Niki Smart, Jay Brett et Nick Mynott (ça fait boy’s band, non ?), sont les créateurs et constructeurs du tricycle SUB G1.
Niki Smart est designer de formation et bosse chez GM actuellement.
Lors de son passage au très réputé Royal College of Art de Londres, son projet d’étude était un tricycle à moteur de moto.
Si certains designers restent essentiellement des virtuoses du crayon à papier (ou de la table graphique), Niki a le gène manuel incrusté dans l’ADN.
Papa fabriquait les échappements pour moteurs de F1 et son cousin travaillait chez Williams à l’époque glorieuse des titres de Damon Hill et consorts.
Même son prénom, Niki, a été choisi sur les tablettes du classement du championnat du monde F1 de l’année de sa naissance !
Bref, Niki a donné corps à son projet en réalisant 3 prototypes roulants et homologués (comme moto en fait).
Avec ses associés, ils ont dépensé argent, temps libre et huile de coude pour arriver au résultat que vous avez sous les yeux.
Et même si depuis, le projet n’a pas réussi à passer le cap de la production (trop cher à produire et marché restreint), on peut admirer la somme de 2 ans et demi de travail.
L’esthétisme du projet était important et le SUB G1 n’est pas qu’un bricolage génial, il est l’expression d’une vision formelle.
Sous la peau composite, le chassis tubulaire reçoit un 1000 cc de 135 ch et 105 NM extrait d’une Suzuki.
Une moto bien sûr.
La boite séquentielle 6 rapports a suivi le propulseur, évidemment.
La difficulté technique du projet réside dans l’équilibrage de l’ensemble.
Avec 3 roues, ça n’est pas nécessairement évident.
Le SUB G1 répartit sa masse de la façon suivante : 50% sur la roue arrière et 25% sur chaque roue avant.
L’idéal quoi !
Le véhicule est donc stable mais aussi agile grâce à son centre de gravité “posé par terre“.
Sa nature l’aide aussi.
Un 3 roues est forcément plus directionnel qu’un 4 roues.
Les pneus utilisés sont de type moto.
Ils participent à la vélocité de réaction du véhicule mais aussi à l’esthétique recherchée du SUB G1.
Le poids devait rester contenu pour être homologué en tant que moto, il est tout de même de 330 kg.
Mais l’engin n’est pas non plus si petit : 3.20m de long, 1.76m de large et 1m de haut.
Si l’aventure semble au point mort actuellement, il faut franchement saluer ce genre d’initiative dans des pays qui autorisent tout de même un petit espoir de viabilité commerciale et industrielle future.
En France et en Belgique, il y a bien longtemps que cette époque est révolue…
Set up by three individuals Niki Smart, Jay Brett and Nick Mynott, SUB is a small company in southern California that caters to clients who want individual specialised vehicles.
Their first vehicle, G1 a three wheeler is an evolution of work done by Niki Smart years earlier on the “One-up” that sat in London’s’ Millennium dome.
G1 is a ground up build, demonstrating the company’s ability to produce, not just one, but a series of fully functioning, innovatively packaged vehicles that are road legal and that could be used in a day to day scenario as well as being pushed hard on a track.
The original One-up concept was ‘An Engineering Aesthetic’.
The project was about the design beauty that purely engineered forms posses from their focus on performance and efficiency.
Smart looked a lot at castings and fabricated suspension parts as well as WW2 battleships and especially submarines.
The idea was to be as minimal, without being a bike: one seat, three wheels and a small engine.
His original used a 600cc Honda CBR located behind the driver.
The resulting longer wheelbase (2.7m) made for a rear biased weight distribution.
The track was 1.6m. While similar in concept, G1 makes use of a tight packaged V-twin to reduce the wheelbase to 2.3m (same 1.6m track) and to achieve a 50/50 weight distribution.
The 50% on the rear wheel and 25% on each front creates a dynamic, stable platform.
A major aspect of the project was to design and build a vehicle with aesthetic appeal, a single seat, lightweight, high performance machine ideal for quick runs through canyons.
The project was never about straight-line speed or acceleration.
More important was to create a vehicle that handles predictably and controllably and is engaging and fun to drive, while keeping the project within a manageable budget and time frame.
Even the sportiest of cars on the market seem unnecessarily big with much unused volume and weight.
If you spend the vast sums of money that most exotic performance cars cost, the last thing that you want when pursuing the ultimate performance and efficiency is to put your friend next to you, destroying your power to weight ratio and upsetting the balance of the car.
The idea of a single seater seems logical for the ultimate in performance, even for the road.
In the automotive world, the notion of using three wheels where four would do is often received with wonder and mistrust.
It’s usually employed as a sales pitch for vehicles that are generally odd or dubiously functional.
The discussions for and against are largely based on issues of visual and dynamic stability, with the thinking that there is something missing (usually the forth wheel).
The aim of this project was not only to build a vehicle that overcomes some of the stigmas of three wheeled vehicles, but to surpass them and to exploit their advantages in an exciting and desirable product.
Some points of the project philosophy: The cornerstone of the project was to balance the weight of the engine with the weight of the driver. The new package allows the vehicles to achieve a weight distribution of 25% on each front wheel and 50% on the rear. A low centre of gravity and minimal polar moment of inertia provide a stable but agile vehicle. Both recreational and sports driving will benefit from its responsiveness and nimbleness and it does not need power assisted steering or braking; so improving feel and reducing component complexity. Quick steering response is a by-product of reduced mass and low polar moment of inertia, not on the number of wheels or how they are configured. A typical three-wheeler is lighter and has approximately 30% less polar moment than a comparable four wheel design. The yaw response time is the time taken to reach steady-state cornering after a quick steering input. This is around 0.30 seconds for a softly sprung four-wheeler. Four wheel sports cars will respond in about half that time. For a well designed three-wheeler, it’s as little as 0.10 seconds, which is a third less than a high-performance four wheel car’s typical 0.15 seconds. A benefit of using three wheels is to qualify the vehicle as a motorcycle and not a car, provided that the gross weight falls under 1500lbs. Consequently the vehicle does not have to comply with the level of legislation that a car has to. This typically means registration and road taxation. As a motorcycle the vehicle can travel in the car pool lane on freeways, even with just one person.
By using a 1000cc-motorcycle engine, efficiency is ensured (40 to 50mpg); because of the light, compact engine and gearbox, and because the unit has been specifically designed to propel a small mass as opposed to the engine and drive train in a conventional car designed to propel an average mass of 3000lbs. A major surprise is the use of motorcycle tires.
This was to get the right tire contact patch area distribution as well as weight distribution, with minimum tire frontal area and rolling resistance.
As the Morgan three wheeler demonstrated, you can attain high cornering speeds on narrow tires.
While it was easy to find a rear tire with the required contact patch it was difficult to find front ones.
However Avon builds a tire for the cruising market where they have widened the tire by splitting the conventional tire down the centre and added a spacer.
Available in a choice of widths, the Avon’s have the desired contact patch and are designed and built for the weight of the vehicle.
They have low rolling resistance and frontal area, to aid overall efficiency, and lend the vehicle a unique aesthetic quality.
The low centre of gravity makes life easy for the suspension.
Long double wishbones at the front act through pushrods to inboard spring-shock units.
At the rear, twin trailing arms act through a pushrod to a transverse mounted spring-shock unit.
In such a light vehicle using rose joints throughout and needle bearings in the rockers minimizes suspension stiction.
With a single tire at the rear, the front suspension system controls all of the roll.
To minimize pitch under acceleration and braking, the front and rear geometry has a low, central, instantaneous pitch centre.
This geometry also increases chain life by eliminating chain snatch.
Each individual brought a complementary skill set to the project.
Smart is a designer, and fabricator whose résumé includes work on the Aston Martin Vantage concept and the ultra-light weight Ariel Atom sports car.
Brett’s background of Industrial design and his ten-year involvement in film and automotive concept vehicle construction lends the project his expertise in fabrication and program management.
Mynott, a digital modeller, has an extensive background in automotive, product design and engineering and has worked on the construction of 6 concept and race vehicles within the last 4 years.
The combination produced the expertise in design, modelling and build required for the project, the overlapping skills creating an effective team.
Advanced 3D surfacing software was used to model the entire car from the ground up.
From initial suspension geometry in wire frame to the completed wishbones uprights and wheel arches, all modelled and animated through its full range of motion.
The computer enabled the team to design, refine and simplify each component, reduce costs and simplify assembly all before committing to production.
In it’s element as a tool for building and checking interference, fit and assembly the computer was used to speed production, reduce errors and produce a higher quality at a reduced costs to the team.
Throughout the build phase, modifications were updated in data and the physical models continually checked against the digital model to ensure tolerances were met.
Co-ordinate geometry machines and white light scans ensured that all the space available was utilized to best effect, giving a finished product that is tightly packaged, of minimum weight and has a formula feel.
Once surfaced and highlighted, the body tools were CNC cut to produce highly accurate low cost re-usable moulds.
Composite parts were oven cured before being finished and painted.
A complete cross section of tooling from plaster, foam and clay to composite epoxy and even rapid prototype parts were used.
Great importance was given to materials and finishes, from the powder coated two piece custom made forged wheels to the black phosphate finish of the steel bolts that hold the aluminium alloy uprights together.
Everything was given the same degree of consideration and importance to ensure a coherent high quality finish.
The result is three fully functioning road legal custom built vehicles that were delivered on time, on budget and to a very high quality.
Vehicles that have s ince driven over 1000 miles each with only suspension and spring rates needed to be dialled in.
The three cars are each individually fitted to the customers with custom seats and floor mounted pedals positioned to cater to their range in size; from 6 foot 8inches tall, to 5 foot 10 inches.
The car uses a modified motorcycle wiring loom and the gauge pack is carried through as well, with everything functioning including the fuel level meter.
The indicators and lights are positioned around the gauge pack within easy fingertip reach without having to take our hands off the wheel.
Each car is fitted with a four point anti-submarining harness and uses a cut off Momo steering wheel for better gauge visibility.
The cockpit walls are high giving the formula car feel while rear visibility is good due to the positioning of the mirrors.
The steering is quick with one complete turn for lock to lock.
The gear stick is mounted close to the steering wheel on the firewall that separates the driver from the engine which maintains the 6 speed sequential box form the TL1000R.
The brakes are strong and progressive giving good feedback.
Driving on the road you are smaller than most cars and much lower to the ground.
You feel like a race car driver because it has super bike-like speed and formula car handling.
The ability to see the wheels further enhances the formula feel of the vehicle with the ability to place the wheels right on the curbs through corners.
It all combines to create an unbelievably fun and unique experience.
The desire was to use a Yamaha R1 engine because of its low end torque however from the first moment it was apparent that the vehicle would either be very asymmetrical or that the engine would protrude from the bodywork in order to make it work.
The initial packaging study was done using PVC tubing, a basic wooden seat and the TL1000r motor.
The other problem was that it wasn’t possible to sit the engine next to the occupant, the farthest forward it would go was so that the clutch cover was tucked as close to the driver’s hips as was possible, effectively putting the widest two points of both elements next to each other.
This also meant that the wheelbase of the vehicle was not shortened sufficiently to overcome the problems found in the original 1up study.
The V twin however allowed the engine to be situated much further forward in the car.
Its narrowness allowed the car to be almost symmetrical in plan balancing the weight of the engine with the driver and still offered the low end torque that we were after.
Our only worry was the length of chain that would be required.
We then built the suspension geometry in wire frame to ensure that the inboard mounting points would meet the chassis in the required places and work as we intended.
After some initial discussions on how the bodywork would be split to keep it as simple as possible and having agreed on a system for the drive line it was possible to layout a simple tubular chassis that was modular in construction and would hit the points required.
From there with the basic principals of the car agreed upon and the major components such as the fuel tank, radiator and engine situated we built the chassis up in the computer adding roll hoop and triangulating where necessary.
Because of the required geometry and our desire to use motorcycle tyres it would not be possible to use an off the shelf wheel as the offset would not be correct and the bike tyre needs a different rim section to a car tyre.
From here it was possible to split the work between the design team so that different aspects could be tackled at the same time.
In addition the desire to use a common wheel face, to reduce the cost meant we had to find a way of manufacturing the wheel at as low a cost as possible.
Initial research into spinning a wheel face was not successful and turned out to be more expensive than machining wheels.
In the end we opted for forged wheel face welded into a rolled wheel band.
This meant we could use the identical wheel face on all corners of the car and reduce machining costs.
With the feasibility of the wheels established we set about designing the uprights.
Again as machining is a major cost the idea was to design something that was symmetrical across the front and kept cost to a minimum while obtaining a look that was consistent with the theme of the car.
After many iterations the final design consisted of a three piece assembly that used stock material sizes at reduced dimension and therefore cost, that required machining from only one side with a single bit size and pressed and located over itself.
The design eliminated the need for any welding, again reducing assembly costs and was held together by four bolts.
In addition a custom cush drive was made based on the same idea that Ducati’s use.
The same principal was applied to the rear upright although the deeper wheel and necessity to mount the drive sprocket meant that the rear uprights were more complicated to machine.
The problem of a very long chain was eliminated by the inclusion of a transfer shaft that sat on a common face with all of the rear suspension mounts.
The half shaft has several advantages the first being that in having two chains we can completely eliminate chain snatch by having the half shaft center exactly on the instantaneous center of the suspensions motion.
The second being that we can now change the gearing of the vehicle very easily without having to buy large sprockets for the rear and finally hat there is now an ideal location for an additional inboard parking brake and, if required a reverse mechanism.
All of the rear end is mounted onto a single face.
This was decided upon as it meant that we could use common pillow blocks to hold the wishbones and half shaft.
It also meant that chain adjustment could be done very simply by loosening the pillow blocks and shimming them out as necessary.
The rear plate was CNC machined to ensure absolute accuracy and then once jigged it was welded onto the chassis.
As the projected weight of the vehicle is very small great importance was put on reducing stiction in the suspension.
Front wishbones were jigged and fabricated from aero tubing while the rear wishbones were a combination of machinings and mandrel bent tubing.
Rose joint were used throughout and rockers were mounted on needle bearings front and back.
The rockers themselves were deigned and machined with the same feel as the uprights.
While we used Penske shocks throughout.
The fuel tank is a custom made epoxy cell that utilized all of the Suzuki’s fuel pump componentry to ensure that everything works including the fuel level meter.
The seat and fuel tank are the major components of the interior.
The importance was put on maximizing the capacity of the tank so that it would not be necessary to refuel as often as is required on a bike.
The seat and tank are designed to fit together and form a single surface that flows from the shoulders down to the feet.
It also acts as the firewall separating the driver from the engine which sits just an inch from the right elbow.
It was decided early on that the seat would be built to accommodate the largest client, at 205cm tall, and that the pedal box would be individually positioned for each client. In addition the shorter clients would be bolstered in the seats using either a formula type seat form or a custom made bolster.
The seat is a large open form that sits on the chassis rails.
This allows us to build padding in between it and the body panels that overlap as the edges of the seat will be used as hand holds whilst getting in and out of the vehicle and therefore need to be very solid.
The gear shift mounted on to the firewall between the driver and engine and is a direct link to the existing TLR gearbox.
The muffler was sourced from a local manufacturer in CA.
With the engine installed we designed the exhaust headers to use existing off the shelf bends and fabricated them from stainless tubing donated to us from Yoshimura.
At his point we also needed an accurate volume for the airbox as the stock airbox sits over the engine overlapping it on both sides.
We also wanted to maximize the use of the area in front of the engine for additional volume in the airbox.
To do this we digitized the stock airbox base and, because digital data was not available for the engine, took a digital snapshot of the engine, as it sits in the chassis.
All of the parts of the airbox were then CNC machined from foam and female mould taken off them.
This allowed us to build very accurately into the space between the radiator, reserve bottle and piping maximizing the use of the available space.
The body panels were also being developed in conjunction with these parts to ensure accuracy between components.
Finally the wiring loom was modeled in to ensure that there were no interference issues between the plugs and ECM as they sat very close to the fuel filler neck that was situated only by the filler cap on the exterior bodywork.
We then created female epoxy moulds from them so that multiples could be pulled without destroying the tools.
Once complete the two major body panels were CNC cut as male masters from clay over bead foam.
We had initially intended to cut plaster tools however with time running we couldn’t wait for the facilities to become available to us.
However smaller parts such as the rocker panels and roll hoop were machined, in negative, from various materials like foam and, in the case of the rocker panel, bead foam with a skin of gel coat.
Giving a very cheep tool that would not degrade with multiple pulls.
Fiber glass bulkheads were machined and inserted into the nose cone, rocker panel and the two main body parts to ensure that when the parts came together they fit exactly and would simply pin together.
This process of manufacture meant that we could lay up very accurate thickness of glass by hand and not need to do any body filling once the cured parts were pulled from the tools.
In addition it meant we could keep the weight of the panels to a minimum.
The uprights rockers and all other aluminium was sent out to be anodised and the wheels to be powder coated.
With the chassis finished and the first test runs under our belt the chassis were sent out to be sand blasted before being painted.
Bolts for the uprights were Dacromet coated to isolate them from the aluminium, wishbones painted and exhaust wrapped ready for assembly.
The loom was wrapped and he military style bayonet fittings added.
When the wheels returned they were then taken to have the tyres (donated by Avon) fitted, and the final assembly began.
The first weekend after the completion the cars were taken out into the Santa Monica mountains above LA and 300 miles put on them by the clients.
The three cars were completed with wheel arches and lights all together in March of 2005 just one week ahead of the first press article was to be written by the Robb Report one week later.
The cars were in need of some minor suspension tuning and gearing alterations but they drove well and more than met the expectations of their new owners.
A month later two cars reside in the US and one in the UK.
Front: Double unequal length wishbones Fabricated from 16 SWG DOM aero tub. Fully adjustable rodends inboard and outboard. Pushrod activated inboard suspension Penske custom shock absorbers T-bar type adjustable anti-roll bar Rear: Single sided arrangement. Upper and lower trailing arms. Pushrod activated inboard suspension. Penske custom shock absorber. Adjustable camber and toe. Steering Rack and Pinion 1 turn lock to lock Adjustable rodend steering arms 250mm Mono Suede Steering Wheel. Open top for better view of intruments. Quick release mount for ease of ingress and (when you remembe to take it off, Mark) egress. Seating Epoxy composite construction. 5-point quick release harness Suzuki Instrumentation. Braking Adjustable floor mounted aluminum pedal box Cable operated throttle Twin master cylinder front/rear brake pedal with balance bar. Hydraulic clutch Stainless Steel braided lines throughout. Brake components common on all corners. Wilwood 350mm/12″ Single cross drilled discs Two piston billet calipers Custom Mounting Bells Wheels Two piece forged aluminum 18 x 5.5″ front 18 x 6.5″ rear. Tyres Front: Avon AM23’s 180/55R 18 Rear: Avon AM23’s 200/50R 18 Engine Suzuki 996 cc 4-stroke liquid-colled 90° V-twin, DOHC, 8 valves, 135hp (98.6 kW) / 9500rpm 105 Nm / 7500rpm Electronic Dual-Stage Fuel Injection – 52mm throttle bodies Aluminum head block gearbox and sump 6-speed sequential grearbox No reverse as yet. Park uphill or get a push. Chain driven to rear wheel via a twin chain arrangement through a jack shaft allowing mounting for e-brake and in future a reverse gear. Also easy adjustment of gear ratios. Induction Ram air effect bespoke airbox with panel filter. Exhaust Stainless steel tuned length (for torque, not necessarily power) primaries 2 into 1 merg collector. 6″ diameter single silencer. Loud pipes saves lives so they say. Cooling Increased volume aluminum radiator with electric fan Silicone hoses Fuel Cell Epoxy composite Capacity 7.5 US gal
Vehicle Dimensions Overal Length 3200mm / 125″ Overall Width 1760mm / 69″ Overall Height 1000mm / 39″ Weight 330kg / 86.6″ Track 1600mm / 63″ Weight Distribution 50/50 (50% rear 25% on each front wheel) Chassis Tubular spaceframe contruction with aluminum and composite bulkheads. Predominantly 16SWG Mild Steel DOM (Drawn over Mandel) seemless tube. TIG welded. Suspension
P.O. Box 2003
Burbank, CA 91507 USA