Math Motorcycle vs Diesel

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Nov 18, 2005 | 11:24 AM

#16

76supercab2

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Quote:

Originally Posted by triplethreat

I only understand the last line of that. where did the 18.75 come from???

It's the ratio of the weight of the truck to the weight of the bike. If the truck just drives the 100 miles empty, it will have moved 7500 pounds. For the bike to move 7500 pounds it will have to travel 18.75 times farther. IE 7500/400=18.75

I could have used the max GVWR for both vehicles. but I don't have it so I just used the empty weight estimate given in the first post.

Nov 18, 2005 | 11:28 AM

#17

triplethreat

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From: Hubert North Carolina

Okay that makes sense to me now

Dan

Nov 18, 2005 | 11:44 AM

#18

76supercab2

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Now here's another thought that just came to me. Lets say that both vehicles have to move a 7500 pound load from point A to point B (assume the same fuel consumption). The truck has a trailer and can do the job in 1 trip. The motorcycle can somehow carry the load 400 pounds at a time. Then the 18.75 ratio doubles. Why? Because the bike has to make twice as many trips because after it dropps off the 400 pound load at point B it has to return to point A empty. The bike has to travel a 200 mile round trip 18.75 times, where the truck only has to travel 100 miles, 1 time.

Nov 19, 2005 | 09:12 AM

#19

four-sixty-power

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From: Lower Mainland B.C.

Question:

At 65MPH what RPM is the truck turning, what RPM is the bike turning?
If you could ony drive each vehicle for 1,000,000 revolutions of the engine, which vehicle would use less gas(maybe the bike)? Which vehicle would travel further(the truck I presume)?

20MPG is given for the truck and 57MPG is given for the bike

SO, the truck would be in overdrive, I think, and I don't know that number.
Do bikes have overdrive or are they 1-to-1 ?

Whatever RPM they do at 65MPH on the highway should give us a figure for miles traveled up to 1,000,000 engine revolutions to figure out the MPG, I think

I'm not into motorcycles so I'm not gonna try and guess at RPM numbers I have no idea of.

Nov 19, 2005 | 09:30 AM

#20

jroehl

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From: Lafayette, IN

460power, it depends on the bike. My last bike, a '94 Suzuki Katana 750 (GSX750F), with some performance mods, would turn 5000rpm at 65mph. It only got about 35mpg overall, though (many miles were done in the triple digits

). Redline on the bike was around 11,500rpm, I think--which was about 70mph in first. It totally depends on the bike as for "overdrive" or not, but in the sportbikes, top gear is typically near 1:1. However, they also will have a primary and secondary reduction, so the final drive ratio is fairly high in top gear (it would have to be with that large of a tire and that many revs).

Jason

Nov 19, 2005 | 09:36 AM

#21

four-sixty-power

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From: Lower Mainland B.C.

2005 Suzuki 600r is the bike that triplethreat mentioned

If we know the speed(65MPH) and the tire size, won't some online calculators tells us the RPM in 1:1 or do those calcs only apply to v8s?

Nov 19, 2005 | 12:31 PM

#22

jroehl

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From: Lafayette, IN

Here's what I found (I didn't find a "600r", just a GSXR600):

http://www.aperaceparts.com/tech/05gsxr600.html
http://www.suzukicycles.com/products...5/Default.aspx

Looks like the total ratio in top gear is 6.404:1. Rear tire size is 180/55ZR17, which is a diameter of 24.8". From a tire calculater site, that gives it a rpm of 5640 at 65mph.

Jason