18/16 Speedway bike

[RockabillyRobbins]

While in Colorado I met a guy who owns a bike shop and was very interested in our " odd style of bikes" and asked me to keep him up to date on my builds...which I(that day) had none of...until the gears in this twisted little mind got turning. I was trying to think of what I had laying around the shop to use in this build and then it hit me-combine two old BMX frames (one 16'' and one 18'') and make a stretched speedway looking thing. My idea is a mixture of Gaskill's "Dead Little Dove", a boardtracker and a saltflats style record breaker. This is all I have since I won't be in the shop again until Tuesday night but I just wanted to start showing everyone my idea but this is just a VERY early draft and is NOT to scale in any way ...

 

[mastronaut]

Like this you mean?

viewtopic.php?f=37&t=22230

 

[RockabillyRobbins]

Yeah, pretty much the same only mine will have all three wheels rolling and I'll probly do some more bodywork but gaskill's is definitely a huge influence(not gonna be a copy cat though)

 

[udallcustombikes]

Are you going to have any suspension in the frame? I have tried a couple of different ideas using 3 inline wheels and there a couple of issues I have run into.

1. With all three wheels being level, any time you encounter a bump, hill, ditch or any incline one of the wheels leaves the ground. If I am reading your drawing correctly that means you loose steering, drive or brakes. :|

2. Wheel drag when turning. Two of the wheels will follow the arc of the turn while the third will get pulled sideways.

I'm not trying to dog on your design, just throwing a couple things out there that I have run onto.

 

[RockabillyRobbins]

Thank you for your input, I think I've got decent solutions - 1.As far as all three wheels being level I have since changed the design to have 20'' in the front and back with a 16'' in the middle to bring the bike's stance to look somewhat like a V...sorta.
2.The front two wheels will function just the same as on a normal bike and the third wheel (rear) will be stationary (welded) and will not be able to go any way other than straight. Plus this bike is mainly gonna be used for downhill or drag style racing Again,thanks for the input

 

[mastronaut]

So you're saying you don't need steering or a brake just a drag chute? 8)

 

[deorman]

I agree with Udallcustoms, at least one end needs to be suspended for that to ever work, even in your application. :|

 

[RockabillyRobbins]

I'm sorry but what do you mean by suspended? probly something really simple that I'm not catching... And no I think I'll be rolling Burt Munro style "He's got no brakes and he's got no parachute" 8)

 

[mastronaut]

Hehehe :lol:

 

[deorman]

Hinged or sprung. :? The plane of the wheels relative to the plane of the ground doesn't form a straight on a turning bicycles therefore you turn. In order to able correct balance and direction, You need to allow the wheels to change "height" in relationship to the ground. It will still drag, even on a perfect ground if you're not going dead straight, unless both front and back tire turn together. :|

 

[RockabillyRobbins]

Well I'm home now and I did an early mock-up. Looks like with a few minor adjustments it will roll by Christmas day Thanks for the help deorman.

 

[IronSpadeCycles]

Who was the guy in CO that owned the bike shop? I lived in Denver for 14 years and helped start the Denver Cruisers back in 1999. I'm just curious who you were refering to.

Later Travis

 

[RockabillyRobbins]

The guy's name was Jerry Siegel. He owns a place called Mountain&Road Bicycle Repair in Idaho Springs. Oh and I finished the bike. Will put up pics when I get home New Years Eve.