Geoff and I had a correspondence in the '80s...
Thanks for this fascinating insight. I've known Geoff since 1984 and he has never mentioned these Anglo-American links.
However, here's something on the subject from the Cleland Cycles website, written by James Walters.
Cleland Aventura Protoype - the world's first 29er?
Let's get some things straight from the outset. First, rarely in cycling is there anything that is truly new, so while this bike, from 1981/82 certainly pre-dates the current '29er's by a few years, it would not be surprising to discover that something significantly pre-dates this. Second, rather than saying 'this was first so there!' it's a tale of how mountain bike evolution might have followed a different path from the one it did.
The Aventura prototype pictured below, built in 1981/2, featured amongst it's many innovations 700c tyres. The reasons for fitting the tyres back then are the same ones that are making 29ers popular today - a freer rolling, smoother ride over bumps and rough terrain, with improved traction in loose dirt and mud. Supply difficulties resulted in production models featuring 650b tyres, a slightly smaller rolling diameter tyre/rim size in which Nokian also made some suitably sturdy tyres. It's worth recalling that back then there were almost no off-road tyres available in 26" or any other size. As Geoff relates below, but for a better supply, mountain biking history may have been quite different.
In a letter to UK bicycle industry trade journal Bike Biz (published in the December 2006 issue, at time of writing available for download from the Bike Biz site) Geoff explained what happened:
"The photo here shows an early prototype Aventura. It has 700C tyres. This was around 1981/2. Nokia (now Nokian) had this size listed from around 1979/80 but it took ages to get some. I persisted because I knew they would be good. I built only the one 700C machine and sent some of these tyres over to Charlie Kelly and Gary Fisher, who had built a frame in readiness. They loved them and really appreciated the ride they gave, compared to the 26-inch tyres, and also loved the success they had at the races. As far as they were concerned, these 29-inch tyres were the way to go.
"This was the ONLY tyre of this type and size in the world, there was no choice." Unfortunately getting a supply of tyres was impossible. Geoff adds "The 26-inch wheels (on mountain bikes) were not absolutely fixed at that time, so, had the supply situation been better, it is quite possible that 700C tyres and wheels would have been the mountain bike standard now."
"When I tried to promote the 700C idea to UK mountain bikers they just thought it was bonkers Apps, raving again, like he did about short wheel-base, steep angles, sloping top tube, twist-grip gear shifters…"
In the same issue of Biker Biz Gary Fisher, speaking about the growing popularity of 29ers, gives his perspective:
“We got some tyres from Geoff Apps really early on and we [Fisher and Kelly] said ‘Holy Toledo!’” But the poor supply situation of the larger diameter tyres meant the fledging MTB industry stuck with the smaller wheel size."