I was just thinking....

Watch this video in which Gary Fisher explains that he had the idea for a big wheeled mountain bike back in 1979 but it took until the late 1990's to make the idea a reality.
http://www.youtube.com/watch?v=n7xNohTerzU&feature=plcp

Then read the letter below to Charlie Kelly, Gary Fisher's business partner at The MountainBikes company. It is from Geoff Apps and dated September 1980.
In the letter is offering to supply Finnish snow tyres to Kelly and Fisher.

28"x 1"5/8 x 1"3/4 are the same as modern of 700C x 47mm.

28"x 1"5/8 x 1"1/2 are even bigger diameter at 700B x 44mm

Whilst 26 x 2" x 1"1/2 are equivalent to modern 650B x 54mm

Over the next four years Apps supplied many oversize tyres to Fisher and Kelly and bikes many were built to use them. They proved successful in both cyclo-cross and mountain bike races. One Marin framebuilder who made bikes to fit the Apps supplied tyres was Ross Schafer. Schafer had his Salsa Cycles workshop in Crested Butte, next door to Bruce Gordon's workshop.

Only the high costs of importing these tyres combined with the erratic supplies from Finland stopped one of these bigger tyre sizes from becoming the standard for early mountain bikes.

In 1988 with the support of MTB pioneer Joe Murray, Bruce Gordon copied the tread pattern of the 700c x 47mm Hakkapeliitta tyres and had copies manufactured by Cheng Shin. They were narrower at 40mm wide and were marketed as the "Rock n' Road" tire. They were fitted to bikes especially made by Bruce Gordon and Wes Williams. This sorted out the supply issues with the tyres from Finland but by then the smaller and readily available 26" wheels were firmly established as the norm.

Ten years later in 1998 Gary Fisher and Wes Williams were the two key movers who persuading WTB to produce the NanoRaptor 700C x 52mm tyre. Which later became known as the first 29er tyre despite the fact that there overall diameter of 28.6 inches was slightly less than 29"

One of the "two prototypes" that Apps refers to in his letter was built as a Range-Rider bicycle in 1981 using 700C x 47mm Hakkapeliitta tyres. Thus this Cleland style off-road bicycle preempted the the birth of the 29ers by 20 years.

Unfortunately in Britain, manufacturers did not take Apps' ideas seriously. Preferring to copy the smaller wheeled American designed bikes instead.
Later in the 1980's, David Wrath-Sharmans avocation of bigger wheeled off-road bikes was also ignored.

I have just come across what may be the definitive answer to the question why mountain bikes evolved with smaller 26" tyres when better larger tyres could be imported? It relates to a distinction in the US import tax system which taxed adult tyres more than children's tyre sizes.

Bellow is a quote from Lennard Zinn who was one of the Marin frame-builders who build bikes using the Hakkapeliitta tyres imported through Geoff Apps.

..."you should remember that a primary reason 26-inch became the default mountain bike tire size starting in the 1970s and 1980s was simply that import duties on them were cheaper, as the US Customs Dept. charged a higher duty rate on adult bikes than on children’s bikes, and it considered 26-inch to be a children’s-bike tire size".

So it appears that the decisions made back then were more to do with money than with optimal design!

The full Lennard Zinn article can be found here:
http://singletrack.competitor.com/2012/ ... 650b_32195

Hmmm, watched the Gary Fisher video, one thing that stood out:

"bigger wheels equals more momentum, once you're rolling, you stay rolling"

This is basically because they're heavier, but people seem to like the feel of light wheels and pay a lot of money for them. I can't help thinking that the increased rolling weight and momentum, which would normally be seen as a nagative, has been spun (pun intended ) into a positive there. :?

Chopper1192":3usw3073 said:

The gyroscopic effect of 9s over 6s is already noticeable, as is the wheel flex. That why cheap ones are crap. Need to spend ackers on a nice one with light, stiff rims to make them work proper like.

If course, those boys in the states have Geoff Apps to thank for giving Gary Fisher the idea, and we have the Yanks to thank for Jay Leno, McDonalds, and Tippex.

Click to expand...

Nope - Tippex was a German invention. The equivalent from the States, predating Tippex by a few years, was Liquid Paper (invented by Mike Nesmith's mum, as diehard Monkees fans may well know).

David

xerxes":27mgm28g said:

Hmmm, watched the Gary Fisher video, one thing that stood out:

"bigger wheels equals more momentum, once you're rolling, you stay rolling"

This is basically because they're heavier, but people seem to like the feel of light wheels and pay a lot of money for them. I can't help thinking that the increased rolling weight and momentum, which would normally be seen as a nagative, has been spun (pun intended ) into a positive there. :?

Click to expand...

As was also mentioned in the video though, angle of attack is different with a 29er too, and I think that plays as big a part in helping the roll as the extra inertia.

longun":27mgm28g said:

tbh, i think the difference is marginal and another gimmick to boost interest and sales........

Click to expand...

The difference may be marginal, but it is there. It is no gimmick. Try one and you will see. You might not like the difference, because you get nothing for nothing in this world, but it is not a figment of the imagination. And while we are mentioning marginal differences, that's what all our component choices are about, isn't it?

GrahamJohnWallace":3w333rb1 said:

I have just come across what may be the definitive answer to the question why mountain bikes evolved with smaller 26" tyres when better larger tyres could be imported? It relates to a distinction in the US import tax system which taxed adult tyres more than children's tyre sizes.

Bellow is a quote from Lennard Zinn who was one of the Marin frame-builders who build bikes using the Hakkapeliitta tyres imported through Geoff Apps.

..."you should remember that a primary reason 26-inch became the default mountain bike tire size starting in the 1970s and 1980s was simply that import duties on them were cheaper, as the US Customs Dept. charged a higher duty rate on adult bikes than on children’s bikes, and it considered 26-inch to be a children’s-bike tire size".

So it appears that the decisions made back then were more to do with money than with optimal design!

The full Lennard Zinn article can be found here:
http://singletrack.competitor.com/2012/ ... 650b_32195

Click to expand...

Fascinating stuff, and evidence that the truth behind history is often found in small, seemingly mundane details.

In terms of the question of which wheel size works best for a particular discipline, this will ultimately be decided at the races. Unless the UCI etc step in and ban specific sizes.

In this scenario it's by no means certain as to which size will win out.

Maybe a compromise size like 650b?

Or maybe riders will chop and change their wheel size to suit a particular course, or set of trail conditions?

Nike Nesmiths mum? Well I never. You learn something new everyday on RB!

the big wheel theory only works so far on smoothish terrain, take it off road and the margins are minimal, all down to lots of factors, hence the very top pros, not all , still run 26"