From Openbike
Jump to: navigation, search


Intro First of all i have to beg your pardon for my english. I´m untrained because it´s a long time since i was in school ... (Thanks to David M. helping me to correct many mistakes !)

OK, in spring 2006 i discovered the "Python"- Lowracer while searching the Internet for some Infos about Flevo-Bikes. I was immediately fascinated.

I want to document the construction of my python-bike on this page for everyone interested. Suggestions and comments are welcome ! My mail adress is stephan(at)schoeling.net


Summer 2006 My first step was to read every information I could get, e.g. the mailing list and Jürgen Mages Pages at [1]. I started to collect Bikeparts and MTB-Frames and saw then apart. The third frame brought a Bottom- Bracket useable for steering. Then I began to plan the geometry of the frame. I decided to build a Z-Frame finally. The front- and back-frame are parallel and the mid-part has the angle of the seat. This is for optical reasons only, i just like it. To get the rectangular tubing is not easy here, so i use only quadratic profiles. I know, that is not perfect, but i cant´t get 30x10 or 40x10 anywhere. I hope the quadratic profile will also do fine.

2006-9-21 I bought a used Lowracer Seat and a new Seat-Cover. Now there´s no way back.

2006-9-29 Today i have made first cuttings. The Front-Bottom-Bracket (BB) was cleaned from the rest of the old tubes and weldseams. I decided to draw a scale 1:1 plan of the front-frame and the steering pivot. I fear I wont be able to build the frame exactly enough without . (2,5 h)

2006-9-30 I draw a 1:1 plan of the front-part last night. I have a new problem now. It not seems to be too wide at the front BB (thanks to Juergen and Joao), but at the steering BB (SBB) ! Its really too wide ! I have to make a bevel cut like Joao Preichardt shows on the pic with the red background on his website. Today i didn´t spent much time in the workshop because the weather was too good. I did some more cuttings and cleaned the SBB. (1,5 h)

2006-10-2 Although I get an offer for 40x10 Material yesterday i couln´t wait. I did the last cuttings using my 25x25 material. I decided to make one more cut for a turn near the SBB to get an 90° angle there. The Front frame is ready to weld now. Tomorrow we have our national-holiday here in germany. I want to try to weld the front frame. Let´s see if it works or if I am completely frustrated tomorrow evening. Sorry, no picture today. (2,0 h)

2006-10-3 Not completely frustrated, but welding isn´t easy. My electric Welding-Machine is a very cheap one, that´s not very helpful for beginners like me, i assume. Both parts of the Front frame are a bit twisted now, because of my bad welding. Hope its not too much for using them. Now, a Python Builder who lives not far away gave me adresses of metal-shops , so i know where to get 40x10x1,5 Tubes now. Thank you very much, MS ! After the welding-experiments with the 25x25 tubes I will buy the rigth tubing and build a new front frame. No Pictures again. (2,0 h)

2006-10-12 I bought the 40x10x1,5 Tube. Decision: I will copy the geometry of Jürgen Mages P3, exepting the length of the distance SBB - FW-Axle due to my longer inseam. Cutting the two Tubes for the new Frontpart. Tack-welded the dropouts. Adjusting everything took a very, very long time. I think it would be easier to make the Front part with a gauge, maybe a very easy one, made of a wooden plate with some stops. (2,0 h)

2006-10-16 Cuttings 10 cm of the FW-Axle Fixed the wrong (SBB-) Side (see Photo) Adjust everything again Fixed the right (front-) end with a rod weld a plate as fender-holder between the insides of the tubes (1,5 h)

2006-10-17 Cleaned the SBB shell again, cause its rusty after some days without protective oil :-( The SBB will not fit between the Tubes without making 2 more incisions on both sides. Adjusted the SBB and everything else again. Welded the additional incisions and tack-welded the SBB. Not easy to weld because the fender-holder bugs. Next time i will weld the SBB first, then the Fender-holder. (2,0 h)

2006-10-18 Incisions at the frontside (10 / 17,2 cm), the second incision is too big, this shurely will cause troubles with welting it. Adjust the both tubes and controlled everything again. Fix the Tubes with srew clamps. Weld the incisions. As expected there are troubles with the one bigger incisison.

My welding skills are improving. Most seams are acceptable, i think i can show them in public without causing a sudden death of every welding professional who looks to my bike. (2,5 h) 2006-10-20 Cleaned the BB-shell againbecause its also rusty after this long time without protective oil. Adjust everything is easyer here. Checking the chainline and the wheelposition. Tack welded the BB. (2,0 h)

2006-10-21 Frontframe is going to be ready today. I got a new welding machine borrowed from my friends father. Thank you very much for this, its much better then my machine. Its more powerful, but its easyer to use. I would describe it as more softly in use. (1,5 h)

2006-10-23 Completing the frontpart with wheel, gearshifter, cranks,chain and .... IT WORKS ! IT WORKS ! IT WORKS ! (1,5 h)

2006-10-24 The cantilever-sockets are my work for today. I cutted them from an old MTB-Frame, cleaned them and prepared them for welding. For my next Bike i shurely will buy some new sockets, because the work i had with them was too much for this little peaces. The problem is that the rests of the round tubes of the old MTB dont fit to the rectangular tubes of the frontframe. I welded them to the underside of the frontframe and mounted the Canti-Brakes. Frontpart is ready to use now. (1,5 h)

Canti-Sockets Brakes Brakes

2006-10-26 Today i had some deep thoughts about the SBB. I want to have it separable, like Olaf Johanson has done it at his Monty. I invented the "Matchbox-Lock" for my Steering-Pivot. Have a look to the Pictures: You see a fork like Monty has, but the ends of the BB are stucked in. Its a very rusty peace, i found it at my friends metal dump. But it is nearly perfect for that, cause it has the right thickness to fit into the "Matchbox". I will clean it before welding it to the rear frame. A device, wich fits exactly around the fork-end holds the crank-holders in position.I made it from a waste piece of the 40x10x1,5 mateial,which was used for the frontpart. It can be slided away like a Matchbox for dismounting the Frame. (2,0 h)

Matchbox-Lock Matchbox-Lock Matchbox-Lock

2006-10-30 Two M5-screws on both sides of the Matchbox-Lock at my steering-fork are holding the Matchbox in closed position. For dividing the Frame, i have to unscrew them, open the Matchboxes and the frame falls into two parts. (0,5 h)

2006-11-2 Today i have prepared the two pieces of the rear end of the Frame. Its made of 40x10x1,5 tubes, like the front part. I have no useable dropouts, so i made them by cutting the tube like shown in the picture, drilling a hole and cut away the tube for giving the wheelaxle a seat. Hope this will be stable enough. I will do it better next time. The inward bending isn´t enough, there has to follow a second one outward to make the rear end fit to the middle part material (30x40x1,5). (2 h)

rear ends rear end rear part w 2nd cut

2006-11-9 At the first photo you can see both bendings and a peace oft the Middle-part-tubing. The second shows the fender holder, at the third take i already have welded the parts together and fixed the wheel. Details on photo 4. (2 h)

rear part with 2nd cut fender holder rear part with wheel rear part fixed

2006-11-15 Prepared the sockets of the Brake or the rearwheel. (1h)

brake parts

2006-11-16 The middle part has to follow the shape of the seat (I already bought a seat). So i made some triangular cutings and welded the tube together. After that i welded the steering "fork" to the Middle part. (2 h)

v-cut in Middle part middle with link

2006-12-13 In the last few days i only welded the rear part. I have started with the last things to do today. I have to assemble the seat and the handle bar. Today i want to fit the seat. First I checked the position of it. Then I cut 2 pices of the 30x40 tubing and fold the walls inwards. After that i drilled holes of 10 mm diameter for an axle which holds a bracket fitted to the seat. Welded the 2 seat-holder to the Frame. 3 Problems: I welded the rear seatholder to the wrong place, the seat is too close to the frontwheel and there ist not much space for the screws which fit the seat. The iron saw solved the first problem, a pair of new holes in the seat the second and the third is added to the "better next time" list. (2,5 h)

Rear part with wheel Rear part with seat seat holders

2006-12-15 Welded the rear seat-holder to the Frame again, now at the right place. Welded the holder for the handlebar. Fitted Seat and handlebar. Assembled the frame and


I took place at my new Python the first time.

Python Python front left Python front right Python back right

After sitting about 15 min. and rolling back and forth a bit, i would say, it have found a nice angle for the seat and a good place for the handlebar. I´ll see if it is the same feeling on longer tours, than 3 m in the workshop :-) Next Sunday i will try to learn to ride this bike ! And there are some little things to do, like gearshifters, brakes, painting ... (2,5 h)

Total Time for building: 42 h DECISION: My Python bike is christened to the name "42" !

2006-12-17 Made the first attempts to ride the python.

What shall I say? If i hadnd´t seen a video where someone perfectly rides a python, i woudn´t believe its rideable at all.

What I have done today was "walking on my hands while sitting on a lowrider recumbent". Needed a lane of 6m (minimum) for that. The first 800 m i touched the ground about 1000 times with my hands. An elderly woman told me that she does not like that bike. "Dat fing isch ävver nitt jooot, dat Fahrrad", just for those who can understand german with a strong cologne-accent. We arranged to meet again in her street when i have learned to ride the bike. (Hmm, I need a new route to the supermarket for the next time) Then returned to the workshop for fitting the left pedal, both wheels and the seat again. I thought a kind of steering damper would make it easyer, so i squeezed a short peace of washingmachine-hose between the SBB and the steering fork. Its properly damping, but its not helpful.

Next turn: Nearly 2000 m of "handwalk while sitting on a lowrider recumbent". But only 1998 touches to the ground. Now i know pythons have a intense instinct of escape. Escape off the street, into the fields. I managed to ride about 25m without touching the ground with my hands, but still useing the complete lane of 6m.

Tomorrow morning i have to check if its necessary to visit a doctor with my sprained thumb.

2007-04-13 No updates to this site since 4 month. That is not good. Sorry !!!

Ok- let me try to remember what happend... First I found no time to do anything python-related. Then I had no interest. But finally I found back to the path and started to redo some things:

   * Corrections on the chainline - not really successful because there is no space where it is needed.
   * Seatangle is a bit lower now - to achieve that i had to change the upper side of the rear frame. The seat and the frame are parallel now. I hope that with this seat angle my hip stays on the seat. Before i slipped forward.
   * new fixing of the seat. See 2006-12-13 for the Seatholders I used before. Now I use small U-shaped stripes of 2x18 mm material
   * Fenders
   * shifter for the front gears
   * better Brake handles - the old ones were of the brand "Darwin" , i wasn't able to develop faith.
   * Paint - green metallic, not matching to to blue of the wheels :-(

I did not practise riding very much, because i disassembled the bike, but i hope to learn it in th next weeks.

Now have a look to the new pictures:

new 42 behind the seat Frontwheel fixing point for fender

Things to make better next time:

   * complete preparation of the 40x10 tubes first, maybe using a gauge, then welding the BB and SBB.
   * Fix the fender holder last
   * Some more new parts, like BB-shells and  canti-Sockets will shorten the building-time and be better for my nerves
   * Use a good welding machine from the start. No DIY-shop-machine again ! I´ll buy a used professional welder.
   * MTB tires may be too thick. Better buy 44-559 tires. That makes the construction of the frontframe easyer.
   * Spend much time on checking the chainline before welding :-(
   * Need a good idaea for fixing the seat. Maybe some kind of quick-joint-system ?