Are harleys really that slow?

I had a '72 Sportster. It was slow. Quicker than the old Honda Rebel's, but still slow. Top speed on mine was about 65. Anything over 50 it rattled so bad, your whole body would go numb after about 5 min.

 

if torque wins races they should of never built the vrod it claims to only have 84 ft lbs i think the v rod isnt even in the same class. and before the vrod the sporty was the fastest harley and it doesnt make 80 ft lbs torque. just to prove my point if torque wins races how come a 502 boss hoss gets out run by 80 ft lbs hyabusa the boss hoss makes 420 ft lbs more but not important. everyones tastes are different . some people take beautifull bikes and make them into bobbers beauty is in the eye of the beholder. thats what makes everyone different if we were not we wouldnt need all the different bikes out there. i will be the first to admit a harley is no where near as dependable as a jap bike. i guess maybe were kinda jealus because we dont have that kind of money to put into a bike. we all have seen a harley we wouldnt mind having in our garage. but i think just about everyone on here will agree its a really good reason most harleys arent that fast from the factory they dont want law suites not all but most harley riders are mostly white collar workers that dont ride very much at all and party hardy dont respect what they got . could you imagine them on a 10 sec bike vs 14 sec bike. ive worked daytona bike week on main street ive seen just about everything did it for over 20 years

 

The relationship between torque and horsepower is difficult to understand. I have a very good explanation from a physics website below. I hope everyone does their best to understand the physics regarding the two measurements of engine output, torque and horsepower.

People often confuse power and torque because car enthusiasts tend to (unknowingly) use these words for different concepts. This is a physics site, so I'm going to go ahead and use the definitions from physics.

The full-throttle behavior of an engine can be approximately modelled as a device which has some function associated with it. This fixes the torque it can produce as a function of engine speed (rpm). This function is not at all constant, although engineers often strive to make it as flat as possible.

Regardless, given the torque function, there is an associated power . So if the torque is known at all speeds, the power is known at all speeds (and vice versa). You can't have one without the other.

Despite this, it is common practice for engines to be advertised only in terms of their peak torque and peak power. The engine speeds where those conditions may be found are also usually given. The peak power is very important for reasons I'll get to later, but the peak torque is essentially useless all by itself. The reason is that the gearbox can multiply the torque to (essentially) any amount whatsoever at an appropriate speed. But an ideal gearbox cannot change the power.

Staying with the ideal case, the maximum forward force that a car can produce is entirely determined by the power its engine is producing and the car's overall speed. So fixing speed, maximum acceleration is always reached by maximizing the engine's power output. It is the job of the transmission (and driver) to use the gearbox to keep the revs as close to the engine's power peak as possible if full acceleration is desired.

Modern transmissions have many closely-spaced ratios, so except at very low speeds (at the bottom of 1st gear), an engine may be kept close to its power peak for as long as desired. That means that a well-designed car that is driven well may produce a force . This depends only on the peak power (and velocity), and explains why the power-to-weight ratio is such a good predictor of acceleration performance.

Having said that, the torque peak is not completely irrelevant. Its position relative to the power peak is usually a good indicator of the size of the car's "powerband." Essentially, how high do you have to rev it in a given gear before the engine really gets going? Having a wide powerband is extremely important in everyday (or moderately aggressive) driving where you're not going to redline in every gear. It makes the car feel much more powerful even if the maximum performance is the same. Of course, a wide powerband is also useful if your have a poor transmission or don't want to shift as much.

Russ, differences in drivetrain inertia between reasonable designs are not usually not a huge effect. They're certainly significant, but I don't think I'd include them given the approximations already inherent in this sort of discussion.

 

i stand corrected - gear driven, single cam is a huge plus in my opinion. maybe not going to give best possible performance, but should last for ever and be easy to work on.

 

Truth be told... I've grown to like the "cricket" sound of my XJ. In fact, I call my beautiful Maxim; Cricket...

The other dark side is... I really like the low RPMs of the Harleys. I would like a 6th or 7th gear on my XJ 650...

OK... Now you got the skinny on me...

 

Here is how I learned torque and hp and how they relate...

Take a 55 hp harley. It's producing 78 ft lbs of torque. Rear wheel power. Modify it so that you can put a pully on the front big enough to lower the the torque to 20 ft lbs. The horsepower the bike has is absolutely pointless, then. If the torque is 20 ft lbs, you can hold it with your own strength. Now, without changing the gearing, raise the horsepower of the engine until it can turn the pully to to produce 78 ft lbs of torque again.
The gearing sets the amount of torque. The horse power sets what can be done to the gearing for best performance. The best performance means more speed.
If harley had another 100 horsepower, they could re-gear the tranny (same principal as larger front sprocket, smaller rear) and the motor would have the power it needs to turn the gear with the force they need to produce the best torque.
You can go 100 mph with fast enough rpms, big enough gears, and one hell of a long strip of asphault on 10 ft lbs of torque. You might not move at all with 80 ft lbs of torque and 10 hp.

Remember riding a geared bicycle? Remember how easy it was to pump the pedals when you are in first gear? You're the motor with the horsepower in that case. Your maximum h.p. is whatever you have in your legs. Guess how hard it would be to stop the rear wheel with you pumping with all of your might in first gear. Put the bike is it's top gear and now your having to use a lot more of your physical resources to pump the pedals and get the rear tire moving. You are still producing the same strength. But producing the same torque? Much more difficult.

Horsepower is essential if you want to have any kind of race-winning torque. Otherwise you just have the kind of torque that can move a 1000lb bike and two fat people up a steep incline with little effort and little speed.

 

Thats the differance between real bikers and Harley riders. Real bikers enjoy the finer points of all bikes and will ride with you or anyone no matter what they ride. Where Harley riders typically put down all other bikes but Harley's. Im not saying all of them, but a high majority do and every one knows it. Short minded and attitude driven. I wonder if they know the evalution motor was designed by Suzuki and the Harley Jacket I bought with my only Harley I ever owned was purchased at a Harley dealership and made in China. My 84 wide glide looked great, but no matter what I did to it, it didnt have balls to keep up off the line, top end or braking power enough to stop like my Kawasaki 550 spectra. I loved them both, but one was more thrilling to ride and the other looked better. Just my opinion I guess.

 

is that a fact? cuz that would be like rain on your wedding day. or 10,000 spoons when all you need is a knife.

 

or even a free ride that you just can't take. Haha... who woulda thought it figured.

 

I never thought I'd hear Alanis brought up in the middle of a conversation about bikes, haha.

 

...and from skeeter. You'd more expect (from his avatar) something like, "...Now fatty, he's a helluva guy but he sweats like a dancing mule. He likes to hang out at checker gas with the chets he knew from high school..." But ya gotta forgive him if he hesitates.

 

Im no expert either. Been riding since 1971. More of an expert on Huskys, pentons and macios from the 70's and 80's. I bought the bike and jacket at a harley dealer, a snap fell off the jacket within a month and under examination found the made in china lable. Said Harley Davidson on the back with a large eagle as well. I have no idea how I missed it when I bought it. I guess I just took it for granted it was made in the USA. I cant prove that the evolution motor was designed by Suzuki but it been brought up many times by many different sources and has metric bolts in it from what Ive heard and seen.

 

my brothers harley is quick... giant engine, low to the ground and it pulls HARD in very gear. My butt slides back on the seat every time I hot rod his bike.
We drag race a little and my bike does not have a chance.

 

I have rode 4 distinctly different kinds of Harley from a wide glide to a bare bones scary to ride chopper. None of them are anywhere near as fast as my maxim. The only time I wondered was the first 6 feet off the line but very quickly that changed. Stump pulling torque but you have to shift too much, I was shifting into second and this 1200 was shifting into third and was about 100 feet behind me. But each to there own I know some Harley guys that are cool one guy even told me he bought one so he would have something to work on when it broke. Have you ever watched the special on the V-rod from Discovery channel? Watch it and compare some of the high tech stuff they did to make this bike so cool that Yamaha did with the V-max in 1985. And I believe the V-rod motor was designed by Porsche?! I think.

 

I don't know.....my dad has an '04 Road King Custom. Just the basic 88 cubic inch v-twin, as usual. But when we dragged we were neck-at-neck when he had a little head start. I did like how my $600 bike kept up with his $20,000+ bike, however. My uncle did say that Dad's bike sounded "a little loud" (wink, wink) to which I replied "So you didn't hear my bike?" and he replied "HELL NO!" I will be investing in a 4-into-1 exhaust this season...

 

Whats a harley

 

Not just Harleys, I have a thing against most engines that are less than 4 cylinders. It seems to me that an inline-4 would be the smoothest and most reliable common motorcycle engine today. Otherwise you have concepts like inertia forcing the engine to work against itself. It may make good low-end torque, but it also spends less than half of the day in power stroke.

All I need now is the money for that radial engine bike I've been meaning to build. Just gotta get someone I know to part with a Wright R-1820 engine...

 

Two completely different animals. I have a xj650, and I have a Harley heritage softail. If I want to zip around town or play around on fairly short rides I'll take the xj. If I'm going on a ride to Daytona I'll take the Harley.
I reach for another gear on the Harley occasionally out on the road......So you can imagine how many times I hunt another gear on the xj. As I said earlier....two completely different animals....but I enjoy both. Yes, Porsche
did do a large part in developing the v- rod.

 

I couldnt agree more with this one!! I used to swear I would never ride one of those over priced, noisy, slow things. Then I rode one......Then I bought one.......Then I bought a nicer one.........Now I want a bigger nicer one!!

If you do the wrenching yourself and buy the parts online its not that expensive, But god help you if you take it into the local Harley shop!!! They will take all the money in your pocket and the lint too if they can get it!!! Fricken crooks those guys.

The only other sh@$ty thing is that you have to deal with all the doctors and lawyers going through their mid life crises, trying to relate to you. Listen guys take the Harley shirt, hat, jacket, necklace, helmet, sunglasses, socks, boots and tough guy bandanna off and then we can try to communicate!! We get it.........YOU RIDE A HARLEY.

Thats the worst thing about rideing a Harley hands down.

Are they really that slow though? yes...... But Cadillac's are not meant for speed

 

LOL bug. You can take 5 or 6 good guys and pu them in matching vests. Then you've got 5 or 6 a@#hol#@ s. Lot of truth there.