Gravity bikes are somewhat of an enigma. No gears, not even a drivetrain to speak of. They’re usually cobbled together by enthusiasts at varying levels of professionalism. At one end of the spectrum you have those built by Gonz Lab and Gravitybike HQ (seen on our coverage of the 2012 Australian Custom Bicycle Show) and at the other, utterly rudimentary examples like this one.
They do, however, epitomise the purest essence of cycling: the closest that we humans get to flying, without donning a wing suit. Michael Webster-Saraiva lives in Portugal and out of an undiluted need for speed, built himself this ‘Frankenbike’ to bomb the ancient mountain ranges near where he lives. I was compelled to ask him a few questions about his creation:
Why did you want to build a gravity bike?
The past few years have been a bit of an ordeal as I have had hip problems. But my passion for bikes is so strong that I looked for an alternative to your conventional bike. I must confess that the bikes you featured on here got me thinking (Yasujiro, Monkey Likes Shiny and Brett Phillips’s GBHQ bike) so I looked around for other inspirations.
The “Speed with Guy Martin: Gravity Racer” also made me think… If you haven’t seen it you must.
As a small boy my uncle would drive me around on his Yamaha DT125, he would put a pillow on the gas tank and I would hang on to the bars. I used to love it! I can still remember the vibrations of the 2-stroke engine and the keys in the ignition bouncing arround.
My Dad also had some interesting fast hatchbacks.
I also live near the Estoril GP circuit where Senna won his first ever F1 GP back in 1985 so, as you see, all those things have influenced and fuelled my passion.
Plus, when you love bikes, who doesn’t like to go fast?
There is also something amazing about this type of bike… it’s the silence and peace of mind it gives you, almost as if you were flying.
How did you design it? Have you made one before?
After many hours of surfing the net and looking at motorbikes (especially board trackers) and many bicycles I started to draft an idea in my head. I made a sketch or two. Its shape is also the ‘function follows form’ ethos, so as I went along the building process I would adjust things. I looked also at the Moto GP riding positions, and skiers, for the aero position.
I’ve built a few other gravity ‘toys’: street luge, carts, and my son’s wooden balance bike.
I did try building a bike a few years ago but I just didn’t have the knowledge and the tools to make one.
Is there much gravity racing in Portugal? Where are some of the mountains that you ride?
In Portugal that I know of, no. There are some in Galicia (Spain), which is north of Portugal.
I haven’t had a chance to ride, due to my health situation, but where I live there are some interesting roads: Serra de Sintra is a very picturesque mountain. It’s a 15 minute drive from where I live.
About 40km south of where I live you have this mountain range. When I get better I intend to do a 20km long road at the highest mountain range called Serra da Estrela.
Where did you learn to braze steel? Have you built any other bicycles before?
My first experience with oxy-acetylene welding was when I was about ten or twelve. I started brazing this past year as I wanted to try different types of welding.
I wanted to attend some bike building course but they all are just out of my financial reach, so “why not try it myself and see what happens” — a bit like Graeme Obree’s philosophy.
So basicaly a trial and error method of learning, as like most of the things I have learnt. Kind of self taught man.
What components did you use to build it up? Handlebars, grips etc?
The brakes are HOPE M4 front and rear, they’re old school but a good old British brand, and they’re from Lancashire (part of the county where I was born). The rotors are Fibrax 203mm — also UK made.
The handlebars are generic aluminum ones from Decathlon, I got them because of the shape and they are inexpensive. I then bent them a bit more.
The grips and seat are made by me, using leftovers that I bought at a local shop that sells all sorts of leather and accessories used by shoemakers.
The forks, fork crown and frame were all handmade by myself. Some tubes where bought at a local hardware store, just mild steel. Other frame parts were salvaged from other frames I had.
I can’t help thinking of Burt Munro — “The World’s Fastest Indian” — and his garage-built offerings to the god of speed. Michael’s gravity bike may be crude and unsophisticated, but his eagle-like yearning for flight and experience of velocity is something that we all share.