Tilting Quad Velomobile

Thank you, sir. Yours is a posting with huge amounts of experience & desired information. Do you notice weaker side gusts? Obviously, more severe gusts would be bothersome, even dangerous.
If my preliminary 2 wheel body is light, sturdy, & easily enough built, I'll be doing both 2 & 3 wheel streamliners. I've been caught in torential downpours miles from shelter, & had to ride in freezing weather, so a body is highly desirable in addition to the aerodynamic benefits. I want ability to cruise at 30 to 40 mph.
Hi Ronald
About the effects of gusty side winds-- a proper concern as the velo looks somewhat skinny and quite tall parked between my Mazda and the Corolla. I'll definitely test it out after I've installed the tail section.
From my experience with my previous working model, (same width, +5 cm taller with edgy coroplast corners) there were no issues in 20 (+) km/hr winds because I constantly control vehicle tilt. I could definitely feel the force of the wind but it did not feel destabilizing. So I'm optimistic about the roll-over-resistance of my current build in stronger winds, especially since the author of the Left Handed Cyclist Blog claims that with Direct Tilt Control a rider can hold a vehicle at max lean (or in my case-anywhere along the range of tilt), and can corner with an extra .38 Gees compared to a Free Tilter and .61 Gees greater than a Non Tilter of comparable dimensions. I'm assuming that managing the forces when cornering is somewhat similar to resisting the side wind forces--a questionable assumption since I have minimal theoretical knowledge about such stuff.
Your comments about a an enclosed design resonate with me, especially the sheltered part.
I'm focused on building a fun-to-ride machine which is both practical (sheltered with secure storage) and feels safe to ride within my city"s cycle lanes and pathways.
What is your plan? Fast inter-city travel? Racing? Do you have any preliminary sketches of what it will look like? It sounds interesting- looking forward to your build posts.

Below is a photo of the male mould for the very back of the tail section


In the next photo, the formed FG has been separated from the mould, and the openings for the storage compartment, tail lights, signal lights, and air vent have been cut out.

I reinforced the storage compartment opening by bending 8mm round steel tubing to conform with the contours of the opening. I then epoxied the tubing in place and taped the opening with white hockey tape.
My choice of tape has more to do with my national identity than any inherent qualities of hockey tape, eh.
My next post will focus on how the very back of the tail section will connect with the 12mm square aluminium tubing at the front of the tail section.
Loving your build.
Thanks Popshot. I'm feeling good about the outcome. Especially my latest attempt at making two overlapping parts from the single mould. I was able to make the very back of the tail section as well as the lid to the storage compartment using the same mould - in two separate layups.
The following photo shows the inside of the tail section with the compartment lid in place and the 12mm square tubing (which faces the cabin section) attached at the top.

The lower square tubes, coming out from each side of the compartment opening, is where the panels (yellow coroplast strips) for each external wheel well get attached. And, as the rest of the photos demonstrate, the wheel well panels are also fastened to the storage box (blue).

The next photo shows the tray at the top of the storage box (for gloves, extra sweater etc.).

The tray is accessed from inside the cabin.
And the storage box is accessed from the outside.

Next, I will cut out coroplast panels and attach them to each side of the tail section.
The TAIL SECTION is completed and installed behind the cabin.


The quad's overall shape and colours look much like the drawing on page #2 --posted nearly 2 years ago.
This is what I had in mind back then.
WELL .?? My plan was to reproduce that drawing for you to compare, but, I now realize my posting skills are not up to the task.
So, Just imagine that the drawing and the photo above have quite a number of similarities, especially the yellow and blue colours and the pattern they are painted in.
The colour pattern was designed to create a visual blending of the tail section with the clam shell cabin, and ideally, to make the vehicle's tallness less obvious. At least that was my thinking when I picked that particular drawing from the numerous drawings I had sketched out over the years.

Here's a view of the tail section.

I'm relieved that I didn't have to cut a glaringly noticeable amount of blue coroplast out of the tail section to accommodate the up and down pivoting of the rear swingarms as the vehicle is tilted.

And a view from the front.

Hi Paul.
I'll keep trying. Yes, the drawing was originally posted in this thread by you. So thanks for the help--twice over.
Hi Paul.
I'll keep trying. Yes, the drawing was originally posted in this thread by you. So thanks for the help--twice over.
Every days a school day !
No mystery to what I did.
I found your drawing on the first post , Right clicked on it and chose Copy Image Link I then made a new post clicked on the mountain icon [ or use Ctrl + P ] and pasted the link into the box and pressed Insert.
I did the same for the chosen ' finished ' picture , I did highlight the pictures [ just click on them ] and using the squares in the corner and the mouse pointer I made them small enough to display side by side , just showing off really ;)

Amazing! Really like the project and progress so far. I can see the benefit for urban commuting, especially when riding on narrow bike lanes.
Also, I like the aspect, that it feels closer to riding a normal bike compared to other velo quads

The turning capabilities look great too, have you ever measured or calculated the turning radius of the quad?
How do you think a heavier weight of the quad would influence the riding performance, especially when tilting the quad?

I recently found this concept, it is called Begorett and the aspect I like most about is the "roll cage" to protect the rider.
Do you think those two concepts could be combined into one velo quad?


cheers and thank you for sharing your project
Roll cages are only much use if you are strapped in and remain below the cage. There's a lot of chassis on that which will weigh a lot.

From my own tilter also based on free to caster steering the turning circle isn't going to be great unless you can lay it right over. There is no steering at all unless you lean. Whilst lean and steering are separate it has to lean to steer at all. At very slow speeds with little lean it'll turn like an oil tanker. You learn to throw it into a turn at even slow speeds to get the turning circle down. Weight isn't a problem when tilting any more than on a bike as you use cornering forces to get you upright just like a bike. All recumbents are poor at hill climbing and weight only makes that worse.
Hi thegreatfox.
Would a roll cage work on a tilting quad?
Probably, but with additional costs. On my build, the outer skin ( FG + Coroplast) is fastened to a space frame of 12mm aluminium square tubing. A space frame more like the Begorett's roll cage could be incorporated, but as Popshot mentioned, with added weight. And to be protective the the cage would likely affect the ease of entry/exit, or the quick removal feature of the clam shell cabin. And a protective roll cage may not easily facilitate the side windows which slide inside a slot within the 12mm square tubing.
Does the heavier weight influence the riding performance while tilting?
From my riding experience, Popshot is correct. Weight does not seem to be a problem when tilting at higher speeds. But, the added weight of a roll cage would more than likely be felt at slower speeds. When I conducted my ride-feel tests, I noticed that the quad felt more nimble/lighter with the cabin removed, especially while tilting at slower speeds. So, a heavier roll cage would probably affect the ride-feel of a driver actuated Tilt Controlled velo at slower speeds.
Now, about the turning radius and steering controls.
It's possible that F to C arrangements vary in their sensitivity to vehicle tilt, but generally, as Popshot says, F to C is slow to respond to changes in vehicle tilt, which is ideal at higher speeds. My build incorporates two steering arrangements (F to C plus Thumb steering). When in F to C mode, the manual thumb steering linkage freely and passively moves back and forth and does not interfere with the dynamics of F to C. When I slow down to drive through a narrow pathway entrance, or to turn around on a roadway, I use thumb steering. Meanwhile, I'm controlling the tilt with the tilt apparatus in F to C mode and in manual steer mode.
So, using thumb steering, the turning radius on the quad is 3.5 m. This allows me to easily make a 180 degree U turn on an 8m wide residential street.
I've been admiring the Begorett's eye catching and racy looking concept for quite a few years. To my mind, it's the "sports car" while my velo was designed to be more like a practical "coupe style" sedan. Could be because of my age.
Thanks for the positive comments and interesting questions.
Hi velocoupe,
thank you for taking the time to answer my questions. Sticking to your analogy, then I would most probably like to build a coupe style sports sedan 😅 and I totally get your point. After doing some further analysis, I will most probably reduce the roll cage design of the begorett to a bare minimum, probably one arch behind the head/rider and one to cover the knees. Fortunately, I will work with chromoly tube which hast a pretty good strength to weight ratio.

Before I go straight to the drawing board, I would further describe the intended use of the vehicle and also I still have some more questions:
In my case, the velomobil, will be used to commute around 30km in total a day. Most of the time in urban terrain (narrow bike lanes or roads) with low to medium climbs. Since we have a lot of cars in the city, I'd like to feel as safe and visible at all time, but also want to have a good view of sight. The mobil will be assisted, therefore it doesn't need to be super light. The idea is to be able to easily reach 30km/h.

Now to my questions
1. Is the TILT worth the extra effort?
I can definitely see some engineering problems compared to a "traditional" trike or velo quad. It seems that finding the right balance of the system could be difficult, not to mention the more complex mechanical design.
So do you think in general, but also for my purpose, is it worth going down this road?

2. How would your design differ from what you have now if you could start again?
Based on your current observations, are there any fundamental changes you would make to the design to make it simpler, make the tilting feel better, or generally improve the riding experience?

3. Combined steering
Although it seems, you can get used to the thumb steering, I fell like there is room for improvement. Do you have any concept to combine the two steering systems into one lever/motion? Or do you think the system is good as is?

Thanks a lot
Hi thegreatfox
I'll start with the thumb steering. Over the years I've thought about applying e-assist to the manual steering. But, that never happened because I'm intimidated by electronics. Instead, I recently removed the reverse-action brake levers and installed a specially designed thumb lever with a greater mechanical advantage. I'm satisfied with the results-- and, in truth, thumb steering is infrequently used anyway.
Thumb steering and F to C should be independent. So combining the two systems with a single lever won't work. F to C should remain "free" to be guided solely by the tilt apparatus and vehicle speed.
Over the years I have tried to find ways to simplify each operating system of the quad's design. Long before that, I recognized that each system ( Direct Tilt Control + F to C + manual steering ) was totally worthwhile.
The mechanical tilt apparatus is worthwhile because it gives me the feeling that I can't tip over in sharp corners, sided slopes, bumps etc. And there are plenty of tight corners in urban riding. When both components (hand levers+ seat bottom) are combined I have lots of tilt force (even at my age) and each hand lever can also provide a "counter force" to limit vehicle tilt. So I definitely like the feeling and confidence the tilt apparatus provides. I think the novice rider's complaint about "feeling the tilt more than expected" can be explained. She later mentioned that, to her, while taping, it looks like the vehicle is hardly tilting, so she wasn't expecting it. Admittedly, it takes getting use to. For me, I'm very comfortable and confident in the combined actions of Direct Tilt Control with F to C steering. Plus the high ROR has permitted a fairly tall (to see and be seen) and narrow (functional fit with cycle lanes) velo. As you say, suited for urban riding.
I'm not sure what you mean by "finding the right balance to the system".
Is the tilt worth it?
Tilting is not for everyone. But for me it's worthwhile. It's not just the fun of cornering at speed. It's also about minimizing the lateral forces felt while riding over bumps, on side slopes, and even along separated urban pathways where private drives slope down to the curb of the road and cross the pathway every 30 to 50 meters or so. Cyclist have no issue with this because they don't feel the slope changes. But a non tilting quad would.
Thanks for the questions.
Hi again.
It occurred to me that my answer to the "tilting" question may not be that useful to you. I interpreted it as " Is tilting GENERALLY worth it?" Perhaps I should have looked at it as a series of questions such as --- Are all the features of my design really necessary? Do the outcomes (ease of handling, ride-feel) justify the extra weight, material cost, time, etc.? If I had to do is all again, would I go the same route? Would I recommend this route to you?
Would an answer to these questions be more useful for the planning of the design of your commuter quad?
This winter I came up with a different riding technique for making a quicker turn-around on a residential street. It is shown in the following video.
Before this, my technique involved slowing right down with the velo in an upright posture, and using thumb steering to make the turn while holding the velo upright with the tilt apparatus.. Both techniques result in similar size turning circles, but my new approach is quicker and more fun-especially when exiting the circle.
In the video I use the Tilt Apparatus to FIRST lean to the inside of the turn. Then I use thumb steering to tighten the turning circle (in the video I nudged it to max steer angle). The steer angle is at max when the inside front wheel almost touches the concave indent of the nose cone

Too bad the feeling experienced in the "return to upright" motion when exiting the circle can't be captured in the video. It feels really neat.
When it gets a bit warmer, I plan to fabricate the single-sided swingarm for the switch-over from the quad to a delta.
When researching tilting before my first attempts I read that motor cycles are tilted over first then turned otherwise once in the turn the forces trying to make you go in a straight line are harder to overcome to get the required tilt angle.
It also seemed more jet fighter like !
I have also seen bad reports from people who try to use tilt locks [ mine did not need them as yours doesn't ] when the tilt is locked out the steering needs you to start of turned in the opposite direction to the desired turn however when unlocked it behaves in the opposite way ?
ps impressive as usual