Short Stroke Motor
Road Captain
Joined: Jan 2006
Posts: 566
Likes: 3
From:
I back my statements up with actual riding, not quotes out of magazines, if you know so much bring your "fast" little 600 up here and I'll spank you, If you knew how to read you would see that I have already raced these bikes, and I know what I can do on my bike. I back up my words with action, not more words. Put up or shut up!
By the way I said the 600's are faster in the quarter, I said I can smoke them 0-60 or 70mph, pay attention!
By the way I said the 600's are faster in the quarter, I said I can smoke them 0-60 or 70mph, pay attention!
Last edited by Fred00; Oct 29, 2008 at 05:14 PM.
Tourer
Joined: Nov 2007
Posts: 448
Likes: 3
From:
- modern 600 in-line fours are very quick.
- and they're quick everywhere. Whether acceleration , mid-range , or top end.
- but the rider needs understand the bike's rev-range , and where it makes power.
- they're only "slow" when compared to a liter bike on the straights.
.
- and they're quick everywhere. Whether acceleration , mid-range , or top end.
- but the rider needs understand the bike's rev-range , and where it makes power.
- they're only "slow" when compared to a liter bike on the straights.
.
Ultimate HDF Member
Joined: Sep 2007
Posts: 8,831
Likes: 15
From: Nomad
omg
Are we really trying to compare how an XL1200 is almost as fast as a Gixxer 600 or CBR or whatever?
Compare a Sporty to a (not so) old ZX-12R. At least then you've got the displacement matched.
Are we really trying to compare how an XL1200 is almost as fast as a Gixxer 600 or CBR or whatever?
Compare a Sporty to a (not so) old ZX-12R. At least then you've got the displacement matched.
Road Master
Joined: Oct 2007
Posts: 786
Likes: 1
From: Sheridan, AR
I've never denied that. I will also admit that I am pretty cocky when it comes to racing these small bikes, but in my defense "it is pretty damn fun to win".
However the meat of this thread was about torque vs. horsepower, and I firmly believe that if you took a 90ft.lb. HD drive train and put it in a 300lb bike with a light weight rider and put it up against a 600cc bike in the quarter the 600 wouldnt stand a chance and the 600 has more HP. The reason it would lose is because of the acceleration provided by the torque of the HD motor. The 600 would still have a much greater top end.
Elite HDF Member
Joined: Sep 2007
Posts: 4,541
Likes: 1
From: Nuevo México, Los Estados Unidos de América
...However the meat of this thread was about torque vs. horsepower, and I firmly believe that if you took a 90ft.lb. HD drive train and put it in a 300lb bike with a light weight rider and put it up against a 600cc bike in the quarter the 600 wouldnt stand a chance and the 600 has more HP. The reason it would lose is because of the acceleration provided by the torque of the HD motor. The 600 would still have a much greater top end.[/FONT][/COLOR]
The first is that the HD drive-train is half of what's making your bike weigh that might... the drivetrain itself probably weighs almost 300ilbs.
...and you're wrong on the 2nd count... tq does not accelerate you, it's a measure of force applied with every rotation of the engine. Torque is great, it's really all torque. Hp is just torque with moment added in... so that's not the issue, the issue is where you get your torque... and you want it up high, if you want to accelerate quickly. Both because it will produce a higher peak hp the higher you can continue to make tq, and you can then gear the bike down...
Your twinky may make 90 ft ilbs of tq... but it's geared super tall since you have to shift our of 1st by 6ooorpm, and the engine if flat (barring some major work) after 5000rpm... given that you are not racing to 20mph... this mean you are geared pretty high... so your 90 pounds of torque is already pushing less than a geared down sb pushing just 30...
Now 600cc bikes have no low-end. Some of them have a decent mid-range. But it is diffucult, especially on the street, to launch one hard because the power-band is not smooth like on a v-twin, but just "comes on", so most riders will either bog/slow launch, fry the tire, or bring-up the front-end, then have to let off. I say your HD will beat most 600cc bike/rider combinations to 20-25mph... so... for about half a second right off the line...
Once you switch out of first (and the 600cc sb will still be in first when you're in 3rd) you will be giving up even more mechanical advantage, and anything all that low-end could do for you is gone... and you're just working with your 60 horses and a tranny geared too high to put any power to the pavement.
Road Captain
Joined: Jan 2006
Posts: 566
Likes: 3
From:
However the meat of this thread was about torque vs. horsepower, and I firmly believe that if you took a 90ft.lb. HD drive train and put it in a 300lb bike with a light weight rider and put it up against a 600cc bike in the quarter the 600 wouldnt stand a chance and the 600 has more HP. The reason it would lose is because of the acceleration provided by the torque of the HD motor. The 600 would still have a much greater top end.
The article below (written by a Harley man) does a good job of explaining why the Buell (and Harley) has less acceleration despite of their torque advantage. It's all about rear-wheel torque and the Harley engine makes its torque at too low rpms to take advantage of short gearing. The result is that the 600 still puts aout 20% more torque to the rear wheel when going flat out, hence the difference in acceleration. The article is recommended reading, since it's one of the best I've read on the subject:
http://www.nrhsperformance.com/tech_power.shtml
Buell XB12 -04
Test in Motorrad 22/2004
Gewicht vollgetankt 209 kg
0 - 70 km/h - s
0 - 100 km/h 3,9 s
0 - 120 km/h - s
0 - 140 km/h 6,5 s
0 - 150 km/h - s
0 - 160 km/h - s
0 - 180 km/h - s
0 - 200 km/h 15,2 s
ZX-6R -00
Test in Motorrad 09/2000
Gewicht vollgetankt 199 kg
0 - 70 km/h - s
0 - 100 km/h 2,8 s
0 - 120 km/h - s
0 - 140 km/h - s
0 - 160 km/h - s
0 - 180 km/h - s
0 - 200 km/h 10,3 s
Road Captain
Joined: Jan 2006
Posts: 566
Likes: 3
From:
Your twinky may make 90 ft ilbs of tq... but it's geared super tall since you have to shift our of 1st by 6ooorpm, and the engine if flat (barring some major work) after 5000rpm... given that you are not racing to 20mph... this mean you are geared pretty high... so your 90 pounds of torque is already pushing less than a geared down sb pushing just 30...
The traditional Harley engine has the same "problem" as diesel car engines. They make their torque too low in the rpm range to get high horsepower. Diesel engines often have tremendous torque output but rarely keep up with their petrol counterparts when it comes to acceleration.
Last edited by Fred00; Oct 30, 2008 at 11:12 AM.
Elite HDF Member
Joined: Sep 2007
Posts: 4,541
Likes: 1
From: Nuevo México, Los Estados Unidos de América
Yep. 90 lb-ft at 12'000rpm is twice as good as 90 lb-ft at 6'000rpm. With a 12'000rpm engine you can run half as long gears and still get to the same speed in each gears. This will effectively double the torque at the rear wheel and therefore double the rate of acceleration. All this without increasing the torque in the engine at all. The horsepower in the 12'000rpm engine will be twice as high though.
...HD will never produce a long-stoke engine that revs to 10,000rpm...
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Road Captain
Joined: Jan 2006
Posts: 566
Likes: 3
From:
Yes, big-bore and short stroke is the way to go if you want the most performance out of a given displacement.
Last edited by Fred00; Oct 30, 2008 at 11:24 AM.
Road Master
Joined: Oct 2007
Posts: 786
Likes: 1
From: Sheridan, AR
I agree with most of what you said, Torque and HP are directly related. I was just trying to state, that all other things being equal, a bike with high torque numbers will typicly out accelerate (for a short distance i.e. 1/4 mile) a bike with higher HP numbers and low torque numbers.
BTW 71rwhp
BTW 71rwhp