The Mazda MX-5 Miata kicked off the Roadster Revival in 1989 with a bang, and in the ensuing years the BMW Z3, Mercedes SLK and Porsche Boxster followed, albeit as more sophisticated and expensive cars in the league above. All were wildly successful at first.
However, over time the Roadster frenzy subsided, and flagging sales saw the SLK killed off in 2020. Meanwhile, economies of scale and modest sales projections saw the Fiat 124 Spyder created on a Mazda MX-5 platform and made by Mazda in Japan. Meanwhile the fifth generation (G29) BMW Z4 on which the Boldmen CR4 is based, shares its platform with the fifth generation Toyota Supra.
I was not a fan of the new BMW Z4’s looks from day one. To my eyes there is too much going on in a fairly short car, and with so many angles zooming off in different directions, your eyes are pulled this way and that. I would describe the Z4 as a restless design that the passing of time will not look kindly upon.
Haute Couture Tailoring
Even though it has to adopt the proportions of the Z4 inner core, the styling of the Boldmen CR4 succeeds in tidying up BMW’s committee design. Replacing the Z4’s steel and aluminium clothing with their own bespoke carbon-fibre panels gave Boldmen the bandwidth to perform a near complete styling makeover.
The dominant rising diagonal signature line on the Z4’s flanks is the first thing to be banished, and the CR4 is notable for the clean compound curves applied to its front wings and taut rear haunches. This presents classic British Roadster style front and rear wings visually linked by the smoothly curved door panels.
You can specify 20 or 21-inch wheels, and our test car was fitted with the largest wheel option of 9.0J and 10.0J x 21-inch alloys, shod with 245/30ZR21 and 295/25ZR21 Michelin Pilot Sport 4S tyres. These fill the big arches right to the brim, giving the car a lower and more purposeful stance than the Z4.
Lights make a huge difference to the way a car appears. The CR4 ditches the BMW headlights for LED lights set into carbon-fibre frames that keep a similar modern theme but also command a more upright appearance.
You Light Up My Life
Where the Z4’s thin, horizontal tail light clusters enhance the car’s low and wide rear aspect, Boldmen use vertically stacked LED tail lights set into a bespoke carbon-fibre housing just like the headlamps. Their vertical stacking is more in keeping with a classic roadster, and has overtones of the tail light style associated with the Wiesmann Roadster that Friedhelm and his brother produced for so many years.
BMW’s design chief, Adrian van Hooydonk has been in place since 2009, and presided over what many BMW fans agree was the Golden Age of modern BMW design that lasted till around 2018. Unfortunately, things have gone awry since then, and the messy styling of the G29 Z4 is just part of this fallout.
The counterpoint was not lost on us that the Boldmen CR4 uses the essence of the simple and elegant design language promoted by van Hooydonk and his team a decade ago, and is all the better for it.
The Same But Different
If you have driven the latest BMW Z4 then the cabin architecture, seats and all the controls and infotainment system in the CR4 will be familiar to you. However, that is where the similarity ends and the plusher Boldmen cabin takes over.
The cream leather trim with blue piping on the seats, door panels and dashboard, and the Royal Blue carpet mats with cream leather edging are reminiscent of the way Alpina makes the interiors of its cars feel more exclusive and special than a run-of-the-mill BMW. However, the cream leather dashtop reflects badly in the windscreen, something that was most apparent on the warm sunny day we spent with the car.
The only thing I did not like about the Boldmen CR4 Roadster is down to BMW. From the 1960s until 2018, BMW had one of the clearest and easiest to read analogue instrument dial designs in the industry. All that changed with the debut of the current G20 3-Series.
Apparently, the team who designed this new digital instrument panel does not realise that the human brain cannot easily assimilate information from two sources moving in arcs from the sides towards the centre. This panel is also difficult to read in an open roadster with the sun is beating down, or behind you and low in the sky. Change for the sake of change!
Open Air Concerto
Push the start button and the CR4 bursts into life with a crisp bark from its four exhaust pipes and settles into a steady six-cylinder purr at idle. Blip the throttle and a sporty growl comes back from behind your head.
If paddle shifts are present I always use them in manual mode. With Sport mode engaged in first, the dark blue Roadster moves off smoothly and rapidly, with strong thrust in the gears between each of the Steptronic gearbox’s eight closely stacked ratios.
Boldmen offer two states of tune for BMW’s B58 2,998cc turbocharged six. The base car is the Z4 M40i with 340hp and 500Nm of torque, which accelerates to 100km/h in 4.5 sec and on to an electronically limited 250km/h top speed.
So why CR4? The ‘C’ stands for carbon-fibre construction, while the ‘R’ represents a classic Roadster form with a fully electric soft top. Last but not least the ‘4’ means the car is in the 400hp+ Class. The first 30 CR4 and CR4 S cars will each carry a distinctive plaque marking them out as such. To that effect our test car was No 1/30.
The change in body material is very significant to the Boldmen Roadster’s kerb weight. Tipping the scales at 1,495 kg, the CR4 is about 100kg lighter than the equivalent Z4. Bespoke suspension springs take the reduced kerb weight into account, with electronically adjustable coil-over suspension an option for the more hard-core driver.
More Is More
Our CR4 test car boasts 408hp and a healthy 610Nm of torque. The double-edged sword of reduced weight and increased power drops the 0-100km/h time to 3.9 sec, although top speed is unchanged from stock.
If that is still not enough for outright power junkies, the 500hp and 700Nm on tap in the CR4 S flagship model should do the trick. As the stock turbocharger does not have the headroom to reach these power levels, Boldmen give the CR4 S bigger lungs with a modified turbocharger featuring a larger turbine wheel in its custom machined housing and a bespoke exhaust manifold with better flow characteristics. At the other end of the exhaust system the new rear silencer further reduces back-pressure and delivers a deeper soundtrack.
Further gains come from a modified emission control system that improves air mass flow and fine tuning of the ECU mapping to maximise all the hardware upgrades. Finally, the gearbox ECU is also remapped to suit the higher outputs and optimise clutch pressures and shifting characteristics. This total optimisation suite allows the flagship CR4 S to cover the 0-100km/h sprint in just 3.7 sec on its way to a 270km/h Vmax.
On the fast Bavarian country roads where my test took place the CR4 ate up the tarmac with aplomb, eagerly turning into the bends and dancing through them with impressive lack of roll and tons of mechanical grip from its big rubber contact patches. The thrust out of each corner is strong and seamless, with BMW’s eight-speed once again proved that ZF makes the best auto gearboxes in the business.
The Verdict
So is the Boldmen CR4 just a prettier BMW Z4 that costs a whole lot more? Au contraire, it is an attractive, hand-built, low volume roadster that offers the best of modern BMW engineering without the styling drawbacks. This also means you can own a unique limited edition sportscar that any BMW dealer can service no matter where in the world you might live.
Who are Boldmen?
There is an old saying amongst racing drivers, “There are old drivers and there are bold drivers, but there are no old, bold drivers!” And then there is Boldmen, a new German specialist sportscar manufacturer from Friedhelm Wiesmann, the man whose name is on the Wiesmann Roadster and Coupe made between 1993 to 2013.
In explanation of his new company’s name, Friedhelm Wiesmann gave a brief recap of the intervening years between the 2014 insolvency of the original Wiesmann GmbH operation and Boldmen today. “The company was sold to a London-based investor Roheen Berry, who planned to revive it with an electric-powered sportscar and a launch planned for 2024,” he said.
The idea for a new car and company to make it came about by chance when Friedhelm, who hails from Westphalia in North-West Germany, was introduced to Bavarian Harald Käs and his son Michael, by a former boss of BMW M GmbH who knew both parties.
Friedhelm had long since been living in Bavaria with his wife. Having left the original Wiesmann company some years before and retired to Lake Tegernsee, Friedhelm was keeping himself busy advising start-up companies and giving lectures. He certainly had no designs on being involved in a new automotive adventure.
The Partner
Harald Käs is a self-employed electrical and IT specialist who had built a very successful medium-sized company with his wife. But his passion had always been cars, and he spent his spare time restoring young and old-timers.
Harald’s passion rubbed off on his son Michael at an early age, and he went from being an apprentice car mechanic at BMW to the youngest car master mechanic in Bavaria at just 19 years-of-age. His credentials easily got him a job in the bodyshop at Ruf Automobile in Pfaffenhausen, followed by the engine department at Alpina in nearby Buchloe.
In 2014 the father and son car enthusiasts developed their Everytimer 02 Convertible on modern BMW mechanicals with styling influenced by the classic 02 Cabriolet. BMW enthusiasts were delighted with the look and quality of the car as well as the relatively modest price tag. German car magazines loved it too, which put the spotlight on the Käs family and prompted the former head of BMW M GmbH to call Friedhelm to see if he could help them take their small enterprise to the next level.
It Takes Two To Tango
Their first meeting in Welden near Augsburg went well and Friedhelm was taken with the enthusiasm and expert knowledge of the father and son team. On their part they were already thinking of doing another project after the limited edition Everytimer, but had no idea at that point what this might be. A few more meetings sealed the deal, and the three decided to develop a new roadster together and manufacture it at the existing facility in Welden.
“With the Wiesmann handle gone with the old company we had to think of a fresh marque name for the new car,” Friedhelm recounted. “We trawled through English, French and Spanish dictionaries looking for a suitable name that no-one had registered.
“In the spring of 2021 we settled on ‘Boldmen’, the inspiration being ‘Bold Men’ as meaning ‘strong and brave men’. These were qualities they were indeed going to need in the coming months!
Standard & Bespoke Audio
The standard audio system in the Boldmen CR4 I tested was the BMW Harman Kardon Sound System, which is competent but nothing special. Friedhelm explained that music lovers can tick the box for the bespoke 12-speaker High-End Surround System, developed in conjunction with German specialist audio company Audiotec Fischer.
The DSP control unit provides a total of nine channels to control individual speaker configurations, with the 32-Bit platform using multi-stage “Virtual Channel Processing” programmed via the user-friendly DSP PC-Tool software. Audio functions such as Augmented Bass Processing and Real Centre plus a channel-separated Input EQ are stand-out features, the latter with an Input Signal Analyser (ISA) for the easy analysis and compensation of the signals from OE radios.
A Cool Package
Audiotec Fischer’s proprietary Class GD amplification claims to be a step beyond conventional Class D. By varying the internal supply voltage in several steps depending on the input signal this design significantly reduces idle losses, resulting an efficiency being close to maximum at all times. This results in negligible heat dissipation, which in turn enables the use of smaller heat sinks and a reduced package size. Power output is 6 x 65 Watts at 4 Ohms for mid-range and tweeters plus 2 x 90 / 160W RMS into 4 / 2 Ohms for large subwoofers.
Covering the frequency range 100Hz-25kHz, the system uses two-way components speakers with 118mm / 4.65-inch diameter coated paper mid-woofers and 43.3mm / 1.71-inch coated silk dome tweeters. The mid-woofers replace the factory door speakers while the tweeters are mounted on the A-pillars in bespoke housings. A third pair of speakers is installed under the factory dashtop grille. The 12 dB slope crossover units feature three-stage tweeter level adjustability.
A pair of 8-inch fibreglass cone sub-woofers with 200 Watts RMS and 400 Watts peak power handling are mounted under the seats in bespoke 12-Litre vented boxes, whose lower limiting frequency is 45 Hz at -3dB. Given that a 45Hz sound wave is already over 7.6 metres long you will not credibly hear anything lower in a roadster with the roof down!
- Price Boldmen CR4: from 189,900 euros, Harman Kardon HiFi sound system included
- Price Boldmen bespoke HiFi sound system: TBA
- More info: boldmen.de
