Smart Roadster And Roadster Coupe | Part Two

Smart Roadster

 

The Material Concept: A Low Power/Weight Ratio Guarantees Heaps Of Driving Pleasure

With an engine output of around 60 kW and a weight of around just 790 kilogrammes, at 13.2 kilogrammes per kilowatt (9.6 kg per bhp) the smart roadster and smart roadster-coupé offer a power/weight ratio which is extremely low compared with that of other cars and this has a positive effect on the handling performance. Whereas roadsters of the ‘50s and ‘60s were relatively light with a vehicle weight of less than 1,000 kilogrammes, the engine power rarely exceeded 45 kW. Modern vehicles with more power are much heavier, often at the cost of driving pleasure.

The fact that the smart roadster and smart roadster-coupé are setting new standards here is not least due to the quality and weight of the materials used in these cars. The TRIDION safety cell with a weight of just 192 kilogrammes greatly contributes to this. The rigid cell is also the basis for the precise handling and the excellent suspension characteristics. Its sturdy architecture means that the cabriolet shaking which occurs among this species, is unknown to the smart roadster and smart roadster-coupé, even when driving on extremely rough roads. And finally crash safety also benefits greatly from the high structural stability.

The use of so-called tailored blanks is a further reason for the extremely low total weight. Panels of varying thickness make it possible to have thick sheet metal in areas under strain and thinner sheet metal in areas under less strain. In addition to this high-strength and extremely high-strength steel alloy is used in areas where maximum force is applied or acts.

Finally, like the smart city-coupé and smart cabrio, plastic bodypanels also form the outer skin of the smart roadster and smart roadster-coupé. This material, which is much lighter than steel, is used in the front and rear ends, wings and doors. The powder-coated TRIDION safety cell remains visible in the area of the door sill, B-pillars and roll bar as a visual representation of the two-colours and safety concept typical of the smart brand. Like the smart city-coupé and smart cabrio this concept has proved to be robust in everyday use and enables easy repairs in the event of damage. The bodypanels are simple and therefore inexpensive to replace.

Smart Roadster: Notchback And Folding Soft Top As Characteristic Features

For the market launch in April 2003 the smart roadster will initially be offered with an approximately 60 kW SUPREX turbo engine with an engine capacity of 698 cm3 and torque of around 110 Newton metres. The engine does not only comply with exhaust gas standard EU 4, its extra power and torque also give the car driving dynamics appropriate to the smart roadster.

A basic version with less engine power will also be available in the foreseeable future at a net price of around 13,000 euro. Furthermore, smart-Brabus GmbH will offer an exclusive and extremely sporty variant of the smart roadster at a later time.

The smart roadster has the same sequential automated transmission as the smart city-coupé and smart cabrio – in a further optimised form. The sporty close-stepped ratios have been adjusted to the increased engine power and vehicle performance. In connection with this it was also possible to further optimise the gear-change sequence of the automatic transmission. A kick-down function greatly improves the driveability. The smart roadster is equipped with an automatic function as standard which is always activated once the engine has been started.

The smart roadster’s TRIDION safety cell is available in black, or in silver for an extra charge. The bodypanels are available in the colours jack black, shine yellow and spice red. The colours champagne remix, star blue and glance grey are available for an extra charge. The interior of the smart roadster is available in the colours scribble black or scribble red, or in black leather for an extra charge. The smart roadster is available with a soft top or alternatively with a hardtop with a matt surface at no extra charge.

The tyres of the smart roadster have the dimensions 185/55 R 15 on the front and rear axle on spinline light-alloy rims. Trackline light-alloy rims with 205/50 R 15 tyres or spikeline light-alloy rims with 205/45 R 16 tyres are available for an extra charge.

The smart roadster is equipped with the electronic stability program ESP as standard. This enables selective intervention by the brake system to stabilise the car. In addition, ESP offers anti-stall assist and brake assist functions as well as cornering brake control - regulation of the braking pressure on specific wheels when braking in curves.

The smart roadster’s standard equipment also includes SOFTOUCH automatic transmission, sports seats, leather steering wheel and leather gear knob and a flexible service interval display which calculates and displays the change intervals depending on the oil used.

The sports package option offers customers a three-spoke leather sports steering wheel with rocker switch steering wheel gearshift and 205/45 R 16 spikeline light-alloy rims. The safety package consists of fog lamps, electrically adjustable and heated door mirrors and side airbags for an extra charge.

Further options include leather sports seats with seat heating, additional instruments (engine temperature and charge pressure) a radio, CD changer, radio with CD and a corresponding sound system.

A comfort package available as an option consists of cruise control, electric power steering and a trip computer. Useful information can be called up on its LCD display, for example a fuel gauge indicating the remaining level of fuel in 0.5 litre steps and the distance that the car can travel with the remaining amount of fuel. Times travelled and intermediate times can also be recorded, saved and correlated with the sections driven. The trip computer also has an electric logbook.

In addition to this it visualises a number of warnings: it gives a signal when the doors are not closed properly or when the soft top is open. It also informs the driver if the engine temperature is too high, the oil pressure too low and about the brake fluid level. Moreover, it warns the driver when there is a danger of icy roads (from +3 degrees centigrade). The driver can also call up the distance or the time until the next service interval.

Smart Roadster-Coupé: Fully Glazed Rear Section And Removable Hardtop

The smart roadster-coupé with a fully glazed rear section will be available with an approximately 60 kW SUPREX turbo engine with 698 cm3 engine capacity and around 110 Newton metres of torque. The engine does not only comply with exhaust gas standard EU 4, its extra power and torque also give the car driving dynamics appropriate to the smart roadster-coupé. Furthermore, smart-Brabus GmbH will offer an exclusive and extremely sporty variant of the smart roadster at a later point in time.

The smart roadster-coupé has the same sequential automated transmission as the smart city-coupé and smart cabrio – in a further optimized form. The sporty close-stepped ratios have been adjusted to the increased engine power and vehicle performance. In connection with this it was also possible to further optimise the gear-change sequence of the automatic transmission. A kick-down function greatly improves the driveability. The smart roadster is equipped with an automatic function as standard and this is always activated once the engine has been started.

The smart roadster-coupé’s TRIDION safety cell is available in silver or alternatively in black at no extra charge. The bodypanels are available in the colours jack black, shine yellow and spice red. The colours champagne remix, star blue and glance grey are available for an extra charge. The interior of the smart roadster-coupé is available in the colours scribble black or scribble grey, or, for an extra charge, in black leather. A soft top is available as an option in addition to the high-gloss hardtop.

The smart roadster-coupé has 205/50 R 15 tyres on the front and rear axle. The light-alloy rims have a trackline design. Spikeline light-alloy rims with the dimensions 205/45 R 16 are available for an extra charge.

The smart roadster-coupé is equipped with the electronic stability program ESP as standard. This enables selective intervention by the brake system to stabilise the car. In addition, ESP offers anti-stall assist and brake assist functions as well as cornering brake control - wheel-specific regulation of the braking pressure when braking in curves.

The standard equipment also includes SOFTOUCH automatic transmission, air conditioning, sports seats, silver contrast components in the interior including armrests, leather steering wheel and leather gear knob and a flexible service interval display which calculates and displays the oil change intervals depending on the actual lubricant used.

The sports package option offers customers a three-spoke leather sports steering wheel with rocker switch steering wheel gearshift and spikeline light-alloy rims with 205/45 R 16 tyres. The safety package consists of fog lamps, electrically adjustable and heated door mirrors and side airbags for an extra charge.

Further options include leather sports seats with seat heating, additional instruments (engine temperature and charge pressure) a radio, CD changer, radio with CD and a corresponding sound system.

A comfort package available as an option consists of cruise control, electric power steering and a trip computer. Useful information can be called up on its LCD display, for example a fuel gauge indicating the remaining level of fuel in 0.5 litre steps and the distance that the car can travel with the remaining amount of fuel. Times travelled and intermediate times can also be recorded, saved and correlated with the sections driven. The trip computer also has an electric logbook. In addition to this it visualises a number of warnings: It gives a signal when the doors are not closed properly or when the soft top is open. It also informs the driver if the engine temperature is too high, the oil pressure too low and about the brake fluid level. Moreover, it warns the driver when there is a danger of icy roads (from +3 degrees centigrade). The driver can also call up the distance or the time until the next service interval.

The Roof Variants:

Electric Folding Soft Top As An Alternative To The Hardtop

With a roof system consisting of a soft top and a hardtop which can be used together or alternatively, the smart roadster and smart roadster-coupé offer their owners maximum open-air driving pleasure. As well as a two-piece, removable plastic hardtop that can be transported in the rear luggage compartment, an electrically operated folding soft top is available as an option for both the smart roadster and the smart roadster-coupé.

The smart roadster comes with the soft top as standard. However the customer may also choose a hardtop with a matt surface as a basic appointment at no extra charge. This is also available as an accessory. The smart roadster-coupé rolls off the production line with a high-gloss hardtop. Here, the soft top is available as an option. With a system weight of just 14 kilogrammes the folding soft top also makes an important contribution to the overall low weight of the cars.

The hardtop is divided lengthways in the middle. It covers an area 750 millimetres long and 1000 millimetres wide. The roof segments can be removed with a few deft movements, packed into special moulded plastic parts and stowed in the rear luggage compartment. The components weigh a total of just ten kilogrammes and are made of fibreglass-reinforced polyurethane foam.

The soft top can be opened to any desired position with a rocker switch on the centre console, even whilst driving, and closed again by pressing the button. It only takes approximately ten seconds to fully open the soft top which slides back under the roll bar to the luggage compartment. When the soft top is down the driver retains full vision through the rear window.

To reliably rule out operating errors and thus damage to the roof system and cargo there is a folding, spring-loaded strip on the rear luggage compartment floor. When the soft top is open, its vertical position prevents the cargo from touching the soft top. The smart roadster-coupé then has a luggage compartment capacity of 104 litres. When the luggage compartment is fully loaded the strip is folded down horizontally by the luggage on it. In this case the luggage compartment has a volume of 189 litres and the folding top cannot be opened.

Modelled on the smart cabrio, the smart roadster and smart roadster-coupé also have removable side roof bars. When the soft top is fully open these bars can be removed and stowed in the front luggage compartment. For safe, scratch-proof and space-saving stowage, the bars fit into a system consisting of moulded parts and recesses in the plastic lining of the luggage compartment. When the roof bars are stowed here the front luggage compartment offers a capacity of 59 litres. Otherwise it is easy to stow a standard size crate of water or beer here.

Active Safety:

Electronic Stability Program(ESP) As Standard

The smart roadster and smart roadster-coupé come with the driving dynamics control system ESP (electronic stability program) as standard. ESP does not only have the TRUST PLUS functionalities familiar from the smart ciy-coupé and smart cabrio, it also offers several additional features for the two new cars: selective brake intervention, anti-stall assist and brake assist as well as cornering brake control CBC (stabilisation during partial braking whilst cornering). Moreover, the anti-lock braking system ABS including electronic braking-force distribution is integrated in ESP.

Like TRUST PLUS, ESP ensures that smart cars always follow the direction in which the driver steers, even at the stability limit of driving dynamics. In addition to closing the throttle valve and opening the clutch, ESP also offers brake intervention acting on individual wheels. This ensures directional stability and road adhesion when accelerating, braking and coasting. Within physical limits, ESP ensures that during fast cornering the cars neither push over the front axle (understeering) nor push outwards with the rear end (oversteering).

In the event of oversteering ESP specifically brakes the front wheel on the outside of the curve – regardless of whether the driver is braking, rolling or accelerating. The braking torque applied against the rolling direction around the vertical axis of the car prevents the rear end from breaking away. ESP balances understeering by braking the rear wheel on the inside of the curve; this steers the car to the desired course in the curve. The electronics also cause the throttle valve to close.

If the drive wheels lose traction, the drive torque is reduced and the brake system applies force to the wheel with the most traction slip. In this way ESP realises the function of a differential lock by means of braking torque intervention which enables traction even on extremely slippery terrain, when there is different coefficient of friction on the right and left drive wheels, and on hills. This greatly improves the car’s hill-climbing ability. For the extended functions as against TRUST PLUS, ESP makes use of a special hydraulic control unit which is regulated electronically, plus a number of sensors. These make it possible to capture the vehicle dynamics, especially around the vertical axis of the vehicle.

For even more driving pleasure in the smart roadster and smart roadster-coupé and to enable the driver to test the limits of the cars, ESP can be switched off with a push button switch on the instrument panel. This enables the driver to call a certain amount of slip of the rear wheels via the accelerator pedal. However for safety reasons when ESP is switched off only the drive torque regulation and the selective brake intervention during the acceleration phase are deactivated: When braking, the selective brake intervention for stabilising the vehicle remains.

To make starting on a hill as comfortable as in cars with automatic transmission and a torque converter, the smart roadster and smart roadster-coupé have an anti-stall assist AAS. After releasing the brake pedal when stationary ESP keeps the wheels braked for 0.7 seconds. This means that there is enough time to move the foot from the brake to the accelerator pedal without the car rolling forwards or backwards on account of the disengaged clutch. This also protects the clutch and makes it possible to drive off without the assistance of the hand brake, even on steep slopes.

The hydraulic brake assist HBA also makes a decisive contribution to active safety in the smart roadster and smart roadster-coupé. It automatically initiates controlled emergency braking when the driver steps on the pedal quickly, but not hard enough. The system automatically generates locking pressure in order to induce the ABS to regulate. The control variable for this is the speed at which the driver steps on the brake pedal.

The ability of ESP to act on individual wheel brakes creates the basis for a further safety function of the ABS: cornering brake control CBC. In fast cornering there is much less load on the inner front wheel. If the driver steps on the brake in such a situation ESP senses that more braking power can be transferred from the other wheels than from the wheel with a reduced load. The ABS control and pulsating of the pedal in connection with this is therefore not activated unnecessarily.

continues... | Part Three
Published 29 August 2002 Melanie Carter

The information contained this smart news article may have changed since publication on the 29 August 2002. Our car specifications, reviews, and prices may only apply to the UK market. You may wish to check with the manufacturer or your local smart dealer, before making a purchasing decision. E.&.O.E. You may NOT reproduce our car news in full or part, in any format without our written permission. carpages.co.uk © 2017