Prototype-00
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updated: 2026-06-08
Prototype-00 is the result of on going disscusion that still going for decades beteween me and dad about tech, skills, science. About late 2018, as usual over some booze we were talking about FWD and RWD. Although at the time I believed RWD is better than FWD because all the race and high machines like MotoGP, SBK, F1, FDJ, e.t.c.… use RWD. A few days later, I realized dad was right and I have never seen a FWD RWS. Right at that time, I really wanted to buy one to try. After a few months of searching and researching the internet, I could not find any FWD RWS design for 2 wheels that were sucessful.
As far as I know, at that time, the the people in the university still couldn’t explain how does a bike balance with mathematic. All experience, documentation and comments conclude that RWS was not stable. I disagree. Because I could ride a bike since 3 years old, I have my own theory basing on my own experience of how a bike balance. Base on that, I decided to plan the development of FWD RWS bike. This article document the journey of making Prototype-00.
The main goal is to answer the question: Am I insane ?
I started to draw since 2019 and changed the design alot but only till late 2025 opportunity would arise for execution.
The jig I designed in SolidWorks in 2019 uses aluminium extrusion with ready sliding slots, rigid, solid with unimaginable tolorence. Year 2021, after learning about CAD/CAM and CNC, I found LinuxCNC, then Linux, then GNU, then FOSS, and then XMPP. Since Covid-19 stop the filmmaking jobs and the development of the bike and flip life upside down, I chose safer route - research about infomation technology, escape social media; make my personal website and the mail service and the chat service. Seems unrelated but due to this I can write my own content, design, deploy, manage and control the entire infomation system for Trần Phước. Most importantly, since no social media, it is very difficult for me to get distracted from work.
Begins as a child’s bicycle that is completely out of date bought in 2024 for 260.000₫…
Almost all parts are completely worned from the original bike. The headtube is also worned way out of tolorence.
But that’s enough to prove the concept.
The actual jig I designed in FreeCAD uses box tube with 1.2 mm in thickness and slide plate with 4 mm thick.
I only have an angle grinder, a hand drill and hand tools.
Since I don’t have a mill and a lathe to make tools for jig I lost so much time looking for local shop and were very disappointed with quality of service and the outcome. I had to spent so much time to find a solution to hold the steerer and the headtube.
I use Ø26.65×1.1mm for the main frame.
Since it was the first go and absolutely terrible at math the headtube is about 3 cm off to oneside. As crooked as it is, the wheel still fit fine 😜
With experience, the bottom half of the tail was done much faster.
The top half was assembly related. Once again, because I didn’t have a lathe, I welded a section of Ø33.5 mm tube to the headset nut to extend it, making room to assemble the top half.
At first, my design in SolidWorks were very rigid with 4 members - two tube on each side to hold the rear wheel. But only at execution that I realize it only needs one on each side. This design would save 50% and simplify the assembly process greatly ! I use the same tube as the main frame to lower cost of buying material and getting it myself from the shop as low volum purchase.
Since this point I truely believe that CAD skill will never be comparable to hands on experiences.
The seat took a day to design the old parts. Main goal was speed of execution and as cheap as possible when we still don’t know if FWD RWS is ridable.
CHOPPED !
Wheel still fit 😁
The thing I drew in CAD years ago was starting to appear !
At this point I guess the seat’s back can limit the steering angle.
Next is the steering system.
I bought these sets of bearing at a local shop. It says ‘K000 NSK Japan’; pillow say ‘P000’. Price for 4 sets was 600,000₫.
Was so suspectful, I went online and couldn’t find anything of this. I contacted NSK and they was sure there’s none of this and definately not made from aluminium.
The steering system uses two set of bearing for each handle bar. At first, I thought it would look great if one set was on the frame and the other on the seat…
Master bar link to slave bar. Naively, slave bar is a Ø6 mm threaded rod.
After sit test, I thought the structure would hold.
Safety first. New brake - 40,000₫ !
50,000₫ for a pair support wheels.
As soon as I got the bike out and try the pedal, the back bended backward. This is the moment I see my stupidity:
- cut the main frame down way too early.
- how could a Ø6 mm by 20 cm hold 100kg let alone bolted on.
Three pieces into one!
A little over cooked but that’s ok 😁
Practice begins. The support wheels were too in the way and wasn’t neccesary.
After three days still couldn’t pedal. The structure seems fine. The flux is starting to eat the frame.
A bit more copper to reinforce the back.
Clean the flux with citric acid.
Wash off the acid.
Wire wheel and prep for paint.
Acrylic laquer.
Assembled. Keng xà beng 😜
Differ from many other welders, I like leaving the brazed joint as is or use fire to smooth it out instead of machanical sanding. Coz every time I look at these joint, I can see traces of fire.
In the picture below, you can see one set of bearing for the master handle bar is bolted to the seat showing great aesthetic…
Result is broken seat within 3 hours coz the bolt for the seat couldn’t take all the load.
Struggle the entire morning coudn’t remove the seat as the bike flops around too much.
Two days later, there’s a stand and it’s removed.
Removable means a new bolt can be brazed on.
Re-designing the mount for master bearings. I was really afraid of brazing this time as it takes alot of time to paint.
Both bearings bolted on a plate and the plate bolted to the frame. Fine.
This design is easier to adjust the angle as the entire plate can be removed.
!!! RIDEABLE !!!
I took 5 days of walking 7,820 meters while designing and executing. Let say I have talent, normal people on average would walk 1 km everyday for 10 days to ride a Trần Phước. Too easy !
Water bottle like everyone else.
Camera as cheap as possible. (Broke as soon as got the bike off the stand.)
A bit more rigid, using car’s accessory: 300,000₫
Ready for downtown 😁
Drivetrain ratio of the original bike was 32 chainring and 16 teeth sprocket. Accroding to phone’s navigation, after a month of riding, I achieved top speed of 33.3 km/h. You can see my legs are spinning too fast in the video at normal speed.
I’ve since upgraded to 46 teeth chainring and improved drastically. I can reach 0-30 km/h very easily and maintain speed with traffic flow with very little effort thanks to aerodynamic. Top speed on flat road is 38.2 km/h and downhill is 40.2 km/h measuring from the physical wheel. Although Prototype-00 can reach higher top speed going down hill, the brake is insufficient.
You can download all the pictures with this compressed file.
To check the integrity of the compressed file you downloaded, (making sure it doesn’t contain virus,) you can use this PGP signature file.
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