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Trondyne made a point on another topic about Harleys being underpowered, my opinion is that is far from the truth. Horsepower is not even a real number, it is derived from an equation that includes torque and RPM. Harleys on average across their model line have more torque than other makes including the high HP road race bikes. A bike that can produce 10,000 or more RPM to multiply available torque will make a lot more HP than a Harley that only goes up to around 6000 RPM. Realistically how often or how long are you going to ride around on the street at 10,000 or more RPM? Both of my bikes cruise at 70MPH at 4000RPM, a Harley XR1200 with maximum torque at 4000RPM and a KTM 990SMT with maximum torque at around 8000RPM. The Harley Is in the meat of the real power range and continues to make a decent amount of torque up to almost 7000Rpm, the KTM hasn't got there yet. Be honest here, isn't most of your street riding done between 2000- 6000Rpm? Which is truly better in that range? The almost tractor like Harley or the screaming banshee? Not saying the banshee isn't fun, just be real about how much you really use all of it.
 

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I think this video illustrates that point a bit.

 

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Pegasus trapped in a human body on a motorcycle
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Trondyne made a point on another topic about Harleys being underpowered, my opinion is that is far from the truth. Horsepower is not even a real number, it is derived from an equation that includes torque and RPM. Harleys on average across their model line have more torque than other makes including the high HP road race bikes. A bike that can produce 10,000 or more RPM to multiply available torque will make a lot more HP than a Harley that only goes up to around 6000 RPM. Realistically how often or how long are you going to ride around on the street at 10,000 or more RPM? Both of my bikes cruise at 70MPH at 4000RPM, a Harley XR1200 with maximum torque at 4000RPM and a KTM 990SMT with maximum torque at around 8000RPM. The Harley Is in the meat of the real power range and continues to make a decent amount of torque up to almost 7000Rpm, the KTM hasn't got there yet. Be honest here, isn't most of your street riding done between 2000- 6000Rpm? Which is truly better in that range? The almost tractor like Harley or the screaming banshee? Not saying the banshee isn't fun, just be real about how much you really use all of it.
Horsepower is not even a real number
Actually, it is a real number, just one that has less practical meaning on the streets than many believe.

Torque is an instant measurement of how much twisting force is being produced at that moment.
Horsepower is a measurement of how much of that force is being applied over a set period of time.
(Simplest way I can think of to describe the difference between the two.)

Now, for the average, everyday rider, what is needed more is good torque in the RPM range you will be most often in. You are most definitely correct that Harley Davidsons are not lacking in that department. Good low end torque is what makes such bikes so easily to move off the line so briskly.

But horsepower does have some importance. Take the Honda Rebel 250. It has plenty enough low end torque to move the light weight machine around the streets without any difficulty at all. Lets take the rebel onto the interstate. If it is able to keep up with the flow of traffic at all, it will be straining itself to do it. That is because the little 250cc engine does not have enough torque in the upper rpm range to produce the needed horsepower to maintain highway speeds. (Talking flow-of-traffic, and not the legal 65-70 or so) The 250 Ninja does not have this issue, because it makes its power higher in the rpm range, and produces enough to maintain flow-of-traffic speeds without any issues. Even a stock engined Shadow 750 may struggle at highway speeds, if the rider often shops at the Big-n'-Tall stores, has a big windshield, and carries around a lot of gear. (The big reason why the Stage III jet kits, aftermarket intakes and exhaust, ect., are so popular for those bikes) 40-45 hp is generally what is needed at the rear wheel for traveling at 80mph. Easily obtainable with even a 500cc single or twin.

What has everyone thinking that high horsepower is so great is that such numbers are needed to maintain ungodly rates of speed you typically only see in racing and dumbasses running from the cops on youtube. (also, movies and TV) And suddenly, every yahoo out there wants all that power. Nevermind the fact that it cannot be used in any legal way on the streets.

Basically, good low end and midrange is what you want on the street. High top end with respectable midrange is what rules the track.

Except for that one little point, you are fully correct. Most of this was just highlighting and adding on the points that you made.
 

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Or a simple comparison: torque = acceleration, hp = speed.

I've disappointed many a Ninja off the line on my little VS800 V-twin, only to have them go screaming by later, just like the video above.
 

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Trondyne made a point on another topic about Harleys being underpowered, my opinion is that is far from the truth. Horsepower is not even a real number, it is derived from an equation that includes torque and RPM. Harleys on average across their model line have more torque than other makes including the high HP road race bikes. A bike that can produce 10,000 or more RPM to multiply available torque will make a lot more HP than a Harley that only goes up to around 6000 RPM. Realistically how often or how long are you going to ride around on the street at 10,000 or more RPM? Both of my bikes cruise at 70MPH at 4000RPM, a Harley XR1200 with maximum torque at 4000RPM and a KTM 990SMT with maximum torque at around 8000RPM. The Harley Is in the meat of the real power range and continues to make a decent amount of torque up to almost 7000Rpm, the KTM hasn't got there yet. Be honest here, isn't most of your street riding done between 2000- 6000Rpm? Which is truly better in that range? The almost tractor like Harley or the screaming banshee? Not saying the banshee isn't fun, just be real about how much you really use all of it.
HD still making good torque at 7000 RPM? Really? I seriously doubted it so I went looking. Most information I found said it is not safe to rev a twin cam past 6200. There is a big difference between torque at various engine speeds but there is also a huge difference in normal riding, not racing, engine RPM.
Short stroke multis often run well over 5000 at normal highway speeds and for them that is on peak torque. The tractor engine in an HD does produce lots of torque way down low which is why they are ridden way down low. At 60 MPH in a normal cruising gear both the high revving multi and the HD are below peak torque but not by much.
At 45 MPH in 5th, my HD was running right at 2000 RPM. 6th required more speed or the engine seriously lugged. On my old 500 cc Honda, 45 MPH was closer to 4000 RPM and was much closer to its power peak. That meant I could just give it fuel to accelerate nicely. On that twincam you had better downshift unless you have all day.
 

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Pegasus trapped in a human body on a motorcycle
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HD still making good torque at 7000 RPM? Really? I seriously doubted it so I went looking. Most information I found said it is not safe to rev a twin cam past 6200. There is a big difference between torque at various engine speeds but there is also a huge difference in normal riding, not racing, engine RPM.
Short stroke multis often run well over 5000 at normal highway speeds and for them that is on peak torque. The tractor engine in an HD does produce lots of torque way down low which is why they are ridden way down low. At 60 MPH in a normal cruising gear both the high revving multi and the HD are below peak torque but not by much.
At 45 MPH in 5th, my HD was running right at 2000 RPM. 6th required more speed or the engine seriously lugged. On my old 500 cc Honda, 45 MPH was closer to 4000 RPM and was much closer to its power peak. That meant I could just give it fuel to accelerate nicely. On that twincam you had better downshift unless you have all day.
He mentioned the XR-1200... maybe that is the Harley he is talking about. It makes 90hp @7k rpm. Cause I did not see anything about the Twin Cam engine in the post that you quoted. And if you check his profile, the two bikes he mentioned in the post are the same ones he owns.

You made it sound as if he was doin an apples-to-oranges comparison, but you turned it into an apples-to-oranges-to-bananas comparison lol
 

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At 45 MPH in 5th, my HD was running right at 2000 RPM.
Interesting. Mine would be seriously lugging at that speed and would be well below 2k rpm. Just proves it depends on the model of bike and you better know what gear to be in at a given rpm. I'd have to be down to 3rd to hold that rpm. And if I wanted to scoot I'd have to down shift in order to actually move since it would be getting close to lugging at that rpm and speed and gear. Bike specific is my point.
 

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It was that way on my 2010 Ultra and my 2011 RGU. T Ultra was a 96 and the RGU was a 103. Both were 6 speed twin cams.
 

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Discussion Starter #10 (Edited)
Oldman47 Biker Dash has it right that I was only referring to MY Harley, an XR1200 that does redline at around 7000RPM. It has a relatively flat torque curve with 4000RPM showing as the maximum torque and max HP at or very near 7000RPM. The main deciding factor of RPM at any given speed is going to be gearing, the XR is a five speed as all Sporsters from that year(2009) are(if I'm not wrong about that to) and available power. Also I never said I rev it past that often because I rarely need to, don't need to go that fast or get tickets.
 

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Quarter mile times don't lie... While the DOHC 4 Cyl may not come into their power band quite as fast as the large V-twins, once there they stay there and out perform most other engine designs, in many cases by far...doing 11 second ETs with bikes running 600cc engines putting out over 100HP... HP is quite "real"...
 

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Pegasus trapped in a human body on a motorcycle
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Quarter mile times don't lie...
Correct, but you miss the point. The quarter mile is a race. Completely and totally different beast than the street, where you are expected to NOT ride like a complete and total asshat.

And while a supersport bike might do well enough in the 1/4 mile, in the 1/8th, the bike with the better bottom end is gonna pull away sharply.

As I pointed out earlier, 40-45 is ALL you need for ANY legal riding. Hell, the 98 Shadow 750 I had, with only 36 crank horsepower (before mods) was more than capable of getting my flank in serious trouble with the po-po.
 

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Correct, but you miss the point. The quarter mile is a race. Completely and totally different beast than the street, where you are expected to NOT ride like a complete and total asshat.

And while a supersport bike might do well enough in the 1/4 mile, in the 1/8th, the bike with the better bottom end is gonna pull away sharply.

As I pointed out earlier, 40-45 is ALL you need for ANY legal riding. Hell, the 98 Shadow 750 I had, with only 36 crank horsepower (before mods) was more than capable of getting my flank in serious trouble with the po-po.
I missed no point...perhaps you missed mine. My point was regarding performance and I made my point. Keeping one's machine in the power band when one wishes to accelerate isn't being an asshat and it doesn't mean it's a "race", it's riding a particular bike within its designed performance envelope.

As far as 1/8th ETs go you're going to have a hard time finding any V-twin that's going to beat out a 10 second machine 0-anything.
 

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Pegasus trapped in a human body on a motorcycle
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I missed no point...perhaps you missed mine. My point was regarding performance and I made my point. Keeping one's machine in the power band when one wishes to accelerate isn't being an asshat and it doesn't mean it's a "race", it's riding a particular bike within its designed performance envelope.
Just how quickly do you need to accelerate? You seem to be under the impression that unless you have triple digit hp numbers, a bike would not be able to accelerate at all. At least, that is the impression you are radiating like a bright, sunny, ball of wanna-be.

As far as 1/8th ETs go you're going to have a hard time finding any V-twin that's going to beat out a 10 second machine 0-anything.
I can name off numerous bikes, just here in Waterville, including one particular HD that is pushing 130/130 at the wheel, (I watched the dyno run. It is a legit all motor machine) has been clocked at over 150mph, and I would place my money on it against most liter class supersports in the 1/4 even. And these are V-Twin bikes I refer to. The other bikes, maybe in the 1/4, they might be passed by a 600 supersport, but they will own that bike in the 1/8.

Horsepower is great, but not as great as you seem to think it is.
 

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Just how quickly do you need to accelerate? You seem to be under the impression that unless you have triple digit hp numbers, a bike would not be able to accelerate at all. At least, that is the impression you are radiating like a bright, sunny, ball of wanna-be.
This has nothing to do with "how fast I want to accelerate", as I stated it has to do with performance... Further, your derogatory comments only serve to demonstrate a juvenile and obnoxious attitude.

I can name off numerous bikes, just here in Waterville, including one particular HD that is pushing 130/130 at the wheel, (I watched the dyno run. It is a legit all motor machine) has been clocked at over 150mph, and I would place my money on it against most liter class supersports in the 1/4 even. And these are V-Twin bikes I refer to. The other bikes, maybe in the 1/4, they might be passed by a 600 supersport, but they will own that bike in the 1/8.

Horsepower is great, but not as great as you seem to think it is.

I am talking production machines... I am not aware of any v-twin 10 second production machines... But this is getting off topic... I think idea is clear.

"Great as I think it is..." lol That's wonderful.
 

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torque gets you going, horsepower keeps you going. 5235 rpm is the magic number where HP becomes the mover. It takes both to tango.
 

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This has nothing to do with "how fast I want to accelerate", as I stated it has to do with performance... Further, your derogatory comments only serve to demonstrate a juvenile and obnoxious attitude.




I am talking production machines... I am not aware of any v-twin 10 second production machines... But this is getting off topic... I think idea is clear.

"Great as I think it is..." lol That's wonderful.
It is called having a low tolerance for ignorance.
And Ducati makes a 10 second V-Twin streetbike. Then again, you never did specify whether or not it had to be production. Adding such criteria after the fact seems a move of someone who finds that their arguments do not stand very well.
 

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I always looked on it as HP gives you top speed, torque gives you the ability to get up to speed faster.

I like the cruisers' torquey motor, it makes it easier to pull away in traffic in a wider range of gears yet gives me enough HP to keep up with traffic on the highway. But then there are those who like the buzz of a high revving sports bike and it's high speed ability, and good on them.

Hey, as long as everyone is on two wheels it doesn't matter what their preferred bike style is, cruiser, adventure bike, sports bike or chopper, we're all members of the two wheeled brethren.
 

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Subversive
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It is called having a low tolerance for ignorance.
And Ducati makes a 10 second V-Twin streetbike. Then again, you never did specify whether or not it had to be production. Adding such criteria after the fact seems a move of someone who finds that their arguments do not stand very well.
There is no argument the DOHCs 4cyls out perform the v-twins, and always have in full blown ET performance... Anyone can modify a machine, it makes no sense to bring up custom machines unless your argument is flawed...

Low tolerance for intelligent, rational discussion is more like it...
 

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Pegasus trapped in a human body on a motorcycle
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There is no argument the DOHCs out perform the v-twins, and always have in full blown performance... Anyone can modify a machine, it makes no sense to bring up custom machines unless your argument is flawed...

Low tolerance for intelligent, rational discussion is more like it...
Ducati Diavel. 1200cc V-Twin that will do the 1/4 in 10.2. That is stock, btw.

And my initial comment was referring to street machines, and what can be used on the street. (without placing the rider in a jail cell or on a slab, depending on how unlucky he is) And yet, all you wanna hear about and spout off about, is how fast a machine can go down the quarter mile track.

I have been quite rational. Your insistence that track performance has any real world bearing on the street is what is lacking in rationality.
 
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