Right, but the next question is: who invented Geoff Apps?!
Like the mountain bike he was not invented but evolved.
His influences were different to those of the NorCal pioneers. Geoff Apps' background as a motorbike Trials rider taught him many things and especially the value of wide low pressure tyres. He experimented with riding a wide variety of existing bikes of various wheel sizes in the English mud convinced him that generally speaking, large diameters work best off-road. So all he had to do then was tenaciously search the world for some suitable fat large diameter tyres with aggressive treads. No internet back then so his main sources of information where all types of cycling and motorbike publications from around the world. It was this widespread reading that led to him reading about Fisher and Kelly in the US and then making contact with them in 1980.
From a historical point of view it's the connection of many insignificant and seemingly inconsequential events that is most interesting. Break the chain of events at any point and the modern 29ers and 650b bikes may never have evolved. The order of events look something like this:
For the first time in their history, Nokia start producing bicycle tyres at a newly built vehicle tyre plant. Geoff Apps is already on the lookout for large diameter fat off-road tyres. Meanwhile someone at Nokia has the idea of using the Hakkapeliitta tread pattern to produce specialist Winter tyres for bicycles.
Nokia start producing wide, large diameter snow and ice tyres. Probably to meet the needs of the Finnish Army?
Geoff Apps reads a cycling magazine article about winter cycling in Finland and contacts the UK importer of Nokia car and tractor tyres. They do not import Nokia bicycle tyres but he eventually persuades them to supply him with tyres.
Apps builds his first 650b Hakkapeliitta off-road bicycle.
Apps reads about Gary Fisher, Charlie Kelly and their mountain bike and makes contact.
Apps sends over the first of many Hakkapeliitta tyres, some 650b x 44mm (1 5/8") Hakkapeliittas. (This is size of Hakkapeliitta fitted to the alleged 1977 Ritchey. The 650Bx54mm tyres that Apps later sent would be too wide to fit that bike).
Late 1981/Early 1982?
The first 650b Hakkapeliitta mountain bikes are made in the US. In England Apps built the first 700x47C Cleland off-road bicycle.
Apps exports more Hakkapeliittas to the US including 650x54B and 700x47C tyres. More NorCal frame builders become involved in building Hakkapeliitta tyred bikes including: Ross Schafer, Lennard Zinn and Jim Merz.
Fisher/Kelly stop importing Hakkapeliittas from Apps.
Gary Helfrich and Bruce Gordon rediscover the 700x47C Hakkapeliitta. (At the time Ross Schafer's workshop was next door to Bruce Gordon's)
Charlie Kelly publishes a picture of a 700c wheeled Geoff Apps designed off-road bicycle in his "Mountain Bike Book"
Bruce Gordon, and Joe Murray? copy the 700x47C Hakkapeliitta and manufacture the copy in the form of the 700x40C Cheng Shin' Rock n' Road tyres.
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.
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"