The Velassi


Edit:13 sept. 2023, Cre:21 juin 2019

The Velassi

The Velassi, a not so reclined recumbent (but more than a ‘semi-recumbent’).

That, this is when you can’t choose
between the bike and the couch.
Anonymous seing the Vélassi
Here you see, he pedals and he take a nap.
Another anonymous
Hooo, to tan you shall go to the beach, sir.

Build a recumbent

Why a recumbent ?

  • To avoid butt pain
  • To look to the landscape and not to the road
  • To avoid neck pain
  • To avoid wrist pain (that I damaged abusing of hammer drill while renovating my house)
  • To improve aerodynamism compared to an upright bike (Which shall be very upright due to my wrist troubles)

This, finally allow larger range of bike rides.

Why a not so reclined bike ?

  • To ease first handling
  • To avoid clipless pedals
  • To limit neck angle and avoid head rest

Why a wooden bike ?

  • Why not? Practically, because I don’t have equipment neither experience to TIG weld or braze neither to build a composite frame, and that I have a limited experience of wood-epoxy building. That is a technical choice and not as for many wooden bike builders, a will to create a work of art (How come, you can see that ?). The philosophy of design of this bike is more inspired by aircraft building than by other wooden bikes that I was aware of. Indeed, if I was more respectful of aircraft building know-how, my bike would have been lighter, I will came back on that…

Is there a motor?
For miscellaneous reasons, a lot of people were persuaded that on the Vélassi V1 there is a motor, but no… The big rear hub is a geared hub (8 speeds) and the front hub is a dynamo. There is though a mid-dribve motor on the Vélassi V2 but what people notice is the big battery…
When I have time to answer, I just tell: I am the motor!
The frame of the V2 was modified to be able to instal the motor with torque sensor (A tongsheng TSDZ2).

Evolution of the Vélassi

IN practice, the Velassi is not one bike but two. The first, built in oakand finished in April 2019 did rode about 5800 km, the second one is an improvement of the first, built in pine and fir, motorised, finished in January 2022 rode about 6700km (in september 2023). This new one, with the motor help, rode much more and is equipped for long distance travel Travelling(in french).
A specific page gives details about this V2.
ON the page about the Velassi V1, you will find a general assesment of this ride.

Superposition between version 2 and version 1

Images of the Vélassi V2



Vue 3D

https://rouzeau.net/tmz/VelassiV2.html

It is build starting from that (template printed on paper glued on wood then cut):

en passant par ici:


Specifications

-Vélassi V1Vélassi V2
Wheel base1652 mm1650mm
Front wheel diameter20” (406)20” (406)
Rear wheel diameter26” (559)20” (406)
Front tireSchwalbe Big Ben
406–55
Schwalbe Big Ben Plus
406–55
Rear tireSchwalbe Marathon
559–38
Schwalbe Marathon GT365
406–55
Seat height above ground520–540 mm520–540 mm
Bottom bracket height above ground400 mm415 mm
Crank length145 mm140 mm
Steering58°82°
Fork offset89 mm−47 mm
Trail59 mm84 mm
Rear suspensionRubber blocksPneumatic shock
Suntour Raidon 190mm
adjustable damping
Front suspensionRigidRigid
Rear frame length390 mm500 mm
Rear articulation height
Rear chassis
235 mm220 mm
SteeringIndirect with low handlebar
(possible to adapt an above handlebar)
Indirect with low handlebar
TransmissionHubgear Nexus 8 (306%)Hubgear Nexus 8 (306%)
Transmission36 * 2444 * 21
Gear-inch 1,60m - 4,90m1,80m - 5,52m
MotorisationMusclesMid-drive TSDZ2
Battery-48V, 830 Wh
SeatRigid mesh seat
Rans Stratus seat
Foldable mesh seat
DIY with ICE mesh
Front brakeV-Brake
Common lever
V-Brake
variable pull lever
Rear brakeHydraulic rim brake
Magura HS 22
V-Brake
variable pull lever
EclairageHub Dynamo 6V, 3W6V, 3W on motor output
Rear frame bearingsIGUS 16mm rigidIGUS 16mm on ball
Handlebar bearingsIGUS 16mm rigidIGUS 16mm rigid
Steering rodAlu Tube 16mm, ball joint 8mmAlu Tube 16mm, ball joint 8mm
Kickstand-Rear side
Panniers support-Front & Rear
Dashcam-Front and rear on motor battery


Transmission with geared hub (Nexus 8) with simple chainring (same for both bikes). Very short gear-inch: 196” in 8th gear (=development 5 m), I did not pedal while descending.

I did modeled multiple frame types and among them a monobeam frame but pratically two scissor trellis frames, one in wood and the other in steel looks preferable while remaining reasonably light. Loads on a long wheelbase bike are not negligible and I did not trust much a monobeam frame while this was already done.

Is it reliable and durable?

Even though I made a few design errors on the Velassi V1, which I explain in the details page, this bike has proved comfortable and reliable, and has covered (as of January 2022, when it was replaced by the Velassi V2) almost 5800 km (including 400 km on a home-made ‘home-trainer’ during the 1st lockdown) without having spared it (I do most of my mileage on unsealed surfaces or paths). The seat cover (bought second-hand) is very tired, and as it’s a US-made seat, it’s a bit complicated and expensive to replace. The handlebar pivot bearings were the main mechanical weak point, and had to be reinforced. What’s more, depending on the ambient humidity, they either jam or have too much play. My fears about the handlebar’s fragility proved unfounded when I cut it to modify its shape. The brakes had to be reworked and the rear cable brake replaced by a hydraulic rim brake (Magura HS22). The problem was that water was getting into the sheath because of the position of the brake handles. Following a stupid maneuver, I fell into a drainage groove and had to replace a few spokes. The chain tensioner had to be modified after 2000km and I finally made an external spring which lacks a bit of strength.
The chain tensioning principle of the V1 has to be reviewed (replaced a double wheel tensioner with a single wheel one and repositioned it). Even though the V1 was clearly a prototype that’s been replaced, I was happy with it, as self-built bikes often don’t last very long compared to commercial bikes. As I had anticipated the need for modifications (which I did), I never applied a final coat or two of varnish over the resin and the bike remained sensitive to humidity. On the Vélassi V2, I did this varnishing after it had covered 2500km and finished its tuning phase.
The Vélassi V2 now has more mileage than the V1 (6700 km in September 2023) and although I’ve had a few problems with the motorization, mainly due to an error on the part of the seller, I haven’t had any mechanical problems (apart from breaking the chain tube attachment, which is minor). This version seems to me to be a success, and I can’t really see what I could improve on. The relatively heavy weight (31 kg with battery) is not a problem with the motorization, but it would be interesting to have a more limited weight when lifting the bike over obstacles or stairs.

Building in wood

Building in wood:
This is a bit a choice by default as a steel frame might be slightly lighter and less sensitive to weather. That was looking more simple for me as I already have a small experience of epoxy-wood building and associated difficulties while I yet have to learn to braze. Though at the end the design was much more difficult than steel/aluminium frame due to the lack of stiffness of wood. One of the main goal of the V2 version was to improve the torsional stifness (successfully). Construction required a great deal of organization, due to the short curing time of the resin and the short time between layers.
We know how to do very strong glued joints, stronger than the wood itself since the invention in 1943 of resorcine-formol glues which are practically stronger than epoxy but need very well adjusted parts and strong tightening during drying. Wood aircrafts are nowaday only built by amateurs, but there was wood built light aircraft till the end of the XXth century, including aerobatic airplanes.

Welding/Brazing steel structure

Brazing shall always be preferred to stick welding or flux-core wire welding for resistance and metallurgic quality. When it is well done (no excess heat), a brazing have the advantage to not drive to thermal modification of base steel. TIG welding allow high quality welds but you need argon gaz (and it is also required to inject argon inside tubes). To have quality MIG weld you need BOTH gas and flux-cored wires because gas only creates inclusions. Beware, the rod metal for brazing steel is different from the one used for copper welding, you need specific rods which is not always well explained.

Modelisation

As all my projects since four years, this was developed on OpenSCAD and is entirely parametric, but yet there is only one pre-defined dataset for small size, the one built. It is relatively complex to develop a dataset and you have sometime to dive in the program to chack what the data is modifying.
OpenSCAD had evolved and since more than one year there is a module to easily enter parameters named ‘Customizer’ which is quite comparable with the Thingiverse customizer (Thingiverse is a large library of 3D printable models). There is no limit to the number of datasets which can be recorded.
Modelisation was by far the longest step and the one which takes most hours, it have taken me multiple month. To avoid surprises and too frequent modifications, I always do quite detailed models.
The big advantage of OpenSCAD is that it does allow relatively easily to do parametric models because the model is in fact a program. Creating parameters need significant complementary work but allow easyfurther modifications. These are parmetric models which really give the interest of computer modelling.

2D projection (drawings) and cuts

On this model, I did more than a simple computer mock-up and also created a module projecting the beam shapes on drawings. I then use a CAD program to add dimensions. I then printed beam shapes on paper, cut the shapes with scissors and glued the paper on many wood planks. I cut the beams with a track saw with the help of a jigsaw for contoured elements. A track saw is very precise and you have no need to rework the straight cuts. After drilling, I did a pre-assembly to control structure. The rounded edges were sandeed by hand which is quite long with oak hardwood. A table tank and disk sander is required but I did’nt have one when I started the manufacturing.

Transport the bike

Transporting the bike
The Velassi can be transported on a standard bike rack with the rear wheel frame folded, which is one of the basic elements of the bike’s design.
The bike is easy to place on the rack (after strapping the rear wheel in folded mode), and protrudes slightly beyond the bodywork, but remains well within the width of the mirrors. In the first rail (out of 3), the handlebars pass easily through the rear window, but this isn’t necessarily the case with all cars.



Since I built and installed a folding backrest seat, to transport the bike in the car I no longer need to remove the bike seat.

The rack is a Mottez A007P3RA cantilever-mounted on the hitch ball without any other attachment, so the total load on the rack is limited (45kg) and you mustn’t lean on it otherwise you deform the hitch. The rack is easy to install, but needs to be adjusted for each type of hitch. The rack tilts to open the trunk, which is quite clever.
The support bars fold away to store the rack.

It is also possible to transport inside the car (I have a relatively small station-wagon -by today standards)


Publication

As for some of my other projects, I had the intention to publish the model (made with OpenSCAD) and information about building. Though at the end I find the wood structure a bit complex and I abandoned this idea. I find this geometry interesting and I still have in mind to redesign the same structure in riveted aluminium to be easier to build with less risks of wrong build.

Construction photo gallery

Moteur et pédalier

//Parts and assembly

Cable wiring

Miscellaneous details

Finished bike

References

General information

On this forum the Velassi thread
This forum is quite active and have a lot of technical information. Recumbent market is limited so there is probably more need for a place to share stuff than for upright bikes.

Other plans

Atomic zombie diffuse many recumbent drawings, including the WildKat USS that I did buy. I was not really convinced by these plans as they are relatively general and focus more on the manufacturing than on design details and neglect important elements. They recommend a given head angle without taking into account fork offset (rake) which varies significantly from one fork to another in 20” wheel size (typically from 30 mm to 50 mm), which will make a trail with significant variation depending fork parameters, so the handling will be somewhat random. Handling of recumbent is a complex problem where you can write a book, which was indeed done:The lord of the chainring I did bought (after building and some handling problems) the kindle version of this book but there is a big problem in the kindle version and formulas are not understandable. However, the book author (William Patterson) defined an equation advising a trail for a recumbent which can be found here. The recommendation of Atomic Zombie will give a trail notably lower than what recommand Bill Patterson, though the ‘wheel flop’ will be lower, which is more benefitting for low speed handling.
Also on Atomic Zombie plans, there is no recommandation about handlebar installation, which is shown by the fact all built WildKat have very different steering installation. For safety and ease of handling, I highly recommend to have the handlebar with a substantial vertical rise, in order to be able to maintain your body when braking. Indeed, there were reports of faceplants on really under seat handlebars without vertical rise.
The handlebar installation is one point were I expensed the biggest design time. I hesitated for a long time and was willing to make a double lever ‘tank’ steering. That may be better but heavy and very fragile, the lever support being really exposed when you fall (which WILL occur). I did create ‘amplification’ say the fork rotate more than the handlebar to take into account limited possible angle of handlebar.

On the other hand, Atomic Zombie publish a book:Bicycle builder bonanza that I bought used and that I recommend if you want to build a steel frame bike.

Long wheelbase similar bikes

  • The bike Fold Rush from Easy racer, long wheelbase bike with folding rear, but with above seat steering handlebar. Price 4000$ (which may end to 4500 Euros once imported in my country -France)
  • The bike Linear Limo, long wheelbase version with and underseat steering (really underseat, bars not rised). There is a disassemblable version to ease transport (2975 USD).
  • The bike Longbike Slipstream, underseat steering long wheelbase bike, however with a seat way too high for me even with the ‘Small’ frame. 2900$
  • The bike Rans Stratus With above seat handlebar, one of the most succesful long wheelbase bike. 2700$.
  • Sunseeker also build the EZ-sport,evolution of the EZ-1 which resemble the Rans but is built in asia, and sold for 1410 USD
  • Bachetta also sells the Bachetta Bella with a geometry very near to the Rans one, but a slightly different design for the frame.
There was Lightfoot mountain long wheelbase recumbent but they are no longer produced.
An amateur (Richard Ehrlich) had remarkable mountain recumbents built for him.2 3 4 first built in aluminium then carbon fibre. He race with these bike.
Long wheelbase bikes for touring are mainly diffused in the USA, by opposition to short wheel base bikes, often more sport oriented which are monopolising European market. In Europe, touring demand for recumbent often drive to choose ‘tadpole’ tricycles, which may be easier to transport with good stability and good performances.
Recumbent sector is relatively confidential, and among them long wheelbase bikes are fairly rare in Europe. We are there is the ‘niche of the niche area’.
One main problem of recumbent bikes is that they are relatively costly which may be one reason why their diffision remains limited. Conservatism also maintain this situation.
It shall be noted that these US bikes costing more than 2000 to 3000 USD are delivered in standard without lighting nor mudguards, you still shall add some money for this basic equipment… This sort of thing makes me cringe.
  • The bike Longbike L3 rider from Fateba, built in Swiss. Instead of their north american counterparts, this bike is properly equipped, but its cost is 4180 CHF as a base price (around 3700 Euros). And it is still too tall for me…
(c) Pierre ROUZEAU
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