Tech trends: What are 650b tyres and road plus?

This was a good article to whet the appetite.

I've just splashed out on a 650B 'Road Plus' bike  having test ridden one at my local bike shop in Bristol.

Test ride new kit if you're a wee bit sceptical. You'll soon find out if it feels "right" or not.

I've been into mountain biking since it became a 'thing' in the UK and have seen loads of weird trends become firmly established. Mountain bikes have improved hugely over the years and some  of the best recent developments have emerged by playing around with wheel size and tyre setup.

Have road bike makers simply followed the trend? Maybe - I think some framebuilders have always been interested in playing with these idea. Bristol is lucky to host the Handmade Bike show and I've seen a trend towards different wheel combinations on road bikes. It takes tyre manufacturers and bike manufacturers tro commit to the idea before it can really fly - something that seems to be happening at the moment.

If you're worried about it being a fad that might be unsupportedin the future, mountain biking seems to show that all these variations in wheel-size / tyre-width / tread-type can happily co-exist!

A quick look online suggests 650b x 38 mm looks doable John. Have a look at this link.

What 650b tyre size is roughly equivalent to 700 x 22? I need a new wheelset for a folding bike I built up. It originally had 26" wheels but I've squeezed in 700 x 22 since. I thought 650b wheels would help me run a bigger volume. 

Another case of 'back to the future' proving there's nothing new in cycling - just new materials and new demands. 

The Caribou RTB (road mountain bike) used 26in wheels in a custom road bike frame in exactly the same way in order to accommodate up to 1.75in slick tyres. 

Its true that there's more scope for different geometry when using small tyres but what manufacturers have actually done this?

the main benefit of 650b appears to be the greater tyre width that is getting used by road bikes anyway these days but 6590bs are actually going for it rather than adding 2mm at a time to avoid shocking the stalwarts. 

"Wouldn't use them for a gravel race"

That's exactly what Jan Heine talks about his Compass stuff (which is the exact same philosophy as the WTB) being used for, with a pretty good level of success. Outside of certain conditions the large volume is more useful than some half-hearted tread that a lot of gravel tyres seem to sport.

Call me cynical but manufacturers seem to be pulling every trick in the book to get you to buy new stuff. And why not I suppose?

I remember when people could win a downhill race on 26inch wheels but now you'd think they where square or something the way magazines and the like talk about them.

Just one comment.  This is yet another obscure tyre size to confuse people, including me.  The only thing I really want to know about 650b is what is the ETRTO size?