Exclusive BMW K1600 GS Mammoth motorcycle test


Special K on two wheels

6 cylinders in line of 1,649 cm3, 160 hp, 175 Nm, 310 kg full made, 39 liter fuel tank, tubular frame, Dynamic ESA suspension…

BMW has always been able to maximize the number of model segments that can be reached with its different platforms. It is therefore surprising that, since the introduction of its top-of-the-range six-cylinder K1600 models in 2011, the more than 50,000 models sold have not given rise to other versions than the road K1600GT and GTL not to mention the bagger. K1600 B. Not even a custom against the Honda F6C nor a production version of its Concept 6 which was all the rage at the Milan show 2009. And above all, given the resounding success of the R1200 Boxer version, no K 1600 GS . Well, not yet because one can expect drawings and maybe even a prototype to probably exist somewhere deep in BMW’s R&D department. !

Test of the Bakker BMW K1600 GS MammothTest of the Bakker BMW K1600 GS Mammoth

“I bought a K1600 GT for my job and I am very happy with the engine, which sounds good and is very pleasant to drive,” said Willem, 61, a returning rider who had said goodbye to two-wheelers for get married and start a family. Sound familiar to you? But with his business booming and his grown-up children, at 48 Willem returned to motorcycling, riding the R1200GS to visit his clients across Europe, from London to Milan, from Stockholm to Paris..

I much prefer the motorbike to the car for long distances. If I only do 20 km I take the car because it is more practical not to have to put on and take off all my equipment. Months to go from my home near The Hague (Netherlands) to a client in Berlin 700 km away, I always go there by motorbike. It’s a lot faster, especially with all the work being done on the Autobahn these days and it’s nicer anyway. So my BMW dealer suggested that I buy a K-16 and I did. But when I gave it back to him for the first service, he saw that I had rubbed the crankcases on both sides, that’s when he told me to go see Nico Bakker !

Willem Heijboer and his 'Mammoth'Willem Heijboer and his ‘Mammoth’


Bakker is the chassis maker tailor, weld magician, and the go-to guy when looking for a quality frame to create a unique bike that holds up. Plus, not many people can compete with Nico’s experience to design a better BMW. In addition to bringing to market the first Deltabox aluminum chassis for the air-cooled Boxer engine, Nico worked as a consultant for the German manufacturer in the development of the Telelever for the R1100 RS. Outside of BMW’s R&D department, he knows better than anyone how to design a manoeuvrable Boxer chassis and it was under his brand that the first sports car using the 8-valve air / oil Boxer with the Bakker BMW Bomber was launched. But the creation of the K1600 GS Mammoth, as Willem aptly baptized it, was the first for which Nico had to design a frame for a BMW in-line multicylinder engine.

Nico Bakker's workshopNico Bakker’s workshop

Willem came to my store and asked me to make a GS type version of his K1600GT. My first reaction was "Are you really sure you want to do this?!". But after talking with him, I realized he knew what he was doing, especially since he already owned a 1200GS. So I told him it wouldn’t be easy or cheap, but that I was going to give it a try !

To create the Mammoth, Willem Heijboer purchased a 2018 K1600GT from his local dealer; an already slightly revamped K1600GT with new catalytic converters and updated engine management. An evolution which allowed the six-cylinder engine with double overhead camshaft of 1,649 cm3 and 24 valves to comply with the Euro 4 standard without any loss of power, namely 160 horsepower at 7,750 rpm with a maximum torque of 175 Nm at 5,250 rpm and 70% of which is available from 1,500 rpm. The bike is also equipped with a ride-by-wire throttle offering three modes (Road, Dynamic and Rain) as well as ESA Dynamic as standard, this system which automatically adjusts the suspension settings in Road and Dynamic modes..

Nico Bakker at work on the K1600 GSNico Bakker at work on the K1600 GS

By receiving this motorcycle and all its standard equipment, Nico dismantled it to keep the engine, the final drive shaft, the trio of 320 mm brake discs with Brembo calipers and Bosch ABS as well as all the electrical and electronic systems, including the ESA function and accompanying suspensions. Everything that came out of the project was sold to the BMW dealership. Bakker then measured everything and started designing the frame he chose to make from CrMo steel tubes in order to achieve the best stiffness / weight ratio..

I wanted to make the bike lighter and easier to handle than the stock K1600, while also fixing Willem’s ground clearance issues with the engine. To be fair the engine is already very narrow for an inline six, it’s just the way it was fitted that needed to be changed..

The tubular frame was custom designedThe tubular frame was custom designed

Indeed, to create the most compact inline six-cylinder ever on a motorcycle, BMW designed a 24-valve semi-dry sump unit with chain-driven DOHC timing and which, despite its short stroke of 72×67.5mm , is only 555 mm wide, barely more than the majority of 4 cylinders. It weighs only 102.6 kg with its 10-disc clutch in oil bath, 6-speed gearbox, alternator and 52mm throttle body, all kept on the Mammoth with a modified airbox to allow more space to a larger fuel tank.

The 6-cylinder in-line of the K1600The 6-cylinder in-line of the K1600

When designing the Mammoth’s chassis, Bakker slightly lengthened the wheelbase to 1,635mm from 1,618mm on the production model and significantly refined the steering geometry. It ditched the Fior-style BMW Telelever fairing in favor of a more conventional but fully adjustable 48mm WP inverted fork and tailored to the specific needs of the Mammoth by Dutch specialist HK Suspension who also adapted the rear ESA shock absorber to its new application.

There is now an inverted WP fork at the frontThere is now an inverted WP fork at the front

The fork’s caster angle closes at 25 ° with 100mm of drag versus 27.8 ° and 106.4mm. To adapt the design philosophy of the R1200 GS to the K-16, Bakker opted for a 19-inch front wheel to match a 17-inch rear and because Heijboer likes the look of the spoked rims, got a kit from Kino from Forged aluminum rims with steel spokes allowing tubeless tires to be fitted. These are a Pirelli Scorpion Trail II train in 120 / 70R19 at the front on a 3 "rim and a 190 / 55ZR17 on the 6" rear which had to be specially manufactured for the Mammoth in order to be able to integrate it. transmission by shaft. "It took them a while to do it, otherwise we would only have taken 6 months to design the bike from A to Z."

The Mammoth adopts Pirelli Scorpion Trail II tiresThe Mammoth adopts Pirelli Scorpion Trail II tires

But the big difference is in the weight: the Bakker K 1600 GS weighs 310 kg with a 48/52% distribution to the rear and all the full facts, including that of the huge 39 liter tank! You have to put that in comparison to the 319 kg of the K1600GT with only 90% of the full capacity of its 24-liter tank. For a liter of fuel weighing 0.77 kg, that gives us a dry weight of 280 kg for the Mammoth versus 299 kg on the stock GT, each without luggage..

Although less heavy than a K-16 GT, the Mammoth lives up to its nameAlthough less heavy than a K-16 GT, the Mammoth lives up to its name

As far as luggage is concerned, the Mammoth carries two left R 1200 GS suitcases, one of which was adapted for the right by Bakker who also mounted a rack to place a top case. The side stand is accompanied by a central stand.

The Mammoth is also adorned with everything you need in terms of luggageThe Mammoth is also adorned with everything you need in terms of luggage

The liquid cooling radiator fitted to the Mammoth comes from an Aprilia RSV1000 and comes with an overflow tank on the right side of the bike. The Akrapovic 6-2 exhaust with its two carbon silencers from the Slovenian factory at the request of the brand agent and former superbike rider Mile Pajic, was also specially designed for the Mammoth and came to satisfy Willem’s wish to "sound a little better than the production BMW, not noisy, but just a little more exciting and efficient, plus it really makes it look better".

Kineo rims and Akrapovic mufflers were made to measureKineo rims and Akrapovic mufflers were made to measure

The original BMW ECU has been modified by local electronics wizard Rens L’Ami de De Jong Alphen BV to optimize the injection mapping with the new exhaust, but also to refine the adaptation of the ESA to the construction of Bakker.

After taking possession of his Mammoth in April 2018, Willem Heijboer covered no less than 17,000 km in 14 months, not counting from November to March as he put it away to ride his R1200GS on salt and frost..

I ride all year round, except when it snows, and I travel about 25,000 km per year. The Mammoth totally exceeded my expectations, although it is a heavy bike, the smoothness and ease of handling provided by the production model now equals the handling. And the engine is not touching the ground anymore, just the footrests !

Willem even took his Mammoth on the racetrack!Willem even took his Mammoth on the racetrack !

It’s quite common to come across well-driven R1200GSs on track days in Europe that put sports to shame, but I wonder how many drivers Willem shared the track with realized they had just been dropped off by a 6 cylinder adventure tourer.

In the saddle

Willem generously insisted that I could test drive the bike to see for myself how well it met his expectations..

The original K-16 speedometer is still presentThe original K-16 speedometer is still present

You have to prepare for this imposing motorcycle at rest and giving off a feeling of comfort. After climbing aboard and settling into the very comfortable GS saddle, I found myself in a fairly upright position, well protected by the screen and its subframe, both taken from the GS, just like the headlight. front and the wide handlebars complemented by hand guards, an essential accessory for riding in the rain or in the cold, just like the heated grips. This subframe also leaves a spot used by Willem to mount his TomTom GPS, but it is also his only source of criticism of the Mammoth: "The screen flexes a bit when I cruise 200 km / h in Germany. C is irritating, I have to try to fix it. "

Part of the cockpit is directly from the R1200GSPart of the cockpit is directly from the R1200GS

I did not encounter any ground clearance problem on the Bakker GS apart from the scraping of the toe clips on both sides, these being quite low. The driving position is quite spacious for a 1.80m driver like me and is ideal for long distances. Willem is 1m87; it is therefore designed to be comfortable for him. The saddle perched at 820 mm, however, only allows me to touch the ground with my tiptoes when stationary, the bike inevitably being wide between the legs due to the tank..

If the saddle is not very high, the width of the tank makes it difficult to put your feet on the groundIf the saddle is not very high, the width of the tank makes it difficult to put your feet on the ground


The sound that escapes from the Akrapovic carbon twin silencers is melodic and musical, the note of the Bakker GS thus resembles a "sotto voce" version of the wonderful sound produced by the manufacturer’s racing touring cars. It begins to sing as soon as the start button is pressed then comes to life and settles on an idle of 950 rpm.

Bakker BMW K1600 GS Mammoth road testBakker BMW K1600 GS Mammoth road test

Despite its long wheelbase, the Mammoth is a true fan of small spaces. It provides a very balanced ride at low speed in town, also thanks to its light clutch and its perfect mapping in Road and Rain modes (it didn’t rain, but I had to try). Dynamic mode is exactly what is written and on Dutch country roads delivers an extra touch of acceleration.

Despite its size, the Mammoth is at ease in small spacesDespite its size, the Mammoth is at ease in small spaces.

The engine is so smooth and supple that it is possible to let it run at 1,500 rpm in the last gear, which corresponds to 40 km / h on the TFT screen, then to open the throttle fully so that the power arrives smoothly up to 8,500 laps of the red zone without the slightest hesitation. With its offroad capabilities that allow it to come home by road, we end up with an Adventure model capable of reaching 250 km / h. So if the R1200GS is a Range Rover on two wheels, the Bakker K1600 GS is the equivalent motorcycle to a Lamborghini Urus.

The Bavarian 6-cylinder is a model of flexibilityThe Bavarian 6 cylinder is a model of flexibility

But the most captivating thing about this bike is the simple yet precise way it negotiates corners at low and medium speeds. It is a rail in curves at 120 km / h. But in the corners to be taken half as fast, it is incredibly comfortable for a bike so big and long. It doesn’t shift effortlessly from corner to corner on winding roads, but requires minimal rider investment when changing direction in a very safe and confidence-inspiring manner. The choice of geometry allows you to keep control when setting on the angle without having to sweat or ground clearance becoming an issue.

The Mammoth is much more agile than you might think at first glanceThe Mammoth is much more agile than you might think at first glance

At low speed, the massive bike is bulky but well balanced, with the clutch and fluid mapping of the electronic accelerator allowing confident U-turns or maneuvers in town. And the 320mm triple disc is undeniably effective, with the two 4-piston front calipers paired with the rear dual-piston through the adjustable lever and the original BMW ABS providing an extra margin of safety on wet spots..

The Bakker BMW K1600 GS Mammoth on Dutch back roadsThe Bakker BMW K1600 GS Mammoth on Dutch back roads

We quickly forget the large engine, with its oil tank integrated at the rear of the crankcase to offer a lower center of gravity to the whole bike. This is partly because it cannot be seen from the saddle anyway, but also because it apparently has no effect on the behavior of the K1600 GS. Looking at the bike from the side, I guess the reason is the way Nico Bakker positioned the engine crankshaft with the cylinders facing forward at 55 ° almost in the center of the bike. This means that the EVO K-16’s center of gravity is close to its peak, resulting in more neutral handling and greater agility that you notice as soon as you drive..

The Mammoth is very well balancedThe Mammoth is very well balanced


Sweet, sleek, sporty, seductive, sophisticated and blazingly fast, my apologies to Kellogg’s, but the Bakker BMW K1600GS is the Special K on two wheels. What a beautiful motorbike.

So much so that we can’t help but think that BMW should make one. Well, it wouldn’t be the first time that Nico Bakker has taken care of product development for them! Assuming they don’t, how many would ask Bakker to build a twin of Willem Heijboer’s transcontinental express? "We can do it again, that’s no problem. Expect double the price of a standard K1600GT to turn one into a GS. But it takes time, we need six months from ordering." This equates to 50,000 euros and wheelbarrows. Amateurs ?

The Bakker BMW K1600 GS MammothThe Bakker BMW K1600 GS Mammoth

Strong points

  • Smooth and powerful motor
  • Handy and precise
  • Powerful braking

Weak points

  • For large sizes
  • "Tailor-made" motorcycle with the corresponding price

The technical sheet of the Bakker BMW K1600 GS Mammoth

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13 thoughts on “Exclusive BMW K1600 GS Mammoth motorcycle test

  1. Mine … Rouge Candy, 1st registration December 2012 … Not much driven from December to April and I just spent 12,000 km with.

    Average consumption 5.55 l / 100.

  2. my first sold to my brother (ST100, to replace his "old" 7 years old), second a used ST1300, which is now 10 years old. Zero problem.

    We have just returned from a 4-day walk, never a problem of autonomy 🙂

    And we see exceptional mileage on the Pan, certainly the highest on the market.

  3. Wasn’t the editor very wide awake ?? lol

    "she didn’t lose a wrinkle in the end" >> basically she looks old or not ??

    "twelve stars dressing the grille." >> since when there is a grille on a motorcycle ?

    "On the other hand, the ST 1300 is easily raised for the same pilot" >> what is the meaning of the sentence ??

    "The first kilometers of hours are therefore done with caution" Pardon me ?

    Personally, I had the opportunity to ride a Pan a few times and I still have the feeling of having driven a very good machine, really successful, which impresses a little by its size at the start but once the first turns of the wheels are done , It is happiness..

    In short, a good machine, INCREUVABLE, as the world’s leading engine seller knows how to do.

  4. I am thinking of buying one and I am looking for someone who will speak ill of me for two years ….. still no one.

    So it will do it.

  5. gnarf

    All this for a ground clearance problem on a K1600, there are guys who have ideas …

  6. Me, I have 270,000kms without problem. Only change of the three brake discs which were below the tolerance of 200,000 km

    Tire change every 6.500kms (Metzeler Z6) and brake pads change every 10,000kms.

    Indestructible motorcycle. This is a 2002 model with poor road holding … Blast the front tire to 3.2kgs and rear to 2.9kgs, setting the bubble lower when the speed is at maximum. Timed at 224kms / h max.

    Here is the little news.

    Good road

  7. Thank you for all these comments..

    After having tried a Pan ten years ago following the advice of a former who had had about fifty bikes in his life – as he said – and who placed it in the lead, I was very pleasantly surprised by the test. I was driving a 750 VFR Carat with which I was more than satisfied until the days when a C. cut me off and kept me away from the bike for a few years..

    I decided to take the bike back a month ago. So I just bought a PAN that I went to look for at the other end of France.

    At the returns that float. I regretted my purchase and was about to resell it. I was driving 110 on the highway and never have so many cars passed me. And then this afternoon, following your advice I removed the top case. Nothing to see. I picked up speeds that I won’t mention. The total foot. I think I’ll keep her looking pretty. If it is not its penalizing weight at the stop and still I start to get used to it, it is perfect and it is a good bike that I recommend. I have only done 2000 kiosks so far but seeing your comments, and all the Honda cars I have had without a problem, I think it will be a long time. The first a 125 XL … 43 years ago. Already !!!! Damn. Never done anything on it. Indestructible.

    Thank you all and thank you for this site which is really a very nice biker haunt.

  8. This Honda was homogeneous, like the VT500E for that matter; but they have passed without pain or glory next to icons like the 350RDLC.

    Have a good trip if you have one, Julian

  9. Well I just put one aside, I fell in love…

    it comes in the middle of a collection of hondas in the middle between the smallest c50m and the biggest st1100, it is a very pretty little punchy machine which will increase in value as the restorations (expensive ) of the last remaining models. The Germans even made comparisons against the 500 rg Suzuk at the time (less than 10,000 € we forget today) and it held its rank … The article is very accurate and very well written, bravo to you …

  10. And to think that I leave one "to rot" in my mother’s garage … It makes me want to go look for it!

  11. Hello biker friends,

    I had the pleasure of "loaning" mine to my daughter and I am particularly happy to see this beautiful machine hit the road again (I am 58 years old and it had been in the garage for too long).

    The healthy behavior of this motorcycle reassures the father !


  12. "I had the pleasure of ‘lending’ mine to my daughter"

    That, that must be a BIG pleasure.

    I hope I can with this joy, and pride, one day.

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