Gravity Bikes, What's getting me started?

For the past few weeks I've been building my own personal Gravity Powered Bicycle. Until a few weeks ago I had never seen a gravity bike or even heard of one. So what got me started building one and got me so obsessed to go out and make a blog about them?
Recently while at the bike shop I work at my boss was talking to a couple kids that go to the local College he noticed that one of them was holding a longboard. So he commented on it and brought up the fact that he thought they weren't his style but he had a GPV that he made in the early 80's. Neither of them knew what a GPV was and I had no Idea either so off he went to retrieve it from the stores basement. After a minute or two he resurfaced with on of the most interesting bikes I've seen. He called it his Basin Racer basically he used an upside down BMX frame, some MAG wheels, and some very interesting modifications to various other bike parts. After he demonstrated how he road it and telling us his fastest time on the bike was 45mph (recorded) I told him that I had to get in on this (being the curious crazy ass that I am). After bringing it back to life with freshly greased bearings and new tire slicks we decided to close the shop early and take it for a spin for the first time in 20 years. We took it out to sandeo hill (the only hill within 20 mins of us) it has about a 5% grade the first run we did my boss hit 40mph and the second run he hit 46mph (beating his previous recorded record). So we went back to the shop and decided that we need to build me one so here I am building my first one to set my own speed records.

What's a GPV/Basin Racer?

A GPV (Gravity Powered Vehicle) in this instance it is in the form of a bike. These bikes have many designs and come in many different forms but proper ones follow these guidelines. No driving chain, cranks, sprockets, or chain rings. These bikes are solely meant for going downhill as fast as possible. The idea first arose in the early 80's in California back then it was something to do for fun guys would build their own gravity bikes from any random bike parts that they could get their hands on trying to build the fastest racer for the cheapest price typically from old BMX frames. There were many guys that would show up to these unofficial events and race what they had, basically there were no rules except race what you brought. Some had fairings, some had added lead to random parts for the extra weight. Eventually the cops found out and tried to stop it giving tickets to riders from impeding traffic for going to slow, speeding if going to fast, and no headlights for night runs. Eventually the gravity bike craze mostly died out. . . or did it?
In the late 80's BMXplus had an article about the craze which inspired many BMX riders from all over the world to ride. One rider (Jared Hanebrink) was featured in both the BMX Plus and later the Action Now magazines for GPV riding with his full fared gravity bike (No. 1, photos below). Dan Hanebrink became a big name for gravity bikes pretty soon after the beginning eventually riding his fully fared gravity bike in the 2000 X-Games when it was featured as a demonstration sport.



Photo's taken from an old issue of "Action Now" Magazine