My 16" Python Recumbent Project - "Cherry Bomb"
This project is my take on the center-steered, front-wheel drive, recumbent bicycle inspired by Olaf Johansson's Monty recumbent bike who drew from Jürgen Mages Python who was inspired by the flevo-bike.
Design Plans
- Dimensions:
Wheels - 16"
Overall length - ±56"
Overall height - tbd
Ground clearance - tbd
Drive train - Sachs Torpedo internal 3 speed - Color/Accessories:
Finished to be ivory powder coat (if budget allows, otherwise automotive paint) with Cherry Red accents/lettering. Fenders to be constructed out of cherry wood (hence the name). - Raw Materials:
±20" - 1 1/2" x 1 1/2" x 1/8" square tubing from local metal supplier - paid $29 for 10' of this plus 4' of bar stock below (extra is for my next project :) )
1' - 2" x 3/16" bar stock from local metal supplier
1 - Raleigh child's 16" bmx bike. Using front wheel, back wheel, front fork. $6 from Goodwill.
1 - off-brand child's 16" bmx bike. Using front fork, steering tube. $0 from Uncle
1 - 30+ year old Dahon folding bike. Using rear hub, crank and gear. $10 from Thrift Store in Sunset Beach, NC
1 - found trash mountain bike. Using bottom bracket shell, chain stays, and maybe the seat tube. $0 found in trash missing rear dropouts and steering tube.
1 - gooseneck from an old 10 speed found and removed from the Cuyahoga River. $0 found in the river
1 - 10' length of 1" electrical conduit from Lowe's. $7Braze-ons - water bottle and cable stops. $7ish from Nova Cycles
Progress
Prety much all of the parts have been gathered. I had a difficult time deciding what would be used from my old bike collection. I get attached to unique bikes and hate to cut up bikes in good shape no matter how little I paid for them.
The Dahon folder is the most difficult. This poor bike has been through the wringer. I bought it all siezed up after sitting in salty sand for who knows how long. The frame is in ok shape, but the hinges are starting to go (as far as I can tell, the bike is from the early 80's). This bike was built with good quality parts, though. It has a Sachs Torpedo 3 speed hub. When I got it, it had a nasty layer of salt/sand/chain grease all over it. I then rode it around for 6 months after squirting some WD-40 in it to loosed up the shifting mechanism. When I finally pulled it out, it cleaned up and looks like new. The insides had old thick grease in it, but it was clean - no sand and very little wear. I cleaned it up and lubed it with some heavy oil and Lucas oil additive and laced it into a 16" rim. The spokes from the original hub just fit.
To the right is the front end laid out. You can see where I had to heat up the fork at the top to open it up a bit so the hub would fit:
01/02/2007
Started this page today (notice the lack of dates previously). Yesterday, I removed all the seat stays from the mountain bike, did some measurements and created a fairly accurate scale drawing to go by. I also cut out square tubing for the front frame. The drawing will give you an idea of how the whole thing should go together.
01/05/2007
I finished cutting out the main frame pieces today. Everything is cut and fit, but still needs welding. I'm working on picking up a welder (I also need a conduit bender). Here's a photo with the general layout:
I don't think I'll have to sacrifice the folding bike after all (other than the rear hub). After Looking over all my pieces and parts, I think I'll have what I need.
The steering hinge will be made of a steering tube and a homemade bracket. I had to heat up the front fork to bend it open a bit so the drive wheel would fit. I may need to bend it a little more.
06/24/2007
Things have finally calmed down a little and I've picked up a welder. For the past week and a half, I've been furiously cutting, grinding and welding pieces together and have come up with a rideable bike! You can see the video to the right. I will post nice close up photos when it's totally completed.
I've had a chance to practice on it for a couple of hours and am surprised at the progress I've made with balance. It's pretty twitchy and not at all like a standard upright bike or any recumbents I've ridden. Leather gloves are a musti (for the landing gear), but I find I am using them less and less. I broke a weld while practicing, so I need to do some repairs - this is my first welding project, so most of the welds are a little rough. They are getting better.
Refinements:
- Fix any crappy welds and grind and wire wheel all welds
- Make the seat stays in the back bolt-on instead of welded on
- Add some sort of rubber or plastic to the bottom of the pivot bracket to keep from scuffing everything up when it falls over
- Add some gussets to high stress areas
- Lighter plywood seat (instead of 3/4")
- Better road tires
- Lose the caliper brake in the back
- Figure out a better mount for the gear shifter
Still to do (once I get good at riding):
- Remove the rust from the rear wheel chrome
- Shape and pad the seat
- Paint!
07/24/2007
I've gotten pretty proficient at riding, but the faster you go, the more unstable it is. I'm not comfortable with more than just tooling around. I plan to remove the 3-speed wheel and replace with a single-speed. It's just for cruising around the parking lot with the kids - more of a novelty than anything else.
I fixed up the seat mounts and got ride of the superfluous rear brake. I've also fixed up some ofthe welds.
Paint is going to wait until I finish some other projects so I can do them all at once. Other than seat padding, it's done!
I'm happy to answer any questions or even take some detailed photos as long as you email me a photo of your finished project. :)