OK, I’m not asking about the advantages (or otherwise) of 650B. We’ve done that to death. But why did the mountain bike industry go for this old touring wheel size rather than just invent a new one? It’s not as though they are averse to inventing new standards in other areas (headsets, bottom brackets, stems, bars etc). Even when it comes to getting wheels made they are happy enough to change the width of the rim, so why not the diameter? If you want an in-betweener size to sit between 26 and 29, why not just ask a rim maker to make you something exactly half way between the two, rather than saddle yourself with this old standard?

650b started years ago and was pushed by a guy called Kirk Pacenti. He was pushing it for years before “the industry” took notice.
As an individual/small business I guess it was much easier to approach a rim manufacturer with a set of pre-defined measurements.

Well if the wall street journal says so
http://m.us.wsj.com/articles/SB10001424052702303978304579475643264222298?mobile=y

Fair point. I can see why Pacenti went with an existing standard, in the same way that the original mountain bike pioneers went with the existing 26″ standard. But once the big boys decided to wade in I can’t see why they didn’t just invent a new standard that was bang in the middle. Giant, for example, are happy to push a steerer size that is pretty much all their own, but still went with an existing wheel diameter.

In fact, despite all the talk of wheel sizes, the mountain bike industry has not developed a single new standard in this area. I guess this also highlights a flaw in the “26 is dead” argument. Standards never die, they just go in an out of fashion.

A “standard” is useful as it allows manufacturers to develop products around a known set of parameters. Given they are all competitors anyone trying to develop something new is likely to face competitive pressure/ambivalence (why should we support our competitors design?) so given 29 didn’t really work outside the US picking something in the middle made sense and an existing standard was there to be used.

But once the big boys decided to wade in I can’t see why they didn’t just invent a new standard that was bang in the middle.

It’s only a 1/4″ out from being bang in the middle – or 3mm radius to put it another way. Why does it need to be bang in the middle though?

Did you read that article Kimbers?

The difference between the numbers involved may sound trivial: Mountain bikes with 29-inch wheels—so-called 29ers—have been the standard for 15 years…….

But why did the mountain bike industry go for this old touring wheel size rather than just invent a new one?

Matt’s right, ‘The Industry’ didn’t go for anything really, it simply followed what some riders started doing maybe 7 or 8 years ago. Using a 650B rim that existed with a new tyre that Pacenti had made to do something different with their bikes. A few 650B-designed frames have been around about that long too. It grew from there. Same as how 29″ took off – 700c road rims, a nanoraptor or rock n road tyre, a few ideas and a bike that worked but wasn’t quite right until there was support for the idea, ie more tyres, etc.

I’d take a off-top-of-head punt that if we started from scratch and went for an MTB-specific rim spec we’d have something like a 30-40mm wide x 600-610mm OD, with tyres around 2.4-2.7″. Will something like that ever happen? Possibly. Would riders ever agree again that there is one wheel size that is optimum for the huge range of bikes and riding styles out there? No chance ) Brands may say different but it’s not that simple.

agreed – bang in the middle between two pretty randomly selected previous standards makes no more sense than choosing a 3rd preexisting standard.

Whatever standard we arrive at I hope that’s it for the moment. I’m not that convinced that someone of my meagre ability would really notice the difference anyway but if I’m buying new I would rather it had some sort of longevity.

The whole wheel size thing has probably done me a favour – I resolved to make do with what I’ve got (no hardship really) until it all settled down. The fact that it has coincided with the recession and 5 years of pay freezes has help prevent me scratch the new bike itch when I probably shouldn’t have been for financial reasons.

@convert – whatever do you mean by ‘whatever standard we arrive at’? 😕

It’s about the journey my friend! Not the destination! 😀

bang in the middle between two pretty randomly selected previous standards makes no more sense than choosing a 3rd preexisting standard.

That’s a very good point and well made. I’d now like to declare my own thread dead 🙂

If you replace the crazy dancing guy with ‘Pacenti’ this explains why 650b wheels – well kind of.

[video]https://www.youtube.com/watch?v=_Tuh8Ff3V8k[/video]

😆

@ Elliott – Brilliant! 😀

Thanks for posting!

Loving that Elliot!

My cynical view is, the manufacturers found that 29 didn’t work as a standard for everybody, and rather than admit defeat and return to 26 they come up with something which is pretty damn close to a 26 but not a 26. Just like they won’t go back to square taper BB – because it works and it’s cheap.

I guess with the 650 there was already a fair amount of R & D, although mtber’s including myself had hardly or at all heard of it.

The Emperor’s new clothes is one way to sum it up

My cynical view is, the manufacturers found that 29 didn’t work as a standard for everybody, and rather than admit defeat and return to 26 they come up with something which is pretty damn close to a 26 but not a 26. Just like they won’t go back to square taper BB – because it works and it’s cheap.

I don’t see why there has to be a standard wheel size for everybody considering that mountain biking encompasses everything from riding XC bikes to 200mm+ DH bikes. Is square taper really better than a well executed external BB and hollow axle – if you can sort out the bearing life (no problems here!) then an external BB and hollow axle is much stiffer for the same weight.

I’d take a off-top-of-head punt that if we started from scratch and went for an MTB-specific rim spec we’d have something like a 30-40mm wide x 600-610mm OD, with tyres around 2.4-2.7″.

The problem with a wheel that big (almost 29er rim but bigger diameter once you include the tyre) is that you can’t package that into a mid-long travel full-sus frame to fit 95% of humans. However, considering that for the first 10-20 years of MTBing there was almost no suspension, it would have made sense to start out with wheels and tyres that big – and then in the last 15 years we’d have seen newer smaller wheel sizes appear to work with the longer travel suspension that’s become popular.

The problem with trying to come up with one wheel size for all purposes:

FWIW I think we’ll end up with 29ers mainly being hardtails/short travel FS, 650b mainly for longer travel and 26″ for the low end, but as long as people keep buying parts, they’ll keep being made.

we’d have seen newer smaller wheel sizes appear to work with the longer travel suspension that’s become popular.

Yes, but various people tried 24″ rears for long travel, and they never really took off, did they?

New wheel size means lots of new frame, fork, wheel and tyre sales. Is it any wonder the industry collectively opted for a new wheel size?

Yes, but various people tried 24″ rears for long travel, and they never really took off, did they?

From the videos I’ve seen they did a lot of taking off! 😉

It’s the usual engineering thing of tipping points in the balance of compromises. The pros of 24″ weren’t enough to offset the cons for DHing. It seems the pros of 29″ at DH aren’t enough to offset the cons vs 26″ – but 27.5″ does win for most DH. 26″ isn’t as good as 24″ for cruiser class BMX racing but is better for slopestyle. So if we’d been running James’s suggested 28.5+ standard then I bet we’d have seen 27 come in for enduro/DH bikes. I have no idea what would have happened with 4X and jump bikes!

Confirmation bias – where are all the videos of mad dancing bloke where nobody else joins in?

CGG, I didn’t mean that would be a 1-for all, more suggesting that 29″ is a bit bigger than ideal for many (most?) but personally I think 26 and 650B are only subtly different. But if 650B can work in DH, a 600 or so rim dia could fit up to 160mm w/o issue for most riders. Daft point tho really : )

The only reason why mountain bikes started off with 26″ in the first place is because it was an existing and readily available wheel size. Nothing to do with any level of logic, science or engineering to determine and optimal wheel size…if such a thing exists. It could just have easily been the 27.5 wheel. If that was the case I wonder if all these wheel size threads would be debating the benefits of or the cynical marketing of the all-new 26″ wheel size.