High torque velomobile

Another radical concept: two 500w motors, one on each axle….hopefully with cooling fans and fins. Probibly twice the price, but it would take care of the axle problem and the lopsided traction problem. :lol:

And possibly even avoid the hills over 10% rise…..leaving me with one hill to the library.
 
Jawnn,
I am kinda laughing, I guess I am confusing you. As I get more information from you I try to narrow the power transmission design down to something that will work, we are well past the 2.6 inch motor pulley. We have determined that it will not work. I don't know where you came up with an 11 inch pulley, Tractor supply has v belt sheaves in the "B" size with diameters of 12, 10, 9, 8, and smaller, very cheap. That is why I would like to incorporate this drive.
My 8" 3vx sheave cost $80, the bushing was about $15 I think, My whole 1st stage in the 3vx cost about $120.
The "B" drive 12 inch sheave is about 17 dollars, bushing about 10 dollars.

The parameters that I know, and that I am working with are as follows:
Motor, Mars 909
Motor rpm, 2130 at 24 volts
Wheel size, 20 inch diameter
Weight, 600 pounds
Maximum slope, 16%
Top speed, 20 mph
Cruising speed, 15 mph
Maximum rear sprocket size, 5.5 inch in diameter, This Will Fit? This really helps us

I spend about an hour figuring out these drives, not really doing anything, kinda of relaxing hobby the last couple weeks.
Now before I continue,
Answer this, do you feel that this trike can be converted?
Will it handle the weight?
Can the steering be fixed? Is the steering trail and rake incorrect. Or, is the front of the trike too light?
Can the trikes brakes stop this load safely? If not can they be improved?
Is there a problem with the rear wheels? Spoke breakage, tire slippage, poor rims?
Do you feel the frame of this trike is strong enough?
Explain the axle and how this works. Is it a live axle with one wheel drive? What is the diameter of this axle?

The motor and drive train will probably add about 30 to 35 lbs to the trike itself. I would put the batteries in the trailer. Get rid of the cargo behind the seat. Put that stuff in the trailer.

If the above problems are easily and cheaply solved then lets proceed.

Jawnn, I don't know a thing about these kinds of trikes. I commute in the northern suburbs of Dallas, TX. If I rode your trike here on a daily basis for my commute I would calculate my life expectancy to be less than a week. This is not a joke. This town is not designed for bicycle traffic, most certainly not safe for a trike. To protect my life, I take shorcuts on my ebike that your trike could not navigate.

I have ran a small business here for years, mostly metal manufacturing and installation of metal products for light commercial construction. I have the metal fabrication tools, skills and facilities to build just about anything out of steel. My Dad is a retired engineer, He designed machine tools, heavy industrial equipment, etc. I worked with him a lot, installing drives of all kinds, for applications from the extremely small to the gigantic, I know this power transmission stuff inside and out. Soooo,,,

If that trike frame is strong enough, I would fix that steering wheel flop you talk about on your blog. The front wheel of your trike, from your description, cannot supply much stopping force because it is too light. Well adjusted brakes of any type should be fine, don't waste the time on hydraulic disks, without weight on that front wheel the stopping force cannot be improved with expensive brakes.

I would like to keep the pedaling input. Two hubmotors on the rear would eliminate this, and require some expensive welding fabrication.

Now again, if that trikes frame is strong enough,,,,,,
Motorcycle wheels.
this is what I would do.
Go to a motorcyle salvage yard.
Find two small matching rear motorcyle wheels with hub brakes, not disk brakes. Something off of a small dirt bike. Bald dirt bike tires that are not dry rotted.
Get the brake cables and foot pedals too. Get a couple of motorcycle front brake levers, have them throw in the front brake cables if you can.
Get as much of the rear brake system as possible.

Saw the back of the trike off.

Make a live axle.
The rear wheel of the motorcycle has an axle bolt, have a welding shop cut the heads of the bolts off and weld these bolts to each end of an axle tube. Now you have a stub axle. You will need a couple of bearings for a live axle, think go kart live axle. Many types availble that will fit that axle tube.
Mount the motor so that it drives one wheel directly, using a 2 stage reduction, 1st stage a belt, second stage #40 chain.
Have the welding shop mount your current freewheel on the live axle. Near the opposite motorcyle wheel, have the welding shop weld a plate to match up to the sprocket holes on the second wheel.

See, let me describe how this works.

Both wheels get mounted to the stubs. Just inside of the wheels on the axle tube go the live axle bearings. These bearing have bolt holes so the whole axle assembly gets bolted to the refrabicated rear of the trike.

One wheel is attached to the live axle by the plate that is welded to the live axle. The plate on the live axle is bolted to the old sprocket holes on one wheel. Your freewheel is mounted directly to this axle tube. Your freewheel for pedal power is mounted on this tube.

The other wheel is freewheeling on its axle stub. Only the motor can drive that wheel. A freewheeling adapter could be mounted to the jackshaft sprocket , making pedaling easier.

Now you can pedal, keeps you somwhat legal.
You can stop. The motorcyle hub brakes will stop you just fine.
That axle will handle the load just fine.

This is what I would do. To your trike.

Any metal fabricator will know exactly what I am talking about. You supply the parts. The axle bolts, motor, and jackshaft assembly. Make sure they have all the parts necessary, including the belts and chains, sprockets. They will refererence this for holes, spacing etc. I would say it could be fabbed up for about $500 labor, $100 for steel. Shop around, some shops do not want your business, or do not have time. They will overbid. And they have good reason for this. They may not have the right person for the job, etc. Small welding shops generally starve in the winter, too busy in the summer, just the way it is.

You do the actual installation of wiring, motor, jackshaft, wheels, brake cables etc.

So, before I do more calculations, kinda sit down with a pencil, determine exactly what your needs are, what your budget is.

Oh yeah, #40 chain is much stronger than bicyle chain. I strongly advise you not to even think about bicycle chain of any kind on the motor drive. It will fail promptly. On a motor this size, it could kill you. No shit.

I have a 1.6 Hp Scott Permanent Magnet Motor. I travel 30 mph. Bike and me weigh 370 lbs. I use #41 chain that is many times stronger than bicyle chain, I am past its rating. When the bike weighed a hundred pounds and had a 1 hp motor the chain went about 8000 miles with a couple of adjustments. Now that I am beyond the #41 chains rating, not much though, the chain needs adjustment quite often. When it needs replacing I will go to #40 chain that has about 3 times the power rating. If I used bicycle chain of any kindI doubt it would last a week on my ride.

Bicycle chain is made for very low power inputs, does not last many miles on a bike, is not designed in any way to run at the power levels we are talking about.

chuck
 
What would happen if I used an 8” pulley in place of the 12” would it still climb hills with out over heating? Well I can fit an 8” under the motor, a bit low on the frame, it may get wet.

The 12 pulley will fit if I stick it out the back 16” from the motor (centers) see photo of mock up: http://funnyfarmart.com/scans/mockup.jpg the 6” motor and every thing, will be a tight fit.

The sprocket on the axle should be 5” to be sure to have clearance, and the final drive must have a chain (not bicycle) to fit around the tubes.

The axle I just got measures 14 and 5/16th inch (365mm) long with 95mm of .787 or .788” for the sprockets and 66mm for the wheel hub. 190mm in-between. And a keyway of .233”

I may need a new trailer but the B.O.B. I have will not interfere with the 12” pulley, I hope. How much do the batteries weigh?

I should build a new trike for sure but I am hopping I can put it off till next year…assuming I can raise enough money. Well maybe I will get rich from my paintings this year….

I can move all the power system to it if I ever build one.

I have two cheap disc brakes on this trike’s rear, could convert to hydraulic if need be.

The wheels are custom built to my specs of 36 14g spokes triple crossed, that’s like 4 cross on a big wheel. And extra wide BMX rims. http://commutercycling.blogspot.com/2007/10/trike-wheels.html
I had problems with cheap factory wheels when I bought the thing 5 years ago.

I also had problems with tires puncturing too easy so I fixed that with tire liners that cannot be bought. http://commutercycling.blogspot.com/2007/10/tire-liners-expose.html

The frame of the trike is very strong. the steering can't be helped, its just not made for speed, I actually spilled the trike once when I hade my shoes clipped in and changed direction too fast, and could not get my foot off the pedal fast enough to catch my self. The front brake is just a simple v brake and there is not much weight on the front end.

Hub motors cannot be aliped to this trike’s rear end and the front would just have problems steering with a hub motor.
If you don’t know the difference between a tadpole trike and a delta trike, mine is a delta trike and this is the tadpole:
http://wildnaturesolutions.com/rockettrike.html

I can't add a single axle to my trike because they are both canted to compensate for the lateral stress. My high-pressure tires handle this fine.

At this point I have only $1000 so I am working on some paintings that can not be resisted, yes people will love them so much that they give me their cars and boats and jewelry rather than live with out them.

The fabrication will have to be done at the welding shop and I will just have to design the thing....

Getting hot may not be back for several days....I grew up in San Antonio tx and had to escape the heat, now its going to follow me up here north west of Seattle. Olympic peninsula.

000000000000000
 
Where can I see a picture of the motorcycle stub axle set up?

is there any way to put a free wheel sprocket on a motor cycle wheel?
 
Wheel flop of the front wheel is due to too much trail, I may fix it by adding rake, but the under seat steering will not be enough counter balance. http://commutercycling.blogspot.com/2007/10/ultimate-touring-bike.html

I reduced the trail on my bike to half inch by rotating the steering fork to 79 degrees, and it does handle better at slow hill climbing speed. But for fast speed the tail needs to be longer. http://commutercycling.blogspot.com/2007/09/actionbent-expose-what-makes-good-bike.html

So this guy built a fork that will add trail when destabilized by something like a bump.
http://www.sugarbearchoppers.com/

The only way to fix the instability of this trike is to use two front wheels farther apart than the rear wheels, and a bit closer to the rear. And they should be spring-loaded.

Although zero trail steering may be possible for a hub motor on a delta trike. See this page, bottom photo: http://commutercycling.blogspot.com/2009/02/ultimate-commuter-bike.html but it would still want to throw you off if cornering too fast. A leaning trike would be the best.

I am so grateful that you enjoy helping people build e bikes. Wish I had a machine shop to build some of these.
 
Hi Jawnn,

Your welcome. I am not just helping you, I am sure others are interested also. With a little study of what has been written here I think most could get a grasp of the math required to calculate power and energy.

A lot of people do not know the difference between force, energy and power. Without this knowledge it is impossible to do the calculations needed to determine the power and energy required to build an electric vehicle.

Browsing through the forum here today there is a lot of talk of the 9C hubmotor. It comes in different windings, or speeds. The low speed motors are the ones you should be looking at for your hills. Sounds to me that with the correct 9C hubmotor and the correct bicycle, you could get 15 mph performance, hill climbing ability and the comfort you need for about a thousand dollars. I am not up to date on the latest bicycle battery technology. Others here could help you with the battery type.

There is a bicycle, basically a standard style, somewhat laid back, I think they are called comfort bikes. Comfort bikes have been tested here on this forum. Maybe that could help with your transportation needs. Any bicycle you chose should have at minimum, a good front suspension, and disc brakes front and rear.

It would be nice if you could ride a quality electric bike. I think you would be amazed at how powerful they are. No pedaling is required at all on the right set up.

No Jawnn, I do not have a picture of a stub axle. It is a tube of steel, with two bolts inserted and welded to each end. Should be fairly easy to visualize.
Yes, I agree, I do not think your trike is a very good vehicle to convert.

chuck
 
A lot of people do not know the difference between force, energy and power.
Click to expand...

It's ok, you got it wrong too...

The battery pack is not rated in torque, it is rated in Watts (power) and Watthours (energy). .
Click to expand...

watts is energy....watt-hours is power. :wink:
 
REdiculous,

A watt is a metric unit of power. A watt is 1 newton x 1 meter/ 1 second,,,,,, or also defined electrically as 1 volt x 1 amp. Nothing to difficult to understand.

watt hours is a unit of energy. Not a real pratical unit, it is equal to 3600 joules, and the joule being the fundamental metric unit of energy.

If one was to study physics, the study of energy, these two fundamental metric units are covered extensively, from the first day of your physics class in your freshman year of college.

After the statics portion of physics, maybe a month into your study of general physics, the amp is broken down to its fundamental units of coulomb's / second. After a year of physics, these fundamental units of force, energy and power are explored much more deeply.

So yes, a lot of people here have not had the chance to study energy and how to apply the principles. I have an extreme depth of knowledge in this field of study, I am not the best teacher though. I try hard to simplify the subject to those here.

Because of the unit conversions, and conventions, it can be mighty confusing to some.

My field of study was antenna. Probably one of the more in depth fields. The same units of force, energy and power still apply, though, quite abstract.

Here is a professor at MIT, teaching a non calculas based freshman level general physics class, this is the start of wave theory, still very early in the first semester, the fundamentals which apply loosely to antenna theory,

http://www.youtube.com/watch?v=AuYFcjBmMJ0&feature=related

The standing wave, the killer of some controllers, caused by an electrical impedance mismatch, do you see how this applies?

chuck
 
where can I get the sprockets and #40 chain? I located a tractor supply that is not a tractor supply......
 
Jawnn,
Before ordering sprockets, we need to determine a reduction ratio for the primary and reduction drives. If we limit the size of the primary drive jackshaft sheave to 8" then the B belt will not work. I briefly looked up a drive using the gates belt software that will get us under the 8" pulley size. I will get some pricing for you in a few days. Just so you know this drive will be quite a bit more expensive.

The number 40 sprockets can be ordered from Tractor Supply online.

McMaster Carr is also a very good supply source.

Also, Surplus Center, is a good source for drive components. Generally, Tractor Supply is the lowest cost for this stuff, just not much selection.

https://www.surpluscenter.com/powerTrans.asp?catname=powerTrans


Yea Redicolous, it can be confusing,

In the States here, I try to use the foot, the pound and the second as the fundamental units. This usually works best for vehicular motion in the bicycle, motorcycle and car size. Some use inch pounds. What I don't like is rpm, which we must convert to revolutions per second.

What I should do, since ultimately it is an electrical problem whose standards are metric, is to convert mph, weight and all the other data to meters, newtons and seconds. Right off the bat. Should make things less confusing than converting ftlbs to joules etc.

chuck
 
Is that Tractor supply.com??? An 8" pully sounds easyer to mount, but I have been thinking about haw to do the 12" pully, but it will be a tight fit. Did you see the photo of the paper mockup I did.

Well I am hoping that the axle will be too small for the motor (117ft/lbs torque?).....then I will have to build a new trike for sure. In fact I really must build one even if it takes two more years and $2500 I don't have yet.

I may need to just do this trike now and take it easy on the excellerator. But I have been thinking about what it will take to build a good strong tadpole trike. I think the part that I should have made, or machine my self would be the front steering for some kind of roller bearings....I have no idea what it should look like. I don't know how to machine it, but realy if I had some plans I might be able to do it on my landlords lathe.

Got any ideas?

"Atomic zombie" has plans for trikes made from bicycle parts, but it would realy be nice to use some real bearings. Bicycle parts are so fragel.

I also had a thought that a single front axle would be easy, but then I would have to use U joints on the ends, and I have no idea how that would work. Probably not a good plan.
 
Jawnn,
I saw the paper mock up. Just looked at it again.

I am going to define some common drive terminology to help simplify this discussion.
A single drive consists of a driveR and a driveN pulley, the R being the motor pulley and the N being the jackshaft pulley. We need to incorporate two drives, a second drive that also has a R and an N. Let us call them Rm and Nm for the motor drive and Rj and Nj for the 2nd stage.

The limit of 5 inches on the diameter of the Nj sprocket is limiting us to a 30 tooth #40 sprocket.

This limit of 5 inches for the Nj makes a very poor drive solution.

The limit of 8 inches for the Nm pulley has completely eliminated any possible viable drive solution.

Yes, I can design a drive with these limitations, but its cost is prohibitive! And not very efficient. The drive solution with these limitations will probably cost more than the batteries. And, as I stated before, is not a satisfactory drive.

The alltrax controller and the mars 909 motor will cost about $800 to $900 including a manual contactor, fuse, wire, connectors, throttle etc.
And will perform very well with the resistive forces you have described.

I found some batteries, thundersky's, what, about $900. Also will handle the task very well.

The platform you are trying to adapt though, has some serious limitations. I feel that you need to seriously consider a different vehicle unless these limitations can be dealt with cheaply.

chuck

What is the possibility of mounting the motor underneath and near the center of the trike, with the jackshaft below your hambs?
 
Jawnn,

Let's approach this from another angle.

The 909 motor specs are here:

http://www.cloudelectric.com/ProductDetails.asp?ProductCode=MO%2DME%2D0909&Show=TechSpecs

A twelve volt controller here:

http://www.cloudelectric.com/product_p/co-axe2444.htm

At 15 mph on the flat, you should be using less than 250 watts, very conservative estimate, yes, I calculated this.

At 12 volts, the 909's loaded rpm is 1066 rpm,

At 15 mph your wheel rpm is, wait, I'll post then come right back.
 
At 15 mph, your wheel rpm is about 252 rpm,

About a 4.23 reduction ratio.

A 72 tooth driveN, a 17 tooth driveR, #40 chain will handle 5 hp with this combination, will be fairly quite also.

One stage, cheap drive.

Yes, the controller costs twice as much.

The driveN sprocket will have to be mounted to the wheel. This 909 specs list it as a ccw motor, meaning that it will have to be mounted to the left side wheel.

A hundred pounds of wet cell lead batteries, about $150. Interstate deep cycles, take care of them, should last over a year. I can teach you how to charge them.
Will be a cheap alternative,

the motor will handle 300 amps for 3 minutes, hmm,
that is 3600 watts, which is almost 5 hp.

2 gauge wire for the hills should be more than sufficient.
Is there a way to mount that 72 tooth sprocket? to the wheel, or at the axle next to the wheel, or make an axle that will be able to do this.

think about it,

chuck
 
I think that anything lower than the axles is going to bottom out on the street. I did think of cutting one of the tubes that restricts the size of the Nj sprockets, but it would only add about .75 inch. And the chain must add even more.

I also thought of the 72 sprocket gear a while back but I don't know what diameter it would be, and there is a disc brake, but mostly there is the problem of building a long jack axle to the wheel.

So maybe I really should just start building a new trike. What is the smallest motorcycle hub that I could build into a BMX rim? Or maybe I should get an expensive hub brake bicycle hub for tandems to build into a BMX rim.

I think I could get by with using bicycle headset bearings for the tadpole trike, to make it easier.

This may take me all winter but the effort would be worth it if my legs will hold out.

The mars 909 would have enough power even at 12 volts? This may be the answer.....
 
I keep thinking that I need a controller that uses soft wear. Probably because I don’t know what a controller can do.

Can I use a programmable controller for the 12volt and then later for the 24 volt? This would be good for using smaller pullys and sprockets, still a two stage reduction.

Will I need a bigger battery for the 12-volt? And do gel batteries work for fast charging?

Does this motor run counter clockwise?
 
jawnn,

What are the laws concerning electric vehicles in your area? Probably should know this before spending your money on parts.

Why put a bmx rim on a motorcycle hub? A motorcycle tire, rim, and spokes will be cheaper and perform much better for your intended application.

So far, we have discussed the power required, and matched a motor that will handle this.
We have calculated the energy required, and found a battery type that will give the range you desire and handle the maximum currents that you will use.

The battery supplies the power and the range.
The motor converts electrical power from the battery into mechanical power to provide the propulsion.

Controllers.
A controller is a regulator of sorts.
This will be difficult to put into words, bare with me.

The controller regulates the speed of the motor with a signal generated by a manually actuated throttle, usually a potentiometer. There are thumb throttles, twist throttles, cable actuated pot boxes that provide a signal to the controller to regulate the voltage the motor gets. Remember, the 909 motors speed is determined by the voltage supplied to it. The controller manages the voltage level.

A wound rotor, such as a series wound motor like the 909 motor, at standstill, has characteristics similar to an inductor.

What this means is at the start of motion, the motor offers no resistance to current flow, the motor does not act like a resistor in a circuit, and the battery sees what is essentially a short circuit. The larger the load, the longer the battery is involved in this short circuit condition. The mass of your vehicle means that under acceleration, large currents will flow through the motor. The weight of your vehicle means that during hill climbing, large currents will flow through the motor. Combine acceleration and hill climbing, very large currents could flow, damaging the motor and the batteries, melting connectors and wires.
The controller regulates these inrush currents, to prevent damage to the electrical system.

If we chose a motor that could not handle the load, the motor would slow to such a rate on a hill that it would not offer any resistance to current flow, ie, a short circuit condition.

Jawnn, the vehicle you wish to build shares many of the attributes that a golf cart must endure. Large accelerative loads, large hill climbing loads. The alltrax controller is a golf cart controller. I chose this controller for that reason. It is very robust.

So, A controller is the speed control for the vehicle. Behind the scenes, it regulates inrush currents caused by short circuit load conditions.

The alltrax controller I linked to earlier is programmable. It will operate at 12 or 24 volts. It is described on the alltrax website very well.
I use the non programmable alltrax controllers, but they are not available in 12 volt models. They would work well for your application at 24 to 48 volts.

If the mass was low and there were no hills, a switch could be used. It would not last long because the short circuit conditions would cause arcing across the switches contacts, which would ruin the contacts.

A contactor is a type of switch that is designed not to arc, preventing the contacts from getting damaged. But, a contactor offers no limits to inrush currents, and offers no speed control.

So, that is why we use a controller.

chuck
 
Jawnn,

Now, another problem crops up. A controller has capacitors in it. A capacitor behaves mechanically about 180 degrees out of phase as does a inductor in a circuit. Too put it simply.

Why we use a contactor rather than any old switch

Manual Contactor
We need an on/off switch to turn the vehicle off. The controllers capacitors store electrical energy. When the vehicle is turned off, the capacitors lose their store of electrical energy. When we turn on the vehicle with a switch, the controllers capacitors are charged very rapidly, kind of a temporary short circuit condition. A normal switch will arc under these conditions. So we use a contactor to turn the vehicles electrical system on and off. Further, we add a resistor that essentially short circuits the contactor. This short circuit across the contactor keeps the capacitors in the controller charged when the vehicle is shut off. This resistor across the contactor saves the contacts in the contactor and prevents damage to the controller from large inrush currents.

Another type of contactor has a coil of wire in it, this coil wrapped around an iron core. This is a solenoid actuated contactor that operates such that when a current is applied to the contactors solenoid the contactor is activated which powers up the electrical system. Now, a solenoid, being an inductor, stores energy. When the solenoid is turned off, very large voltages are released from this solenoid which can damage the controller To prevent damage from a solenoid, the controller is isolated from this contactors coil by a diode, an electrical component that limits the direction of current to one direction. ie, the diode is turned in such a way as to only allow power to flow to the solenoid, and not from the solenoid.

Solenoid contactors are used as a safety feature in electric vehicles. Jawnn, you are at a power level that this safety feature probably should be incorporated in the electrical sysem. Along with a big red manual off switch.

chuck
 
Can I use a programmable controller for the 12volt and then later for the 24 volt? This would be good for using smaller pullys and sprockets, still a two stage reduction.

Will I need a bigger battery for the 12-volt? And do gel batteries work for fast charging?

Does this motor run counter clockwise?
Click to expand...

The 12 volt alltrax controller also works on 24 volts.

No, you will not need a bigger battery, the energy content will be the same at 12 volts or 24 volts.

I have never seen fast charging gel cells, the gel cells I am familiar with charge slower than all other types of lead acid batteries. I used gel cell deep cycle batteries in my boat, a 36 volt system, they were very canterkerous, would not stay balanced at all in a 36 volt series connected system. There life was very short. It would require humongous gel cells of the types I am familiar with to provide the current necessary for your hill climbing. Gel cells are very expensive.

Yes,It is a ccw, counterclockwise motor, per the manufacturers spec sheet.

Remember Jawnn, we are still in the design stage, these are not recommendations, these are options to help us come up with a final solution to your electric vehicle.

There is a member here who goes by the name of Papa, I was browsing and he posted a very simple, is it a delta trike. It looked extremely simple to build, just beef it up quite a bit, use light motorcyle wheels and brakes.

Since I have never driven a trike, I do not understand the instability issue of a delta or a tadpole. Is this a wheelbase issue. I have driven motorcyle trikes that have no instability, then there are 3 wheel electric vehicles such as the corbin sparrow driving on the freeways.

Explain this instability, or is it just poor design.

chuck
 
http://www.lightfootcycles.com/big_tall.php

rralwayz[1].jpg

Jawnn, I browsed around this site for a minute. The above picture shows what I would consider a comfortable bike. Should have some decent front wheel braking. Plenty of room for the motor, jackshaft, pulleys and batteries for the most part beneath the seat level.

A tadpole design has a dangerous braking issue if one wheel loses traction it can spin. One of your parameters is it is often wet.
The other braking problem associated with a tadpole is flipping foward at high speeds. At very probable event in a panic stop with a greater than 600 lb gross vehicle weight, I see a tadpole as not being a good candidate for your application.

The delta in the above picture looks like it should get adequate braking from all three wheels, pretty important with the weight and wetness that you describe.

The tadpole on the above website is discussed. Cargo increases the instability of a tadpole, according to lightfoot cycles.

Cargo increases the stability of the delta, in my opinion, properly placed.

Maybe work up a design similar to the above bike, with a similar steering setup; looks pretty stable, good load carrier, good braking, comfortable.
Think about motorcycle rear wheels, do you have a motorcylce salvage yard near you? If not, call your local auto salvage yards, they get motorcyles too.

chuck
 
Jawnn,

Well now, browsing around the web on tadpole design.

This is the first site that popped up,

http://www.eland.org.uk/steer_intro.html

Just about everthing is covered here on tadpole trikes. I read a lot yesterday on steering geometry and suspension for tadpoles.
One would have to have a lot of mechanical aptitude, and a very well equiped handyman shop, to economically build a tadpole.

Is there a significant advantage in the tadpole design vs the delta?
Aerodynamics. It is obvious that the standard tadpole design wins here, but we just are not going fast enough for this advantage to be worth the complexity.

Stability. I think that only a very well designed tadpole could have a stability advantage over a delta. Then, it is not a physical design advantage, it is a center of gravity advantage that makes the tadpole less likely to flip in a rapid turn. The lower COG and the location of the COG make the tadpole more likely to spin than flip. At 15 mph, and with a trailer, a well designed delta should be more stable, almost impossible to spin.

Coolness factor. I think a tadpole is a pretty cool bike. Grandpa and Grandma, being old fashioned drive delta's because they are practical, ,,,,,easier to get on and off,,,,,,great grocery getters,,,,,In a race, the tadpole wins, better aerodynamics.

Take a tadpole, spin it 180 degrees. drive it backwards. now it is a delta. With the COG located over the rear wheels, a heavy handed throttle could cause a spin, or a wheelie. Move the COG forward to lesson this effect. Move the COG forward, more weight on the front wheel, more braking and less tendency to spin.

To build a stable delta, shorten the wheelbase a little, move the COG forward some, increase the distance between the rear wheels, use direct steering like a bicycle uses. Proper trail and rake. Comfortable, stable, good braking, responsive steering. Lowering the COG on a delta, decreases comfort, but will lesson the tendancy to flip. At 15 mph, proper COG and good steering, I would think that tipping would not be much of a concern.

The electric vehicle laws. In Texas, we have three sets of laws, one allows electric bikes that weigh no more than 100 lbs, 1 HP and 20 mph top speed. A second law that allows electric mopeds with 2 hp, 30 mph, restricted to streets 30 mph or less, with a minimum seat height of around 20 inches or so. A third law covers neighborhood electric vehicles such as golf carts.

There are a lot of restrictive parameters to cover in these human powered 3 wheel vehicles. The wheels themselves get in the way of the pedal input and the steering ability. The design is built around a prone individual. Then the parameters of the human inputs are maximized which decrease stability. To maximize the human input and minimize weight and vehicle size the vehicles become unstable.

We can design a 3 wheeler with a motor and are not concerned with maximizing the human input to the propulsion. Relax the restrictive human powered 3 wheeler parameters. We are not as concerned with weight, aerodynamics and complex steering geometries to maximize the human input. Design for an electric motor and the intended use of the vehicle. Design for comfort.

chuck
 
I spilled my delta trike once at slow speed because I could not uncleat fast enough. the trike I realy want to build is a leaning tadpole trike.
http://commutercycling.blogspot.com/2007/12/theultimate-trike.html

it could have a higher center of gravity. and I do under stand how tadpole trikes can grab your feet and drag them under the front mangling your shins, it happened to some guy in town. Thats why I would design the seat higher and front wheels forword a bit. and have two thirds of the weight on the rear.

I would much rather spin a trike than roll it. in fact I did try to spin my delta trike on ice one winter, but the tires were not slick enough. (snow tire)


I realy want to use a motor cycle hub brake on the rear also, the front brakes can be bad...I know of some one that saw one of these trkes wobbling out of control the other day.
but I need to know hot to put a bicycle free wheel on one of these hubs. I want the whole thing to look like a bicyle with three wheels. not a motorcycle. ( the reason for the BMX rim)

ok I will have to search the only junk yard in the area, all I need is a car to carry the parts.... bagh!

I am itching to get started on something because winter is only two months away.... so is my delta trike going to work?

I don't like the wet batterys,not sure why, what is the weight difference,and what is the truth about the Odyssey batterys? and why can't I get a lithium gell?

and will thge motor do ok on the hills etc at 12 volts? sure it will....seems almost too good!

I will still be illegal...because the state of washington limits power assist to 1000watts, and mopeds require motorcycle helmets and a full set of lights, can't evven use LED lights unless aproved.....well maybe inside a motor cycle head lamp?

Are those LED lamps on your ultra light motor cycle? I had a La Verda 30 years ago, at 400lbs it was a race bike, and always in the shop! but platinum points was nice.
I don't ever want to deal with motors with too much mecanical movement again.
 
Jawnn,

Wet cells are generally lighter than agm, sealed or gel lead batteries. The interstate batteries weigh about 50 lbs each. I just mentioned these as a low cost way to get started. I feel the thundersky's would be a better battery, but more complex to charge and keep balanced.

Now, a leaning tadpole, what about cargo?

chuck
 
You must log in or register to reply here.

Similar threads

J
Looking for input on chain-sprocket combo for 8kw drivetrain
Replies
4
Views
854
scianiac
scianiac
H
    • Like
Dahon Mu P8 that can pull 200kg up 20% grade
Replies
19
Views
2,505
Guerney
Guerney
R
Mid-drive high RPM, overheating, and max controller amp rating
Replies
15
Views
2,395
richj8990
R
T
    • Like
My first scratch build: 30kw full suspension tandem velomobile.
2
Replies
27
Views
4,151
amberwolf
amberwolf
R
    • Like
A critique of mid-drive riding recommendations (and hub drive criticisms)
Replies
22
Views
12,894
ebike4healthandfitness
ebike4healthandfitness
Back
Top