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Old 01-08-2003, 08:03 AM   #41
SRMark
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Default Re: Mr Leno your bike is ready

Now this looks like something that Dan Gurney should have had his fingers in, instead of the Alligator. Looks just like the blending of car and bike design he should have come up with.



Should be fun in the corners.



I'm waiting for the off-road Ram/Durango series before buying. Sure would shorten the trip to the Arctic Circle. I'd be wanting the high torque Cummins diesel engine though.
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Old 01-08-2003, 08:04 AM   #42
jmeyn
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Default Bull

To get to 300 mph with 500 hp requires a drag of about .0074 lb per mph-squared. The best of the superbikes run around .01. Assuming this brick could be faired to achieve .013 lb/mph-squared, it would go 250 mph, and would require 1650 horsepower to get to 360 mph. At that point the drag would equal the weight and the wheels would spin.



This is a first approximation without consideration of aero lift and serious stability problems.



Please, guys, don't volunteer to test this thing at the limits. Leave it to The Highwayman who is stout enough to face the consequences.
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Old 01-08-2003, 08:09 AM   #43
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Default Re: Mr Leno your bike is ready

Both figures are fanciful; 400 mph is insane.

It'll beat 200 mph all right (see my post above) but not with anyone sane riding it.

I think you've seen the first test: riding it across the show room floor. I'll be surprised to see any more of them.
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Old 01-08-2003, 08:30 AM   #44
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Default Thanks for pasting that link

I had seen it earlier but coudln't find it again. I recommend reading the designers' comments. Very interesting (and no 300-400mph claims)



Bob
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Old 01-08-2003, 08:31 AM   #45
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Default No fun

Sorry, but this thing would not be fun to ride. Other than the gawking stares that you would get from people it would be quite unenjoyable. Just think of the torque twist created by that huge cast iron crank spinning around in that engine. The thing would feel like it was going to flop over. (if it didn't, actually, flop over)



Crazy cool though!
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Old 01-08-2003, 08:40 AM   #46
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Default Re: Power/Weight Ratios

Your're right. My model shows that a MotoGP bike will start walking away from the Viper at about 120 mph. So they'll beat it's 1/4 mile times handily. Up to 120, they'll both be doing 1G. Both will do the 1/4 in the 9s at over 160 mph.

The only advantage the Viper has is raw top speed. Show me a rider who will hold the throttle open till he passes the MotoGP bike at about 210 mph and I'll show you a fool.
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Old 01-08-2003, 08:52 AM   #47
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Default Re: Mr Leno your bike is ready

I'll take your word for the calculations -- the last time I was in engineering school (before I switched to business school -- still kicking myself for that) was in 1968, so I'm a bit rusty. Sounds reasonable though -- but you are assuming a fairing. Also, this thing must have, what, 3 times the frontal area of a GP bike, so even with a very slick fairing, it might be hard to get down to your total drag numbers.



My comment was directed to the bike as shown, which must have a drag coeficient somewhat worse than a brick.



Based on the published data, I am fairly confident that its top speed would be less than 185 mph. Peak power is at 5600, red line is 6000 rpm. Given primary ratio of 23:25 and final drive of 14:25, and assuming rolling radius of 14" (guesstimate, based on 150/50RR-20 rear tire size) gives rpm limited speed at redline approximately 183mph, and at power peak about 172.



Note, all data per www.motorcyclenewswire.com/news.cfm?newsid=2140



And yes, I have too much time on my hands!



Cheers

Bob
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Old 01-08-2003, 08:56 AM   #48
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Default Re: Mr Leno your bike is ready

Nice theory, but probably incorrect.



Skydivers (I have around 2700 free-fall skydives) routinely do 200+ MPH dives without tearing off our jumpsuits/heads/what-have-have you.



Normal body to earth speeds are around 120MPH, head down is 180+, some have been clocked around 300MPH. Skydivers have also been known to make jumps in regular street clothes, shirtless, wearing lingere, or naked, all without disasterous consequences from buffeting.



I suspect that Rollie had a *****-poor taylor if they couldn't make *leather* sewn with heavier thread hang together through 150MPH. I can only imagine how useless it would be in a crash (which would generate a *lot* more force on the seams that air resistance at 150MPH). My skydiving jumpsuits are spandex and lightweight nylon sewn with nylon E thread and have no where near the structural intregrity of an Aerostich suit....



Yes, a lot of the stats are PR crap, but buffeting aerodymanics won't be tearing your leathers off unless you've got *really* crappy leathers.
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Old 01-08-2003, 09:21 AM   #49
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Default Re: No fun

Yeah, people complain about the torque reaction of BWMs and Guzzis? They ain't seen nuttin' yet!



Maybe that is why it needs 4 wheels. Sounds like a good application for active suspension, sensors linked to the motor to add roll stiffness in response to acceleration of engine speed, to keep the sucker more or less upright.
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Old 01-08-2003, 09:28 AM   #50
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Default Woops

I was intending to post the reply to the post above yours.



The German custom you linked is an amazing work of art. I have seen several others in that general style. Some really excellent design work (and fabrication).
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