R1300GS / the good the bad & the ugly

[chrisjk]

I used Chat GPT to calculate HP requirements as per the following . The calculated result of 85 HP suggests that 155 HP might be overkill...

Calculate the horsepower required to power a motorcycle weighing 230kg with a rider weighing 90 kg up a one in four hill, at 80 miles per hour. Assume common averages for wind resistance


GPT-4

To calculate the required horsepower, we need to account for three things:

The force to overcome gravity while going uphill.
The force to overcome wind resistance.
The force to maintain the desired speed (rolling resistance).
Let's first convert the weights and speed to SI units:

Total weight = 230kg (motorcycle) + 90kg (rider) = 320kg
Speed = 80 mph = ~35.76 m/s (1 mph ≈ 0.44704 m/s)
Gradient of hill = 1 in 4 = 25% = 0.25
1. Force to overcome gravity
The force required to overcome gravity is given by the formula:

Copy
F_gravity = m*g*sin(theta)
where:
m is the mass (320 kg in this case),
g is the acceleration due to gravity (approximately 9.81 m/s²), and
theta is the angle of the incline.
Since we are considering a 1 in 4 hill, which is a 25% grade, we can consider it as a right triangle with the vertical side 1 unit long and the horizontal side 4 units long. Therefore, the angle theta is given by:

Copy
theta = atan(1/4)
Let's calculate the force:


Copy
theta = atan(1/4) ≈ 0.245 rad
F_gravity = 320 * 9.81 * sin(0.245) ≈ 783.8 N
2. Force to overcome wind resistance
The force needed to overcome the wind resistance is given by:

Copy
F_drag = 0.5 * Cd * A * rho * v²
In this formula:

Cd is the drag coefficient, which varies but is usually around 0.9 for a motorcycle.
A is the projected area of the motorcycle and rider. Without more specifics, we can estimate this value as 0.7 m².
rho is the air density, which is about 1.225 kg/m³ at sea level.
v is the speed of the motorcycle.
Plugging in these values:

apache
Copy
F_drag = 0.5 * 0.9 * 0.7 * 1.225 * (35.76)² ≈ 524.8 N
3. Force to maintain the desired speed (rolling resistance)
This force depends on the coefficient of rolling resistance (Crr). For a motorcycle tire on asphalt, this might be around 0.015. The equation is given by:

Copy
F_rolling = Crr * m * g * cos(theta)
Plugging in values:

Copy
F_rolling = 0.015 * 320 * 9.81 * cos(0.245) ≈ 466.8 N
Total Force
The total force needed is the sum of the three forces:

Copy
F_total = F_gravity + F_drag + F_rolling = 783.8 + 524.8 + 466.8 ≈ 1775.4 N
Power
Finally, the power (in Watts) required is given by the product of the force and the speed:

Copy
P = F_total * v = 1775.4 * 35.76 ≈ 63457.5 W
To convert this to horsepower (1 horsepower = 746 Watts):

Copy
P_hp = 63457.5 / 746 ≈ 85 HP
Therefore, to drive a 230kg motorcycle with a 90kg rider up a 1 in 4 hill at 80mph, we would require about 85 horsepower, assuming average conditions for wind resistance and other factors. This is a simplified calculation, and real-world conditions might require slightly more or less power.

 

[markyparky]

I got to see one in the flesh yesterday and had a sit on it.
It feels much more compact and looks much less fussy from the side due to the move to cast rear subframe and infill panels. It will be much easier to keep clean which may be more important to some than others
The new finish on the engine looks very nice and matt and hopefully a bit harder wearing than current, so less warranty replacements
When looking at it from the front it looks much more svelte especially the area above the headlight although they did have a small screen on it. Maybe with the additional winglets and screen would balance this out.

Over all, looking good but will wait for the Adventure variant before consideration of changing from my current GSA

 

[Baked Bean]

One thing i noticed was a small piece of plastic on the front of the forks to stop some of the wind (noise) coming up through the fairing.

 

[Shinyface408]

Clifton I love BMW boxers and could buy a S or M1000XR and would have the bike that is practical and fast enough to suit my needs or wants…But I prefer the boxer that protects bike and legs , love the Telelever and prefer a shaft over a chain for obvious reasons ! The new GS did not move the goalpost far enough so I keep the 1250 where I would have loved to buy a new GS after 4 years on the old one…Despite Arsey who is just here because he hates BMWs I actually own and ride one ! And Reggie is the fellow who buys a new GS every other year here on the board and puts 17 inch cast wheels and 320 mm rotors on it like Thousands of other Reggies around the world despite the shortcomings and no additional power to actually take advantage of the sportsbike rubber on a trackday…Hooefully the M1300GS will be this bike done right by the factory !

You really are seriously fekin boring, your constant over technical shite and ramblings. I think most people even on here would you believe feel similar from the responses you could read if bothered......if it were football you would have had a red card along time ago.
Next time the nurses come around make sure they give you a double dose of your tablets and make sure they lift the sides of the bed up so you don't bang your head......

 

[Boxerlust]

Chrisjk…If 155 hp in a bike as heavy as a GS would be overkill than what are 205 hp in a lighter bike like the new M1000XR…LOL

 

[stick]

Well , I had 170 HP (94 ftb torque) with the V4 Multi , came back to the GS as the Multi was hard work , fast , but exhaustive and in the long run no real improvement from the last 1250 I had.
The dream of the additional power was spoilt by the revs needed to get to the sweet spot. Came back to the Gs and found that great motor again , constant pull , so by all accounts the new one should be a dream , so you cam stick the extra power you dream of in a pipe and go outside and smoke it , its annoying here.
Want 200 bhp , go find a long road and whilst your at it , add some nitros to give you the buzz you crave. I get all the figures you quote but its your arse that makes the decision along with your ........brain perhaps

Bugger just realised he's pushed me buttons ...sorry chaps.

 

[GB.]

Well , I had 170 HP (94 ftb torque) with the V4 Multi , came back to the GS as the Multi was hard work , fast , but exhaustive and in the long run no real improvement from the last 1250 I had.
The dream of the additional power was spoilt by the revs needed to get to the sweet spot. Came back to the Gs and found that great motor again , constant pull , so by all accounts the new one should be a dream , so you cam stick the extra power you dream of in a pipe and go outside and smoke it , its annoying here.
Want 200 bhp , go find a long road and whilst your at it , add some nitros to give you the buzz you crave. I get all the figures you quote but its your arse that makes the decision along with your ........brain perhaps

Bugger just realised he's pushed me buttons ...sorry chaps.

Post of the day for me that one.

 

[Boxerlust]

Stick the MS is not fast…From all the Adv tourers only the S1000XR is fast if you keep the rpms above 8000 rpm and the upcoming M1000XR that has another 40 hp on top going all the way to 14500 rpm will be Real Fast…I like Torque and the great Telelever chassis that makes the GS so easy to ride fast but with another 1000 rpm on top the GS would have been more fun and close to perfect for a road engine / road bike…! But oh well its all good as the let go BMW motoboss said in an interview about the upcoming GS getting only moderate power gains as the GS does not need more power…Myself and others who wanted more power as a more exiting topend dont have to buy a new GS and can spend the money on something else…So its all good but boring as after 4 long years I was looking forward to buy a new GS…

 

[stick]

I used Chat GPT to calculate HP requirements as per the following . The calculated result of 85 HP suggests that 155 HP might be overkill...

Calculate the horsepower required to power a motorcycle weighing 230kg with a rider weighing 90 kg up a one in four hill, at 80 miles per hour. Assume common averages for wind resistance


GPT-4

To calculate the required horsepower, we need to account for three things:

The force to overcome gravity while going uphill.
The force to overcome wind resistance.
The force to maintain the desired speed (rolling resistance).
Let's first convert the weights and speed to SI units:

Total weight = 230kg (motorcycle) + 90kg (rider) = 320kg
Speed = 80 mph = ~35.76 m/s (1 mph ≈ 0.44704 m/s)
Gradient of hill = 1 in 4 = 25% = 0.25
1. Force to overcome gravity
The force required to overcome gravity is given by the formula:

Copy
F_gravity = m*g*sin(theta)
where:
m is the mass (320 kg in this case),
g is the acceleration due to gravity (approximately 9.81 m/s²), and
theta is the angle of the incline.
Since we are considering a 1 in 4 hill, which is a 25% grade, we can consider it as a right triangle with the vertical side 1 unit long and the horizontal side 4 units long. Therefore, the angle theta is given by:

Copy
theta = atan(1/4)
Let's calculate the force:


Copy
theta = atan(1/4) ≈ 0.245 rad
F_gravity = 320 * 9.81 * sin(0.245) ≈ 783.8 N
2. Force to overcome wind resistance
The force needed to overcome the wind resistance is given by:

Copy
F_drag = 0.5 * Cd * A * rho * v²
In this formula:

Cd is the drag coefficient, which varies but is usually around 0.9 for a motorcycle.
A is the projected area of the motorcycle and rider. Without more specifics, we can estimate this value as 0.7 m².
rho is the air density, which is about 1.225 kg/m³ at sea level.
v is the speed of the motorcycle.
Plugging in these values:

apache
Copy
F_drag = 0.5 * 0.9 * 0.7 * 1.225 * (35.76)² ≈ 524.8 N
3. Force to maintain the desired speed (rolling resistance)
This force depends on the coefficient of rolling resistance (Crr). For a motorcycle tire on asphalt, this might be around 0.015. The equation is given by:

Copy
F_rolling = Crr * m * g * cos(theta)
Plugging in values:

Copy
F_rolling = 0.015 * 320 * 9.81 * cos(0.245) ≈ 466.8 N
Total Force
The total force needed is the sum of the three forces:

Copy
F_total = F_gravity + F_drag + F_rolling = 783.8 + 524.8 + 466.8 ≈ 1775.4 N
Power
Finally, the power (in Watts) required is given by the product of the force and the speed:

Copy
P = F_total * v = 1775.4 * 35.76 ≈ 63457.5 W
To convert this to horsepower (1 horsepower = 746 Watts):

Copy
P_hp = 63457.5 / 746 ≈ 85 HP
Therefore, to drive a 230kg motorcycle with a 90kg rider up a 1 in 4 hill at 80mph, we would require about 85 horsepower, assuming average conditions for wind resistance and other factors. This is a simplified calculation, and real-world conditions might require slightly more or less power.

Stick the MS is not fast…From all the Adv tourers only the S1000XR is fast if you keep the rpms above 8000 rpm and the upcoming M1000XR that has another 40 hp on top going all the way to 14500 rpm will be Real Fast…I like Torque and the great Telelever chassis that makes the GS so easy to ride fast but with another 1000 rpm on top the GS would have been more fun and close to perfect for a road engine / road bike…! But oh well its all good as the let go BMW motoboss said in an interview about the upcoming GS getting only moderate power gains as the GS does not need more power…Myself and others who wanted more power as a more exiting topend dont have to buy a new GS and can spend the money on something else…So its all good but boring as after 4 long years I was looking forward to buy a new GS…

You do realise I am on the top ramp of the multi at the moment contemplating the paragraphs of quotes ... awaiting silence ...... but wait ..... do I hear a 1500 GSM 17/200/150 coming ... no.. its a pipe dream .
Thank god , get off the barrier

 

[GB.]

Stick the MS is not fast…From all the Adv tourers only the S1000XR is fast if you keep the rpms above 8000 rpm and the upcoming M1000XR that has another 40 hp on top going all the way to 14500 rpm will be Real Fast…I like Torque and the great Telelever chassis that makes the GS so easy to ride fast but with another 1000 rpm on top the GS would have been more fun and close to perfect for a road engine / road bike…! But oh well its all good as the let go BMW motoboss said in an interview about the upcoming GS getting only moderate power gains as the GS does not need more power…Myself and others who wanted more power as a more exiting topend dont have to buy a new GS and can spend the money on something else…So its all good but boring as after 4 long years I was looking forward to buy a new GS…

Total tosh, a v4 multi will destroy a xr1000, not an M but a xr for sure

 

[Boxerlust]

GB I actually have ridden Both or better all 3 not on a short dealer testride in Mexico…1290 Super Adv , MS V4 and S1000XR gen 1 & 2 and can tell you a XR is much faster in straight line & turning than either Ducati or KTM…Except for straights the 1250GS is even faster because it has better handling because of Telelever and is easier to ride ! Between Ducati and KTM the Ktm is faster than the MS but the Duc steers quicker but the XR eats them alive ! And the M with 40 hp more and another 3 grand more on top will even get real superbikes on trackdays a run for the money…Hang with them without having to fold yourself up!The M1000XR if available with bags if not crazy expensive might be my next bike…Despite loving the combo Boxer-TL&shaft more…LOL

 

[GB.]

You must get the watered down multi stateside then, 170hp vs 160hp I think the figures spray for themselves.

 

[OnHellas]

I

GB I actually have ridden Both or better all 3 not on a short dealer testride in Mexico…1290 Super Adv , MS V4 and S1000XR gen 1 & 2 and can tell you a XR is much faster in straight line & turning than either Ducati or KTM…Except for straights the 1250GS is even faster because it has better handling because of Telelever and is easier to ride ! Between Ducati and KTM the Ktm is faster than the MS but the Duc steers quicker but the XR eats them alive ! And the M with 40 hp more and another 3 grand more on top will even get real superbikes on trackdays a run for the money…Hang with them without having to fold yourself up!The M1000XR if available with bags if not crazy expensive might be my next bike…Despite loving the combo Boxer-TL&shaft more…LOL

I think we may have next years MM93 replacement….anyone got Alberto’s phone number at HRC??

 

[Pukmeister]

Why do you pointlessly crave more power and revs for a bike that has the aerodynamics of a barn door ?

You could add another 30 bhp to the GS engine and it wouldn’t do much for the bikes top end, and would probably ruin its rideabilty and character.

 

[J biker]

The GS is quick. Probably quicker than the rest on poor and unknown windy roads.
Faster than 1290 adv and others? Erm, depends entirely on the roads.
Pro riders have tested the 1290 adv against GS on track and..the 1290 is quicker. On track the XR1000 will destroy all of the other advs.
Yes, I have ridden one and I owned/ran an S1r , Multistrada 1200 and also put in 6k on a 1290gt with two Euro tours (including melted tyres..)
Thing is, with mountain roads, poor surfaces, bumps, tar bands, potholes…rain…the pick of the bunch is the GS.
If you are a straight line person, never use the edge of the tyre, bypass the rest and go straight to the XR. Anaemic and bland except when revved hard. Lacks torque, not the bike to be on for character or when roads are wet.

 

[Boxerlust]

Jbiker...Of course on straights a MS or 1290SADV is faster than a GS but on curvy and bumpy roads the GS is way faster & easier to ride and has even more power than Both up to 8000 rpm...The XR is even better and faster but you have to keep the revs between 8 and 11000 rpm...And the M1000XR has even another 40 hp on top of that...So new R1300GS with another 1000 rpm on top giving it another 10-15 hp on top would have been perfect because the XR has to be shifted to go Fast...! I should have bought one long time ago but I love Boxers & Telelever front suspension that is so comfortable and works so much better on the shitty road surfaces we ride on today !

 

[Boxerlust]

Of course 149 NM of the 1300 GS is nothing to sneer at but the 19 L tank kills it for me...Also how can the mechanical sound of the engine be louder than the exhaust note ? Horrible ! I hope Akrapovic offer a quick solution or at least the db-killers are easily removeable to make it sound like a proper motorcycle !

 

[Pukmeister]

Not a lot of use fitting an Akra and removing the baffles if you intend riding anywhere in mainland Europe now, especially Germany. Many countries are getting hot on noisy bikes and cars, with "noise pollution" hot on the agenda right behind the drive to EVs.

Personally I think its no longer worth the hassle of replacing a bikes OE exhaust just to gain 1-2 bhp at certain revs and then be looking over your shoulder or rolling the throttle shut every time you see a patrol car, not to mention roadside drive-by noise measuring devices.

 

[Arsey]

Not a lot of use fitting an Akra and removing the baffles if you intend riding anywhere in mainland Europe now, especially Germany. Many countries are getting hot on noisy bikes and cars, with "noise pollution" hot on the agenda right behind the drive to EVs.

Personally I think its no longer worth the hassle of replacing a bikes OE exhaust just to gain 1-2 bhp at certain revs and then be looking over your shoulder or rolling the throttle shut every time you see a patrol car, not to mention roadside drive-by noise measuring devices.

Agreed.
Always makes me laugh when someone fits an Akra or similar to make the bike sound better and save weight !
Save weight on a 250kgs ish bike with a 90/100kgs blob sat on it ?
If he lost half his beer gut he’d double the weight saving !

 

[Pukmeister]

Save weight on a 250kgs ish bike with a 90/100kgs blob sat on it ?
If Pukmeister lost half his beer gut he’d double the weight saving !

Fixed, for accuracy.