I'm building a trike; how do trikes avoid flipping over?

[parajared]

I race rc cars, and when you race an unmodified rc car around a corner it will flip over. We get rid of this problem in the rc world by lowering the ride height, widening the wheel base, angling the camber in, stiffening the shocks, and keeping all the weight at the bottom. I am thinking about building an atomiczombie streetfox trike, but I am worried that with the ride height the way it is in the plans the trike will have the same affinity for flipping I see in an unmodified rc car. I can build this trike any way I want to build it, how would you guys who ride your trikes hard build this thing?

I am hoping for near street luge performance and and speeds, but comfortable enought to be a sporty commuter:
I am lucky enough to live in a city with "urban pathways" throughout the city that cyclists and pedestrians can use
It can't be too wide, I occasionally need to hug the shoulder of busy roads, fit between trail pilons, and squeeze down both smoothed dirt and paved bike paths
It should have the ability to ride down sidwalks too, including the little dip at the end of the sidewalk
I would like to be able to go over speed bumps
I would love to race this thing down windy roads and curvy sidewalks and not die

 

[migueralliart]

Lean into the curve when hard cornering and you will smile

 

[Lessss]

By slowing the F@#@$ down.

 

[Ben Wilson]

Lean into the curve when hard cornering and you will smile

Exactly, your body weighs a heap more than the trike so you get the advantage of movable ballast.

If you want to get really excited, look up leaning trikes

 

[ebent]

You are asking for 2 different trikes. The number one issue to avoid rolling is the placement of the battery. Try to place the battery below the rear axle and the back of the battery in front of the rear axle. i place mine in 2 boxes on the chain stays. The bottom of the box is about 3 1/2" above the ground. About 1/4" more clearance than the deraulier. On my catrike pocket it actually made the CG better than stock. However it is improved it is not absolute. No matter what you do, if you try hard enough it will roll.

Now for your other trike. If you want to jump the curb you will need more clearance which makes it more likely to roll. So I do not think one trike will fill your requirements. But good luck.

 

[TylerDurden]

Some info on trike CoG here:

http://www.jetrike.com/why-does-tilting-matter.html

 

[dogman dan]

FWIW, on detla, high CG, "adult trikes" you very oddly lean out on turns. To counerbalance the outside wheel that just lifted off the ground.

The lean out instead of lean in is very wierd at first, and of course none of this works at much more than 15 mph. But once you get one wheel off the ground, you now have a bicycle again, and it can turn much shaper corners. It just rides really funny, because the wheels are not in line with each other.

 

[docnjoj]

I found out very quickly in both my own designs and the Steintrike I ride now that lower is more stable, leaning out helps cornering but these two areas are much less important than seeing and being seen in traffic. Here higher is better. The 2 trike system if you plan on racing really makes sense. Higher and/or tilt really makes the most sense, but very few tilters are availible and those that are can be quite expensive. Varna makes an interesting and not too costly tilter.
otherDoc

 

[ebent]

once you get one wheel off the ground the additional force to roll the trike is so small that a roll would be eminent. Dogman, did you ever ride a trike on 2 wheels?

 

[parajared]

Any ideas on a optimal ride height.
The plans call for 9 inches off the ground, but streetfox's brother "the warrior" is 5 inches off the ground.

 

[speedmd]

To take full advantage of aero type ground effects, you want to be almost touching the ground. :lol: Seriously. I would err on the lower/ wider side of design range. Most of the mass below the axles if possible.

 

[MikeFairbanks]

A delta trike (standard tall trike like Schwinn Meridian) should never be operated at high speeds. Twenty or so on the straights and very slow turns is smart.

Can you make a full speed turn? Yes, but you better not lose even one second of focus or you'll lose control, hit a tree, bend the front fork, destroy the battery, call your wife to pick you up, and have to spend a lot of money to rebuild your trike.

That happened to someone I know.

 

[TylerDurden]

You are asking for 2 different trikes. .. So I do not think one trike will fill your requirements. But good luck.

Build the first trike incarnation of the switchbike... 2-in-1:

[youtube]8H39NiWbeOw[/youtube]

 

[parajared]

I don't think it looks too hard to do a tilt mech. Actually now that I look at leaning trikes I want to do a front wheel driven delta trike tilter instead of tadpole. Rear suspension too. Do you think a bunch of head tubes will work for the bearings? Any cool plans out there for making a good front wheel drive? Does the front have to steer, or can you just make that piece solid?

 

[TylerDurden]

Most references indicate steer should be separate from tilt. Check out the Jettrike lit.

 

[Lessss]

The problem with leaning into the curve when the bike deos not lean is that you risk spoke failure in the wheels and boy is that NOT FUN when it happens.

 

[Nehmo]

The problem with leaning into the curve when the bike deos not lean is that you risk spoke failure in the wheels and boy is that NOT FUN when it happens.

How are the spokes going to break if the rider leans and the trike (you must mean "trike") frame & wheels remains vertical?

 

[amberwolf]

Side loading.

 

[StudEbiker]

I don't think it looks too hard to do a tilt mech. Actually now that I look at leaning trikes I want to do a front wheel driven delta trike tilter instead of tadpole. Rear suspension too. Do you think a bunch of head tubes will work for the bearings? Any cool plans out there for making a good front wheel drive? Does the front have to steer, or can you just make that piece solid?

A couple of years ago I was CONSUMED with the idea of building a tilter. I scoured the internet seeking the best design and execution that seemed to be the most easily replicated in a home shop.

This was the one I found that I thought really hit the nail on the head on every point.



It's a poor image. He did have the images on photobucket, but it looks like they are not there any longer. There are a few more here though.

http://tiltingvehicles.blogspot.com/2012/11/eileen-by-peter-heal.html

Out of curiosity, I e-mailed the builder to see how he was enjoying his creation and surprisingly, he didn't seem to like it very much. This was the e-mail he sent:

Eileen has been a long process just to get it to the stage it is at now.
From the start I tried to make it as compact as possible so it would fit ina narrow and short full fairing.
It's not that fast in the nekid format compared to a two wheeler but it goes along OK.
There are some issues about this format which no ones seems to mention.
- Locking the tilt does nothing other than to keep teh bike upright at rest
- The steering goes completley screwy if you try and lock the tilt and ride up a hill for instance
- It's not the ultimate slow riding vehicle
- Mine has a tendency for the rear wheels to skip sideways on rough chip corners or any slightly rough concrete surface. I think this is a combination of the narrow rear track and teh fact the rear wheels share half the load each.
- This is very unnerving when trying to descend a swoopy hill at even basic speeds - what will it be like with a full fairing? You get used to it I guess.
- The picture on the web of the fast guys racing around tracks in trike races must be on very smooth surfaces.
- The design really only gets around multitrack vehicle rules for races I think. I can't see any other reason to lug around an extra wheel and the additional weight.

Ever since then, I haven't been too interested in building a tilter. :wink:

If you widened the track on this one though, I still think you could have a winner. Someday I might still build one, but for now the 2-wheel recumbents satisfy my need to lean. The only reason I really wanted the trike is so I didn't have to put my feet down and stoplights. Probably not worth the effort. 8)

 

[amberwolf]

I can understand why for him (and maybe you) a trike, even leaning, isnt' the answer.

But for some, it could be. For me, carrying heavy cargo, a bike can only do so much without having to have much stronger wheels, better tires, tubes, etc. Plus keeping it upright at stops or really slow speeds is tough, especially when there is an unbalanced load (whcih can't always be helped).

So a trike could fix both of those problems--if the cargo load is spread over another wheel, it helps significantly. There's no need to balance the vehicle while stopped or slow, as the other wheel holds it up for me. Plus it's unlikely to have an unbalanced load very often, since there's little need to put a heavy object on only one side--put it in the middle instead (whcih can't always be done on a bike).


That's the reason I am pursuing a leaning trike...already done a delta non-leaner and experienced the dramatic versions of it's shortcomings (even a better design of delta non-leaner is still going to have some of those, which a leaner should be much better at avoiding or overcoming).

 

[docnjoj]

Check out the new Tripendo in the trike thread. Not cheep but seems to have a good design.
otherDoc

http://endless-sphere.com/forums/viewtopic.php?f=3&t=48536

 

[dogman dan]

Replying to a question I didn't see months ago, and now off topic. Yes I've done lots and lots of two wheel turns on delta adult trikes.

I was talking about riding the adult trikes, delta type, with the really high CG. At LOW speeds like below 15 mph, you can tip the bike onto two wheels and turn very sharply. It turns the trike into a bike, but with really weird wheel misalignment.

You let the bike tip outside by leaning out encouraging the inside rear wheel off the ground, then crank the front wheel in in a sharp turn. Very weird and not intuitive. It won't work at speed though. Too fast, you'd likely just flip er. I may have done a few at 20 mph, but not much more.

AW, you need to build yourself some Aussie Jester outrigger wheels for your cargo bike. Turn it into a trike at the lowest speeds, then they flip up at 5mph and faster.

 

[MadRhino]

A trike can be built many ways to resist flipping.
The funniest way to do it is the drifting trike

 

[etriker]

Seem like there are more delta trikes on the road than ever.

Going 50, 60 mph with girlfriends on the back too ?

Some use Harley motors and some are VW motors.

Why don't they tip or they do ?

Must be the weight down low keeps them more steady ?

They do prove that a delta trike can go faster than 20 mph and not wreck ?

 

[etriker]

once you get one wheel off the ground the additional force to roll the trike is so small that a roll would be eminent. Dogman, did you ever ride a trike on 2 wheels?

I got to where I could go down the hill fast and whip it up on the left rear and front wheel then whip it the other way on the right rear wheel and front wheel.

I am glad my axle broke when I was not doing that.

The only time I wrecked my Schwinn trike was when the defective Currie axle broke.

That was after 1000s of miles of Schwinn trike riding.

It took me a lot of trike riding to get those skills.

I am a slow learner.

So the answer is to your question is riding skill ?

Keep in mind if you push on something hard enough it will fall over ?