For the nervous, a video is found at the end of this post.
After almost 2 years of planning, building, testing and a constantly growing frustration, due to the complexity of this project, the final result is now ready for you here to be commented or criticized. Since my stealth bomber is the best thing ever to be ridden around i decided it was time to fabricate a pimp worthy of this bike. So John, if you read this don’t feel offended and please don’t see me as a competitor. Your work is brilliant and deserves my utmost respect This is and will remain a custom built prototype. The only one of it´s kind. That’s why this is not, like already done by someone here on ES, a plain 100% copy of your ideas. No, this is, although very similar in design, my very own interpretation of the Bomber. But let’s start from the beginning. After a couple of month as a totally satisfied Bomber owner, the strong urge emerged to personalize this machine. Since range is never enough the first thing was to fit a bigger battery. The standard frame was to small for my Turnigy Nano Tech 32 Ah and 18 cell custom built pack so obviously a new frame had to be created. A real pimp needs just that! Like people cut up and redesign the famous Harley Davidson motorcycles. So why not do the same with the Bomber? Ok, it would have hurt my heart to touch the original frame, so redesigning it was a better option. To keep it looking like a bomber the original lines weren´t altered to much.
The first steps are those weeks of drawing and building frames out of cardboard ( CAD -cardboard aided design- ) in order to materialize the mental construction. Rapidly the idea was born that by just copying John’s ingenious sheet metal design and making it bigger to fit more battery cells couldn’t be considered something personal. So, even though precious space would result in being wasted, my frame was welded out of rectangular 30*10 mm 25Cromo4 tubing. It gives the bike that Ducati motorcycle tube frame look. The spaces between those tubes where filled with sheet metal and the battery was mounted onto an aluminium plate that bolts to the frames bottom. It took weeks to weld, heat treat, grind and manually sand down the steel structure to reach perfection.
Another wonderful detail was the enjoyment during all those month of gear shifting using the Vboxx. Since an E-bike is a high tech machine antique, ugly looking and maintenance intensive derailleur systems never came to my mind. Designing and welding the Vboxx mounting structure was a terrible task that almost killed this project. After all wheel alignment is critical and once the Vboxx support has been welded into the frame there´s absolutely no more margin to play with. So it had to be perfect and nothing less. For those who like hard facts, the frame, without the swingarm and Vboxx, weighs 9700 grams. Sheet metal wise a thickness of 1.5 mm was utilized.
On the electric side, Lyen´s 24 fet controller is integrated into the frame and 3 battery medics give me information on the state of each cells voltage. This is vital as a BMS is not used. The charging is done via 3 i- chargers that are connected to the bike by a custom built plug that establishes all connections at once. Even the balancing leads are in use. The idea to bulk charge the pack was found as being something for the electronics guru. Mechanics is my thing so this was the retard method for people like me. To ensure a perfectly balanced pack every cell was charged individually using a cheap 1 amp single cell charger. It took weeks to bring all cells to exactly 4.15 volts, but that´s what you should do prior to it´s first use. After all the intention was to have fun with this machine thus doing every possible thing to prevent a lipo fire!!
The rear wheel features the X5403 motor laced into a 24 inch rim and using the hookworm tires by Maxxis. On the front part the Marzocchi 888 fork makes for a plush ride. The internal spring was replaced by a stiffer one that effectively prevents the fork from ditching in when hitting the brakes hard. Instead of a picture loaded thread it´s video time now. The machines creation was filmed in many occasions and then rendered into a short film. Enjoy!
PS: The main intention and motivating force behind this project was the joy of diving deep into the making of a personal e-bike. Oh and yes, I spent almost four times the money my bomber once cost me. Not only on bike parts, but for the tools necessary to make this machine. Money buys you everything, but nothing is more satisfying then building your own stuff!!
The complete tool list:
1. Milling machine
2. Motorized variable angle tube cutter ( another custom built machine )
3. Lathe ( with added digital displays for precise adjustments )
4. TIG Welding system ( fully programmable )
5. Custom built welding table with absolutely plain die cast metal plate for alignment purposes
6. Stand drill
7. Taps and dies in all metric sizes from M1 – M 20
8. Angle grinder
9. Dremel ( The number one tool for delicate manual grinding work! )
10. 2 new work benches for assembly
11. A stereo sound system to keep me grooving.
12. Metal bender
13. Soldering system
14. Tube notcher
15. 10 Power supplies with custom switch grid for generating any voltage from 3 – 120 volts DC at 20 amps
17. A 12 ton hydraulic press. ( Yeah, just the tool to rectify the frame )
18. A washing bin with pump and brush
The complete parts list:
1. 54 meters of steel tubes in the sizes 30*10, 60*30 and 100*30
2. Sheet metal with a thickness of 1.5 mm.
3. Suntour VBoxx ( The center piece was removed and painted brown )
4. Crystalyte X5403
5. Sun Ringle MTX39 24 inch rims
6. Maxxis Hookworm tires
7. Motorcycle spokes ( 8 AWG!! )
8. 12 Turnigy Nano Tech 8000 mah packs
9. 4 I-Chargers ( 1 as a spare, now in use to recharge my robot lawnmower )
10. 4 27 volt and 30 amp power supplies.
11. Tons of bullet plugs
12. 5 contactors
13. Cycle analyst
14. Key switch
15. DC – DC converter In 12-80 volts Out 12 volts
16. 4 battery medics
17. Marzocchi 888 fork ( Pimped with a stronger spring )
18. Motorcycle shock stage 6 RS
19. Maxxis hookworm tires
20. Custom built plug for charging the bike ( I spent days figuring that out. It was made out of a solid block of aluminium. )
21. Custom milled housing for the battery medics
22. 2 * Cycle Lumenator.
This is the bike in it´s final state, standing in the sun after it´s first real joy and not test ride.
Here with 18*1,60 inch motorcycle rims and Heidenau K65 tires.