blazingpedals said:
Whew! I need a break from the idiocy of the 'who's faster' threads. Tyler, what kind of bike do you ride? Homebuilt? Details of your USS!
I agree completely. I have added a few of those folks to my ignore list. It's a shame because they might have something useful to say but i don't feel like wading through all the childishness to find it.
I have an old "hypercycle" which is sort of a toy recumbent. I bought the frame and built it up about 20 years ago and then made some modifications to the drive train make it quieter, smoother, and improve chain control.
Here is a recent photo of my neice riding it. You can't see a lot of the bike from the angle the photo was taken.
hypercycle
The seat position on this bike is rather forward, so the steering is an almost normal set of handle bars that go right into the steerer tube on the fork with only a little backwards sweep. The hand position puts the backs of your hands facing forward, just adjacent to either side of the seat. I can u-turn on this bike in the width of a sidewalk! I have some ancient sun-tour bar-end shifters and some two-finger bmx bike brake levers mounted on the handle bars.
The drive train uses a single chain ring up front. There is an idler that I made from a rear wheel hub and freewheel (minus the pawls) that splits the chain into two sections- one for front and one for rear. The front chain drives a largish gear on the idler and the rear chain is on a smaller gear, so the front chain ring at 42 teeth looks more like 50 or so teeth (I have forgotten the actual gearing and the bike is at my father's house right now).
I had the 27" rear wheel built using a Sachs two speed internal mechanism, drum brake, and 6 gear freewheel, so I have 12 speeds available and a more than adequate brake for the rear end. I think the tire is a 1.125" fat-boy. The front wheel is a 16" wheel I had built from a cheap aluminum rim and an expensive racing hub (the only hub I could find at the time with the same number of spoke holes as the 16 inch rim). The front brake is a crappy bmx thing that was all I could find to allow cable clearance back in those days. It is a terrible brake considering how much rider weigth is over the front wheel.
The seat is a hard fiberglass shell that looks like a miniature version of a typical school desk seat. It has some dense foam padding glued on. The riding position is quite upright, and VERY comfortable.
Before I installed the idler gear in the drive train, there were two pulleys made from derailleur jockeys to lift both the top and the bottom of the chain. I experimented with a split chain ring that I made by cutting a chain ring in half and then mounting the two halves on an aluminum plate that I cut to mount in the crank. It was sort of extreme- If I recall correctly it started as a 42 tooth ring and I turned it into a 60+ tooth ring. I oriented the long axis of the chain ring so that the maximum gear ratio would occur at the top of the pedal stroke when legs are bent and ready to push hard. At the bottom of the stroke the ring was at minimum gear ratio allowing my legs to snap through to the next power stroke. I used that ring on a 75 mile ride from Tecate to Ensenada, Mexico one year and never stopped on the whole length of the ride including some very long moderate grade ascents up mountains. It felt like climbing stairs. Once I installed the idler, I was no longer able to use the split chain ring so I retired it to a box in the garage.
This bike has a lot of limitations- I don't care too much for the hard shell seat, especially for long distance riding. The short wheel base makes for some really fun high speed turnability, but the fork rake and weight distribution make the steering unstable for no-hands riding. If you very lightly put a couple fingers on the steering and let it do what it wants, at any speed over about 10 mph it starts to wobble. It only takes a light touch to stabilize it, but I'd prefer something that is inherently stable.
I am in the early stages of gathering tools, materials, and reading on the process of building frames using carbon fiber. I will start with something simple- probably just a swb, rear drive bike with over seat steering. After I make some mistakes there, I'll try for the final format. I am hoping to ultimately make a front wheel drive, mid height, short or mid length bike, USS, and maybe with suspension on at least the rear end. Right now I am thinking about 20" wheels front and rear, but may go bigger on the rear depending on the drive-train configuration.
For front wheel drive I want to try to put in a universal joint to allow the front wheel to steer independent of the drive. Check this site:
FWD.
I also like this drive mechanism a lot, but I do not have the necessary machine tools or the budget to have something like this made:
lucabike. I especially like the way the pedals/cranks are driven in an eliptical path by the gear belt. Very elegant!
That's it. I showed you mine, now show me your's!
TD