Why sportbikes aren't beginner bikes

[Easy Rider]

Originally Posted by Rickster

For example, a 600cc RR bike is making about 25% more HP than the XB9SX.

(Tip-toeing carefully.......)
Nothing personal, Rick, but this is one of my pet peeves.

That is true but might not be significant for some (many ?) riders.

The extra 25% for the RR ONLY comes into play above 7-8K rpm.
Below that, their response might be similar and some R bike riders never (or very seldom) actually ride in that "turbo" range.

Point is: Quoting only peak HP specs. for two bikes of vastly different design doesn't tell the whole story and may, in fact, be mis-leading.

And then there are the feeble old farts like me who fall back to a little thumper to just enjoy the RIDE!

[Thundurburd]

How do the torques compare? Is it possible that the higher HP is due the higher rpm available on the R bike?

Just asking. I'm pretty much clueless on sport bikes.

[Clint]

Yes, that's generally the case.

[CaptCrashIdaho]

Originally Posted by Thundurburd

How do the torques compare? Is it possible that the higher HP is due the higher rpm available on the R bike?

Just asking. I'm pretty much clueless on sport bikes.

The thing that makes singles and v-twins fun is the fact that sooo much torque is available right at the bottom. If you want to have some fun watch what happens when a v-twins suckers an inline 4 into a stoplight drag--you know just a block long run between stoplights.

V-twins win the first 100ft easily then shut down just as an inline 4 starts to spool up. (Unless of course the inline 4 is willing to do a true drag start and hold the throttle at 7K before launch, then all bets are off and you should have your thumb on the 9 on your cellphone 'cause bad things are about to happen).

The best explaination I ever heard about horsepower v. torque was this:

Horsepower is how much you can lift. Torque is how fast you can lift it.

Hence, a 600cc sportbike has plenty of HP (up to 120 on some) but not as much torque.

A 900 Buell has only about 90 HP but plenty of torque--so is comes off the bottom better.

There are those who feel that the v-twin is a more 'ride-able' engine. I tend to agree. I ride a 400cc single right now, coming off an 1100 inline 4. It's easier for me to get usable, tractable power out of the single. The 1100 (where all hell broke loose at 7 grand) needed to be wrung out a little to make the big power. (The equivalent of 'riding the pipe' on a 2stroke).

For an experienced rider the question is: which do YOU like more. IF you can a couple of test rides would be nice. I, personally, think that maybe a 3 cylinder might be the best of both worlds but I haven't got any seat time on one...bummer.

If we're betting on this? I imagine you'll be more comfortable on the Buell. The hard part is choosing a color...them translucent airbox/tank cover things are pretty darn cool....

[Thundurburd]

Originally Posted by RowdyRed94

Yes, that's generally the case.

Thanks.

[Ext1jdh]

This is excellent information. Now I just gotta get the guy at the Harley dealership to pay attention to the people checking out Buells.

[Thundurburd]

Originally Posted by CaptCrashIdaho

Horsepower is how much you can lift. Torque is how fast you can lift it.

The way I read that statement makes me think you have these reversed.

For example, the torque at the back wheel corresponds to a force on the road.

If you travel a certain distance the Work done is equal to the force times that distance.

Power is the quantity of work done in a time interval, in other words the rate of doing work. So if have a force, distance of travel, and a time interval, you can determine the power.

I would rephrase your statement as follows:

"Force (or torque) is how much you can lift. Power is how fast you can lift it."

[Easy Rider]

Originally Posted by CaptCrashIdaho

The best explaination I ever heard about horsepower v. torque was this:

Horsepower is how much you can lift. Torque is how fast you can lift it.

WOW! Another good post!
Just lots of good information........that's no fun......take a swipe at somebody!

I do think, however, that the above is backwards:
Torque is how much you can lift; HP is how fast you can lift it.

My little diesel tractor has GOBS of torque. It could move a loaded semi with the wheels locked (if it had enough traction) but it sure wouldn't move it very fast!

[Clint]

Originally Posted by Thundurburd

The way I read that statement makes me think you have these reversed.

I would rephrase your statement as follows:

"Force (or torque) is how much you can lift. Power is how fast you can lift it."

Yup. He did have it backward. Torque is a measure of rotational force, horsepower is a measure of work done.

BTW, we can't make that type of generalizations about an engine based on cylinder orientation and number alone. Comparing engines of equal displacement, many variables are more significant than those. For instance, my 1157cc inline four is both more torquey and more powerful than an HD 1200, even at low rpm. We just can't generalize like that.

Now, comparing a GSXR 600 with a Buell 900 does allow that type of comparision.

[Thundurburd]

Ok Crash, I've finally digested the rest of your post. Thanks.

I'm finding all of this more and more interesting. I just bought my cruiser last summer and really like the S50 and plan on never getting anything else, unless I wear it out of course, but I'll probably wear out first. On the other hand I'm afraid to get on a sports bike or take one out for the ride because if I like it I know I'll want one of those too. I have to admit that the day is coming when I wonder across the showroom and take a look at one of those things.

I'd have to find some more room in my garage for another bike. I suppose I could leave my minivan outside, wait a minute, my minivan already is outside.

Regards,
-Tburd

[Easy Rider]

Originally Posted by RowdyRed94

We just can't generalize like that.

CAN'T....Oh, we absolutely CAN......as evidenced by about 50% of the posts on here.

Now if you mean we shouldn't.........

[Clint]

Can't realistically. How's that?

[CaptCrashIdaho]

Yes, torque v. horsepower is another of the black arts of motorcycling and engines. Personally, I still like my definition because it works best for bikes.

Torque is rotational force OR force applied to rotate the rear wheel (to make it push against the ground and propel us forward).

Lots of low end torque (like HDs have) makes for wonderful launch characteristics...meaning HDs should always have an advantage at takeoff. But HDs run out of horsepower quickly. That's why thier top ends runout, they don't have the horsepower to keep pushing.

A tractor and an v-twin have one important thing in common--lots of low end torque.

Remember a 600cc in line four will run in about a 11 second quarter mile. Partly because it's power to wieght is better than a v-twin but also because is makes lots more horsepower. Torque (when used in talking about bikes) is the engines ability to turn the rear wheel quickly. Once it's moving...well that's where horsepower pushes it.

There's a reason that a ZX10R will do a clean ton in first gear...and it's horsepower.

Again, when I speak to folks about torque and horsepower and bikes:

Torque is how fast you spin up, horsepower is how fast you can go. That's why you need 200+HP to be over 200mph--torque at that point means nothing to bikes. And that's why when one single slug the size of a coffee can fires the torque spins the rear wheel with so much more torque.

One of the intersting features of most scooter mag articles is the torque AND horsepower charts. They are interwined and make a big difference on how a bike rides. A bike with big low end torque goes as soon as you turn the throttle--but if it has no high end horsepower it just kinda runs out of oomph. A bike with little low end torque but tons of topend ponies will lag off the start and then turn on like it's turbocharged.

A bike like a Suzuki Hayabusa (and yes I was in possession of one for a time) makes 100ftlbs of torque and 160bhp. And my friends, it was a mind bending experience. The power is just all there all the time and...it's hard to describe.

So that's why I say: Horsepower is how much you can lift (top end) and Torque is how fast you can lift it (launching).

Personally that's why I would suggest a newbie rider try to find a bike with modest torque and horsepower. Too much torque and the bike is 'lurchy', too much horsepower and bike 'takes off at speed'.

Feel free to disagree. It's OK.

[Thundurburd]

It may seem like a black art but we all have to live by the same laws of physics. Torque and horsepower are what they are because of basic definitions and applies to planes, trains, and automobiles (and motorcycles.) Not that it's always easy to come up with a technical explanation why something happens, but if we have a result that doesn't match our prediction it's not because we have violated a law of physics, it's because there is something we missed, always.

In the case of a motorcycle the engine and drive train deliver a torque to the rear wheel. Depending on the radius of the rear wheel the torque applied will result in two forces acting on the wheel. One on the bottom pushing on the road and one at the the center of the wheel pushing the motorcycle forward. If the mass is known we could calculate the acceleration and in turn other performance data. My point is that it is a known science.

It's really that simple, assuming of course we have frictionless bearings, no wind resistance, full traction, and other good stuff they keep in the physics lab. Notice that there is no mention of horsepower. The motion of the motorcycle and the work done is all determined from forces and torques, and drive train ratios. Power is a calculated value and is the rate at which work is being performed. A useful piece of information perhaps, but not exactly what moves the bike.

I gather that different engine configurations (thumpers, v-twins, in-lines) have different torque and horsepower curves. That makes sense to me. My guess is that your descriptions of the sensations riding different types of motorcycles is the result of engine configuration and drive train characteristics such as gear ratios, shift points, and so on, as determined by the designers as best they could to obtain some goal given what they had to work with.

Haven ridden only one bike this year I have no practical knowledge of anything but mine.

However, the same laws of physics apply to all of us. A torque is a rotational force, and horsepower is the rate of work being done.

Regards,
-Tburd

[Easy Rider]

Originally Posted by CaptCrashIdaho

Personally, I still like my definition because it works best for bikes.

Here we go again.

Don't confuse me with facts 'cause my mind is already made up!

I quit.

[CaptCrashIdaho]

Originally Posted by Easy Rider

Here we go again.

Don't confuse me with facts 'cause my mind is already made up!

I quit.

You know, this really speaks to a gap in terminology. Long ago and faraway I was purchasing a GS550 (inline 4) and selling an XL500 (Single). And Pat Hennen was working as a mechanic at the shop I was buying the GS at. This was after Pat got mangled at the Isle of Man. And one of the things that came up in conversation was that the GS would not be 'as torquey' as the XL.

Since then I have learned that there are practical and applied uses of terminology as well as pure technical definitions.

For example: Jessica Alba may be hot. But only when her internal temperature rises above accepted medical norms.

Or a cool song is one that is physically colder than the others?

See, words mean different things in different context. My mistake here was to assume that we all speak the same motorcycling dialects. Which we clearly don't. Honestly, this speaks to the fracture in the sport, we don't have a common vernacular and we really don't seem to want to.

Try this: go into a Japanese motorcycle shop. Ask for a bike with lots of torque--you'll get pointed at a v-twin. Ask for one with loads of horsepower--you'll get pointed at an inline 4.

So torque and horsepower, when applied to yapping about bikes, are discriptors not definitions. I apologize for assuming that we were speaking West Coast Racing like it's spoken up at Alice's. (And if you don't know what Alice's or the Rock Store are, then that's OK! We're from different tribes! Ain't it cool?)

All this leads back to the problems with 'starter bikes'--newbies don't speak motorcycle, we all speak different dialects of it AND salespeople tend only to speak MONEY.

Now, am I wrong in my use of "torque v. horsepower'? Sure if I'm taking a test at SLO (calpoly san luis obispo--see "slo" means 'without undo haste' to some).

With this all in mind I'm off to the poll section with another question.

OH and really torquey bikes are hard for beginners to ride. I'd suggest a very tame bike.

[Thundurburd]

Originally Posted by CaptCrashIdaho

Since then I have learned that there are practical and applied uses of terminology as well as pure technical definitions.

Crash,

You seem determined to stick to your "practical and applied" uses of terminology even though they contradict engineering facts. It appears to me that you have experience with many different bikes and while your evaluations may be accurate (I only ride my bike so I don't know) your attempt to explain these conclusions using engineering terms contains faulty logic. This is more than a "gap in terminology" or differing "motorcycling dialects," it involves basic principles of science that are either right or wrong.

As I write this post there are 13 members logged in and 287 non-members viewing this forum. Of these 300 how many are new or relatively new to motorcycling? Based on your experience poll there are possibly quite a few. Wouldn't it be nice if this forum could help correct some of the old wives tales and witchcraft that still float around in our community.

Rather that debate the merits of engines and motorcycles I have attempted only to clear up the torque and horsepower issue in my posts. Regarding these posts if anyone has questions, comments, additions, subtractions, or corrections please let me know, I would be happy to discuss further.

BTW I did a search for "motorcycle horsepower" and found several sites on the first page with very good technical explanations of torque and horsepower. These would make interesting reading for anyone looking for a better explanations than mine.

Regards,
-Tburd

[CaptCrashIdaho]

It's OK by me. I'm cool...(wink wink). It's language I'm comfortable with so I probably won't change.

I would agree that communication is strikingly important and we all need to be careful with the terms we use....but, If it ain't broke don't fix it. Ya start talking one way back in 1981 and it's hard to change. Especially if it works.

In fact, when I was working out how to change my gearing on the DRz after I bought it I wound up having the Torque v. Horsepower conversation with the parts guy. I'm not gonna say "you must use this language this way" but I would suggest you might encounter this more than you might expect.

One bird said to Billy Pilgrim, "Poo-tee-weet?" So it goes.

[Thundurburd]

I think many times on forums like this discussions most often don't end up in complete agreement, in particular the more technical ones. I sometimes visit another forum that is more into the physics of motorcycling and have watched discussions argued almost to the point of exhaustion. IMO when carried to extremes is a lot of waisted effort.

If we all agreed on everything there wouldn't be much to talk about I suspect.

Regards,
-Tburd

[Clint]

Crash, physicists and engineers the world over would appreciate if you'd happily find other words to describe an engine's characteristics at various rpms. Like Tburd said, it's clear that you know bikes, but the misuse of scientific terminology with very specific definitions frustrates more folks than you seem to realize. As far as we're concerned, it is broke.

But feel free to disagree.