Wednesday, September 02, 2020

When 26 Is Like 27

Kona Bikes Dew Plus
WARNING: Intense bike nerding out to follow. Please move on if the consideration of the minutiae of bike tire and wheel technology finds you falling asleep!

 I had a chance to build up a Kona Dew Plus yesterday at Andy''s Bike Shop and it got me to thinking. "Twenty Six is like Twenty Seven". If you know your wheel size history, you'll understand. No- this is not my goofy understanding of math coming to the fore. But yeah....I can see where you might think that. My math skills are not what you might call 'very good'. 

Anyway..... Years ago there were tons of bicycles sold at retail which had the 630ISO bead diameter. These were commonly known as "27 inch tires". They are slightly bigger in diameter than 700c, which is the modern road bike derived size that also supports 29'er MTB and most all gravel tires. So, what happened to twenty seven inch tires and wheels? 

Well, they were phased out in the 1980's when Mavic and some other racing oriented companies moved to the ISO622 diameter sized wheel, or otherwise known as 700c (French designation). These tires and wheels were slightly smaller in diameter, but more importantly, they were lighter. Most manufacturers copied this for their designs on road racing style and lightweight bikes going forward. 27"/630ISO became a 'dead' wheel size, but of course, there are a million of these bikes out there yet, so tires are still available, albeit in limited options. Since 27"/630ISO is now relegated to having no new development, the 'replacement' tires and wheels tend to be- but not always- very low quality items. This has been the norm since I started in the bicycle business in the early 1990's. 

Compare this to what has happened to 26"/559ISO diameter tires and wheels. Once the darling of every high end mountain bike line, with scads of high end wheel and tire offerings, this wheel size has shrunk down to resemble the standing of 27"/630ISO in a very short period of time. It's really one of the startling, untold stories of the bicycling world. 

Think back ten years ago. In 2010 26" wheels were in a heated race for market supremacy with- ironically - a 622ISO based wheel, once again, fitted with 2"+ sized rubber, dubbed "29"ers".  At the time many said there was no way that 26" MTB would ever fade away. 29"ers were just too big and cumbersome for many things off-road riders wanted to do. Meanwhile, in 2007, Kirk Pacenti hacked a tire down to 27.5" size, claiming this 'new' MTB wheel/tire combo, presented as half the good stuff of 26" mixed with the other half of the good stuff from 29", was now going to be the "Next Big Thing". 

Of course, three tire sizes for off road was ridiculous. One of them, or two of them, had to go. Without beating the story to death, we all know which bird got pushed out of the nest. It was 26"ers that were doomed to the dust heap of forgotten tire and wheel sizes. 

I'd say that without fat bikes, anything 559ISO would pretty much be replacement type fare, just as with 27'/630ISO stuff. The 27.5" thing became a MTB size, which you all know now, but it isn't really 'new'. It is a derivative of an old French utilitarian/tandem/commuter wheel known as 650B in the French and 584ISO by the bike industry. In fact, it is a variant on 26" diameter wheels in reality. However; that has been pretty much lost to the depths of time now. 

What matters now is that, for all intents and purposes, adult, lightweight, sporting bikes are either 650B/584ISO or 700c/622ISO and the old 26" MTB and 27" road sizes are dinosaurs of our past. I think it is a fascinating turn of events, and the Kona Dew Plus was a sharp reminder of what has happened in a very short period of time.


fasteddy said...

I do remember those days. There was a time when 650b was a weird size only mechanics with a penchant for gauloises knew about in the US. Thanks for reminding us of the changing of the times and the seasons.

youcancallmeAl said...

Fortunatly there are still some tire manufacturers still making good quality urban, touring and mtb tires in the 559 format for those of us who dont race or ride gravel specifically.

Zed F. said...

I've heard of putting 700c wheels on a 27" wheel frame to allow wider tires. Does it work the other way?

I have a bike designed for 26*2" tires. It has rather heavy wheels. 650b x 35 tires appear to have a similar O.D. The one thing I'm not sure about is whether I can get canti or linear brakes that can handle the larger rim diameter.

So I'm curious about your opinion on 1: is it feasible?
2: would it be worthwhile?


Guitar Ted said...

@ Zed F - Have a look at THIS PAGE: (Copy and paste into your browser)

I think you will find there that what you are looking at is possible. Brakes are an issue, but Paul Moto-Lite brakes sometimes can be used to get around such issues. there also may be other canti-long pull type brakes that will allow for this adjustment as well.

Good luck!

Phillip Cowan said...

If anything saves the 26" wheel it will probably be the move toward all road bikes. I'm building a set of 26'ers now with Velocity cliffhangers to go on an old mtb drop bar conversion. I freely admit the whole project is just an excuse test the Rene Herse Rat Trap Pass tires. If I like it as much as I think I'm going to I may end up having a frame built just for these.

teamdarb said...

Zed F. you can get away with it easily.
1. Current brake pad sits low on the arm.
2. Rim is equal width or wider. (wider allows the pad to sit lower on the arm i.e. less travel) You can also get away by using a thicker pad.

Look for lower end model of brake. Longer arm V brake tend to have longer pad mount slot. I tend to use bolt on pads versus post mounted smooth ones. The bolt on ones have a smaller diameter shaft. Plus you get an array of spacer. You can tailor all things easier.

*2- Is it worth it? Depends. That is a very personal answer. So many varibles.

teamdarb said...

Kona Dew model is soooo overlooked! I am a huge fan of the Coco! In Europe, they come kitted with rack, dynamo, and lights. All one needs is an offset seat post and a dropbar to make them a wee bit more sporty. I agree the 26 to 27 (28, cough cough) comparison. I still say the 27/630 (28) wheel makes the best overall road touring setup. Those long spokes just soak up bumps so well.