32-inch Wheels and Mountain Bikes

Frankly, DirtySixer are outright COWARDS for trying to come out with a 32 inch mountain bike despite their name being a pun on 36" wheels. Pathetic stuff, really. 

BTW, as a bitter old man: way to go, bike industry — play the “new wheel size” card again instead of doing the one thing that would actually grow the sport. Like, I don’t know, building a sub-$1k thermoplastic single-pivot full-sus that fits anyone, lasts for years, and doesn’t age like an avocado left on the counter. Then maybe even those “billions of Warner Bros. MTB viewers” (aka TikTok cat videos + YouTube highlights stapled together) could actually afford a bike.

But nope — MTB will stay niche, and the industry will keep carving smaller niches inside the niche, until we’re all broke but very well-segmented. Growth plan or milking plan? Guess which one actually pays the bills.

As someone 5' 9" who test rode a full 29er once, experienced  tire buzz, and never rode a full 29er again (other than hardtails) I can confidently say that I will never own a full suspension bike with a 32" wheel. I struggle enough with manuals and some last second jumps on my mullet bike. 29 rear and 32 front for me, and millions of other "average" sized riders would pretty much be a strictly wheels-on-the-ground affair, and that sounds about as fun as watching paint dry, compared to the actual mountain biking we do on a regular basis. For the long legged crowd, I can totally see the appeal, and I hope that the 32" niche gets filled.

That's surprising, I'm 5' 9" and my primary bike is a full 29" 150 travel bike. The only time I have tire buzz issues is when I get stuck behind the seat on janky drops and get sucked into the wheel. If the seat tube was straight I could fit a longer travel dropper and I don't think it would be an issue at all. You should try a modern 29er. From riding my buddies' mullet and 27.5 bikes I can tell that the 29 definitely helps on tech climbs and on flat boomer tech. A 32 would probably help even more, but as a rear wheel tire buzz probably will be an issue. 

I would be interested in a full 29er XC bike, or short travel trail bike, but I never really do that kind of riding. Soon enough, I'll probably get a full suspension e-bike, and the XC/ short travel bike will never get used, so.. For trail/enduro riding the 29er front helps enough with rollover and uphill speed without being too much of a hindrance for jumps and side hits (definitely not as easy to get airborne as full 27.5 though). Full 29er, I know wouldn't suit my style because I like to bunnyhop over small obstacles on the trail. I only really 'plough' through stuff when there's many bumps/roots in succession and I can't accurately judge where a perfect takeoff and landing spot would be.

Relating to your last point: 

The 26 to 29 change, people didn’t really understand how certain geometry aspects worked. 

Most notably was some brand’s insistence that handling performance was mostly or solely based on wheelbase. Hence the 29er version of bikes coming with a steeper head angle (and a messed up fc:rc ratio, thanks to the longer chain stays) than the 26 equivalent. With predictable results  

Now I hope designers are more used to the effects and consequences of changing wheel diameter. 

As a tall guy with long legs and an appetite for big dumb rides that often include shitty 4x4 roads, I’m actually really stoked to see where this whole 32” thing goes. I’d like 32” x 2.4” mezcals for my next lap on the white rim please. 

I saw the 32x2.4 Aspens weigh about 820g. Has anyone heard about any other tires in development? I'd love something more gravel oriented. 

I'm definitely interested. I'm not an early adopter though. I'll let the industry shake it out and bring the price down while I enjoy the bikes I have. Going from 26" to 27.5+/29" was an absolute revelation for me. Instantly conquering features i never had before. I could definitely see the potential for 32 front and rear. But like Jeff said, there has to be an upper limit of practicality here.

Same with eBikes, I'm willing to wait years for a decently priced Pinion MGU. I'd rather stay a Luddite who can't afford an eeb or 32er anyways.

The "invention" of 30.5" wheel size in 2027? 🙃

You joke, but I am wondering if anyone in here from the industry can shed some light on why we need to go 3in bigger on an already big wheel? Why not 1in or 2in?

I’m just going to leave this here 

Photoshop? 57-622 is the same rim diameter as a regular 2,25X29"?

Good eye. Yes, it's a 29" tire. "622" refers to the bead seat diameter of the rim (in millimeters), and "wheel size" tragically refers to the outside circumference of the tire. So 29" MTB tires are much larger than 29" in diameter, apparently 30.5" according to this sidewall. 29", 26", 27.5" are outdated numbers that correlate to nothing on an actual MTB tire or rim.

This is from a video my buddy filmed at one of factories for low-end bikes in China.  It's very likely they just put the outside diameter on that tyre for whatever reason just like ROBOT suggests

As a tall guys, I’m just here to chime in and say I’m about this. Bring it on. Ready for 32s

and that kids, is the reason why you should always use ERTRO measurements when talking tire sizes. and the metric system in everything else

Yeah. With more info I got I’m now more convinced that they actually specified a wrong etrto, and 30.5 rims and tires are actually a thing

Buddy reports that the outside rim diameter he measured is 648mm (obviously etrto iso bsd should be a bit less)

Also, chaoyang tires (a relatively well known Chinese tire brand) specifies (unreleased yet as of time this pdf was created?) 30.5x2.25 phantom wet tire with an etrto of 57-642, so that seems to match with the measured wheel: https://www.zc-rubber.com/upload/2024/08/14/172364152262697da3m.pdf

Sorry for the derail - I know the lowest end of bikes isn’t exactly what we typically discuss on vital - but it’s semi relevant to what we might see in wheel developments for the nicer bikes…

just look at the smaller wheels, there are 7! different 20“ wheel sizes, pure madness

Just a thought that crossed my mind while doing 32" frames in bikecad, with the better rolling capacity of 32" wheels, and less suspensions travel available, could we see more softail frames (for XC/trail), or frames with flex stays and a simpler suspension device than an air/coil shock. There used to be elastomers back in the days but these were not great AFAIK, but with limited travel (50-100) could that make a come back with some more advanced materials like D3O, sorbothane, or is there no "magic" material that exist that can act like some sort of damped spring ?

BMC MTT is a bit like this isn't it ?

I'm sure a softail will work in the sense that the various Trek and BMC softtails have worked over the years, but back when 29ers were breaking onto the scene I think people played with the idea. Maybe the 32 inch wheel and advancing technology in materials puts it over the edge into viability but personally my guess is we may see really low travel numbers but where suspension is called for, we will see it. 

29x3.0 like the Surly Krampus have an outer diameter of about 30.5".

I fucking love my rigid Krampus. 

Had a shower thought today: Us “normal” sized folks (size M and L) have fetishized the 27.5 front wheel for being more nimble and playful, so why are so many tall riders so stoked about 32? Wouldn’t a giant human on a 29er be in the total sweet spot of it feeling nimble like a full 27.5 bike feels to us but also with the better rollover of a 29? Am I just in the Vital/PB bubble of liking the handling of full 27.5?

Does everybody forget about the attempt from WTB in 2023 to bring 750d to the (gravel) market? That was 660mm BSD...

Hmmmm. Worth a watch.

At 6 foot 4 I have no idea why ppl keep saying big wheels are good for taller riders. The terrain you are riding on doesn't get bigger ?? Il fight you all day on stack height not being proportional , but it’s getting better and it’s fixable with the new crop of 80mm plus bars. Big wheels dont help bigger ppl, buy a bigger , longer frame ??? And enjoy the riding the trail rather than steam rolling it ? 

Amen! On the upper end of sizing the sky is literally the limit. LeBron could ride a XXXL 27.5 bike with really high stack, stem spacers, high rise bars and it would fit him AND have the ride characteristic that all the other sizes of that same bike have. (save for the wheelbase but that's unavoidable) It's absurd to say a given frame in size M on full 29 and that same frame as an XXL on 32 are the same bike whatsoever. It's akin to releasing a 150mm bike for all sizes but size XXL gets 170mm travel. They will ride totally different. 29ers barely fit on some singletrack out there!

Small front wheels may make sense for small riders because the stack can only be so low with a given fork travel and a 29in wheel (although as we're seeing with the geo flavor of the year being stack, most bikes are too low so maybe every bike except for kids bikes can be 29 front) 

I’m sure I will catch flack for this and don’t want to make sweeping generalizations, but if the chainstay thread is anything to go off of, it would seem that a lot of vital posters genuinely don’t seem to understand why someone would want a “playful” bike. It felt a bit like trying to explain why a manual transmission sports car is fun to someone who in response keeps insisting that you really should get a cvt as it is more practical.

At 5’10” I know I personally am not the intended audience, but can say that even if I was, it would be hard sell for me as not only do I like a maneuverable bike, but I already have enough trouble keeping 27.5” wheels straight.

I know this isn't the point of your comment, but if you haven't tried it, you might find it easier to keep a 29" front wheel straight than a 27.5" wheel, due to the gyroscopic stability and better roll over. For example, the reason I left my hardtail 27.5 is because it doesn't like to stay straight so it gives a different experience of picking lines compared to my "plow" 29er bike. 

Actually my current bike is set up mullet and I don’t mind that most of the time. I’d like to try out a smaller front wheel, but do enjoy the extra plowing ability the 29 gives me when trying to keep up with longer travel friends. When I was talking about keeping a 27.5 wheel straight, I was more referring to how I have a long history of bending back wheels. From my understanding of things, smaller wheels are inherently stronger than larger diameter wheels.