Evel Knievel
Sun, December 2, 2007 
An American Icon died on Friday. On the last day of November he took his final jump into the next realm. What makes this man an icon? He was the first to do what he did, on the scale that he did. All who follow are merely imitators.
Evel Knievel passed on at 69 years, a relatively young age by today’s standard, but maybe not so young when one considers the punishment he put his body through over the years.
I don’t know what effect this man had on the sport of motorcycling, or motorcycle design; but I believe the design of bicycles, and the way they look today can be traced back to Evel Knievel.
The moment this larger than life character began appearing on television in the 1970s performing these seemingly impossible jumps, every boy child in America went out the very next morning and built some form of crude wooden ramp and attempted to jump on his bicycle, to emulate Evel Knievel.
The heavy cruiser bikes that had been popular through the 1950s and 1960s were too heavy for jumping, and the bicycle of choice for all young boys eventually became the smaller and lighter BMX bike.
Early BMX bikes were built with a brazed lug construction the same as all other bicycles. Soon manufacturers realized that these frames could be welded far cheaper than brazed lugs, because, after all, children are not interested in the niceties of lugged construction.
Fast forward to the 1980s and another entity is developing, the Mountain Bike. Initially a sport of “downhill racing,” hence the name mountain bike. Mountain bikes were also built, using lugged construction, with level top tubes, and using the same standard size tubes as a road bike. Head angles on early MTBs were a shallow 69 degrees; like I said, designed for riding downhill.
Move forward again to the late 1980s and a genuine mountain bike-racing scene had developed, just as there had been a BMX racing scene. However, not all kids became BMX racers, and not all adults who bought a mountain bikes used them off-road.
The generation from the 1970s who as kids had emulated Evel Knievel, were now young adults and saw the mountain bike as a reincarnation of the BMX bike. These people were not interested in racing or riding down mountains, they wanted to jump over stuff, and perform stunts, just like when they were kids.
I remember a proliferation of MTB magazines in the 1980s. Each had a picture on the front cover of a rider on a mountain bike in mid-air doing some seemingly spectacular jump. A low camera angle made it appear the rider was several feet from the ground, when in reality he was probably at a much lower altitude.
The magazines showed pictures of people “Bunny Hopping” on and off picnic tables, and performing all manner of spectacular stunts. With all the abuse these bikes were recieving, it became necessary for manufactures to “beef up” the frames by using larger tubing, as well as adding suspension.
Larger tubing meant that frames had to be welded, because there were no lugs available for the oversize tubes. Welded frames were not accepted on road bikes at that time, but MTB customers were used to welded BMX frames. There is something about the look of a welded joint; it has an “Industrial” look, utilitarian, strong and very masculine.
The first idea the mountain bike borrowed from the BMX bike was the “Uni-crown” fork. In reality, this is a “No-crown” fork, with the round fork blades curved at the top and welded directly to the steering column. Cheaper and easier to produce than a brazed crown fork.
By the mid 1990s manufactures had borrowed another concept from the BMX bike; namely the sloping top tube. With the resulting longer seat post, manufactures were able to get away with building less frame sizes.
Once this look and concept was accepted, it was not long before road bikes were being made in this same style with welded joints. Throughout history, bicycle manufacturers and framebuilders have used cost-cutting ideas, and then sold it to the customer as an advantage.
A classic example of this was the notion in the 1970s that braze-ons weakened a frame. Leaving the braze-ons off a frame saved a tremendous amount of time, and was a cost cutting ploy that was sold to the customer as a benefit. When braze-ons reappeared in the 1980s there were no wholesale frame failures. Where was the argument that braze-ons caused a weakness?
People can argue that a sloping top tube frame is stiffer, but the pros in Europe are using both level top tube frames and sloping; there is no huge difference. So if anyone has cause to wonder why a road frame has a sloping top tube? The main reason is that it benefits the manufacturer who has to produce less sizes.
The practice became acceptable because of the mountain bike. Mountain bike design was influenced by the BMX design; not so much by public demand, but by manufacturers realizing welded frames, built in fewer sizes is cost effective.
The BMX bike had a sloping top tube for no other reason than style. Just as the old cruiser bikes of the 1950s and 1960s sometimes had fake gas tanks. The sloping top tube of the BMX bike represented the upward slope of a motorcycle gas tank. Because after all as its name suggests, the BMX (Bicycle Motor Cross.) is a bicycle pretending to be a motorcycle.
The popularity of the BMX bike is closely linked to the popularity of Evel Knievel, which is why I say that he indirectly influenced the design of all bicycles today.
Just this one man’s opinion, and one that no one is obliged to agree with. It is an opinion that I have held for many years, at least since the late 1980s. I felt that I couldn’t let the passing of Evel Knievel go by without sharing my views.
Reader Comments (9)
You say, "The sloping top tube of the BMX bike represented the upward slope of a motorcycle gas tank". The only sloping motorcycle petrol tanks that I can remember were the Harley chopper peanut tanks, none of which were used on off-road motorbikes. The BMX bicycles, as you say, were based on Schwinn Stingrays, which were a kid's bike with 20 inch wheels. So they were small bikes to begin with, and ridden with the saddles set very low (still the BMX style today). So, sure, the top tubes were low and sloped upward to get to the steering head. American bicycle frame design (1930 to 1960) used curved top tubes which sloped down in back, like beach cruisers of today.
Over the years, I became very sensitive to both motorcycle and bicycle handling as affected by the vertical mass centre of gravity. Low motorycles (Ducati Singles, rigid frame Brits) seemed to me to handle the best. Nowadays, bicycles with the mass concentrated low, appear to me to handle better than top-heavy bikes. This is confirmed every time I load up my bicycle-mounted milk-crate with groceries. I pack heavy items low and forward, else my handling goes to pot. I feel (or imagine) my Mixte and compact frame bikes handling better than my Peugeot UE-8, all else being equal.
My ramble is over. Thanks for some interesting reading, I especially enjoy your early exploits. :-)
Harv
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Am I missing something? Don’t all motorcycles have the seat lower than the gas tank, and the head tube is above the seat, so doesn’t that make the motorcycle frame and tank curve or slope upwards.
Anyway, I think you are missing the point, it doesn’t really matter why a BMX frame had a sloping top tube, the fact is they did, for whatever reason.
Rob.
Unfortunately, one of my friends lost all his front teeth when his front wheel came off his modified/greatly-extended front fork in mid-jump. I think he learned about fear that day.
I don't know when the BMX bicycle began to make its appearance, but it was well after my dreams of jumping the Grand Canyon were well behind me. As harv above said, BMX bike frames and wheels have always seemed too small with low-set seats for me, a tall gangly kid, as they never looked particularly comfortable to me.
But by then, I was tooling around town on my Kawasaki dirt bike -- just barely street legal, of course. And even more amazing on the bigger dirt bumps east of town.
Decades later, as a growed-up adult now full of fear, I returned to cycling. And still, every now and then, I'll take my carbon-framed road bike over some sweet jumps next to the local bike path just to remember the Good Old Days of Evel Knievel and fearlessness.
Anyone who has bailed out on a technical trail and ended up straddling the bike frame with both his feet on the ground is very happy to have the extra crotch clearance.
My chief complaint about my beloved Surly Pugsley is that it doesn't have a sloping top tube like my other off-road bikes.
And while I can appreciate the artistry in old-school lugged frames, I appreciate the efficiencies of manufacturing techniques like TIG welding. Nothing wrong with a solid design that keeps bikes cheap enough that I can afford to own more of them.
I'm one of those boys who destroyed an old Schwinn by jumping it off a ramp in my yard back in the '70s. I wish it had been built half as well as my Specialized Epic!
I'd like to extend your comment about sloping top tubes being a way to make fewer frame sizes. I think we have also been programmed to believe that 170mm cranks fit everyone. In years past you could buy quite a range of lengths but now, the high end component manufacturers only make 170-175mm cranks (with a very few exceptions like TA) to go with the one-size-fits-all frame. In comes the BMX world again: I have resorted to BMX cranks to better fit my 5'3 wife.
Thanks again,
-Rob
Not a lot of riders could have done what he did with that equipment.