Joe Breeze on Repack - courtesy Wende Cragg (Rolling Dinosaur Archives)

Looking for new thrills and a change of pace from riding the local roads, these avid cyclists took to the wilderness on single-speed bicycles with balloon tires and coaster brakes – usually old Schwinns from the 1930s and ’40s. They’d ride or push these 45-plus-pound beasts – affectionately known as clunkers, ballooners, bombers, fatties or fat-tire flyers – up the hills, then blast down the treacherous slopes at death-defying speeds . . . just for the thrill of it. Despite the seeming madness of this behavior, the clunkers of Marin were not alone in their antics. About 75 miles to the south, another group was doing much the same thing in the hills around Cupertino. Dubbed the Morrow Dirt Club (after the Morrow coaster brakes typically found on their fat-tire bikes) the Cupertino riders took their ballooners a step further by grafting on 10-speed derailleur gearing, thumb-activated shifters, drum brakes, motocross handlebars and motorcycle brake levers. These modifications enabled members of the Morrow Dirt Club to ride up hills, as well as down. Surprisingly, given their geographic proximity, the two groups continued their two-wheeled adventures completely unaware of each other’s existence for some time. It wasn’t until December 1, 1974, at the West Coast Open Cyclo-Cross Championships in Mill Valley, California, that the clunkers of Marin and the Cupertino riders crossed paths. Cyclo-cross is a European type of off-road circuit racing in which riders must occasionally dismount and carry their bikes to surmount obstacles – sometimes as much as they ride them. At the time, the cyclo-cross mount of choice was a traditional road bike with narrow tires and drop handlebars, but riders could compete on any bike. For the ’74 Mill Valley race, several members of the Morrow Dirt Club, headed by Russ Mahon, brought their modified ballooners to give the race a go. Also at the event were four cyclists from Marin who chose a more traditional form of participation: Gary Fisher and Otis Guy raced their cyclo-cross bikes, and Charlie Kelly and Joe Breeze watched from the sidelines. While these names are no doubt familiar to anyone with more than a passing interest in mountain biking, in 1974 they were just four local riders out for a day of sport.

When the Marin contingent spied the modified clunkers of Russ Mahon and the other Morrow Dirt Club riders, their interest was piqued: These were by far the most advanced balloon-tire bikes they’d seen to date, and they immediately recognized the potential for their own mountain bombers. Unfortunately, the two groups had no opportunity to compare notes. After the race, Russ Mahon and the Morrow Dirt Club returned to Cupertino and essentially disappeared, not to be heard from again until 1994. The same cannot be said of Joe Breeze, Charlie Kelly, Otis Guy and Gary Fisher, who left the race inspired by what they’d seen, and excited to discover that the interest in clunkers extended beyond their area. They began modifying their own clunkers . . . and then kept going. What followed was a regimen of rigorous field-testing (also known as having fun) on the trails and fire roads around Mt. Tamalpais in Marin County. With each new design or modification, the Marin riders would head out for more testing. The Cascade Canyon fire road, just west of Fairfax, proved particularly suited to this activity. Plummeting 1,300 vertical feet in just over 2 miles, the twisting and often precipitous descent provided the ultimate field test for both bicycle and rider. CONTINUED>>> go to page 2