Why have 29-ers arisen only recently? I have been hearing for the past months about twenty nine inch wheels for bikes, and seeing such at the showroom windows and on the street.

Also heard that they have a lot of advantages and a couple of drawbacks.

My question is why now? The diamond frame has been around for ages. I suspect the disc brakes and, later, the hydraulic disc brakes were not introduced right away due to technological limitations. But the size of a wheel is certainly not constrained by technology.

So why is this new fashion emerging exactly now?
Although 29ers have been around since the early 80's they have only been in production from a major producer for the last decade. Trek was the first big brand to offer a 29er in early 2000's. 

Reasons why you may not of seen many are:


Until the last couple of model years model years 29er's have predominatly been in the XC category (HT and FS)  while recently more all mountain and trail bikes have been developed. Depending on what riders were doing in your area there may not have been a market.
There has been an increase in world cup/ champs and olympic riders using 29ers in the past few years. At the 2012 Olympics there were very few 26" bikes in the mens (more in the womans due to size.


People don't change their bike that often. If you live in an area where there is not a lot of riders the market for a new wheel size retailers will stick to what they know.
Entry level bikes have predominantly been 26". Big box store retailers (of which makes up a large portion of the market) will follow the trend for what they see selling the most of. Now there is a critical mass of 29ers they will follow.
Most people don't read media about bikes they are driven by what a salesman says, which will generally be in the direction of the most sales and biggest margin.



I do find it interesting that you are commenting that you see a lot of 29ers retailling where you live, in New Zealand apart from XC bikes a huge proportion of the 2014 model years bikes that I am seeing at the moment are 650Bs. I think our market replicates that of the US where companies are moving to this as the new "standard". A good example is Giant who have committed to phasing out both 29 and 26" models on a 3 year glide path. Other manufacturers are offering strong 650B models in intemediate and advanced AM categories this year such as GT, Trek, Merida and Santa Cruz just to name a few.