spridgets
[Top] [All Lists]

Re: [Spridgets] Bentley-RR Trivia: was calculating speed

To: Spridget List <Spridgets@autox.team.net>
Subject: Re: [Spridgets] Bentley-RR Trivia: was calculating speed
From: Lester <oldsaabguy@comcast.net>
Date: Tue, 21 Oct 2008 15:40:41 -0500
hmm.. lemme correct a few typos..


On Oct 21, 2008, at 1:58 PM, Lester wrote:

> Maybe this is a matter of semantics...
>
> True, the motorcycle "absolute top speed", for lack of a better  
> term, is limited by drag and HP.
>
> However, for a motorcycle with a top speed limited by gearing or  
> limited by engine revs then a larger diameter tire will allow for a  
> higher top speed ALTHOUGH this top speed may not be the "absolute  
> top speed" limited by drag.
>
> For example a 20 hp bike motor that will turn 6000 revs (and  
> pretending that the tranny is direct drive) will turn the tires  
> 6000 revs.

> If those are 10 inch circumference tires then the bike will go  
> speed x,(no, I'm not going to calculate it out.) but if you replace  
> those tires with 20 inch circumference tires then the bike will go  
> twice as fast *** IF *** the bike has not reached is theoretical  
> drag-limited top speed and that the engine can turn the 20 inch  
> circumference tires at 6000 revs.
>
>
> Lester
>
> On Oct 21, 2008, at 1:06 PM, Weslake1330@aol.com wrote:
>
>> Not so.
>>
>> Top speed is limited by aerodynamic drag and BHP.  To go faster  
>> you  need
>> less drag or more bhp or both.
>>
>> Acceleration on the other hand is limited by lb/f torque to weight  
>> ratio  (to
>> the point where the drag is greater than bhp and limits top speed and
>> therein acceleration).
>>
>> The motorcycle has less drag than a car (less frontal area really)  
>> so needs
>> less bhp to reach its maximum speed.  The wheel diameter is  
>> neither here  nor
>> their because the gearing controls the gearing and the wheel  
>> diameter is  just
>> one factor.
>>
>> W e s l a k e 1330
>>
>> In a message dated 21/10/2008 18:15:47 GMT Daylight Time,   
>> bmwwxman@gmail.com
>> writes:
>>
>> Fact
>> is, BHP or HP by any measure really has nothing to do with  speed.  
>> Only in
>> elapsed time to reach a given speed. I have seen a 20 HP   
>> motorcycle reach
>> 110 mph because of its wheel diameter and gearing.  Likewise, I  
>> have seen 200
>> HP V-8s that couldn't hit 90  MPH.
>>
>> Cheers!!
>> Jim
>> _______________________________________________
>> Support Team.Net  http://www.team.net/donate.html
>>
>> You are subscribed as oldsaabguy@comcast.net
>>
>> http://www.team.net/archive
>>
>> http://autox.team.net/mailman/listinfo/spridgets
> _______________________________________________
> Support Team.Net  http://www.team.net/donate.html
>
> You are subscribed as oldsaabguy@comcast.net
>
> http://www.team.net/archive
>
> http://autox.team.net/mailman/listinfo/spridgets
_______________________________________________
Support Team.Net  http://www.team.net/donate.html


http://www.team.net/archive

http://autox.team.net/mailman/listinfo/spridgets

<Prev in Thread] Current Thread [Next in Thread>