Posted by Eeyore on March 26, 2009, 10:15 pm
Alistair Gunn wrote:
> Eeyore twisted the electrons to say:
> > In fact the only change from a 4 wheel vehicle was the SIX wheel Tyrell.
> > http://en.wikipedia.org/wiki/File:ScheckterJody1976-07-31Tyrrell-FordP34.jpg
> There's also the March 6 wheeler from the same time period :-
> <http://www.geocities.com/simontmallett/240march1.html>
You know I didn't know March did one, albeit with the extra wheels at the other
end.
> ... of course looking at F1 for ideas to what makes a good technology is
> not necesarily a good idea as a lot of stuff (four wheel drive, oval
> pistons, diesel power, traction control, active suspension) is banned.
The FIA do strange things. They almost seem to be turning the clock back at the
moment ( to keep costs down it seems ).
Graham
Posted by Alistair Gunn on March 27, 2009, 8:58 am
Eeyore twisted the electrons to say:
> Alistair Gunn wrote:
> > There's also the March 6 wheeler from the same time period :-
> > <http://www.geocities.com/simontmallett/240march1.html>
> You know I didn't know March did one, albeit with the extra wheels at
> the other end.
I only remembered because I used to have the Scalextric version! :-)
--
These opinions might not even be mine ...
Let alone connected with my employer ...
Posted by Lord Gow333, Dirk Benedict's n on March 25, 2009, 1:42 am
>> On Fri, 20 Mar 2009 12:48:05 +0000, Eeyore
>>
>> 3 wheelers are inherently more stable as the suspension does not
>> require any compliance to keep all wheels on the ground - like a
>> tripod.
> You can't really talk about stability without mentioning what type of
> stability you are talking about. According to this SAE paper that
> compared 3 and 4 wheel conficurations, you get one answer for lateral
> stability, and another, very different, answer for rollover stability.
> Sorry, only the absttact seems to be available on the web.
> http://www.sae.org/technical/papers/820139
> There are many dead and maimed farmers that learned the hard way about
> three-wheel roll problems when their tractors rolled over...and they
> learned it at dead slow speeds!
As a farmboy who grew up driving both styles of tractors I just wanted to
add that there were occasions when a tricycle tractor took a corner where a
wide front tractor would have dropped a wheel in a hole or a ditch and
rolled. True, the wide fronts are generally more stable, but there's no
spring to the front "suspension" so the tractor just pivots at a higher
point off the ground. Then it all depends on whether it has the momentum to
go over when the frame bottoms out on the axle.
Already stated, it basically comes down to knowing your machine.
LG (survived a few close ones)
--
Failure is the opportunity to begin again more intelligently. - Henry Ford
Posted by daestrom on March 21, 2009, 3:02 pm
> On Fri, 20 Mar 2009 12:48:05 +0000, Eeyore
>>
>>
>>harry wrote:
>>
>>> Also, threewheeled cars can inherently be made to outperform four
>>> wheeled cars.
>>
>>What a curious staement.
>>
>>Graham
> 3 wheelers are inherently more stable as the suspension does not
> require any compliance to keep all wheels on the ground - like a
> tripod.
> 2 wheels front, 1 rear, like the old Morgan Sport can give phenomenal
> handling. Front drive or rear can both be used to advantage.
> Low unsprung weight and low roll center are also easy to achieve,
> which both help handling.
For a given width between the two wheels, the center of gravity of a
three-wheel vehicle is inherently closer to the tipping point than a four
wheel vehicle. It has to be, it's simple geometry.
For a given CG height above the road a four-wheel vehicle is less likely to
tip up on two wheels. I suspect the 'phenomenal handling' you speak of is
solely due to moving the CG forward towards the two-wheel/steering axle, not
because there is a one-wheel rear-end instead of two.
daestrom
Posted by daestrom on March 19, 2009, 11:40 pm
> harry wrote:
>> Ha! You got it coming!
>>
>>
>>
>>> harry wrote:
>>>> Forgot to put in the link!
>>>> http://www.greencarsite.co.uk/electric-vehicles-cars.htm
>>> Must be awfully big shoes to come in these boxes ;)
>>
> With gas less than $/gallon now, they say hybrid car sales are in a
> slump.
For now. Oil closed a bit higher today around $1/barrel. Not
sky-rocketing like it did last summer, but I think the days of <$0/barrel
are over.
Some will invest in alternates now, some will wait until gas is up to
$/gallon again. YMMV
daestrom
> > In fact the only change from a 4 wheel vehicle was the SIX wheel Tyrell.
> > http://en.wikipedia.org/wiki/File:ScheckterJody1976-07-31Tyrrell-FordP34.jpg
> There's also the March 6 wheeler from the same time period :-
> <http://www.geocities.com/simontmallett/240march1.html>