Monster-motored personal vehicles are silly.

I didn't read the details of this thing before posting.

It has 4 wheels and is RWD, so it won't have "torque steer" like a FWD car. You are correct.

It also apparently has 2 chains, so both rear wheels are driven, so it shouldn't have the problem that cheap (non-limited slip) RWD cars with differentials have - namely the wheel with less traction spins faster.

However, 525 lb.-ft. of torque for something that weighs 1500 lb, and a 2 speed transmission, could lead to lots of unintentional wheelies. I don't imagine it steers very well either, though they claim it can lean 45 degrees either way.

But torque steer, I agree, isn't the correct term for it - at least if it has a proper limited-slip setup in the rear. I would be concerned though that if there's any difference in torque reaching the ground the back end will want to swap places with the front (a consequence of "over steer" rather than "torque steer").

It looks like a deathtrap to me, though it is an interesting piece of sculpture.

Cheers,
Scott.

...and shaft drive. An addition to your "That's every BMW ever, then", turning it into "That's every BMW, Moto Guzzi, and Gold Wing ever, and that old Indian and the big new Triumph too, then". (Well, every BMW ever except for the somewhat newish single-cylinder off-roaders, F65 or whateverthefuck they're called, and the two- or three-year-old K1200S [or some such], which all have transverse crankshafts and chain drive. And I'm not sure about early Pleistocene Guzzis either.)

And "how it works", BTW, is not anything as esoteric as gyroscopic effects, but just the simple force-counterforce principle: Any engine, if the crankshaft were braked by some force, that would tend to apply a rotational torque in the opposite direction to the rest of the engine. Think Superman flying up and grabbing hold of the propeller of a Spitfire: The plane would start twisting around its long axis at some 2000 rpm. Or think helicopters: That's why most single-rotor ones have that boom with a little propeller at the back, to apply a counter-counter-twist to the counter-twist that the engine driving the main rotor is applying to the whole airframe.

HTH!

Post #285,471 by Another Scott 5/27/07 7:33:39 AM Reply	Monster-motored personal vehicles are silly. I didn't read the details of this thing before posting. It has 4 wheels and is RWD, so it won't have "torque steer" like a FWD car. You are correct. It also apparently has 2 chains, so both rear wheels are driven, so it shouldn't have the problem that cheap (non-limited slip) RWD cars with differentials have - namely the wheel with less traction spins faster. However, 525 lb.-ft. of torque for something that weighs 1500 lb, and a 2 speed transmission, could lead to lots of unintentional wheelies. I don't imagine it steers very well either, though they claim it can lean 45 degrees either way. But torque steer, I agree, isn't the correct term for it - at least if it has a proper limited-slip setup in the rear. I would be concerned though that if there's any difference in torque reaching the ground the back end will want to swap places with the front (a consequence of "over steer" rather than "torque steer"). It looks like a deathtrap to me, though it is an interesting piece of sculpture. Cheers, Scott.
Post #285,480 by drewk 5/27/07 9:18:11 AM Reply	Nope You've got a longitudinally mounted driveshaft and flywheel. Rotate those clockwise real fast, and the rest of the bike will want to rotate counter-clockwise. No, it's probably not technically accurate to call it "torque steer", but that's what people are talking about. === Kip Hawley is still an idiot. === Purveyor of Doc Hope's [link\|http://DocHope.com\|fresh-baked dog biscuits and pet treats]. [link\|http://DocHope.com\|http://DocHope.com]
Post #285,482 by CRConrad 5/27/07 9:42:48 AM Reply	"Torque lean", "Counter-torque lean", something like that?
Post #285,483 by drewk 5/27/07 9:55:24 AM Reply	On a bike, if you're leaning you're steering === Kip Hawley is still an idiot. === Purveyor of Doc Hope's [link\|http://DocHope.com\|fresh-baked dog biscuits and pet treats]. [link\|http://DocHope.com\|http://DocHope.com]
Post #285,506 by CRConrad 5/27/07 1:20:03 PM Reply	Not if you counter by actually steering the other way.
Post #285,578 by drewk 5/28/07 12:45:06 PM Reply	Ever ridden a bike? It's called "counter steering". If you want to turn left, you steer to the right, which will lean the bike over to the left. I don't care where the wheels are pointing, a bike will go in the direction it's leaning. If you doubt this, picture the contact points of the tires and the location of the center of mass. If the center of mass is to the left of the contact points, that's where the bike will go. === Kip Hawley is still an idiot. === Purveyor of Doc Hope's [link\|http://DocHope.com\|fresh-baked dog biscuits and pet treats]. [link\|http://DocHope.com\|http://DocHope.com]
Post #285,489 by pwhysall 5/27/07 10:45:46 AM Reply	That's every BMW ever, then. And no-one ever says they've got torque steer or anything like it. The only way the gyroscopic properties you mention would come into play were if the driveshaft/flywheel were mounted perpendicular to the ground, which they're obviously not, because the wheels aren't above the rider's head. Peter [link\|http://www.no2id.net/\|Don't Let The Terrorists Win] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Home] Use P2P for legitimate purposes! [link\|http://kevan.org/brain.cgi?pwhysall\|A better terminal emulator] [image\|http://i66.photobucket.com/albums/h262/pwhysall/Misc/saveus.png\|0\|Darwinia\|\|]
Post #285,505 by CRConrad 5/27/07 1:19:09 PM Reply	Moto Guzzi, Gold Wing, (old) Indian, that big new Triumph...
Post #285,517 by pwhysall 5/27/07 3:32:12 PM Reply	How does that work, then? Do they have a diff? Peter [link\|http://www.no2id.net/\|Don't Let The Terrorists Win] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Home] Use P2P for legitimate purposes! [link\|http://kevan.org/brain.cgi?pwhysall\|A better terminal emulator] [image\|http://i66.photobucket.com/albums/h262/pwhysall/Misc/saveus.png\|0\|Darwinia\|\|]
Post #285,523 by CRConrad 5/27/07 7:25:38 PM Reply	No; just that like BMWs, they have longitudinal crankshafts ...and shaft drive. An addition to your "That's every BMW ever, then", turning it into "That's every BMW, Moto Guzzi, and Gold Wing ever, and that old Indian and the big new Triumph too, then". (Well, every BMW ever except for the somewhat newish single-cylinder off-roaders, F65 or whateverthefuck they're called, and the two- or three-year-old K1200S [or some such], which all have transverse crankshafts and chain drive. And I'm not sure about early Pleistocene Guzzis either.) And "how it works", BTW, is not anything as esoteric as gyroscopic effects, but just the simple force-counterforce principle: Any engine, if the crankshaft were braked by some force, that would tend to apply a rotational torque in the opposite direction to the rest of the engine. Think Superman flying up and grabbing hold of the propeller of a Spitfire: The plane would start twisting around its long axis at some 2000 rpm. Or think helicopters: That's why most single-rotor ones have that boom with a little propeller at the back, to apply a counter-counter-twist to the counter-twist that the engine driving the main rotor is applying to the whole airframe. HTH! [link\|mailto:MyUserId@MyISP.CountryCode\|Christian R. Conrad] (I live in Finland, and my e-mail in-box is at the Saunalahti company.) Ah, the Germans: Masters of Convoluted Simplification. — [link\|http://www.thetruthaboutcars.com/?p=1603\|Jehovah]
Post #285,546 by pwhysall 5/28/07 3:26:08 AM Reply	gotcha, thanks So, in summary, it's high time people stopped using the phrase "torque steer" in relation to motorbikes, because it's frankly nonsense. Peter [link\|http://www.no2id.net/\|Don't Let The Terrorists Win] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Home] Use P2P for legitimate purposes! [link\|http://kevan.org/brain.cgi?pwhysall\|A better terminal emulator] [image\|http://i66.photobucket.com/albums/h262/pwhysall/Misc/saveus.png\|0\|Darwinia\|\|]
Post #285,548 by CRConrad 5/28/07 4:48:29 AM Reply	Yeah, of course; they should never have started using it.
Post #285,576 by drewk 5/28/07 12:38:26 PM 5/28/07 12:42:04 PM Reply	The driveshaft on the K100 is more than twice as long If you've ever seen a 60s-era American musclecar revving at a red light, you probably saw the front end twist from the torque. A long driveshaft and heavy flywheel[1] mounted longways in a bike could have a similar effect, and I do remember people noting it when the K bikes came out. [1] One guy said that BMW had apparently welded a sewer lid onto the end of the driveshaft. [edit] Bah. I knew after walking away from the computer for several hours with a reply open that I should have checked for updates in the thread before posting. Christian got the physica exactly right. === Kip Hawley is still an idiot. === Purveyor of Doc Hope's [link\|http://DocHope.com\|fresh-baked dog biscuits and pet treats]. [link\|http://DocHope.com\|http://DocHope.com] Edited by drewk May 28, 2007, 12:42:04 PM EDT Expand All History
Post #285,602 by CRConrad 5/28/07 4:34:49 PM Reply	What would the LENGTH of the shaft have to do with anything? More rotating driveshaft weight, you mean, or what? [link\|mailto:MyUserId@MyISP.CountryCode\|Christian R. Conrad] (I live in Finland, and my e-mail in-box is at the Saunalahti company.) Ah, the Germans: Masters of Convoluted Simplification. — [link\|http://www.thetruthaboutcars.com/?p=1603\|Jehovah]
Post #285,604 by bepatient 5/28/07 5:30:26 PM Reply	Now exactly where is this conversation headed? Too much of today's music is fashionable crap dressed as artistry._{Adrian Belew}
Post #285,628 by drewk 5/28/07 8:55:39 PM Reply	Yes, I'd guess more than twice the mass === Kip Hawley is still an idiot. === Purveyor of Doc Hope's [link\|http://DocHope.com\|fresh-baked dog biscuits and pet treats]. [link\|http://DocHope.com\|http://DocHope.com]
Post #285,645 by folkert 5/28/07 10:16:23 PM Reply	Not particularly. When a driveshaft gets to a "certain length" or is required to handle a certain power level, they get lighter and more expensive, until you get past another point in length and power handling. It is all about reducing shaft flex, whipping, harmonics and twist. IOW, short low-power shafts do not have to worry about flex, whipping, harmonics or twist. The more requirements... the more "high-tech" they become. -- [link\|mailto:greg@gregfolkert.net\|greg], [link\|http://www.iwethey.org/ed_curry\|REMEMBER ED CURRY!] @ *i_wethey* `PGP key: 1024D/B524687C 2003-08-05 Fingerprint: E1D3 E3D7 5850 957E FED0 2B3A ED66 6971 B524 687C Alternate Fingerprint: 09F9 1102 9D74 E35B D841 56C5 6356 88C0`

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