Certainly there was a formula and AB's website explains it very well. If you start to geek out on it too much you can even see how the formula changes through the 70's as the riders determined what worked best. The early bombers giving way to the hybrids that could actually be ridden up the hill. First old balloon bikes with road bike parts grafted on. By the late 70's the BMX cruisers appeared supporting a wonderful new source for parts. With the BMX 26'ers came aluminum rims from Ukai and Araya. A huge improvement in weight savings and stopping power. In steps Joe Breeze with his now famous first mountain bike specific frame. Followed closely by Tom Ritchey at Gary Fishers/Charlie Kelley's request. Mike Synard got on board and by 1983 there were Mountain bikes for the masses. Before 1981 the odds were you had to live in Ca. and drop a lot of money for a custom built mountain bike ($1500 +/-). This changed a little in 81/82 when Synard imported about 1000 bikes that could be had for the reasonable price of $750. In 1983 Synard imported 40,000 Stumpjumper Sports that could be had for the low low price of $499.
So unless you were ready to drop some big bucks and lived in Ca. , I think the Klunker phase was going strong until 1983. After all how many of us in the early 80's were actually willing to pay $1500+/- or even $750 for a new bike to ride in the dirt.
Kinda a brief paragraph skipping a lot of other tangents like Jeffery Richmond, the Koskis, Lawwill, VVA, etc... but I tried to keep things short.
If you look at old video and pictures of these vintage rides, one thing is for certain. People were riding what they had and everything from road bikes, balloon tired bikes, to kids stingrays were being used.
Ride what you got, if it breaks, oh well.
A few of my early Mtn bikes mostly posted here before. Some complete most not:
Project 39 Schwinn. This will be completed with pre 1980 parts Tandem drum hubs:
Schwinn DX with a mishmash of road, motorcycle, and BMX parts:
1979 BMX cruiser converted to Mtb. This frame could be had for $350 bitd. Th rest was up to your imagination:
1981 Ritchey Everest. Hand built frame. Certainly one of the first Mtb. specific bikes ever made. Still a mishmash of road and BMX parts:
1983 Mountain Goat. The first year Shimano and Suntour came out with MTB specific components. Formula established for mass production MTB's. "Klunkers step out stage left". Bike at time of pickup, now collecting proper parts :
