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I was wondering what the difference is between riding a v-twin sport bike like Suzuki TL1000 or a Ducati and say a gsxr 1000? Is riding v-twin different in some way?
 

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v-twins are the engine configuration used on Harelys, so i would guess that:

• v-twins rev lower than an inline 4
• v-twins have higher low-end power
• i know that the exhaust tone is very different. like comparing a mustang with a little civic.
 

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V twins have a better low end response, lot's of torque, and rev quickly. They will beat an inline 4 coming out of turns because of this. Where they have loads of torque, they don't get the top end rush like I4's do. If you've never ridden one, I'd say try it out. There really is nothing like the sound of a v-twin with the right pipes on it. If only Kawi made a v-twin sportbike. I'd buy it in an instant.
 

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NX and Ken are on the right track. Inline 4's rev a lot further out than twins do, where twins have more low-down grunt and instant torque typically. I've ridden a TL1000R several times and find that it is very punchy but never gives you that real rush of top end speed like an inline 4 does, and for the record, the '03 636 is significantly faster in a straight line than the TL. Twins by displacement will not put out comparable peak power to an inline 4, which is the reason Gixxer and Ninja 750's have been (up to this year) running in superbike classes with 998 Ducatis and RC51's, why this year the Gixxer 1000 had to be detuned to run in WSBK with them, and why the 748S Ducati is compared in shootouts with 600 inline 4's (and is still down significantly in peak power and test times). For a comparison, the RC51 puts out roughly 123hp where the Gixxer 1000 puts out some 155hp, despite having the same displacement and engineering focus.

Depends on who you are and what you like. Some people love the thump of a v-twin with the grunty, torquey delivery. Some people like the rush of an inline 4 catching it's stride.
 

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Just to add a point... When you roll off the throttle on a twin it's like applying the brakes as the revs will quickly come down and slow the bike.
 

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Bshap, very true except that most v-twins now will have slipper clutches to reduce the effects of engine braking. The TL-R was actually one of the first.
 

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Originally posted by NX MX5

• v-twins have higher low-end power
Not true.

V-twins have lower top end power than an inline four and maybe that creates a feeling of more low down grunt.

Compare the power/torque curve of GSX-R 1000 to any 1000cc v-twin. I'm pretty sure that you will not find a v-twin whose power/torque curve goes higher than GSX-R 1000:s curves in any rpm.
 

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Most high performance twins will rev to about 8000ish and be producing around 120 or so horsepower (at 6500-7500rpm) and at least that in ftlbs. If that isn't higher low end power I don't know what is.
 

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Originally posted by Liambane

Most high performance twins will rev to about 8000ish and be producing around 120 or so horsepower (at 6500-7500rpm) and at least that in ftlbs. If that isn't higher low end power I don't know what is.
Well, I consider Aprilia Mille R to be a high performance twin and it's nowhere near the GSX-R 1000 in power or torque. Well, the Mille has more a tiny amount of more torque between 3400-3500 rpm and that's it. Other than that, the GSX-R gives Mille a sound trashing all over the rev range...

Check the dyno chart and you see what I'm talking about (chart taken from motorcycle.com shootout gsx-r 1000 -03 vs. mille r -03 vs. zx-6r -03):

 

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Originally posted by Liambane

Most high performance twins will rev to about 8000ish and be producing around 120 or so horsepower (at 6500-7500rpm) and at least that in ftlbs. If that isn't higher low end power I don't know what is.
Just look at the dyno chart that Routa posted. It says about 75-90 ponies between 6500-7500rpm from the "high low end power" Mille.

I think that "V-twins have more low down power and torque" -myth is one of the most common fallacy in sportbike communities. It simply isn't true.

Torque is mainly determined by engines total displacement and compression ratio. Power is determined by torque and revs.

More displacement/more compression --> more torque
more torque/more revs --> more power

The engine configuration is not so important.
 

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Actually, Torque has most to do with Stroke vs. Bore sizing, and intake runner cross-sectional area.

Take Ford's 427 and 429 V-8's of the 60's for example, while only two ci separated the two, horepower and torque numbers were radically different. A longer stroke (429) gave the piston more mechanical advantage over crankshaft load, while the short stroke and big bore of the 427 offered high revving power. The 427 was used in NASCAR at the time while the 429 still remains in some dragsters.

Intake runner cross sectional area has to do with fuel delivery speed and volume. (Anybody know Bernoulli's Equation?) Torque producing intakes have smaller runners, increasing fuel delivery velocity for faster response to changing load demands (more torque). Horsepower producing intakes have large runners, capable of moving large volumes of gas/air at relatively low speeds, so when the RPM's are up, the gas speed doesnt matter, the flow volume does.

You can read in magazines etc. about undersquare and oversquare motors, referring to the ratio of bore to stroke. This ratio has the most to do with motorcycle torque and HP since most of the motors that we are talking about have relatively short intake runners and little difference in runner size.

So if I aint mistaken, arent most V-twins more oversquare(larger bore to stroke ratio) than I4's. If not, then my whole argument is shit.....lol
 

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Originally posted by Scuba_Steve_6

Actually, Torque has most to do with Stroke vs. Bore sizing, and intake runner cross-sectional area.

Take Ford's 427 and 429 V-8's of the 60's for example, while only two ci separated the two, horepower and torque numbers were radically different. A longer stroke (429) gave the piston more mechanical advantage over crankshaft load, while the short stroke and big bore of the 427 offered high revving power. The 427 was used in NASCAR at the time while the 429 still remains in some dragsters.

Intake runner cross sectional area has to do with fuel delivery speed and volume. (Anybody know Bernoulli's Equation?) Torque producing intakes have smaller runners, increasing fuel delivery velocity for faster response to changing load demands (more torque). Horsepower producing intakes have large runners, capable of moving large volumes of gas/air at relatively low speeds, so when the RPM's are up, the gas speed doesnt matter, the flow volume does.

You can read in magazines etc. about undersquare and oversquare motors, referring to the ratio of bore to stroke. This ratio has the most to do with motorcycle torque and HP since most of the motors that we are talking about have relatively short intake runners and little difference in runner size.

So if I aint mistaken, arent most V-twins more oversquare(larger bore to stroke ratio) than I4's. If not, then my whole argument is shit.....lol
All sportbikes have short stroke (big bore compared to stroke) engines, so that is not the matter in here.

Bore/stroke ratio usually defines how low or high the peak torque will be at the power curve (short stroke --> high torque at high revs. long stroke --> high torque at low revs) but I'd say that engine displacement and compression plays a bigger role defining the maximum amount of torque. "There is no substitute for cubic inches" should be a familiar statement to all Americans :)
 

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A longer stroke mechanically limits an engines performance (HP and Torque) capabilities at high revs. Linear motion (Distance pistons travel up and down) is related directly to stroke, and is one of the factors that makes these "long stroke" motors less capable at high-revs.

The 2002 TL-1000 and 2003 RC-51 for example, combined average a 99.00mm bore and 64.8mm stroke. Averaging the 2004 R1 and 2004 GSXR1000 yields a 75.00mm bore and 56.3mm stroke.

"Turning" the averaged V-twin numbers into a "Theoretical I4" involves only splitting the piston areas into 4 pistons and extrapolating (nice word) the resulting bore size. The equivalent I4 configuration of a "hybrid" RC51/TL-1000 would see a bore sizing of 49.5mm retaining its 64.8mm stroke.

While this looks oversquare in the V-twin configuration, this looks rather undersquare in the I4 configuration.

Am I right on these calcs? Or is something afoot in the bore/stroke department.

I think that one of the advantages of the V-twin track-wise is spreading out the power band. Gear selection becomes less of an obstacle right?
 

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for the layman, inclusive of myself as well...

If you look at the two curves of the GSX-R and the Aprillia, u see that the curve for the GSX-R is quite erratic. The Aprillia on the other hand has very smooth power delivery.

What does this mean...means it is a lot easier on the rider to exact the power out of the v-twin than the straigh 4. Probably why the GSX-R 1k has to basically limp to the finishing line in superbike. It destroys its tires.

The V configurations have always been known to produce better throttle response. That being v-twins vs. i2, i4; v-6 and v-8 over i6 and i4s.

The best way to demonstrate this phenomenon is to go ride a friends VTwin. Then u can throw all the calculations, theory and other BS and judge it for urself
 

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Isn't it the power pulses? The twin has 2 bigger ones per engine cycle, and the IL4 has 4 smaller ones per engine cycle.

So lets say both put out the same power or tq (100 for simplicity). The twin puts it out 50 twice, and the il4 puts out 25 four times during the same time (roughly). The 50 output is more noticable. Same amount but you feel it more. Over simplistic maybe, but that's essentially it as it was explained to me. IL4's do rev higher and that high rpm surge on a big bike like the gixxer 1k is what eates the tires.
 

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"The V configurations have always been known to produce better throttle response. That being v-twins vs. i2, i4; v-6 and v-8 over i6 and i4s."

-Doesnt the R1 have the quickest throttle response?
 

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Ok I am gonna have to throw my 2 cents in here. I just traded in my 01' Suzuki TL1000R to get my 03' 636. This thing was a wheelie monster, well at least getting it up, i was able to get it up with no problem what so ever, but I could not throttle it to keep it up. Also like someone else said in here when you let off the gas it just stops basically and there is no such thing as giving it just a little gas. I used to hate riding around town just for this reason, well and that the damn thing was so heavy and clumsy. If you have never riden a V-Twin I would suggest that you do before you buy one like I did and get really dissapoited. Don't get me wrong I loved the bike when I first got it but after ridin with my buddies it was apparent that this was not the bike for me. On the highway I would bury them but if there was any turns it was good night for me. The bottom line is that I HATED it very much. Hell I only had the bike for about a month before I decided to trade it in and go back to my ZX6R roots. Another big complaint is that the poor passenger has to hold on like hell because the damn thing has so much torque that it is very hard to get off the line at a reasonable speed. My old lady hated it but she loves the 636. Ok well that is my 2 cents and if I had 48 more i could be a rapper......
 

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I own a yamaha roadstar warrior, 1700cc v twin, It is a blast , 112lbs. at 3000rpm. but its a cruiser. I think v twins work in cruisers because of their exhaust note and idle rythem and they air cool very easily. Most of these pluses are purely for looks and thats what cruisers are all about. If you want straight up performance an in line 4 produces more power has less weight and runs smoother. This is why I have the zx6r also.
 

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I owned an '02 RC51 and nothing happened below 5,500 rpms and then it went absolutely apeshit afterwards. It took a lot of cluth control to get it going due to tall stock gearing. I wish that thing had a slipper clutch though, if you let off the gas at 8,000 rpms you were in for a jolt if you weren't expecting it.
 
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