Whilst searching for some geometry for my old Gary Fisher Paragon Genesis Paola Pezzo frame i stumbled across this:
http://www.vintage-trek.com/Trek-Fisher-Klein-Lemond/2001specmanualFisher.pdf
Its common knowledge that Gary Fisher was pushing for the 29er wheel size from way back, and that his Genesis geometry was likely the first step towards the long low slack approach that we have now.
I thought i’d share the find dated 2001:
Gary rides. A lot.
Gary Fisher does a lot of bike riding. He has for years. He holds the RePack record, and won the National Championship for Masters in 1997. Basically what we’re saying is this; Gary has skills.
Inspiration doesn’t always come easy So one day this skilled rider is out for an epic ride on his fave bike. He’s cruising down a hill, not terribly tricky or anything, when he gets one of those free flying lessons and as he’s laying on the ground he’s wondering “What happened?”. So he picks himself up off the ground only to find that he’s broken his wrist. Not a big deal, but nothing he really wanted. During the next few weeks of recovery Gary has time to think about his little accident and the bike. And that’s how Genesis was born.
Whu’ happened?
Gary analyzed the accident. He had simply been too far forward and pitched over the front wheel. The pivot point of his flip was the front axle. If the axle were further forward, he might have stayed upright. Gary has worked on geometry for years. He even had a fully adjustable bike. It had adjustable dropouts so you could change the wheelbase, chain stays, or fork rake. It had an adjustable head tube to change the head angle. Basically, you could try any geometry you wanted as long as the top tube stayed the same length. Using that bike, Gary developed what we now call “classic NORBA geometry” with a 71 degree head angle and 73 degree seat angle. From all that experimentation Gary knew that changing the fork offset or head angle to move the front axle would make the bike handle poorly. The only way to get the front axle forward was to length en the top tube. But he didn’t want to move the bars forward and change his position. He’d have to use a little short stem.
Gary defies convention Common knowledge said that a short stem would handle weird. In a typical unconventional Gary Fisher way, he ignored common knowledge and built a prototype with a really long top tube. Instead of a 135mm stem, Gary had to use a 75mm stem. This setup added 60mm of top tube, moving the front axle 60mm forward, almost 2 1/2 inches. And it worked!
This first prototype was a revelation. But Gary knows the bike to be an organism, where every thing affects everything else. He had developed enough frame designs to know that he had just scratched the surface and that every dimension on the bike, from chain stays to seat angle, could ben efit from the increased front center. But instead of telling you that long story of test riding and proto types, let’s just skip to the finished Genesis frame and what defines it today.
Genesis features and what they do for you
The primary benefit of the long front/center (distance from the bottom bracket to the front axle) is stability. This certainly helps in conditions like those that caused Gary to crash. But the long front/center makes the bike more stable all the time.
Short stems and their effect on steering
The shorter stem used with Genesis geometry puts your hands closer to the steering axis. Steering can be done with your arms instead of a sweeping sideways movement of your shoulders. Your hands can move faster than your shoulders, so technical steering is precise at high speed. pushed further ahead of you. Anytime you find your self moving back on your bike, its in response to your body wanting to flip over the front axle. This happens on steep downhills, and also any time the bike is mov ing at high speed in rough terrain. With the front axle moved forward, there is added resistance to over-the bars flight. You’re more relaxed at speed, and since you’re more in the saddle than behind it, you’re in & Centered between the wheels On a bike with a long front-center the front wheel is better pedaling position to keep the power on.
How does it climb?
Common sense tells us that a longer front center places less weight on the front wheel. Intuition tells us that with less weight on the front wheel, the bike might not climb well. But geometry charts only tell part of the story, and Genesis bikes actually climb very well. Here’s two reasons why: with a shorter stem, your shoulders stay more over the centerline of the bike, even when turning. When your center of gravity stays over the frame centerline, the bike stays in better ball ance. With Genesis geometry, its even easier to hold your line on steep, slow speed climbs. Secondly, when climbing hard in first gear any bike will respond to the the pressure of pedaling. Imagine if the headset were placed in the middle of the bike, right below the sad dle. The bike would hinge in the middle, between con tact patches of the tires. With every pedal stroke the rear wheel would turn away from the pedaling force. As a result, the front wheel would turn toward the pedal side, and the bike would swim like a salmon heading upstream. But the further ahead you move the pivot (headset), and the closer to your hands, the straighter the bike will climb. With the shorter stem, you stay over the bike, and the bike tracks straighter, making it einb very well indeed.
Short chain stays
Genesis bikes use ultra-short chainstays. This positions the rear wheel more directly under your butt. With more weight on the rear wheel, you get better traction uphill, and the tire bites better when you apply the rear brake. Short chainstays also moves the pivot point for doing wheelies. With a Genesis bike, you can easily lift the front wheel when its time to bunny hop a water bar or climb over a small log
Steep seat tube
Genesis bikes, like most Fisher models, have a steep seat tube angle. The duty, and the effect, of the seat angle is to place the saddle where the rider needs it for support when seated pedaling. The seat angle also interacts with the top tube length to describe the posi tion of the head tube relative to the bottom bracket. For every degree of seat angle, the top tube is com pensated about 10mm. In other words, for every degree the seat tube is steepened, the top tube becomes about 10mm shorter. When comparing geom etry charts, a bike with a steep seat tube may look like it has a shorter top tube than it actually does.
The function of the steep seat tube is to place the rear wheel more underneath the rider. This is useful when the rider transfers from a seated to a standing position. As the rider moves from a seated to a stand ing position (or the opposite), they do not have to move as muoh to maintain traction. It becomes easier to ‘attack’ a limb.
Who’s it for?
The features of Genesis geometry were dreamed up by Gary Fisher, for his own riding. As we point out in “Gary Fisher: A History” on pages 24 and 25, Gary has done a lot of racing. But the same benefits that get a racer around a course faster will also add pleasure to a leisurely ride on the weekend.
Genesis bikes are more stable, especially in more technical terrain or on steep downhills. Genesis bikes allow quick, precise steering. Genesis bikes climb really well, especially for those who like to stand out of the saddle.
With these features, Genesis bikes offer a superior ride to anyone looking for performance off the pavement.
The link also has some kind words to say about Reynolds 853, has a section on tubeless, women’s fit, oversize headsets (remember the Fisher Evolution 1.25″!), frame materials.
Certainly had foresight & his finger on the pulse of our sport.
It’d be interesting to hear him & Chris Porter compare notes.
