125CC sufficient (for aerodynamic custom tadpole trike)? - Page 6 - Fuel Economy, Hypermiling, EcoModding News and Forum

Christ · 12-04-2009, 08:48 PM

A little background so I don't sound like a crazy redneck with a gun:

I'm normally a fairly laid back guy. I just hate having my space invaded. If someone came to my place with intentions to rob me, I'm not going to stand around and wonder if they intend to kill whatever gets in their way, I will shoot first.

The Atomic Ass · 12-04-2009, 11:36 PM

Quote:

Originally Posted by Christ

I literally told the officer: "That field there - that's a swamp. All due respect, Sir, by the time y'all get here, the suspect would either be gone, or gone. No two ways about it."

His response, as seems to be normal from the state police that patrol my neck of the woods - "Less paperwork for us, less tax money spent on court cases, and one less **** for brains loser on the streets making everyone's life miserable. Win/Win."

Of course, I won't mention names, because they're not allowed to advocate this form of martial law, but I don't find it surprising that they're tired of coming out this way.

That's not martial law, that's what we call taking out the trash.

Also, your police are awesome.

The Atomic Ass · 12-04-2009, 11:38 PM

Quote:

Originally Posted by Christ

A little background so I don't sound like a crazy redneck with a gun:

I'm normally a fairly laid back guy. I just hate having my space invaded. If someone came to my place with intentions to rob me, I'm not going to stand around and wonder if they intend to kill whatever gets in their way, I will shoot first.

Cue the Banjo in the Hollow.

Christ · 12-04-2009, 11:52 PM

Taters... Taters... I love taters... Only thing better 'na Tater is two Taters... mmmmhmmmmmnnnn.

Tickersoid · 12-08-2009, 01:49 AM

It's all down to the aerodynamics. Even an 850cc Reliant trike is capable of 70mpg for everyday commuting, school run and shopping. I've done that average over 2000miles driving carefully. I doubt you'll get faster than 70mph though. One wheel at the front tends to have less rolling resistance because you don't need any toe in.

Christ · 12-08-2009, 10:32 AM

Quote:

Originally Posted by Tickersoid

It's all down to the aerodynamics. Even an 850cc Reliant trike is capable of 70mpg for everyday commuting, school run and shopping. I've done that average over 2000miles driving carefully. I doubt you'll get faster than 70mph though. One wheel at the front tends to have less rolling resistance because you don't need any toe in.

One wheel at the front is also a delta shape, leading to either increased skin drag from a longer shape, or a bluff body creating a huge wake behind the vehicle.

I don't intend to go 70MPH with it, but the ability to do so would make it "that much better". I have to imagine on a CB125 that 70MPH would make the engine scream in absolute disagreement.

Tickersoid · 12-08-2009, 12:58 PM

I've given fuel efficient trikes a good hard think and I don't think it matters which end the two wheels are on if you have a tandem seated centre fuselage like a plane or canoe and individual aerodynamic treatment for the wheels.

Christ · 12-08-2009, 02:50 PM

So you don't account for the compression effect between the wheel treatments and the main chassis?

What about stability concerns with Delta designs at speed? I mean, there is this huge concern with braking and steering at the same time...

Tickersoid · 12-08-2009, 03:29 PM

I appreciate the concerns about the venturi effects between the wheels and body but feel that the reduced frontal area is worth it.
You are right about the reduced capacity to brake and steer at the same time with the delta option. Also the weight being thrown forward onto a single wheel for braking is clearly less effective.
I also have a friend who is the designer and builder of the most prolific trike in competition hill climbing who advocates two wheels at the front and a driven wheel at the back. Also in it's favour is the aerodynamic efficiency and stability if a pointy bit rearwards body.
So the two at the front trike has a lot going for it.
When making your choice, I would also like you to consider the centre of resistance both aerodynamically and rolling resistance wise. When going through terrain or varying resistance such as standing water, the delta trike tends to be self centering like an arrow. This is because the centre of resistance is behind the centre of gravity. I remember a time, during a heavy downpour on the M4, when the driver of a mighty BMW M3 was astounded to find he couldn't keep up with me for fear of loosing control when I was driving a Reliant Rialto. Which ever you decide, it should be based on your values. There is no right or wrong answer.

Christ · 12-08-2009, 03:37 PM

Back about 5 pages ago, I already decided on a reverse trike design, for some of the reasons you mentioned.

Keep in mind, this is a limited use vehicle... I'm not taking it on the highway on a daily basis, I'm not commuting with it (I dont' have a job...), or anything like that. I only want it to piss about with, like just about everything else I drive.

If I can get to the grocery store efficiently, or get to wherever I need to go and get what I need to get, it'll do the job fine.