After 20K miles on the 1250 GS & 1250GS ADV - A honest review

[Arsey]

Knut I have 2 more good Harley sayings worth remembering...
Harley-Davidson - The most efficient machine to turn gas into noise without the side effects of horsepower.
And What is the difference between a Harley and a vacuum cleaner ? The different position of the dirtbag...
Enjoy

Doesn’t say much about your knackered old boxer engine then if Harley can produce a new motor that puts out 20bhp more than the GS 1250 from the off.....

 

[Boxerlust]

Arsey you got that right
If Harley can get 152 hp and 125 nm from 1253 cc a company like BMW should be able to get at least 152 hp/NM from 1254 cc
M1300GS - 160hp/nm and 17" wheels...

 

[Arsey]

It’ll never happen.

 

[Boxerlust]

Arsey I don't know how old you are but I remember when the first BMW 4 cylinder came out the K100 in 1983 me just my license in hand a far step from the old 980 cc 2 valve pushrod boxers that made 60 hp on a good day conceived in 1969...Then in 1993 in new fuel injected 4 valve boxers making 90 hp and 10 years later the K1200 making 167 hp...And then in 2009 still never able to really shake the pipe and slippers image coming out of the closet and beating the japanese in their own game with the best sport-bike made the S1000RR
Back then people like you thought/said it will never happen...It will happen because the cake is getting smaller but BMW wants a bigger piece

 

[knutk]

Doesn’t say much about your knackered old boxer engine then if Harley can produce a new motor that puts out 20bhp more than the GS 1250 from the off.....

But it does say a lot about your lack of understanding of engine caracteristics and the correlation between torque and HP when you find this impressive.

The Harley is able to get out 120Nm from a 1250. That is less then 10Nm/100cc. This is numbers that would be impressive 40 years ago.... Winding up the RPM will give you the HP, at high RPM

 

[Boxerlust]

You hit the nail on the head Knut as the BMW shift cam motor has lees displacement but makes even more torque than the 1301 cc KTM engine...All BMW has to do raise the rpm ceiling on the engine another 1000 rpm and we would be at 150-160 horsepower which would give a fun top-end rush without loosing the torque that is so useful in a rpm range used 90% of the time...This would be the perfect motorcycle engine for ROAD riding !
As also Arsey the boxer is not an old turd but a very modern design that gets more pressure/torque out of 35% less fuel burned compared to the latest shit the italians were able to cook up...And the japanese lost their plot long time ago...The Africa Twin uses as much fuel as the BMW but makes more than 30 hp less than the BMW twin...Think about who makes the real turd before making statements you do...As also lets see how many hp the Harley actually makes...But if it makes 152 hp and 125 nm torque than they are better than BMW was in 2012 when the R1200GS-LC came out making 125 hp/nm at 1000 rpm less than the Harley....155 hp/nm would be cool and feasible for the next gen GS...If you have more torque tire wear will go way up anyways unless you want to plod around in ECO mode...B.t.w. ECO mode on the 2021 1250 will you get the same hp/torque numbers the all new in 2004 R1200GS had...I guess it is o.k. if you are far away from home in a foreign country with tire dealers and gas stations far apart traveling on a budget...

 

[tanneman]

You hit the nail on the head Knut as the BMW shift cam motor has lees displacement but makes even more torque than the 1301 cc KTM engine...All BMW has to do raise the rpm ceiling on the engine another 1000 rpm and we would be at 150-160 horsepower which would give a fun top-end rush without loosing the torque that is so useful in a rpm range used 90% of the time...This would be the perfect motorcycle engine for ROAD riding !

A flat twin is an inefficient design. The engine suffers more from pumping losses than a v-Twin or parallel twin. It also uses more material to construct than a V-twin or parallel twin which means it is a heavy thing. Raising the engine rpm sounds easy but it brings into the equation other stresses that has to be negated by engineering design to be able to be sold to the public in order to stay reliable. And please do not compare a BMW flat twin to a Porsche engine. They, Porsche, are in a different league and have been investing and researching performance flat configuration engines for decades. The bore and stroke are also smaller than those of a BMW 1250 hence the higher revving nature of the engine. Not even mentioning the materials used and the tech behind pumping oil and cooling that engine and the valve timing. By comparison the BMW flat twin falls far behind in performance and tech. It is not build for performance, the shift cam is an ingenious design in its working for the space constraint of the engine (BMW could have slapped a VVTL ala Honda on it but the design is bulky and not suited to a single piston, remember it is one piston per side, plus the restriction of making the engine too wide) and emissions which is what it really was developed for. With this advancement the engine got a new lease of life until the next emissions legislation comes into effect and those that follow. The by-product of any efficiency gains are better performance and that is evident in the quoted figures. What matters is the power to weight ratio that is somewhat less that what was expected.

The shift cam is not there for outright performance, it is there for emissions. BMW is not targeting the competition for HP and torque. It has it own niche and buyer specific demands. That is why there are better bikes out there than BMW which excels in one or two performance criteria but lacks in others. If you compare all the bikes on equal terms the BMW falls far behind but excels in other areas which are important for their customer and why they buy them, outright performance not being the main criteria. It is a well rounded bike but it is also flawed. The idiosyncrasies is what makes it a popular bike. By comparison to the biggest motorcycle manufacturers out there, BMW Motorrad is small fry.

 

[Micko123]

Isn't the 360° crank parallel twin just as bad as a boxer twin for pumping losses ? The Porsche flat sixes or Honda Goldwing engines don't suffer such high pumping losses because there are always some pistons going up the bore whilst others are descending.

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[Micko123]

A flat twin is an inefficient design. The engine suffers more from pumping losses than a v-Twin or parallel twin. It also uses more material to construct than a V-twin or parallel twin which means it is a heavy thing. Raising the engine rpm sounds easy but it brings into the equation other stresses that has to be negated by engineering design to be able to be sold to the public in order to stay reliable. And please do not compare a BMW flat twin to a Porsche engine. They, Porsche, are in a different league and have been investing and researching performance flat configuration engines for decades. The bore and stroke are also smaller than those of a BMW 1250 hence the higher revving nature of the engine. Not even mentioning the materials used and the tech behind pumping oil and cooling that engine and the valve timing. By comparison the BMW flat twin falls far behind in performance and tech. It is not build for performance, the shift cam is an ingenious design in its working for the space constraint of the engine (BMW could have slapped a VVTL ala Honda on it but the design is bulky and not suited to a single piston, remember it is one piston per side, plus the restriction of making the engine too wide) and emissions which is what it really was developed for. With this advancement the engine got a new lease of life until the next emissions legislation comes into effect and those that follow. The by-product of any efficiency gains are better performance and that is evident in the quoted figures. What matters is the power to weight ratio that is somewhat less that what was expected.

The shift cam is not there for outright performance, it is there for emissions. BMW is not targeting the competition for HP and torque. It has it own niche and buyer specific demands. That is why there are better bikes out there than BMW which excels in one or two performance criteria but lacks in others. If you compare all the bikes on equal terms the BMW falls far behind but excels in other areas which are important for their customer and why they buy them, outright performance not being the main criteria. It is a well rounded bike but it is also flawed. The idiosyncrasies is what makes it a popular bike. By comparison to the biggest motorcycle manufacturers out there, BMW Motorrad is small fry.

The BMW motorcycle engine isn't a flat twin it's boxer engine.

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[Boxerlust]

Tanneman you know a little more than the average guy but still not enough to make the statements you made which are plain wrong...Like your semantics about pumping losses and being an inefficient design and Porsche boxers/flat engines being build for more performance.And yes with your logic the new Harley engine is no real V-twin because it does use 2 crank pins that are 30 degree off which makes it as a 60 degree twin fire and sound like a 90 degree V twin...It does not matter for power but for high rpm reliability as also how much the engine vibrates if the crank has 2 or 3 bearings like the new R18 boxer has.
As also the Porsche 911 GT3 that can be compared easily to the 1250 shift cam except for the 1254 should be a 1333 as both engines have the ability to rev 9000 rpm max...The bore is the same but the Porsche has 4 mm longer stroke which actually limits max piston speed.Not like you said Porsche being smaller in bore & stroke...So it would be no problem at all for BMW a company that knows how to build very powerful and reliable engines like Porsche does naturally aspirated or turbo charged to build a shift cam boxer that makes 150 nm torque and lets say 160 reliable horsepower @ 8500 rpm !
And everybody would be happy and the GS' top-end on par with the 1290 KTM which makes 155 hp or the MS V4 which makes 165 hp on the same dyno where the current GS makes 136 hp and the S1000XR 179 hp.
And I give you this the only inefficiency of a boxer or flat 2/4/6 engine that the intake runners can't be positioned to archive the optimal downdraft for obvious reasons but 125 hp per liter from a naturally aspirated boxer/flat engine like in the GT3 is nothing to be sneered at
As the boxer has so many advantages like low center of gravity,no gyro,no loss of power when applying a drive shaft,protection of riders legs & bike,low center of gravity,less vibration/good balance,easy to service as negative only more aerodynamic drag at high speed come to my mind...And last but not least easy application of Telelever...

 

[stever1]

Tanneman you know a little more than the average guy but still not enough to make the statements you made which are plain wrong...Like your semantics about pumping losses and being an inefficient design and Porsche boxers/flat engines being build for more performance.And yes with your logic the new Harley engine is no real V-twin because it does use 2 crank pins that are 30 degree off which makes it as a 60 degree twin fire and sound like a 90 degree V twin...It does not matter for power but for high rpm reliability as also how much the engine vibrates if the crank has 2 or 3 bearings like the new R18 boxer has.
As also the Porsche 911 GT3 that can be compared easily to the 1250 shift cam except for the 1254 should be a 1333 as both engines have the ability to rev 9000 rpm max...The bore is the same but the Porsche has 4 mm longer stroke which actually limits max piston speed.Not like you said Porsche being smaller in bore & stroke...So it would be no problem at all for BMW a company that knows how to build very powerful and reliable engines like Porsche does naturally aspirated or turbo charged to build a shift cam boxer that makes 150 nm torque and lets say 160 reliable horsepower @ 8500 rpm !
And everybody would be happy and the GS' top-end on par with the 1290 KTM which makes 155 hp or the MS V4 which makes 165 hp on the same dyno where the current GS makes 136 hp and the S1000XR 179 hp.
And I give you this the only inefficiency of a boxer or flat 2/4/6 engine that the intake runners can't be positioned to archive the optimal downdraft for obvious reasons but 125 hp per liter from a naturally aspirated boxer/flat engine like in the GT3 is nothing to be sneered at
As the boxer has so many advantages like low center of gravity,no gyro,no loss of power when applying a drive shaft,protection of riders legs & bike,low center of gravity,less vibration/good balance,easy to service as negative only more aerodynamic drag at high speed come to my mind...And last but not least easy application of Telelever...

It says in your profile you're a professional driver. What type of electric milk float do you drive ?.

 

[Boxerlust]

Yes I am ! ..No milk float and nothing electric ...Never !

 

[Arsey]

Yes I am ! ..No milk float and nothing electric ...Never !

Uber.....cool

 

[tanneman]

A GT3 engine is so different in design to the BMW boxer engine you cannot even compare it. It is a race engine, developed for racing and the components for it is specific for that engine. You cannot compare the normal Porsche flat engines either because they are now turbocharged and smaller capacity, even before the forced induction the engine could not be compared to a BMW boxer. As an engine used in a car it is a bit bonkers today but Porsche has made it work through evolution and much investment. Porsche has been very successful in rally events because the weight is over the drive wheels. BTW, rally Porsches in the WRC class is limited to 320 bhp. I stand corrected on that figure but it is limited.

Harley is a V-twin. An engine restricted in design by the heritage looks which is what their customers prefer.

I stand by it that having an engine with 2 separate heads is inefficient because it complicates the engineering and then there is additional losses due to duplicated drives. The parallel twin is by far a better design in making use of space and minimising components and reducing driveline losses. The nature of the boxer is the orientation of the engine which will make it a heavy engine from design and the driveline connected to it lends itself naturally to a shaft drive which is not only more inefficient than a chain but also heavy. This increases drive line losses and you need a more robust design rear shock to cope with the unsprang weight of that drive shaft. The reason BMW bang on about low down mass is that the engine is so heavy everything else fitted to the bike is very light and has minimal impact on raising the CofG unless of course like me, you fill up the GSA to the brim and feel the difference 30l of fuel makes to the handling.

If the boxer is such a great engine then why doesn't all motorcycle manufacturers adopt the design then? You should get on the phone to the biggest motorcycle manufacturers out there and tell them they are making a mistake to continue building in line 4 engines. Same with Porsche, nobody else puts a big 6 cylinder out the back with all the difficulty in engineering a neutral handling car. But who would buy a 911 without that configuration? Ask any other manufacturer if they would build a car in that config and the answer would be no. A 911 is what a Porsche is. Do you understand that concept?

But instead of acknowledging the weakness of certain designs and the brilliance of others the same old mantra is spouted here that the BMW boxer is the absolute very best. It is actually very much the emperors clothes. It is what it is and it wont go away because it is the identity of a brand. The engineers have to find ways of improving it and thus it becomes a more widely accepted concept due to the majority of customers being older and more affluent than in previous decades. It is as far removed from the very early production engines that it would be impossible to think there is a link apart from the sticky out cylinders.

And before we get to the old my bike is faster than that bike on shitty tyres. The secret to riding a bike fast is to start off by mastering it riding slow, very slow, to learn the basics. Then as we improve and the speed increases is to figure out what is happening beneath us and then when you think you are the dogs bollocks ride something different and the learning curve starts all over again because what worked on one bike won't necessarily work on another. By the time you think you have mastered it all have a look at what a desert racer like Toby Price or an enduro rider like Graham Jarvis or a motocross racer does with about 50 hp and how competent they are in the handling of the bike in less than ideal conditions without breaking it. Then maybe you will understand that MotoGP is not where it is at when you have to feel what is going on below you and no forum can teach you that and no claims on a forum of your brilliance or one sided story will ever top the experience and knowledge of the very top 0.1% of riders in all disciplines. Which, by the way is not only sponsored but also help develop the bikes and components being sold to the public. Probably also the reason why the telelever isn't such a mainstream thing amongst manufacturers. It basically is outdated but once again an identity to a brand and a demand by its customers.

 

[dean0n0]

Yes, but 17" wheels blah blah kin blah.

 

[Boxerlust]

Tanneman not all you said is wrong but let me explain to you the new watercooled Harley motor is no V-twin because it has 2 crankpins and not a single one like the old Harleys do...Also a porsche flat 6 is nothing different as a BMW boxer except one has 2 the other 6 cylinders...And Porsche has plenty of normal engines that are non-torbocharged.Yes in the 911 even the non-Turbo is a turbo but the 718 has a naturally aspirated 4 liter boxer that is pretty much the same engine as in the GT3 but has a lower tune...But this is for marketing reasons as Porsche wants the more expensive 911 be the faster one than the mid-engine 718 but this could change soon with the arrival of the 718 GT4RS.Compared to the 1254 GS the 718 put out about the same power and yorque than the GS boxer (actually a little less) so it would be no problem at all for BMW to bring the 1254 shift-cam to 1350 cc with a little more bore or stroke or both , raise the rpm ceiling and make the heads a little better flowing (bigger valves,cnc ported runners) to get to 170hp and 155 nm Torque which would be perfect As for why other motorcycle manufacturers except for Honda don't use boxer engines like aircraft engine manufacturers do for obvious reasons (RELIABILITY,vibration canceling opposed pistons,low center of gravity) I honestly don't know.But already as it is the 1254 shiftcam boxer is probably the best and strongest up to 7000 rpm motorcycle road engine
As why they don't use it in road racing - Aerodynamics and less than ideal intake runners because the airboxes cant hang off to the sides for obvious reasons...

 

[tanneman]

I still wonder where the similarities start and end between Porsche flat 6 and BMW boxer. The only similarity is that it is a horisontally opposed engine. By your reasoning the Subaru has probably more in common with the BMW boxer and the Honda Goldwing should be a rocket ship.

Look at the picks below and tell me what is similar between a 997 NA flat 6 and a 1250 boxer?

I very much doubt that the 1250 engine would be able to reliably push past 150 bhp without same major consideration being made to the engine balance ie vibrations (rocking couple), breathing and exhausting, rpm limit for such a big piston and oil supply. The twin cam HP2 couldn't be engineered to handle more hp without modifying the oil pump to be reliable in the long run.

Talking HP and displacement is pub talk ie bullshit. By that reasoning I should be able to drag race and win any car with a Scania V8 for example and a Unimog 5023 would be a piece of shit but yet there are few vehicles that can do what it does. Just piss off with such ridiculous unsubstantiated statements.

 

[Boxerlust]

Tanneman you are a clueless idiot...I thought you knew some stuff but obviously you don't have a clue...The only limit of an internal combustion engine to make horsepower to make horsepower is how much air the heads can flow and piston speed...Here your Porsche 911 GT3 race engine has 4 mm more stroke than the 1250 BMW shiftcam thus the BMW can make even more horsepower ! Obviously there would be another factor like having only 2 crankbearings instead of 3 like the R18 has but since both engines Porsche 911 GT3 & 1254 shift cam boxer are set for 9000 rpm max there is no reason why the BMW GS could also make 167 hp and 155 nm torque with a slight ccm boost either through bore or 80 mm stroke...Enough said ! I don't expect you to understand it though with your big mouth spewing clueless misconceptions... But who cares !

 

[tanneman]

I have read some crap in my life but you are right up there Anyway it has been some form of entertainment while I'm on compulsory leave.

 

[Mr Bean]

I still wonder where the similarities start and end between Porsche flat 6 and BMW boxer. The only similarity is that it is a horisontally opposed engine. By your reasoning the Subaru has probably more in common with the BMW boxer and the Honda Goldwing should be a rocket ship.

Look at the picks below and tell me what is similar between a 997 NA flat 6 and a 1250 boxer?

I very much doubt that the 1250 engine would be able to reliably push past 150 bhp without same major consideration being made to the engine balance ie vibrations (rocking couple), breathing and exhausting, rpm limit for such a big piston and oil supply. The twin cam HP2 couldn't be engineered to handle more hp without modifying the oil pump to be reliable in the long run.

Taking aside the fact that the bike engine is shown with the gears attached and the Porsche engine is detailed with some ancillaries, they're not too different, at a base level. 4 valves per cylinder, chain driven cams, short-skirt pistons etc. The one big difference is that Porsche have one main journal between each big end (6 cyl 911's always have), whereas BMW can make do without - shorter engine and less potential for flex.

Is referencing the HP2 a bit misleading as the design is 20 years old, aircooled and has less similarities than the 1250 to the Porsche...