Failure is the best part of anything you create and operate. What aluminum alloy did you utilize for the axles? The engineer in me is confident aluminum can be used with minimal challenges. The realist in me says move to steel, and spend the saved time modeling the geometry. I would still increase the diameter as much as is practical. I should have some free time this weekend. I'll download your drawing and see what kind of solutions I can produce.

Awesome project! I think you could make bent arms (U-shape) so the ball joints meet the knuckles at more open angle.

More brilliant work, this is starting to look super clean and I'm excited to start my own!

Fantastic to see the evolution. You certainly have more experience than me, however since a few failures I've developed a nagging fear of metal fatigue in aluminum. I'd probably want to consider steel. But, then we have the potential for galvanic corrosion. There's no way that joint won't have an electrical connection as well as electrolyte (road salt etc.). So I'd be interested in hearing what you think. I'm starting my builds with a bike trailer (non tilting 😂) but would like to someday build a recumbent trike ❤

Excellent work! Very cool design. I think that type of bike would be great for bike delivery especially in winter conditions.

Thanks for sharing your project with everyone. At 14:14 .. I noticed your damaged left thumb. Something that everyone should learn about this. When you hit your finger like this .. stop what you are doing .. and with the other hand .. wrap around the damaged area .. with pressure and at the same time .. begin to hyperventilate .. which increases the oxygen in your blood and improves circulation. You want to breathe fast until you notice that you are feeling dizzy .. then slow down your breathing .. to maintain the dizziness .. and keep pressure on your finger .. until the pain greatly subsides. Then you can let go .. and while there may be some redness and tenderness .. there will usually be no blackened fingernail. Remember .. we are told to elevate a damage limb to keep the tissues from swelling. The swelling has the effect of drowning your damaged cells as they release fluid .. slowing oxygen transfer. By applying pressure directly on the damage area .. you keep the tissues from blowing up and capillaries from releasing blood. In a very few minutes of breathing fresh oxygen .. your cells will have a chance to repair. If you have broken a bone .. it will take a while to mend .. but the tissues around the bone will be in much better shape. I learned this from a doctor .. and have experienced it several times .. others too. ALL the BEST!!

You may not need to go to steel.. 7000 series aluminum might be enough to solve your strength problem along with increasing that diameter.

Great work ! Thanks a lot for sharing :)

Steel axles most definitely. Aluminium fatigues very easily. I'm amazed at how well the trike handles the off road stuff.

Waaw, that is nice ! Just one advice before I finish your awesome (as usual) video, in order not to forget. I am not a professional TIG welder (not yet I hope) but it appears quite obvious that you should have less tungsten stick length out, unless you waste much on gas flow. Even on inner corner you might be able to have less stick out. And it is recommended not to move your torch immediately after your weld, to let both your weld and your tungsten under argon protection against oxydation. But my be it is not so relevant when welding aluminium, i am just recommending what I learnt;

Bad Obsession Motorsport has good explanation of that. In project binky

Some trikes have a locking mechanism to prevent the bike from leaning when going slowly or when parked. Have you found need for this type of mechanism?

Very good improvement have you think how could other benifit from your work in there DiY trike

I previously mentioned my doubts about the cable steering, but I'm no glad to hear that it seems to work that well! Did you ever retension it during your tests now?

YT just recommended this to me and I'm glad I'm here! Your design reminds me a bit of the design Johansson (part of Pierer NewMobility now) uses on its Oscar S and Oscar M cargo bikes. They also have a double wishbone design with a single damper between both sides. When the damper, and especially it's rebound, is set up properly, the Oscar M (which I have) is *very* stable going fast. Going downhill, I've reached speeds of 50-60kph with it! It's also capable to do some limited offroading. I've taken my Oscar M to places no cargo bike has ever been before (and probably never will again, lol). Johansson has some videos of the handling online, if you're interested. If you're interested and are still looking for some inspiration for your design, I could also film some video of the Oscar M suspension at work (I have some action cameras that should provide good footage). Also, in a video about different kinds of steering for recumbent trikes (non cargo), Utah Trikes also mentioned the Ackermann geometry. My Azub recumbent trike also turns the corner inner wheel more than the outer wheel and it feels very stable. I can also provide footage/images of how they've done their steering. It's basically a parallelogram steering as well using rods as linkage. I already subscribed just now. I'm very interested in what you do next and how you solve the outstanding problems! If you're looking for a new project soon, I'd be very interested in how you'd approach the build of a recumbent trike with suspension ;D

1. Aluminum is fine for the axles. Just make the connection at the same size as the larger hub bearing. Taper the axle as well. There’s a reason Canondale does this. 2. You’re wanting to produce a cargo bike, not just a tricycle, so make sure you’re doing the tests with varying cargo loads. How does the front suspension perform when it’s at a higher pressure to account for a payload? How will the vehicle handle when it is calibrated for a payload but is currently empty? Can this performance be improved by using a lock out in one of the travel modes (loaded vs unloaded).

Hi Pedro, another solution for decreasing the kingpin inclination angle is to use "deep dish wheels". With these types of wheels, the hub is positioned farther towards the outside, which allows for smaller kingpin inclination while maintaining a small/zero scrub radius. Google "wheel offset" for lots of examples.

What if you use cables instead of struts between the steering axle and the wheels?

The steering seems very soft, easily crazy. Maybe install a damping system on this steering

You made such an incredible job Pedro! I'm so impressed!

Go for steel on the axles, also pretension with enough torque to ensure increased fatigue. My guesstimate is that the aluminium axles failed due to fatigue rather than actual stress

Great progress. It is good to see the performance improvements. One thing I was wondering about your testing, how is it with a cargo load? I don't have the time right now, but I am very interested in using your design in my own build. Thank you for putting out your work for others to use.

Lots of streets in Amsterdam feel like offroad riding.

Always make axles out of steel. Aluminium has a very limited fatigue life. If you don't overstress steel, it should last forever. Same with cranks, crank-shafts, etc.

On the bush trail, the vehicle seems difficult to control. It seems to want to spear off the path. The tilting will steer it as well as the steering mechanism. A standard bike when titling doesn’t need much actual steering. Most is done by the tilt. Do you think the rider will get used to this, or is your steering too sensitive. I like the variable steering idea from the other guy!

Thank you so much for taking us all along on the process of designing, iterating and building this wonderful trike. Also it's great that you've done most of the work in what looks like the back yard of your flat. It shows that you don't need an expensive workshop to make beautiful and innovative contraptions.

Re the 30 degrees angle of the ball joint. Would a simple fix be to modify the bottom control arm with a bend before it attaches. so that when it fits onto the stub axle , it’s closer to a 90 degree? I’m also wondering about the angle of the steering rods (tie rods). I wonder what would happen if they are closer to 90 degrees to the frame? Hard to explain without a drawing.

Hi Pedro, as always thanks for posting and being a source of inspiration. I'm trying to finish the front suspension, I also have a problem with the ball joints limiting the tilting. But i dont know how bad is it until i can ride it. Still have to do the steering and some other things,this video couldn't come up at a better time. I feel indebted to you since i got so much from your channel.

13:05 "Eh Car***!" 😅

Let me first say i’m a big fan of your videos, but that whole jiga thing is a major issue for me! As someone who is currently building a business myself i’m a big fighter for keeping money inside your local community. Why not build a relationship with a local machine shop?! A quick google search should give give you plenty of options! Also it’s more sustainable not only for the environment! You’re directly undermining your local economy. No wonder prices are higher than ever! You can change this! Imo everyone should quit Amazon temu and all that other BS! Take a look around your local area! Everything is already around you!

Díd you think using lefty hubs in front wheels?

I love the bike you made! Could you show us how does the front suspension works? Like with more weight on it. The offroad videos were a bit shaky 😁, maybe a stationary suspension compression test? I come from the mtb world and our roads need a good suspension.

Absolutely steel axels and a high grade alloy steel.

Actually steel and aluminium have very similar strength to weight ratio. So either can be built low weight. Steel is much more resistant to fatigue fractures.

At 7:05 the headset doesn't seem to sit in the frame properly? Anyways, cool project and videos, thanks!

Steel axles , a small compromise. I think your machine is brilliant and I would definitely buy one if I could

Pedro, thank you so very much for your transparent review of your tilting cargo trike design. You did a very thorough job, and have earned the respect of your viewers! I look forward to seeing your design solutions and improvements in upcoming videos! Keep up the excellent work!

What an awesome trike build! Yes you should absolutely switch the material of the axles to steel. Aluminum never has an infinite fatigue life, whereas steel can. So under repeated loads, like you would expect in an axle, the aluminum will always eventually fail. Even if you increase the diameter where it joins into the knuckle, it will still eventually fail. In an axle that has that large of a diameter you could likely make it out of hollow steel without losing too much strength compared to solid steel. So you could save a little bit of weight there. But there is probably math you should do before you start hollowing out the axles lol. Also I would suggest making the knuckle out of steel as well. It will receive the force from the axle and also eventually fail, if it is made from aluminum.

I haven't look at the design yet but I would make the axle from steel.

I love this project . Great job! My suggestions: For the Axle bore out your part and use a central 8.8 steel bolt. It should be plenty strong and you simplified the Design. From a manufacturing standpoint avoid the sharp corner between different radiuu next time. Putting a slight radius around the circumference will reduce shearing stress at this point immensely . Keep on inspiring!

Expect Aluminum to fail when stressed. Also expect failure at sharp transitions. Use at least .050" radius.

Great work! Thanks for sharing not only your success, but a failures too. It makes your solutions more understandable. According to the front wheel axle I'd use steel. It won't demand to raise axle diameter and, probably, allows you to keep the front knuckle unchanged.

I am sorry that the design isn't finished... but not sorry that there are going to be more videos! I love this. Keep up the fantastic work!

I would agree making the axles out of steel. What a magnificent development. Thanks.

Unfortunately, to mitigate tilting problem you need much more than swapping the ball joint. This effect will simply appear at bit greater angles, but the inner wheel will still bear most of the weight in the turn. Instead you have to rework linkage for change in camber angle through the suspension travel just like you fixed toe angle change due to change in travel. That will solve third problem as well. And - maybe even more importantly - decouple suspension, adding second damper.

Describe a turn not as an angle but as a radius. There are 90º turns that are sharp and 90º turns that are not sharp. The critical question is the radius of the turn.

Have you had any thoughts about doing the rear wheels in the same way? I'm keen to try a small electric car using motorcycle wheels (small ones, like off a 80cc motorcross bike). I think this is the future of transport.

A steel axle sounds like a good idea. It won’t add much weight.

Axles should be mounted on standard M16 or something like that screw. This is such a simple part and important component - it should be easly replacable and made of hardened steel - just like a solid bolt.