BMW K1600GT review [ashonbikes.com]

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miles:
Quote from: chesthing on December 29, 2011, 12:20:29 PM



I took a short test ride on a 12RT. Immediately after sitting on it I knew BMW numbers were bogus. You really believe your bike is within 10 lbs of a Blackbird? c'mon.
I could go on and on about how much BMW fibs, but I'll take just one example and be done with it. Hp measured at the crank is a stupid way to publish power, when every independent test takes it at the wheel. This in itself is misleading at best. What I don't get though is how BMW just adds hp on top of that just because they feel like it. Lets take the R1200RT - they publish 110 hp. MCN dynoed it at 95 at the wheel. This is reasonable, and is a rare example of BMW being honest. That's 15 hp it takes to turn the wheel. It's going to take approx 15 hp for an engine to turn the wheel of any shaft driven motorcycle - why on earth would you take 15% of an engine's power to do that calculation? why would it take, for example, 25 hp on a 167 hp K1200S to turn the wheel, but only 15 hp to turn the R1200RT wheel?
Going on common sense now and deducting 15 hp from engine to the rear wheel power, BMW's claimed 167 hp for the K1200S calculates to 152 rwhp. MCN dynoed this bike at 134 hp though, exactly the same as the Blackbird. Even if you were to calculate 15% off the claimed 167hp (which is completely stupid to do so) you get 142, almost 10 hp off of reality. This is just one example of many where BMW lies their asses off, why they haven't lost credibility with their buyers who knows? I know I'd be ticked to spend 20k on a bike only to discover I was lied to by the salesman and BMW.




BMW claims 160 crank horsepower (all manufacturers use crank horsepower because it's higher, and all magazines use rear wheel power, because that's what they can test).  The magazines test it at around 133 RWHP.  That is a 17% loss, which is believable for a shaft drive bike.

chesthing:
BMW claims 167 hp.
Please explain your reasoning behind applying a percentage of engine hp when converting rear wheel to/from the crank? Why would a 200hp engine lose more hp at the wheel than a 100hp engine? if you had a 1000 hp engine, would you expect to see a 150 hp difference between the crank and wheel? or would you expect to see the same hp loss with the exact same car with a 300 hp engine?
Sorry, applying a percentage makes absolutely no sense. Neither do dry weights or crank hp figures, it's just completely useless info. The reason BMW doesn't use rear wheel power figures is because they have found an easy way to make their products look better than they are compared to the competition. The facts are out there, but most buyers don't bother to look - they would rather go around believing what the BMW brochure says - it helps rationalize the overpricing. I've got a couple riding friends that absolutely believe their K1200GTs have 152 hp and are convinced they are significantly more powerful than the FJR (Yamaha lists an accurate 140 hp at the crank). It doesn't matter that I've told them this bike dynos at 124 at the wheel same as the FJR, they just look at me with clueless looks in their eyes.

miles:
Quote from: chesthing on December 29, 2011, 11:19:47 PM


BMW claims 167 hp.



Link?  All I've seen says 160.

Quote from: chesthing on December 29, 2011, 11:19:47 PM

Please explain your reasoning behind applying a percentage of engine hp when converting rear wheel to/from the crank? Why would a 200hp engine lose more hp at the wheel than a 100hp engine? if you had a 1000 hp engine, would you expect to see a 150 hp difference between the crank and wheel? or would you expect to see the same hp loss with the exact same car with a 300 hp engine?


Here's a lengthier and better answer than I would have written:
http://rusubaru.com/drivetrain-loss/

Quote from: chesthing on December 29, 2011, 11:19:47 PM

Sorry, applying a percentage makes absolutely no sense.


Read the info in the link.


Quote from: chesthing on December 29, 2011, 11:19:47 PM

Neither do dry weights or crank hp figures, it's just completely useless info. The reason BMW doesn't use rear wheel power figures is because they have found an easy way to make their products look better than they are compared to the competition.


All the manufacturers post dry weights and crank HP.  They do that to make the bikes seem lighter and stronger than they are, but it does in fact serve as a good apples-to-apples comparison, because, like I mentioned, they all do it.

Quote from: chesthing on December 29, 2011, 11:19:47 PM

The facts are out there, but most buyers don't bother to look - they would rather go around believing what the BMW brochure says - it helps rationalize the overpricing. I've got a couple riding friends that absolutely believe their K1200GTs have 152 hp and are convinced they are significantly more powerful than the FJR (Yamaha lists an accurate 140 hp at the crank). It doesn't matter that I've told them this bike dynos at 124 at the wheel same as the FJR, they just look at me with clueless looks in their eyes.



Sure.

chesthing:
I guess I'd like to see a link showing 160hp, all I can pull up is 167. Either way it's a bullshit number pulled out of the ass of a rich German.
Sorry I'm not going to read your link. If it contradicts what I'm saying it's not worth reading and if it confirms it what's the point?

miles:
Quote from: chesthing on December 30, 2011, 12:12:28 AM


Sorry I'm not going to read your link. If it contradicts what I'm saying it's not worth reading and if it confirms it what's the point?





QFT.  That's sig line material right there.

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