Delta trikes with leaning saddle and front wheel

[Harold in CR]

There is a thread about a front leaner, BUT, you don't actually turn the wheels. As it leans, it steers itself. Might be you could adopt that system for the rear steer option ???

This thread. http://endless-sphere.com/forums/viewtopic.php?f=10&t=21109

[docnjoj]

^ hi, docnjoj, where did find that info? or is it just ur guess?

it is a tadpole the lean is controlled by springs and shocks.

Actually a bit of both. If you go to the Drymer website and watch the trike corner you can see (I believe) the connection between the R & L wishbones. It makes sense to use a solid but light axle for the front. Also check out AutoSpeed's Julian Edgar and his new trike build with a solid front axle with DiDion type locaters. Cool stuff and easier to build than my Steintrike independent front suspension. Lighter too.
Here is the thread on E-S to get started.
otherDoc


viewtopic.php?f=3&t=19633&start=15&hilit=drymer

[docnjoj]

I just checked the Drymer site and saw that the front upper and lower suspension arms only have a single central pivot in each therefore the most probable explanation is solid arms through the center and parallelogram tilt, not IFS. A true IFS would have to have 2 sets of pivots, one for each side and for each arm (or 2 for A-arms), like my trike and any Formula 1. They also state that they are starting to manufacture this summer, which is just about over. I tried to get info but the site doesn't seem to like English e-mail addresses. It is all in Dutch. I would definitely have to try it first but if i liked it................!
otherDoc

[John in CR]

A bit of youtubing shows that both BMW and Mercedes have leaning 3 wheel deltas with non-leaning rears, so I think I'm on the right track. I'm guided by simplicity though, along with my lack of any knowledge about front suspensions for 2 wheelers. I couldn't even copy the Drymer's front with confidence, which does look fairly simple.

I also feel that good cargo space is easier to add to a delta, and based on the Eurobike showings 2 wheelers with no cargo or passenger space is the focus. To me those aren't much more than toys for recreation, especially in areas where the infrastructure makes commuting by ebike a dangerous proposition. Ebikes exploded in use in China out of necessity, but in the west, wide spread adoption is more likely to be as an extra vehicle or to replace a second vehicle. They need to carry stuff and a couple of kids or an adult to get out of the primarily for recreation classification.

I'm not saying very bike-like ebikes can't be useful as transportation, just that cargo and passenger room greatly broadens the market. It doesn't help that in a hundred years they haven't figured that out yet for motorcycles unless you count a tiny cargo box and a bit of space on the seat, but that's a pretty weak-ass attempt at more usefulness than just getting one person from point A to B. Electric cars, Volt, Leaf, etc, aren't really all that much better than gas cars. They're just too big and heavy and wasteful in terms of resources, so I have little doubt that EVs will look totally different by the end of this electric revolution. Since our ebikes put us at the cutting edge with the only EVs that make real economic sense, we should lead the way in exploring totally new classes of vehicles.

[docnjoj]

As usual you are right on, John. That leaning 2 seater motorcycle that looks like a jet should be the way things will go, but not for 100G's. Make a true protected 2 seat motorcycle at a reasonable price and lots of folks would use them. Make it electric and you got it made!
otherDoc

edit: I've been looking at Joyces trike with an eye towards making it a front leaner and it looks do-able. It would have to be extended a bit to account for the swivel and I dont know enough about how to make it progressive but I think it could be done. Those trikes sell for as little as $800 new with the handlebars above the seat and I have seen them for as little as $300 used. Might make a good starting point as the wheels are 40 spoke heavy duty and they come with Maxxis high pressure tires.

[TylerDurden]

Since it hasn't been mentioned yet in this thread; the jettrike site has plenty of technical info on leaning deltas.

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

[sk8norcal]

A bit of youtubing shows that both BMW and Mercedes have leaning 3 wheel deltas with non-leaning rears, so I think I'm on the right track.

which mercedes?
the bmw simple have tilting rear wheels,

http://tiltingvehicles.blogspot.com/201 ... fejet.html
http://tiltingvehicles.blogspot.com/2009/10/bmw-s.html

[sk8norcal]

I couldn't find the bit again about the Carver rear turning. It was in a write-up about the development history as part of the son's computer controlled lean steering system.

sounds cool,
I been looking for an animation (bare chassis) for some of these tilters. Its hard to tell what's going on from a video..

Excellent point regarding the pivot axis and the front contact patch, so any difference higher or lower will create some rear wheel steer, and if I'm visualizing it correctly we only want the pivot axis at or lower than the contact patch or the rear wheels will turn in the wrong direction...at least that feels like the wrong direction to me unless you're just changing lanes, not turning.

the gyro's pivot appears to be horizontal..

100_3168.jpg

(206.4 KiB) Not downloaded yet

bmw clever front...

[John in CR]

Excellent point regarding the pivot axis and the front contact patch, so any difference higher or lower will create some rear wheel steer, and if I'm visualizing it correctly we only want the pivot axis at or lower than the contact patch or the rear wheels will turn in the wrong direction...at least that feels like the wrong direction to me unless you're just changing lanes, not turning.

the gyro's pivot appears to be horizontal..

100_3168.jpg

It's hard to tell but the angle of the pivot may change with the compression of the suspension. It seems like that care should be taken wrt the lean pivot, and we'd want to keep it near the rear wheels and only a slight steering effect if any, because otherwise it might turn into a real handful and become something like a python low racer. The pythons have some very exacting angle requirements, and this could be even more complex due to an additional steering pivot at the headset.

If handling, especially at speed isn't adversely affected, it would be nice to get some gravity caused stability at vertical to make feet down at stops optional once accustomed to the trike. The problem I see though would be for a strong effect is the seat height being too low for my tastes, or too wide a track at the rear.

Realistically I may have to go to all 3 wheels leaning to get what I want, and I'd be inclined to go with simple like this http://www.fastfwd.nl/index.php?id=36 or the Black Max http://www.fleettrikes.com/blackmax.htm#7mar09. Both of those show enough detail to copy and are pretty simple. What appeals to me about the non-leaning rear approach is all that space that becomes mostly unusable with tires leaning in there. I know some great mountain roads with almost no traffic that would be great for carving up with a full leaner, but realistically I'd only get to go do that rarely, so my focus should be on cargo capacity, not handling better than a gokart.

John

[docnjoj]

Thanks TD. I had actually read through the Jet Trike stuff and found the conclusion a bit vague. He mentions 100mm raise in seat height will cause problems handling on a tadpole, but Rassy has done this and I just raised my seat about 50mm with the other 50 to come from 20" wheel replacing my 16" fronts. You notice the difference in handling but it seems not to affect the trike stability as much as I thought it would. I do have to corner slower , however. No surprise there.
otherDoc

[docnjoj]

Hey John
That Kantletrike really looks fairly simple and has a rear suspension. At the speeds you travel that may be important.
otherDoc

[sk8norcal]

another thing I have concerns about is all that unsprung weight..
and the need for a differential..
(not sure if the gyro have a diff..)

http://tiltingvehicles.blogspot.com/201 ... ta-12.html

[veloman]

http://www.schultzengineering.us/chap6.htm

Not sure if this was posted before, but it's very thorough.

[John in CR]

another thing I have concerns about is all that unsprung weight..
and the need for a differential..
(not sure if the gyro have a diff..)

http://tiltingvehicles.blogspot.com/201 ... ta-12.html

I've got a go-kart differential, though I won't need one if I opt for a motor for each wheel. I do want some form of suspension, but I'm thinking about leaving the space between the wheels for just the motor(s) and cargo. I like the idea of putting the batteries in line below the tilting axis of the frame, because then I should be able to get the trike to self balance when it's parked. It would be nice not to have to worry about some type of lean lock when I get off. That can save some weight too by making the support structure for the batteries and integral part of the frame structure. The lean pivot can take a number of different forms so it's placement is flexible in relation to the frame as long as it's height from the ground is less than half the width between the rear tires, that is if I correctly understand the tipping point info discussed at jetrike.com .

JOhn

[John in CR]

http://www.schultzengineering.us/chap6.htm

Not sure if this was posted before, but it's very thorough.

No, I haven't seen that before. I especially like the idea of 2 riding positions.

Thx,

John

[purplepeopledesign]

If you want one, I'll can build it for you. The trike in the signature video is the original Magic designed by my late mentor Paul Smith in 1992. The frame was welded by Georgiev in trade for help designing one of his early speedbikes. The new trike has a video that is listed in my YouTube faves that was taken by Ray of Blue Velo. It has a low modified Magic pivot, slim rear track and handles the same as Magic on smooth surfaces. It's even better on the road and rough surfaces because it has a longer wheelbase and fatter tires.

:)ensen

[John in CR]

If you want one, I'll can build it for you. The trike in the signature video is the original Magic designed by my late mentor Paul Smith in 1992. The frame was welded by Georgiev in trade for help designing one of his early speedbikes. The new trike has a video that is listed in my YouTube faves that was taken by Ray of Blue Velo. It has a low modified Magic pivot, slim rear track and handles the same as Magic on smooth surfaces. It's even better on the road and rough surfaces because it has a longer wheelbase and fatter tires.

ensen

OK, just tell me when to send someone by to pick it up.

[purplepeopledesign]

Okay, then. Let's start with you sending a PM with your measurements, preferences for BB height, a side view photo of your preferred seated position including handlebar position, etc. I'll work out a few variables and come back with a quote for the frame.

:)ensen.

[John in CR]

Sorry, I guess you missed my weak attempt at humor. You didn't mention anything about a price in your first post, so I was jokingly going on the assumption you wanted to build one for me out of the goodness of your heart or that you hated seeing me as the school bus for our boys on a dangerous 2 wheeler. One can hope anyway.

I will do this though, I'll share what I come up with. If you see some glaring holes, please let me know. If it looks so bad as to be dangerous, I'll even pay for some design assistance.

John

[sk8norcal]

If you want one, I'll can build it for you. The trike in the signature video is the original Magic designed by my late mentor Paul Smith in 1992. The frame was welded by Georgiev in trade for help designing one of his early speedbikes. The new trike has a video that is listed in my YouTube faves that was taken by Ray of Blue Velo. It has a low modified Magic pivot, slim rear track and handles the same as Magic on smooth surfaces. It's even better on the road and rough surfaces because it has a longer wheelbase and fatter tires.

ensen

Hi Jensen,

I dig your trike, can you post a closeup pic of the rear pivot?
btw ur trike looks familiar to me, I was at IHPVA in Eureka in 96? and met george georgiev,
and trying out a handful of leaners..

including this one..
http://2.bp.blogspot.com/_Q1dyW07vBRo/T ... a+tilt.jpg

[purplepeopledesign]

Let me be very clear. The trike in my signature video is not a Varna (even though many people attribute it as one). Rather, the frame for the trike was welded by George Georgiev and that's why they assume it's lineage. Unknown to most people is that was designed and belonged to my late mentor, Paul Smith. You will remember Paul for his big yellow coroplast tail fairing with the logo of an electronics sponsor. Anyway, the trike is called the Magic because it is. Georgi welded it to Paul's exact specifications as repayment for help with his early streamliners. Magic was first shown in public at Yreka/Montague '92 and was also brought to Eureka '94 and Vegas '96. I acquired it from Paul when he left for Europe before the new millennium. He made me promise not to reveal the secrets of the tilt mechanism so now it never goes out in public without a cover for the important bits.

At the '94 IHPSC, I never had anything as sophisticated as Paul's Magic. At the time I was still experimenting with a fully suspended tadpole made of riveted aluminum. The only features of note on my trike at the time were the self-equalizing front brakes and USS direct steering off the low-hanging Ackerman links. The third guy in our Vancouver builder's clique is (also) the late Dan Trayling. At '94, he brought the 17lb blue weight weenie CLWB with the sling seat. Dan liked things light... his front wheel had 6 spokes.

The photo you've linked is a later model of one of George's Sprite trikes. The original handles much better than the one in your pic because the geometry was kept the same but the wheels were swapped to all 20's from a pair of Moultons and and a 24. In '92, the Sprite was the only machine capable of turning small high speed circles with the Magic.

Now, my current daily driver is a low racer tilting delta and can be seen in these videos taken at 2009 Niagara Velomobile Gathering. The first video is just me coasting along no-hands. It can seen doing it's thing at 2:35 in the second video.

http://www.youtube.com/watch?v=rA0FAeAA9to
http://www.youtube.com/watch?v=hpZtcSsirc0

This new trike I call the Magic V2.0 out of respect for Paul. As you can see, he taught me well.

:)ensen.

[John in CR]

I'm sorry, but if it really is that good then sharing the tilt mechanism now would honor his legacy. One of the great things to come out of the internet age is the concept of open source. Too bad it still hasn't caught on with people who build mechanical things. If an idea is worthy and you know you won't bring it into mass production yourself, then share it freely with the world. If someone does take it into production hopefully they will have the honor to include a small royalty % for you.

Will you at least say, is it the angle of the pivot that is critical, or is what's so special the slick pivot mechanism itself?

[sk8norcal]

cool info,

so I probably did see that trike at Eureka 94..
I don't remember test riding it.. (it was a long time ago )
definitely remember riding the 'Sprite'..

is this the same trike at 1:28 ?

[purplepeopledesign]

I'm sorry, but if it really is that good then sharing the tilt mechanism now would honor his legacy. One of the great things to come out of the internet age is the concept of open source. Too bad it still hasn't caught on with people who build mechanical things. If an idea is worthy and you know you won't bring it into mass production yourself, then share it freely with the world. If someone does take it into production hopefully they will have the honor to include a small royalty % for you.

Will you at least say, is it the angle of the pivot that is critical, or is what's so special the slick pivot mechanism itself?

Dan Trayling was the first one I know of with a CWLB bike in '94. A couple years later, BikeE comes out. Dan's bike also had the first ultra-lightweight linear brakes. After that, they started appearing on mountain bikes. Paul helped Georgiev work the aerodynamics on his first speedbikes. Not a public word of thanks.

Open source is a just a buzzword for freebie. Maybe it makes sense with software where millions of people will use it and 10,000 people will "donate" something to the author. But in a limited market with only 5000 users, having only 5 people pay does not make sense. If I release the specs to Paul's trike, you can bet there will be any number of clones the following year. In fact you've already said as much.

And... who ever said I wasn't trying to bring it to production. I just happen to be running on a shoestring and tilting trikes is a very limited market. BTW, it is that good, which is why I offered to build you one (for money of course). If you want to try to reverse engineer it after that, go for it, but just so you know, the production unit will be welded shut.

But all that aside, I promised my friend and mentor I would not reveal it. Keeping a covenant is about honour. If it dies with me, so be it. Let some other genius figure it out next century.

:)ensen.

[purplepeopledesign]

is this the same trike at 1:28 ?

Yes. I'm proud to say that while Paul conceived the design. I helped him tune it. We were watching Dan turn circles with it one day and Paul saw that it was a little skittish. How he saw that is beyond me, but he used to race both cars and sailboats so he must know something. Anyway, I suggested what I thought was an obvious adjustment to the rear axle and afterwards, we all agreed that it was much more stable. Of the three of us, Dan was the fastest, Paul could do 3-wheel drifting turns and I could make small tight circles. In one episode, I actually had to stop from a headache, which Paul told me was grey out.... G-forces slowly depleting cranial blood pressure. The last time that trike was out in public was in 2008 at an HPV ride in Toronto. The ride ended with a group display at a street festival and for one demo, I managed high-G circles inside one lane of east Bloor Street. The Magic V2.0 cannot turn circles as small because it's wheelbase is nearly 6" longer, but it's close. More important is that the longer wheelbase makes it a better behaved road machine overall. The original Magic is more of a parade trike.

:)ensen.