Bringing back the 2-stroke: Interview with Langen Motorcycles Founder

Even now, 16 years after the last mainstream two-stroke sports bike was removed from the market and nearly two decades after the format was replaced by four-strokes in top-level racing, there’s an undeniable cachet to strokers.

The increasingly rare whiff of burning two-stroke oil as an elderly scooter passes, accompanied by its distinctive metallic ring, is enough to fire the synapses and bring back a torrent of nostalgia to any rider old enough to recall the 80s and 90s heydays of bikes like the Yamaha RD500, Suzuki RGV250 and Aprilia RS250. Now as a growing number of the generation-X youths that caught the end of the two-stroke era reach the age and affluence to indulge themselves, we’ve seen prices of used strokers rocketing. So why not make a brand new one to fill the demand?

That’s precisely what new British firm Langen Motorcycles is doing. The firm officially unveiled its machine, simply called the Langen Two Stroke, at the exclusive Salon Privé event at Blenheim Palace this week, so we caught up with the firm’s founder, former CCM chief engineer Chris Ratcliffe, to find out how he’s managed to create a road-legal stroker and what the firm’s plans for the future are.

When every major manufacturer dropped two-strokes years ago under pressure from ever-tightening emissions limits, how has a start-up from Wigan managed to bring one to the market? The answer is a combination of clever engineering and, initially, some quirks of the law.

The Langen Two Stroke uses the 249.5cc, 90-degree V-twin two-stroke developed by Italian engineering firm Vins Motors, an all-new engine created using patented technology to combat traditional emissions problems of two-strokes. It’s direct-injected, so the fuel is squirted straight into the combustion chambers after the exhaust ports are closed to prevent the usual two-stroke problem of unburnt fuel getting into the exhausts, and the lubrication is achieved via another injector that doses small amounts of oil into the crank cases, altering the flow depending on revs and throttle position to make sure there’s no excess oil-burning.

Chris explained: “At the front, between the cylinders, we've got some carbon-fibre reed valves and in between them we have two fuel injectors and the oil injector. So the fuel and the two-stroke oil ECUs talk to each other.

“Traditionally you'd have a premix and you'd be dumping the same amount of oil in at all RPMs, which results in burning lots of oil off or leaving oil residue on the pistons. This system literally puts vapours of oil into the engine, which means we can control everything and meet emissions standards. You don't need so much oil low in the RPM range and you need lots more at higher revs.

“The fuel injection is into the heads, and that's talking to the lubrication system and letting it know what oil it needs, so it squirts in just the right amount. The oil injector goes into the crankcase, but because it's a 90 degree V-twin the injectors are located in the same place, just pointed in different directions.”

At the moment, despite the technology, the engine still isn’t certified to Euro5 emissions standards, although that’s something that’s in the pipeline for the future. So to manufacture the first 100 bikes – the only machines Langen will ever make to this spec, built purely for the British market – the firm is using Single Vehicle Approval to register them in the UK.

“Vins is working on Euro5 emissions at the moment. We're going to make 100 bikes for the UK first of all, and if there is a demand in other countries - and it seems to be quite popular in Japan and the States - we're looking to type-approve for Euro5 as well. That will follow in probably 2022,” explains Chris, “We're using Single Vehicle Approval, which we can do more efficiently. It also means we don't have to put ABS on there. This bike is all about the purity of the rider being connected to the bike, and the feel of it.

“If there's demand we'll make a further 150 for the rest of the world. That bike will have ABS and things like that, which water it down a little bit, but it will still be a fantastic bike. Also the noise regulations in the UK allow 99dB, which is a bit better than Europe, so we're at 98.5dB or something like that...”

Langen Motorcycles has an exclusive deal for the supply of the Vins engine, making it just the second machine to use it. Vins’ own machine, the Duecinquanta, is a very different offering – a carbon-framed, track-focussed sports bike – leaving Langen an open market for a more road-oriented two-stroke option.

Chris told us: “Vins is an engeering company at heart; they want to make engines. They did a track bike, which they're very focussed on themselves because they're motorsports guys. We wanted to create something more useable, more like the RDs were; a lightweight, fast bike for British roads. We've got an exclusive deal in Europe, so we're the only ones using this engine apart from Vins, who are really focussed on the track aspect.”

The engine itself makes 75hp and redlines at a screaming 14,500rpm, while torque is a more modest 33lbft. So you’ll have to use the gears and all the revs to get the most out of it, but that should be a pleasure rather than a chore.

Such is the bespoke nature of the Langen Two Stroke that each engine will be built to order to suit the individual customer’s demands. Chris said: “We've got a great relationship with Vins and Vincenzo [Mattia, Vins CEO and Technical Director], and he loves this project. He's a great fan of British vehicles and bikes. So each of the 100 built will be completely customised, and each time we have a built, we talk to Vincenzo and they build us a specific engine. We've got a cassette gearbox, so we can change the ratios for that particular engine, and each one will be matched up, 1 to 100, with each bike. So the engines are literally built for the bike.

“Customers can specify gear ratios and everything else. If somebody wants something to be machined into the casings, they can have it, everything is possible with this. That's what really keeps it interesting for us and why we're not going to higher volume. If people want to change paint colours, suspension, add carbon fibre wheels, change the upholstery... everything is up for grabs, within reason, because it keeps things interesting when we're making these 100 bikes.”

Customisation is very much the route Langen is taking with the Two Stroke.

“A lot of people might like the bike as it is, and will keep it as it is,” said Chris, “But in terms of customisation, you can change the frame colours, the anodising, the suspension, but the best part is the ergonomics. As standard we've got fully adjustable clip ons with infinite adjustment. There are three different axis of rotation and height adjustment, and when it comes to the footpegs, if it doesn't quite fit somebody, then we'll machine some new rearsets. It's tailored to fit each rider.”

While it’s possible to modify the specs depending on a buyer’s whims, it’s easy to see why people might simply opt for the setup of the ‘base’ version.

Chris ran us through its setup: “We've got Ohlins right-way-up forks, but they've been customised because the bike's so light. Ohlins didn't have anything for this weight of bike so we've got custom springs and settings in there, straight from Ohlins. For the rest of the bike we're trying to go as British as we can, so we've got twin Hel Performance radial calipers on the front, with 320mm discs, so it probably stops quicker than it goes. We've also got Hel on the rear, a CNC machined caliper, and we're working with K-Tech on the shock absorbers. We've got this twin-shock arrangement in a modern format, with some custom valving done to suit the set-up, which isn't quite like anything else.

“The rest - all the carbon work and the chassis - is our own. We're making the carbon-fibre in-house and trying to use local suppliers for fabrication. The frame is 1 1/2 inch aerospace aluminium tubing, with CNC machined bonded joints in the ends of the tubes to keep the tolerances right, and it looks quite pretty as well. There are no forgings or castings - any metal that isn't fabricated is CNC machined from solid.

“The weight is a real achievement for us. The target for the last 18 months was 115kg and we weighed it a few weeks ago at 114kg. And with 75hp, we've got a better power-to-weight ratio than most supercars. But the best thing is that it's controllable. It's going to surprise a lot of bigger sports bikes on the road, and on the track if people want to take it there.”

While we haven’t had a chance to ride the Langen yet, it’s already undergoing tests and Chris Ratcliffe has spent plenty of time on the prototype. So what’s it like to ride a modern, V-twin two-stroke?

“I've ridden with the engine quite a lot, using a mule chassis” he said, “The geometry has been derived from small sports bikes like the Aprilia RS250, but with some of our own tweaks for stability because it's so much lighter. It's very much a sort of road-racing geometry, with almost Triumph Thruxton-like ergonomics but with added adjustability.”

“When it comes to power delivery, with traditional two strokes you tend to have no power then everything comes all of a sudden. But with this, because it’s fuel-injected and we've worked so hard on the fuelling, we've got a nice, linear torque delivery everywhere. It almost feels like a 500cc or 600cc four-stroke across most of the rev range, up until you get to 10,000rpm where there’s a little green section on the rev counter... That's when things get a bit exciting. So it's still got a powerband, but with a nice, user-friendly delivery everywhere else. You can ride it like an ordinary motorbike, which is fantastic, but you can be silly when you want to.”

While you might be concerned about the idea of dropping £28,000 – plus VAT – on a 250cc two-stroke, Langen promises a two-year warranty and an unparalleled level of customer support and involvement.

Chris explains: “There's a standard two-year warranty, but the difference is that we want to be a very personal company. We want customers to drop in for a coffee, to come and see us, to get involved with the bike being built at all its different stages. With 100 customers, you can know everybody by name, and we'll have people who can come to your place of work and pick the bike up, things like that. It's a very bespoke machine, almost like buying an expensive racing car, and you get the same level of service. That's what I want the company to be about.”

Despite the high price of entry, that prospect is already proving tempting to customers. “We're a bunch of engineers, not very good at marketing or PR,” said Chris, “But we launched the order form on the website a week ago and we're getting a steady run of deposits coming through. It seems to be sparking peoples' imaginations, and a road-going, two-stroke, road-racer is something that hasn't been available for decades. The fact that it's British helps, too.”

While the Two Stroke is Langen’s first bike, due to reach production in the middle of next year, the firm plans to do much more in the future.

“We start building these next summer, at around two to three per week, so that takes us to around a year to build the first 100 bikes,” said Chris, “By that time we could be starting the further 150, which will take an extra year.

“Beyond that, we don't want to regurgitate this bike in different forms. We'll probably produce some kits of add-on extras, like fairing kits - we've had a lot of requests for things like that - but purely for owners who already have the bikes. After that, we've got loads of ideas.

“Basically we want to make small runs of bikes, like this. For us it's all about the engineering, and a bit of nostalgia.

“What I want to do is to continue to innovate and push boundaries. The two-stroke really intrigued me and trying to put that into a well-engineered bike was exciting. So we want to carry on with projects like that. I don't know whether we'll stick to 100 each time, if we get a bit of a following we might be able to up it a little bit, but we don't want to mass-produce. We want to keep a small team of really passionate people who are there for the love of it.”

Want to get a glimpse of the Langen Two Stroke in action?