Tuesday, August 18, 2009
sexiest bike concept EVER
D: fuzed some upright designs into 'bent bike.
1) that style of upright
2) steering from Triton trike
3) mid steer from Python DIY
But mixed together, man, that would be one sweet ride!
This design can go with 20" wheels where my concept cannot.
I was just gonna put the pedal crank thru the front wheel axle.
Sufficient road clearance pretty much dictates 24-26" wheels.
And that pretty much precludes a lowracer, if only to see over one's own knees.
A problem with 26" wheels is for people with short stature to stop and steady the bike.
The Orca is a good example of this problem.
D: note how the body suspension pivot point pretty much cries out 'internal gear hub'.
Leaving the wheel hubs naked, or for...
The right hub depends on the rider, his planned type of ride, and the bike gearing.
I'm pondering chain efficiency.
This favours the largest chainring possible.
But then we face a weight penalty.
Having 2 medium sized toothed chainrings/cogs is likely a decent compromise.
Keeping the chain taut is tricky if the front boom is not adjustable.
A slight pivot, even with an internal-in-frame chainline is doable.
You'd wanna switch from square to rectangular tubing for that.
And it still works better with a frame pivot point and embedded gear hub.
A taut chain is important for effiency.
I was pondering how a FB GM (Flevobike Green machine) layout could be made at home.
I think the frame will try to twist sideways.
The front and rear parts are both off-centre, to work around wheels.
In my case, the front boom is on say the left, and rear the right.
I looked at Fuller's 'octet truss'.
This can be simulated somewhat by welding triangular cross struts in a left-right layout.
I'm sure a weight sweet spot exists.
D: I had the chance to try an electrical power assist last weekend.
It was a lithium bionx unit.
Nice assist, but wow does full assist ever drain the battery fast.
D: a bike frame starts running out of places to attach widgets in a hurry.
I'm all about the fold out baskets.
Even so, they preclude use of a luggage unit - a pannier.
A bent bike might favour some attached under the seat and beside the rear tire.
Posted by Dino Snider at 9:47 AM