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Automotive Powered Off Road (AKA: Buggys, Jeeps, Trucks, Etc,Etc. ) => Chassis and Suspension => Topic started by: JimmieD on January 31, 2010, 10:13:13 AM
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Hi guys!
Couldn't find a forum section for 'Weird Stuff' so I'm tossing this here :) Just about finished with final design & ready to start fabbing up a 2F/1R 3 wheel vehicle for street, trails & offroad. Vaguely, very vaguely, similar to a Morgan 2 wheeler, at least in general chassis layout. Roughly 140-175hp 4cyl w/ 5 speed, about 1000 - 1,100 lbs. Bunch of good reasons for going 3 wheeler, but that's beside the point.
So, these 3 wheelers have a potential to flip over in a really hard fast turn. Chassis can't load to the outboard rear wheel 'cause it isn't there, only having the single central mounted rear wheel. Just like a 4 wheeler lifts the inside wheel on a hard turn, 3 wheeler has the same loads, but nothing for it to feed into, so chassis wants to roll instead of flexing.
Scratching my head 1/8 awake this a.m. and sat looking at an overhead view drawing, had one of those 'Hey, wait a minute...' moments. You guys have played with all kinds of stuff and some really expert minds here, so what do you think:
Similar to how a wheelie bar is used on a dragster, why couldn't I add a mini wheel at the outboard rear corners of chassis, at a height from ground that would only contact when chassis was in a position to flip? Of course using a small wheel/tire assembly stout enough to handle the loads, can you see any reason it wouldn't work? It would be almost completely covered by rear bodywork.
Seems it should all react similar to having a normal wheel there, except center rear wheel is fully in contact and is taking most of the side loading, with mini wheel only preventing rollover. Only used as safety measure and instantly back off a little when reaching point of contact.
Think it would work?
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As far as I can find, http://en.wikipedia.org/wiki/Campagna_Corporation (http://en.wikipedia.org/wiki/Campagna_Corporation) don't have a problem with rolling over.
http://www.youtube.com/watch?v=38TFetQAe2o (http://www.youtube.com/watch?v=38TFetQAe2o)
Neither do http://en.wikipedia.org/wiki/Can-Am_Spyder (http://en.wikipedia.org/wiki/Can-Am_Spyder).
http://www.youtube.com/watch?v=cKXUwJfpewg (http://www.youtube.com/watch?v=cKXUwJfpewg)
I would imagine that three-wheeled chassis stability requires fairly different balance and suspension geometry to a four-wheeled vehicle, ideally you'd need the front track fairly wide and the rear roll-centre as low as possible, right? And the grip balance so the rear tyre tends to slide rather than edge into the bitumen and grip, high-siding you into the road-side shrubbery?
Maybe there is a book on the subject in your favourite technical bookstore?
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Thanks, Chris!
T-Rex is similar all right. In general I haven't heard of problems with flipping those. I chased around a bunch of forums and did months of research and unfortunately the tip-over was mentioned a few times. When you finally reach the limits there's nothing to prevent the inner wheel lift so the chassis just keeps lifting and apparenly it all happens very fast, maybe too fast to back off.
I definitely agree it's probably a non-issue, but thinking I'd hate to find out the hard way? Figured it wouldn't hurt to add some insurance, but yeah, not even sure it's a problem I'd ever have to deal with.
May experiment with the bare chassis w/o bodywork & see what happens.
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A front sway bar is a must. I would also move the front wheels back slightly. The less acute your triangle is, the harder to roll it over.
The golden ratio comes to mind, only tweaked a little.
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my only thought about an outboard "training wheel" is what happens if that small tire snags a pothole?
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Thanks guys!
Front track near 60", wheelbase 84"-87", very low COG. I've beat the measurements to death and that's the best possible from what I can see, but just maybe I can pull another 9" out of wheelbase. Planning on a 48" x 48" cabin/seating area, maybe slightly different when I actually build, possibly take 6" out of that too.
Yes, I have a front sway bar, couldn't figure out if that would actually help or not, confusing to me. I plan on [famous last words] using aerodynamics to advantage, maybe even tunnel effect but that's only good at speed. Hopefully low mount spoilers would help keep things planted?
On the potholes, I dunno, not likely on pavement where I'd be driving but could be interesting. Figuring on some spring loading? Attach a strut like a lever angling downward/rearward, wheel at end point, spring to press down on lever. I know there's a tech name for it but it escapes me right now. Almost like a girder front end in reverse.
Wide open to ANY suggestions! Never done a 3W before.... ??? eyes :-\
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With two extra wheels wouldn't it be a five wheeler?
I say make it a quad and be done with it.
The reverse three wheeler thing is just a fad I feel. I would like to see one race against a two wheeler bike and and a car to prove it can be fast in the corners.
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From a U.S.A. perspective I would somewhat agree, but otherwise it's doing pretty darned good for a fad: starting in the late 20's to early 30's and going very strong ever since in Europe. I was just amazed at the number of 3W that have been mfd. & sold to the public!
http://www.3wheelers.com/azlist1.html (http://www.3wheelers.com/azlist1.html)
Far as a race 2W to 3W no doubt a bike would always have an advantage, but the same goes for 2W to 4W races on a twisty course. Acceleration is maybe a tie, power to weight being equal, but possible advantage to 3W for superior traction off the line. I think my design will offer the best traction overall of any layout, 2W, 3W, or 4W.
I suspect that except for the pushing the ultimate limits to rollover a 3W and 4W would generally be very close on handling, but the old Morgans and other 3W regularly mopped up on any 4W for years in what we'd call offroad courses in the USA.
I'm building off a Dodge Omni drivetrain, 2.2L, 5 speed, tube frame to accomodate the stock K member & stock suspension at front. Used a Mopar V8 distributor & converted it to the 4 cyl. to eliminate computer control, changing stock computer carb to side draft Webers, adding cam & fab headers so maybe 150 or so hp, more or less.
I think I've figured out 3W drive with a limited slip in front, need to look closer at stock config. to see if my plan to drive single rear wheel will also work. If it's mechanically possible that means driven wheels hitting 3 different tracks for traction, so lots better than a 4WD that only hits 2 tracks. Planning a wide rear tire & slightly narrower fronts on mine.
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Now hold on a sec, front wheel drive? I wouldn't worry about a roll over.
And the point of a sway bar is to keep body roll to a minimum which will be a problem with a three wheeler.
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Acceleration is maybe a tie, power to weight being equal, but possible advantage to 3W for superior traction off the line. I think my design will offer the best traction overall of any layout, 2W, 3W, or 4W.
I think I've figured out 3W drive with a limited slip in front, need to look closer at stock config. to see if my plan to drive single rear wheel will also work. If it's mechanically possible that means driven wheels hitting 3 different tracks for traction, so lots better than a 4WD that only hits 2 tracks. Planning a wide rear tire & slightly narrower fronts on mine.
Neither of the above make any real sense to me. I am not sure you have contemplated how the forces are going to be applied in real life.
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3W against 2W, might have a race here:
http://www.brudelitech.com/ (http://www.brudelitech.com/)
I don't know for sure on possible rollover, but have read reports of it with a 3 wheeler. I agree the front drive should lower the tendency, that's what I'm hoping.
"Acceleration is maybe a tie, power to weight being equal, but possible advantage to 3W for superior traction off the line. I think my design will offer the best traction overall of any layout, 2W, 3W, or 4W."
"I think I've figured out 3W drive with a limited slip in front, need to look closer at stock config. to see if my plan to drive single rear wheel will also work. If it's mechanically possible that means driven wheels hitting 3 different tracks for traction, so lots better than a 4WD that only hits 2 tracks. Planning a wide rear tire & slightly narrower fronts on mine."
Neither of the above make any real sense to me. I am not sure you have contemplated how the forces are going to be applied in real life."
The first traction reference is comparing 2 wheels to 3 wheels. Bike may sit there burning while the 3 wheel drive is already gone.
I'm hoping to be able to use 3 driven wheels, not sure it can be done though. If it can then it would be better than 2 or 4 wheels regarding traction. With 4 wheels there's left side wheels & right side wheels, and whatever road surface they ride on. If the front wheel on one side didn't get traction then the rear probably isn't going to either. But with 3 wheels there's a 3rd road surface to get traction on in the center of vehicle, plus the right & left, so it seems you'd have better traction offroad. At least that's what I'm thinking.
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With 4 wheels there's left side wheels & right side wheels, and whatever road surface they ride on. If the front wheel on one side didn't get traction then the rear probably isn't going to either. But with 3 wheels there's a 3rd road surface to get traction on in the center of vehicle, plus the right & left, so it seems you'd have better traction offroad. At least that's what I'm thinking.
That's not how it works....
If you are going to do all wheel drive then it would be best to start with a car that has it. Like an 88-91 honda civic wagon. The front is driven directly from the tranny like a normal front wheel drive and the rear is driven by a drive shaft. No external transfer case. Your front an rear ratios have to be spot on or they will fight and that's wasted power.
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That's not how it works....
If you are going to do all wheel drive then it would be best to start with a car that has it. Like an 88-91 honda civic wagon. The front is driven directly from the tranny like a normal front wheel drive and the rear is driven by a drive shaft. No external transfer case. Your front an rear ratios have to be spot on or they will fight and that's wasted power.
I agree. And thats why it does not make sense to me.
Just cause a tire is not behind a tire in front of it does not mean its gonna have more traction either.
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Still gonna be predominately at a disadvantage as far as traction is concerned due to the single rear wheel. Just curious, but why you wanting to do this?
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I'm talking about all wheel drive, all the time. One front and the rear wheel are directly coupled, the other front is independently driven, but through a limited slip. The ratios are all identical, unless I slightly overdrive the rear, common in 4WD vehicles. The limited slip will prevent the steering & handling from getting too squirrely.
The 3 separate wheels are all seeking traction on 3 different parts of road surface. That is an advantage over trying to get traction on 2 parts of road surface, just like a 2WD limited slip has advatage over a single leg differential 1WD. Even in slushy ruts or wallows where front wheels both lose traction the single centered driven rear would be on higher & drier ground, getting traction. Many 3WD do very well, even offroad, with only the single rear wheel driven.
My front drive will be the nearly stock Dodge Omni setup, but limited slip to give traction to both front wheels. The rear will be driven off one front. Disc brakes on all 4, with those made for a car weighing 3 times as much, so killer brakes.
I am building for several reasons, first because I want to. Also it is cheapest to register and insure, as a motorcycle, plus I beat all SMOG regs, very important here in California. I can easily build the whole machine for way under $1,000. A stock Omni can knock down 41-44 mpg easy, at around 3,000lbs or so. I figure on something like 75+mpg with 1/3 the vehicle weight & good aerodynamics.
It will be a multi-use vehicle for most any road surface and moderate offroad, and should be good in snow, sand and mud. It will have extreme acceleration, crazy top speed if I wanted, very aggressive handling, excellent for the steep & twisty mountain roads here. It could pull my small popup trailer for long trips, with incredible mileage. It will seat 2, look good, handle great with incredible acceleration, handle most any terrain and all with far more than good mileage and be exciting to drive. Complete parts cars are readily available for $200-$300. The tranny I'm using is a direct boltup to the VW 4 cylinder diesel. I've got a spare turbo and can intercool it and have strong power & torque, and bring the mpg's up around 100mpg if I drop in a diesel.
I can't see any reason NOT to build it :)
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I like things that are different and all but at the same time I do not see this being what you hope it will be but at the same time I would find it interesting IF you can do it and build it and make it do what you say.
I am not sure how you think the limited slip will keep it from getting to squirrely. Explain please.
The 3 wheels on different parts of the road surface VS 4x4 vin the same tracks is relative to the terrain. IF you are pushing crap out of the way (slush or loose mud) and riding up on something you may have less traction VS the front tires clearing the path and the rears following in the tracks. At least in a straight line.
3wheeler with single rear wheel driven does well off road? Got examples? I will try to find it on youtube next time I go to the library (no high speed here) I have seen JUST the opposite with that nitemare reverse three wheeler that was a complete flop.
If you drive the rear off ONE front it will try to speed up faster while turning one direction and slow down and drag while turning the other as which ever wheel goes faster or slower as its on the outside. This alone will make for a handling nitemare. Be VERY interesting if you can make this work.
Good luck.
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Dude, everybody likes to dream a little.......time to return to reality.
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I'm talking about all wheel drive, all the time. One front and the rear wheel are directly coupled, the other front is independently driven, but through a limited slip. The ratios are all identical, unless I slightly overdrive the rear, common in 4WD vehicles. The limited slip will prevent the steering & handling from getting too squirrely.
The 3 separate wheels are all seeking traction on 3 different parts of road surface. That is an advantage over trying to get traction on 2 parts of road surface, just like a 2WD limited slip has advatage over a single leg differential 1WD. Even in slushy ruts or wallows where front wheels both lose traction the single centered driven rear would be on higher & drier ground, getting traction. Many 3WD do very well, even offroad, with only the single rear wheel driven.
My front drive will be the nearly stock Dodge Omni setup, but limited slip to give traction to both front wheels. The rear will be driven off one front. Disc brakes on all 4, with those made for a car weighing 3 times as much, so killer brakes.
I am building for several reasons, first because I want to. Also it is cheapest to register and insure, as a motorcycle, plus I beat all SMOG regs, very important here in California. I can easily build the whole machine for way under $1,000. A stock Omni can knock down 41-44 mpg easy, at around 3,000lbs or so. I figure on something like 75+mpg with 1/3 the vehicle weight & good aerodynamics.
It will be a multi-use vehicle for most any road surface and moderate offroad, and should be good in snow, sand and mud. It will have extreme acceleration, crazy top speed if I wanted, very aggressive handling, excellent for the steep & twisty mountain roads here. It could pull my small popup trailer for long trips, with incredible mileage. It will seat 2, look good, handle great with incredible acceleration, handle most any terrain and all with far more than good mileage and be exciting to drive. Complete parts cars are readily available for $200-$300. The tranny I'm using is a direct boltup to the VW 4 cylinder diesel. I've got a spare turbo and can intercool it and have strong power & torque, and bring the mpg's up around 100mpg if I drop in a diesel.
I can't see any reason NOT to build it :)
This is why it won't work as you want.
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Okay, let's see here: the single rear drive was used on all the early 3 wheelers in England, such as Morgan. In trials & rally events a 4 wheeled vehicle couldn't come close to the performance, this was for over 30 years. I imagine all the 4W had a single leg diff. So it can perform, depending on where & how it's used.
On the 3 driven wheels, I'll have a limited slip in normal FWD differential. One half-shaft driving through to rear wheel, with an in/out disconnect, that rear wheel drive can be selected offroad etc. but not necessary on pavement.
With selection of powering rear wheel offroad or in snow/sand the vehicle has traction on 3 different road surfaces, not 2, so quite likely better traction overall. Many 4WD are actually 2WD, one front and one rear driven, with open diffs selecting power to wheel with LEAST traction. In this setup it's more similar to a locker front diff, and more of a constant 3WD, or selectable to semi-locker FWD.
Handling would be similar to a 4WD with lockers front and rear, with possiblility of rear wheel getting squirrely on turns, don't know. However the rear lockup is selectable, allowing change to FWD only but as a limited slip [almost locker] front. Planning a wider tire on rear to help balance traction. 3 wheels driven is intended only for offroad use, otherwise 2WD L/S with Oxlock.
"If you drive the rear off ONE front it will try to speed up faster while turning one direction and slow down and drag while turning the other as which ever wheel goes faster or slower as its on the outside. This alone will make for a handling nitemare. Be VERY interesting if you can make this work. "
I don't think it would be any different than any FWD vehicle with a limited slip like the Oxlock, which still allows differential action instead of full locker. Oxlock can be made more agressive or gentler lockup, I think by changing springs. The pto disconnecter for rear will be my own design.
The 3rd driven wheel in rear will only be used offroad, or going slow in sand or snow. I don't foresee any problems, may be some, but I guess it's hide & watch. I don't have all the answers because it isn't built hah!
Main thing I wory about is flipping it when driving real hard on twisty roads, but low COG and wide-spaced front track may prevent that.
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Okay, let's see here: the single rear drive was used on all the early 3 wheelers in England, such as Morgan. In trials & rally events a 4 wheeled vehicle couldn't come close to the performance, this was for over 30 years.
I have heard this before but you know what? I STILL do not believe this and till I could drive them both myself I will believe it was rigged rigged rigged.
Somebody was likely paying for those results.
If three wheels were faster you would be seeing them raced today at top levels AND YOU DON"T! For a good reason I bet.
As for your project you are sorta pioneering a couple things that may have been daubled with by a few and you may make it work and I hope you do honestly. But you do face a few challenges and it seems to me there are a few things you are either overlooking or pretending will not affect it or will affect it in some different way they many of us here seem to think it will operate.
As mentioned before I like things that are different and its guys who go try odd off the wall things are sometimes the ones that do make some neat discoveries. And I do mean it when I say I hope you do. But I will also admit I am a tad skeptical of some of the claims you make. But look forward to seeing if you may be able to do just what you hope. It might lead to mprovements we can lop onto future thing here.
I have seen a lot of things that work today I would not have thought would work and thats why I think you should try this. Till its built and tried we won't really know. Just theories I guess.
But I would still like to see thiose famous three wheeled Morgans beat anything today with four wheels. Till then its a bought and paid for result in my eyes on those.
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Ditto.
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dude, coupling the rear to one of the fronts is going to be a problem unless...you run a spool instead of a diff, or you use something like the honda tranny I mentioned that drives the rear off of a neutral source.
If you run a spool, you will have turning issues. If you go with a different tranny, you have to locate one. It's kind of an either/or situation.
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"But I would still like to see thiose famous three wheeled Morgans beat anything today with four wheels. Till then its a bought and paid for result in my on those."
Who said anything about racing a 1930's Morgan against a 2010 vehicle? Show me an original 30'-40's 4 wheeled race vehicle that could compete against a stock, out of the showroom 70 year newer car of today? Not a chance. That wasn't the point of what I was saying. Simply saying that under the right conditions even a single rear wheel driven 3 wheeler could, could, out perform a single rear wheel driven 4 wheeler, under the right circumstances, that's all.
Maybe y'all are misunderstanding my use for this vehicle. I'm not planning anything but slow, casual, offroad driving, in 3 WD when needed, or sensible driving on the paved roads, sometimes in snow, with some times of pushing it hard on pavement. It's also super-economical daily transportation. Not building a race dune-runner or anything like that.
Fact is, I only mentioned it here because there's no other good forum with guys building one-off personal design tube chassis rigs. Very few build 3 wheelers except from tab A, slot B kits so there's not even any chat out there about them.
"dude, coupling the rear to one of the fronts is going to be a problem unless...you run a spool instead of a diff, or you use something like the honda tranny I mentioned that drives the rear off of a neutral source.
If you run a spool, you will have turning issues. If you go with a different tranny, you have to locate one. It's kind of an either/or situation. "
Nope, no problem at all. Not going to run a spool. An Oxlock isn't a spool. With a limited slip in the direct-coupled front/rear drive, and a limited slip in the front wheel drive differential, no problem at all.
There's lot's of other unique features in the design so that with it all put together right it will do just exactly what I intend it to do. Safely I hope, as far as pushing the 3W configuration hard, and that's what the original question was about. I already know the design will work just fine.
Thanks all....
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The only REAL good way to connect different tires like this would be to drive each with a CVT. Or at least the rear with a CVT. Then it could adjust some.
I was actually thinking of the civic wagon tranny with a bike's shaft drive rear tire. Get that ratio right and you're done.
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There's some friction starting here. Step back guys and take a breath. ;) So far I have seen suggestions and skepticism in this thread 8) 8). This type of thread is ,IMO, a great way to get ideas discussed. Lots of good things come from threads like this. Now back to the topic. ;D ;D
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With 2 offset wheels under power(1F,1R) the vehicle thrust line is skewed instead of parallel to the direction of travel/centerline of vehicle. Nasty things happen.
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I would have quoted you Grimm reaper Racing but I kept timing out with a "fatal error" that I think is due to my wonderful dialup out here in the boonies.
You can say my idea of driving the rear tire with a CVT is an opinion but I would ask of you or anyone to show a better system that senses load requirements and applies power?
ESPECIALLY at the cost it would take to rig up a decent CVT.
I do see what Boost is talking about if I understand right. He is talking about the Toyota wagon tranny (also used on sedans) with the all-trac (Toyotas AWD system of yesteryear) and to run a shaft back to a shaft drive motor bike kinda of gearbox. Very good idea indeed. Quite possible the only one able to compete with or beat the CVT to the rear tire idea.
But unless a system could like these two above allow slip to the rear tire at the right time this proposed machine is gonna be so SQUIRRELY it will need to be fed nuts! (no not NUTZ) See Fabrs last post. He knows!
Sorry about the "Friction" partz.
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Thing is, I have studied this design in extreme depth for several years now, miles of research. Also machine design and vehicle design has been a major part of my life, an obsession, for a really long time, I'd give anything just to remember the stuff I've forgot hah!
On the 3W versus 4W: Just like the gasoline engine versus diesel engine, there were powerful forces working against 3W's, because 4W were the big kid & had the dough to squash them. In many cases the reason 3W never made it big time in racing is because of that old dirty low down trick you guys know so well: THEY WROTE THEM OUT OF THE RULE BOOK! If ya can't beat 'em, force them out of the the competition!!
If you do some research, and that's real difficult 'cause not a lot of info on the net, you'll find that the 3W's beat the stuffing out of 4W's in the trials and rally racing of the 20's to late 30's or early 40's England. At the war many changes occurred and few performance oriented 3W companies survived. In Europe & England they've been common up to the 70's, like the weird Reliants, but only for ultra-basic transportation. For a real eye opener, check out the assortment here:
http://www.3wheelers.com/azlist1.html (http://www.3wheelers.com/azlist1.html)
Most were low-powered cycle types, to beat tax & registration fees and for people driven to poverty by the war. Development of hot machines was near zip because the base vehicles offered lousy drivetrains with cheap, weak components & junk design layouts doomed to failure. That put a lot of leverage against them succeeding as a major player.
In addition the talk of them flipping over, possibly started by the 4W competition, cuased a lot of people to shy away regarding competition etc. Funny, as mentioned by someone else, it's pretty darned hard to find reports of that actually happening! Hmmmm.....
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Now, regarding my design, there's some problems explaining it all here. Several features are very different, and I hope/pray to generate some patents. Once a few things were figured out after a lot of head scratching, component designs were done so they could be built anywhere with absolute minimum tooling, be super simple mechanically, totally user/owner maintainable with minimum skills, resources & tools, be compact, light weight and useable over a large number of platforms.
Example: transmission design that can be easily built in a shop, if ya had one, with only a drill, cutting torch & grinder, with exception of one component that's already available off the shelf and very cheap. Tranny can easily handle 300HP+ with very light tranny weight, bullet proof, 'full synchro' without actually having synchros, shifts almost as easily as an automatic, requires no clutch on the engine, plus it's dual range and requires no trans lube.
My Limited Slip designs & layout for rear drive & L/S differentials are similar: stone simple, rock solid, stupid easy to build, costs pennies to dollars to manufacture compared to what's now available.
I'd love to tell the world, but CAN'T until the patent stuff happens! That's really hard for po' folks like me.
So, sorry if it all sounds like I haven't got a clue what I'm doing. Fact is I have it all designed 300% and know how it will work, just can't post it on the internet and give away 20-40 years of design work.
Thanks for understanding. :)
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C'mon guys.. Let's talk about the concept.AS for me I think only front wheel drive is practical. One reason for the demise of 3 wheelers was the need for a full size rear seat.If only 1 in back it would be severly unbalanced.
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Aside from the tippyness Fabr the three wheelers could not hold the tail end behind themselves in corners. Even today a car with two WIDE tires back there will loose the tail end in a microsecond. One tire only cannot provide the grip. Especially the tires they had in those days.
EDIT: I should say the reverse three wheelers. One tire aint enough back there. Heck two are not most of the time.
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You can say my idea of driving the rear tire with a CVT is an opinion but I would ask of you or anyone to show a better system that senses load requirements and applies power?
ESPECIALLY at the cost it would take to rig up a decent CVT.
I do see what Boost is talking about if I understand right. He is talking about the Toyota wagon tranny (also used on sedans) with the all-trac (Toyotas AWD system of yesteryear) and to run a shaft back to a shaft drive motor bike kinda of gearbox. Very good idea indeed. Quite possible the only one able to compete with or beat the CVT to the rear tire idea.
Sorry about the "Friction" partz.
I don't know, but I think you just answered your own challange.
I was just stating the obvious. It was an opinion, not fact. I on the other hand know there are any number of solutions to a problem. As an engineer, this is how I make my living.
If you can remember your history lessons, you may recall many inventors/ engineers/ fabricators being chastised for their thoughts and ideas. Hell Thomas Edison's own family nearly had him committed to a mental institution for his "light bulb experiments"
My favorite example is a man by the name of Nikola Telsa. He was an arrogant man, who died penniless and friendless. Yet he was a genius who we should all be giving our thanks to.
I am not saying the JimmieD is a genius nor am I saying he is the next Tesla, what I am saying is stranger things have happened.
Also, I have read this thread and I think it is my interpretation that JimmieD is making his three wheeler to toodle around, not race the thing. So lets help him accomplish that.
As for all of the 3 wheeler vs 4 wheeler "conspiracy stuff" We will probably never no for sure, but one thing is for sure, watching 3 wheeler crash footage is a riot. ;D and who knows, maybe Jimmie will have some more of that footage to show us.
My humble opinion stinks just like everyone else's, but I'm going to throw it out there, so here it is...
A 4 wheeler is better than a 3 wheeler, but a 2 wheeler kicks all of their asses.
That is a little shout out to all of you guys who have ever raced em... you too Spec! bb:
(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi496.photobucket.com%2Falbums%2Frr325%2Fgrimmytat%2FMisc%2FAdamYamaha.jpg&hash=ffbda4791390896c3bc1106577343c3ff5198397)
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Most people know there can be many solutions to an issue. No big there.
So how would you go about it? Powering the third rear wheel? Curious if you have any ideas on that matter.
This is a tad off topic but I agree Nikola Tesla was a genius we may never see again. But not so sure we should be giving a lot of thanks too. His "work" was leading to tapping into things of a powerful nature most of us barely grasp if at all.
Yet his work led to energetic weapons. Are we supposed to be thankful for that?
I wish he was smart enough to get his work out into the right hands. But he sent it to the wrong ones (G-ments of the world) by all accounts of what I have read and heard on him. If you know better please enlighten me.
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I'm with Boost on how to power the third wheel, with a bit of a different version. What about using a Subaru engine and trans, you'd have centered weight, a proven combo and the low profile of the boxer engine.
Kudo's for trying to think out of the box, but I'd still take 2 or 4 wheels over three any day! Different strokes for different folks I guess.
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I personally would not use two different CVT's for the front and rear drives. I for one am not a fan of the CVT. I pretty much don't like anything that is belt driven. I like the control of a gear box. So lets start with that much for sure.
If I had no choice but to use a CVT, I'd only use one, and couple it to a gear box that had F N R. Similar to that of most Polaris 4 wheelers.
I like the idea of a limited slip front axle. As for the rear drive, I'd probably use a shaft driven design similar to that of Honda motorcycles. I still don't understand why anyone wants to build a 3 wheeler. I had a 250R as a kid, that thing damn near killed me. It sucked it the snow and mud, and worst of all, in was so squirrely on tight corners, and when you pegged the throttle in the corner it would come up on the pin and two tires would be off of the ground. It was mad fun, but not safe for off road racing.
To be honest... If I was crazy enough to build a three wheeler, I'd drive it on the road and that was it. To make it light weight, easy to work on ect. I'd use a donor sport bike, and chain drive from the bike and make a new swing arm and rear suspension. That is how I'd do it. Just my opinion.
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nono nono OK,I'm fooking tired of deleting shit and bullshit from this thread. It's fooking ridiculous and unproductive. The topic is legitimate and has a lot that could/should be discussed and ideas presented along with logical,rational reasonings as to why it will/will not work are very welcome. Present your fooking ideas and opinions at will but knock the BS off. thumb down thumb down You guys want to hurl insults -USE THE FOOKING PM SYSTYEM! kick
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thumb down thumb down You guys want to hurl insults -USE THE FOOKING PM SYSTYEM! kick
You have a PM..... ;D
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I'm going to step out on a limb here and say that a 3 wheeler does have some advantages especially in the area of turn radius to make tight parking easier in congested aresa and they can be built to minimal standards to keep them light and basic utilitarian transportation. BUT,I DO NOT agree that there is any advantage to anything with 3 wheels off road. In fact I can see nothing but negatives off road. Any of us that have been off roading with motorcycles or quads or old school 3 WHEELERS,yes boys and girls there were some long ago before many members here were born, 3 wheels offroad only mean that 1 of the 3 are always in the deepest part of the trail. That sux big time. Just the way it is. So ,I saw the guy wants to use it primarily on road for an occasional jaunt off road so what's wrong with that? Nothing in my opinion. Trying to convince us it's going to be superior off road is an exercise in futility. However ,if he builds it and proves us wrong then he will be entitled to publicly make fun of us as often as he wishes. LOL!! Let's all try to keep in mind that what works on road may well be a POS off road. So far the 3 wheel design off road have not caught on for a variety of reasons. Let's discuss those reasons rationally.
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T-Rex was on "How its Made" this morning. For only $50K you can have one of them.
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Thanks for replies. Don't want to get too wordy answering all, but: shooting for a very low Center of Gravity. I have a Honda 3W that I reworked, lowered everything in back to drop the seat height by about 5"-or 6". Helped lots with the tippy, but still a dangerous thing to ride. Problem there is COG and track: thing is too high off the ground & rears too close together.
No plans for a CV belt drive, had one on another rig & it sucked 100% until speed was topped out, flaky there too. Doing chain drive off one front axle, through limited slip, to rear. Selectable for driven rear or not, plus L/S in front, close to a locker but adjustable too. Chain drive eliminates possible torque twist from shaft drive, and way cheaper.
Yep, there are MUCH better drivetrains I'd like to use than the '86 Omni, but serious po' folks here, and the Omni is here & free! Has a 5 speed, one of the better ones, but not their best & I modified the engine to take Webers. Built a distributor out of a Mopar V8 disto to dump the computerized crap & use older Mopar electronic ignition. Have a turbo for it too.
On the plus side Mopar built many FWD off this design and it's really easy to bolt in a whole world of power later if I can afford to. Realistic 300+ out of a 2.8L 4 banger, not bad in a 1,000+ lbs car!
2F/1R is entirely different handling and performance than a trike. Trikes don't handle for nothin', but FWD powertrain can in 2F/1R layout. Another major reason for 3 wheeler is registration, inspection, SMOG requirements [in California] insurance & vehicle codes: it gets licensed as a special built motorcycle, not a car! Regs are lights & brakes, that's about it. Huge advantage $$$.
Offroad use for me will be low speed, just mild adventuring, no more of the roostertails, whoops and airborne ect. just old fart meandering. For transportation I expect around 60mpg, as the Omni got 42mpg weighing 2,000 lbs more and with poor aerodynamics.
So, I guess we'll see how it all turns out?
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I guess I'm stil not sure what you mean 2F1R. Are you planning on powering only 1 of the 2 front wheels? Or are you saying use a front wheel drive set up conventionally and somehow selecting 1 rear wheel drive at will? ??? I really really don't see the need for the rear to drive it for the purpose you describe but it's your project. :) Will it work? Well,yes. Will it work well or better than a 4 wheeled vehicle? I doubt it. thumb down If it were me I'd just drive the Omni and be tickled pink with 42MPG. ;D ;D The thing that bothers me about your plan is the lack of funds. I can tell you first hand the costs of blazing your own path in the offroad world are quite high and without them many plans fail. Anyway keep us posted on the progress of this unique plan. 8)
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Anyone that continues to debate with JimmyD, just refer to Master's sig line:
"Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream." ~Mark Twain
He wants to build it, he will build it. Help him make it better.
Sooooo,... what do you think of outrigger wheels that touch down at mild angles, maybe 25 degrees, but were mounted on suspension arms, allowing a rising rate set up that would stiffen at extreme tip angles. It would seem to work best on pavement, uneven terrain could upset the car with a big hit on the outrigger wheel alone. Or riggers that were deployed after some limit is achieved.
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Personally ,I see no need nor do i see them safely working at all. 3 wheels are as stable as neeeded for the stated use of this project. I can also only see those outriggers snagging a pothole or perhaps a curb. If the tires on those outriggers are smaller diameter they will tend to snag,at least momentarily any obstacle instead of smoothly engaging. If this is built I can see 3 wheels working but 5???? Nope. Think of it this way: those 2 extra "stabilizer wheels" will have to be no more than casters and as such will act as a pivoting wheel and encourage a spinout if they do make contact. Overall ,3 wheels will work but IMO the 2 extras are a very bad idea that at first thoughht seems like a good idea.
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I agree with you Fabr,
The only time I've seen outriggers on a vehicle that worked really well were on a recumbent type 2 passenger motorcycle that deployed them at slow speeds because their feet couldn't touch the ground when they came to a stop as it was a monocoque design.
Outriggers would make for some really cool crash footage though for sure.
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I agree with you Fabr,
The only time I've seen outriggers on a vehicle that worked really well were on a recumbent type 2 passenger motorcycle that deployed them at slow speeds because their feet couldn't touch the ground when they came to a stop as it was a monocoque design.
Outriggers would make for some really cool crash footage though for sure.
You got that right. AS for the 3 wheel design it's not my cup of tea but I can't say it won't work. I do say that offroad it will leave something to be desired,IMO,---like a 4th wheel. LOL!!! Probably nothing wrong for a 3 wheel road vehicle tho if that's what turns you on.
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Driving off one output shaft of a FWD transaxle will not work. It will make it turn bad and in different ways when turning left or right. Since that trans is what you have, I have a suggestion for making what you have work. I have an old Dodge transaxle. It is not the same one, but probably similar. On the left side, there is an oval cover. Underneath it are two gears. If you can modify the forward gear or bolt an extra stub shaft to is as well as modify the cover with a bearing and seal, you could drive off that. It is before final gear reduction so you will have to gear appropriately, but you already had to deal with gearing issues. The positive part is that it is before the diff. So the rear tire will be turning faster than the inner front and slower than the outer front in a turn. The rear will still be trying to turn too fast in a turn, the same as any locked 4x4 on pavement, but it will be better than if driving off one front. You might (big theory on my part here) be able to reduce that by setting the front suspension with a very high roll center, higher than the COG. The unit would lean into corners like being on a bike. The rear tire's contact patch should push to the outside of the turn better matching it's speed to the fronts. Putting the rear tire farther out on the turn will help keep it from rolling too. It would also make it easier for the rider to lean and put the weight farther to the inside. That is assuming it is a sit on, not in, machine.
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I think he wants to sit in it.
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It could still be set up to lean into corners for the benefit of the rear tire. I guess it should also have a reverse camber curve or no camber curve at all.
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"Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream." ~Mark Twain
Thanks, OdyPilots! Yes, that's sort of how I look at life. I fight to be practical at the same time. It's my deep belief that only dreamer's dreams come true...
Computer crashed, couldn't get back. I did a poor explanation in original 1st post because I was half awake. Yes, I was picturing the outrigger wheels mounted on swing arms with springs, very similar to the stock Omni real axle setup and what you describe. They would be mounted as high as possible, only contacting if the thing lifted up enough to roll, otherwise tucked up out of the way & almost invisible behind bodywork. Thinking of a wheel/tire size like those weird little spare tires for cars, you know? That kind of size should lessen the spinout thing. It may be entirely impractical and of course that's why I threw it out here.
I'll take a close look at the front drive differential, LiveWire, might be something I could do. But some Omni have a two piece axle on one side, others don't. The two piece has a Cardan midway. Thinking to set it up on one side similar to stock 2 piece axle, but use a carrier bearing just before where first Cardan would be, with carrier bearing solid to frame. Can't likely use a stock front axle, but have a splined shaft made up for this 1st piece, then inserted into outer axle. The rest of the axle with double Cardan can operate the same as the other side that has a 1 piece axle.
I would then have that stub shaft [axle] coming out of diff and use that for PTO drive, to chain drive to rear, with limited slip between that stub shaft drive and rear wheel. Limited slip diff for right/left front wheel drive. Rear drive selectable, only for use at lower speeds offroad most likely, or in loose sand or serious snow, otherwise free wheeling rear.
Well see how it all turns out.
Thanks, guys!
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The ones with the mid shaft are the turbo ones. It is to reduce torque steer. Most late model FWD cars have some sort of setup like that to have equal lengths shafts. Driving off that will cause a very bad handling and bad steering vehicle. It may steer OK to the right than the left since the right front tire will have less weight on it and will be able to slide since it will be rotating faster than it needs to be.