Isn't that just a fat bike on a diet?

Goldigger - Member
I'm still really hoping 26+ becomes a thing.

Been around since 1998. Buy a Surly 1x1, they fit 3" tyres.