Forum menu
Wrong thread, sorry
I'm still on a 26" hardtail and my next bike will probably be a 27.5 FS frame so I can easily move all my stuff over til I can afford to "upgrade" to 27.5". Still a bit skeptical of 29" for what I ride which is a mix of "bike park" style trails, trail centre and more mellow but twisty woods/bridleways. Just seems like something that would plough through everything will take the fun out of it, but maybe the ploughing through is a different kind of fun! I do get annoyed with repeated small bumps/edges knocking me about a bit when I'm trying to pedal, maybe bigger wheels would help but I feel like rear suspension would be a bigger help!
I haven't ridden a modern 29er either so there's a bit of the unknown whereas I imagine 27.5 feels basically the same as 26. I also have a 29" inside leg so feel like it would feel massive and gate-like.
Bigger wheels are better, and 29" is the biggest practical wheel size.
If you think smaller wheels are better, get a BMX or a Brompton.
<p style="text-align: left;">I prefer 29ers, but I see why some would prefer smaller wheels. I wish they had never pushed 27.5 though, and kept 26 as the smaller option as classic mountain bikes would still be better catered for. Plus there would have been a bit more difference between the main two sizes.
I think we’ve ended up in the right place for adult MTBs regarding tyres - 29” front for most, 27.5” front for v small or tricksy bikes, and then 29 or 27.5 rear depending on various things (riding style, height, trails, etc).
We only got stuck with 26” tyres for about 30 years by accident - it’s just what was available at the start of the sport and no-one dared spend a load of money on making bigger diameter tyres happen. I wish my first MTBs had had bigger diameter and fatter tyres (you forget how skinny MTB tyres were in the ‘80s).
However, we might not have got suspension happening or working as well so soon if we’d all been rolling on 29s!
“If you think smaller wheels are better, get a BMX or a Brompton.”
I’ve tried both of these in my local woods - they’re hopeless!
However, we might not have got suspension happening or working as well so soon if we’d all been rolling on 29s!
And I think it's easy to forget that the change to 29" changed not only sizes of some parts, but has forced the need to introduce both Boost and 1X systems. So while the change to 29" wheels may mean faster speeds and better stability, at least the change the 27.5" didn't need the additional changes to bike components to make it work. Arguably all you need with the change from 26" -27.5" would've been a slightly longer fork lower and slightly revised geometry, the change to 29" as forced wholesale changes making many more components obsolete.
Son has an airdrop so 27.5" He rides wharney and places like that so works really well for him.
I'm more of an XC bimbler and at 6'5" a 29er suits me and my riding style.
We only got stuck with 26” tyres for about 30 years by accident
Yeah, that extra 12.5mm wheel radius has made a world of difference.
I can't even imagine what our lives would be like today if 650b, sorry 27.5, hadn't been invented specifically for mountain bikers 😉
I'm still sticking with 27.5 for now. I'm in no doubt that 29" wheeled bikes are able to travel faster over rough terrain, but I can go faster than I want to on my 27.5.
I demo'd a Specialized Enduro for 3 days in the Alps, but preferred my own 27.5 'enduro' bike with very similar geometry. While the greater ability to roll over terrain and obstacles was noticeable, it was not by a huge margin. On the flipside I found it harder to hustle, which affected my confidence in slow technical sections, and being relatively short legged, I did buzz my behind more (which I know is a flaw in my technique). Add in the additional weight of rims, tyres and forks for 29" and I'm happy on 27.5. If full 27.5" bikes do disappear I'll be looking at mullet bikes, when I do eventually need/want a new bike.
Another +1 for those singing the praises of the Santa Cruz 5010. Had my v4 for a couple of years now, it's just a fantastically trail versatile bike.
<p><span style="caret-color: #000000; color: #000000; font-family: Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji'; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); -webkit-text-size-adjust: 100%; background-color: #eeeeee;">And I think it’s easy to forget that the change to 29″ changed not only sizes of some parts, but has forced the need to introduce both Boost and 1X systems.</span></p>
Bollocks I had a 29er that worked perfectly with 135 qr and a double up front. Current 29er hardtail is 142 and the wheel has barely seen a spike key in 7 years. Boost was just the bike industry doing bike industry stuff </p><p>Can’t see many on here choosing smaller wheels if it meant having to run two or three rings at the front.
"Boost was the bike industry just doing bike industry stuff"
What, like making your bike work better? They're bastards the lot of them
What, like making your bike work better? They’re bastards the lot of them
Tell me you are very susceptible to marketing without telling me you're very susceptible to marketing.
I'd missed that Yeti have launched a new 27.5 wheeled bike...
https://yeticycles.com/bikes/sb135
Looks good. A brave/strong move.
Well, my current bike is better in pretty much every way than every mountain bike I rode from 1990 to about 2015, and every incremental improvement has stayed the corse has contributed to that. If that's Boost, or 1x systems, or forks that actually work, or rear suspension systems now work better becasue of the freedom to experiment, then I guess I'm guilty as charged. Most MTB used to suck balls most of the time, unless you just rode bridleways; now they pretty much don't. That hasn't happened becasue of the sales and marketing team
Well, my current bike is better in pretty much every way than every mountain bike I rode from 1990 to about 2015, and every incremental improvement has stayed the corse has contributed to that. If that’s Boost, or 1x systems, or forks that actually work, or rear suspension systems now work better becasue of the freedom to experiment, then I guess I’m guilty as charged. Most MTB used to suck balls most of the time, unless you just rode bridleways; now they pretty much don’t. That hasn’t happened becasue of the sales and marketing team
There's a few key numbers that influence how a bike handles and they have nothing to do with hub spacing or 1x systems.
These numbers are affected by wheel size but wheel size in itself does not make a bike better or worse. It's just another input in the system.
I'd recommend reading Motorcycle Dynamics by Vittore Cossalter and Motorcycle Handling and Chassis Design by Tony Foale. Unless I've missed something there aren't any push bike specific books that explain the dynamics in question better than these books.
There’s a few key numbers that influence how a bike handles and they have nothing to do with hub spacing or 1x systems.
Well, when it comes to rear suspension, the move to 1x absolutely changed how they are designed and work.
There’s a few key numbers that influence how a bike handles and they have nothing to do with hub spacing or 1x systems.
I was talking mostly about mountain bikes capability to manage the sorts of terrain that the adverts back in the day promised we could, but couldn't really becasue they were pish and made with bits of bikes from the roadie world. Most MTB's back in early days of mountain biking were good for bridle-paths, much beyond that, they'd break with boringly regularity. Now they don't. Part of that is hub spacing and reducing the amount of bits needed for a good spread of gears.
I'm not remotely interested in difficult maths or the theoretical physics that influence handling. Sorry.
Well, when it comes to rear suspension, the move to 1x absolutely changed how they are designed and work.
Just wait until gearboxes with Jack Shaft or idlers become the norm.
You'll look at them and go, 'Huh, is that it? That's just a pivot and a shock absorber'. It'll be mind blowing.
Part of that is hub spacing and reducing the amount of bits needed for a good spread of gears.
No it's not.
I imagine 27.5 feels basically the same as 26.
No the extra diameter does actually make a difference, much the same as 27.5-->29 does!
Here's anecdotal evidence: I found some mounds of dirt and rubble to ride my 26" hybrid over to make my commutes home a bit less dull. There were a few dips in which the front frequently became stuck, but my 27.5" rigid MTB just rolled through them. It was doable on the 26" but it needed the perfect line and well timed body language.
The other advantage the 27.5" bike had were much wider handlebars than the hybrid which I had cut down old MTB bars very narrow for errrrr aero.
Basically, big wheels and wide bars are just skill compensators 😉
No the extra diameter does actually make a difference, much the same as 27.5–>29 does!
The difference in radius is 12.5mm (or an increase of 4.5%). If it was a stem it would be like going from 35mm to 36.5mm.
There is so much else going on you cannot possibly say for sure what the one specific factor making the difference is.
In fact, did you just say your 26" bike was a hybrid while your 27.5" bike was an MTB?
Tell me you are very susceptible to marketing without telling me you’re very susceptible to marketing.
So do you recommend total resistance to change irrespective of tangible benefits just in case someone on the internet thinks you're a victim of marketing?
Sounds like binary thinking.
True, but you can’t deny small wheels get stuck in dips more easily than big wheels do.
You forgot to say, 'It's basic physics'
Yes, it is basic physics. However, bikes are designed by engineers, not physicists. Physicists can look at a problem from a theoretical point of view and make assumptions to isolate the unknown factors. Then can then create experiments to prove their hypothesis.
Unfortunately engineers have to live in the real world where they have to take into account every other factor including actual tyre size, fork travel, rear wheel travel, rear wheel path, wheelbase, front centre, rear centre, front mechanical trail, rear mechanical trail, etc
Once you've taken all that into account the difference your extra 12.5mm wheel radius makes is pretty minimal.
So do you recommend total resistance to change irrespective of tangible benefits just in case someone on the internet thinks you’re a victim of marketing?
Nope.
I was the first in my club to get riser bars and run tyres that were bigger than 2.1".
I got my first dropper post in 2006.
As soon as I found a 12-36 cassette I started using 1x.
I was running 800mm bars and a 35mm stem as soon as I could find them.
And as soon as someone makes a full suspension bike that ditches the rear derailleur and properly takes advantage of this in the suspension design I'll be buying that (we're close but I've waiting for a Williams Racing Products to sort their system out
)
Just please don't try to tell me adding 12.5mm to the rim diameter and 6mm to the hub spacing (when DH hubs were already available) is progress.
And don't even mention 15mm axles!
The difference in radius is 12.5mm (or an increase of 4.5%). If it was a stem it would be like going from 35mm to 36.5mm.
If it was a handlebar it would be 770 to 800mm, if it was a head angle it would be 66 to 69 degrees, if it was reach etc. etc.
If it was a handlebar it would be 770 to 800mm, if it was a head angle it would be 66 to 69 degrees, if it was reach etc. etc.
None of those things are clad in 50mm to 75mm of inflated rubber.
An increase of 12.5mm in rim diameter is a negligible difference.
If it was a stem it would be like going from 35mm to 36.5mm.
If it was a handlebar it would be 770 to 800mm, if it was a head angle it would be 66 to 69 degrees, if it was reach etc. etc.
None of these work as analogies because they dont have the same limits.
a stem - or an effective stem once you get shorter than the diameter of the fork steerer can go from maybe zero or possibly even negative up to 150, 170 maybe.
head angle, maybe betwen 75 and 55 is about the limit that would physically function, assuming offsets, stem lengths being in the normal range.
handlebars, the minimum physical size is 2 hands plus a stem (it would be awful, but would technically be feasible), so maybe 200mm, not zero.
so what would the smallest possible wheel be? for something that you could reasonably define as off road cycling? which would be rubbish but would sort of functional? 10"? 20"?
Just please don’t try to tell me adding 12.5mm to the rim diameter and 6mm to the hub spacing (when DH hubs were already available) is progress.
And don’t even mention 15mm axles!
All significant progress IME.
All significant progress IME.
You went from 20mm to 15mm and you thought, 'Wow, what an improvement!'?
Regards the magic 12.5mm, progress would have been a standard measure for tyres, not just in terms of width but also in terms of aspect ratio. But then people might have realised just how insignificant the 12.5mm actually was.
Just please don’t try to tell me [ ] 6mm to the hub spacing (when DH hubs were already available) is progress.
The 3mm addition allowed for (at the time) 11 speed 2X systems that Trek were developing for 29ers (which at the time, were not at all certain to take over like they have now) while keeping the BB spacing realistic, wheels strong and rear triangles shorter and without changing the Q-factor. Had they known 29" was going to be the nailed on certainty they may have gone direct to DH spacing, or Tandem 145 but that meant (at the time ) a difference in how through axles and QR rests in the drop out. They settled on 148x52mm centreline and 3 different chain ring offsets to accommodate all centreline options and rear axle widths
Boost essentially made the modern 29er (as it exists now) possible.
You went from 20mm to 15mm and you thought, ‘Wow, what an improvement!’?
Regards the magic 12.5mm, progress would have been a standard measure for tyres, not just in terms of width but also in terms of aspect ratio. But then people might have realised just how insignificant the 12.5mm actually was.
Never had 20mm, you invented that, weird. I went from the old skewer thing to 15mm through axle thing, significant improvement.
Regarding 27.5, it increased the diameter by one inch. Significant improvement, all other things being equal. 29 goes a little too far for my taste however so 27.5 a near perfect balance for me. I would have liked to try 28 but that doesn't exist.
Just based on my experience of course, good progress and despite the marketing. I am quite happy if your experience has been different, perhaps you're not very sensitive to stuff.
Diffent people can be...different. No need to be belligerent, weird or emotional about it.
I’m not sure why Bruce is arguing about a 12.5mm change in radius?
29” front wheels are 31.5mm bigger in rim radius (and bigger still in total tyre radius thanks to wider rims and larger volume tyres). For some riders that’s a bigger tyre than they want on the back, which is where 27.5 is most useful. How many riders want an even smaller wheel on the back?
IIRC the first Boost frame I saw was a Rocky Mountain with the 3" B+ tyres. I knew right away that it fixed an issue for me and managed to get Brant to design and procure a hardtail frame for me. I've not regretted that at all and that bike is still doing the job it was designed for.
Boost essentially made the modern 29er (as it exists now) possible.
As Scotroutes said, Boost solve a problem for Plus size tyres. Nothing to do with 29ers. And regardless of the problem it solved, the already existing 150mm hubs would have solved that problem absolutely fine.
Never had 20mm, you invented that, weird.
I'm going on record here to say that I definitely did not invent 20mm axles.
Regarding 27.5, it increased the diameter by one inch. Significant improvement, all other things being equal.
I've explained several times now, all other things were not equal. Multiple factors were changing at the same time in terms of geometry.
Diffent people can be…different. No need to be belligerent, weird or emotional about it.
I agree, and there's no need to start becoming insulting about it either. Admittedly I started it by jokingly suggesting you were easily taken in by marketing. However, that's just me. When you do it it looks like you're becoming flustered.
I’m not sure why Bruce is arguing about a 12.5mm change in radius?
29” front wheels are 31.5mm bigger in rim radius (and bigger still in total tyre radius thanks to wider rims and larger volume tyres). For some riders that’s a bigger tyre than they want on the back, which is where 27.5 is most useful. How many riders want an even smaller wheel on the back?
You're the one who started this by suggesting 27.5 was a significant improvement over 26.
It wasn't. If there was an improvement it was dwarfed by other geometry changes that were happening at the same time. A more significant change was the increase in rim width, something that marketing departments didn't feel the need to shout about. Can you think why?
Here's a hint. You can change the rims on your existing bike without falling foul of any new standards.
The last new bike I bought came with 19mm rims (on a 2017 bike). I guess because they were cheap to spec. I rebuilt the wheels with a 30mm rim on the back and a 35mm rim up front and it was like a different bike.
I'm not against progress. I am against marketing bullshit dressed up as progress.
the already existing 150mm hubs would have solved that problem absolutely fine.
Not convinced. A 148mm hub fits into recesses in the dropout, making the whole thing stiffer (and marginally easier to fit/line up) than a 150mm hub. Remember, by this time we were also starting to see much wider hubs for fatbike frames too and for a while we had 170, 177, 190 and 197 all cropping up. 170 and 190 basically died off for much the same reason that 150 wasn't right.
I’m not against progress. I am against marketing bullshit dressed up as progress.
Is there any other kind of marketing?
Not convinced. A 148mm hub fits into recesses in the dropout, making the whole thing stiffer (and marginally easier to fit/line up) than a 150mm hub
I've never heard anyone complain that DH hubs aren't stiff enough before but if you say so.
Not sure that's a good enough reason to introduce yet another hub standard but whatever sells, I guess.
I’m not against progress. I am against marketing bullshit dressed up as progress
You might struggle but just ignore the marketing and judge a product for its merits then, simples. 15mm, 148 and 27.5 have proved to be good progress for me, all things being equal (repeating the same thing doesn't change the fact that I am well aware that things are not equal - it actually means that I am able to isolate different factors or focus on factors where other changes don't interfere). Despite the marketing.
As for 20mm I am pretty sure that you haven't invented it. But I still don't see how you know I went from 20 to 15. Mostly because I didn't.
I am sorry if you're feeling insulted and that reinforces the impression that you're emotionally fragile. I stil think you're weird but I appreciate that it's subjective and just my opinion.
I am sorry if you’re feeling insulted and that reinforces the impression that you’re emotionally fragile. I stil think you’re weird but I appreciate that it’s subjective and just my opinion.
Ooh, we're at the 'seek professional help' stage of the debate.
I love talking about wheel sizes 🙂
“You’re the one who started this by suggesting 27.5 was a significant improvement over 26.”
I didn’t say that at all. I said we started out on 26” tyres for reasons of commercial convenience and it would seem bizarre to stick with them forever. When everything else on mountain bikes has changed in the last 50 years, why should the wheel diameter remain set in stone?
I didn’t say that at all. I said we started out on 26” tyres for reasons of commercial convenience and it would seem bizarre to stick with them forever. When everything else on mountain bikes has changed in the last 50 years, why should the wheel diameter remain set in stone?
And I didn't say that anything should be set in stone.
However, changes in standards, particularly changes in standards that mean the only practical way to move to the new standard is to buy an entirely new bike, should have an actual benefit and actually be different to what came before.
27.5 fails on every part of that test and the only reason it happened was because Giant and Specialized knew they could increase profits without any actual investment.
Moving to new standards for no reason just increases the price of mountain biking for everyone for no benefit.
Ooh, we’re at the ‘seek professional help’ stage of the debate.
Yes definitely. I didn't think of that but now that YOU mention it, that's probably a good move.
I think you might be taking a debate that happens on here roughly every 3 weeks a bit too seriously.
But hey, going the mental health route means you don't have to bother learning anything about the subject at hand so as a debating technique it has that going for it.
And for the record, I sought help. I got misdiagnosed with bipolar and carried on with medication for about 10 years. Then got correctly diagnosed with Borderline Personality Disorder and I've been sorting things out based on that ever since.
Stay classy out there.
Good to hear Bruce.