Tadpole E-Trike Build

[Kirk]

Are you going to put a damper on the direct steering? Muscling that steering at speed looks like it would need one.

[Goped ESR750]

Not sure about steering, surely a damper would cause more load making it more difficult to steer anyways, aren't they more for smoothing out light jerky steering?

Made some progress on getting the shock mounted. Welded the tabs on the frame to support the linkage arm and the top of the shock. Still need to machine a new linkage, but was able to test it like it is.

Couple pictures of what I got plus a small video of the shock. Is pretty solid, so doubt it will do a lot in use, but looks nice though.

[Kirk]

Not sure about steering, surely a damper would cause more load making it more difficult to steer anyways, aren't they more for smoothing out light jerky steering?

Depending on where your tire contact patch is and what shape it takes, your steering can develop a nasty shimmy at speed. For instance the Catrike Expedition's geometry is such that they had to take the top bearings out of the headsets and put in a bushing for stiction to stop its shimmy. An other way to fix it was to change the wheel/tire size. I run 34-355s on mine rather then the 40-406s that came with it, which changed the contact area of the tire enough to take out the shimmy and back in went the top bearings. On the other hand Matt's screaming fast Yellow KMX in the For Sale section for $7000 uses a damper to accomplish the same thing. From the looks of where your tires sit, it might be an issue. I hope not.

[sn0wchyld]

if you have room to extend the bar I'm pointing at in the pic below, that should have the effect of increasing the leverage you have on the shock, and give a bit more plushy feel...

what kind of steel are you using for the frame? This has inspired me to make a recumbent now as a commuter! probably not 'quite' as beefy though

[Xanda2260]

And I ride i at 40mph with no issues.
I expect the frame will be fine.

I suspect Snowchyld was being sarcastic. He even put an emoticon in just to be sure people got that

yea sorry xanda... sarcasm never works too well over the internets. I did in fact mean that the frame looks insanely beefy!

How hard was it to make a tadpole? I'd really love one for commuting but the $ is ridiculous... so I'm thinking ill make one instead.

Lol, my bad! Must read things properly!
Honestly, building a trike is much easier than I ever thought it would be. I had to teach myself to weld first and was really worried that my welds wouldn't hold. However, it seems they dont have to be pretty to be strong! Got the plans for the warrior trike from Atomic Zombie, and would reccomend it to anyone. If you check out the AZ forum, have a look at Spinners Warrior. It's amazing, he did a really good job with it. Much cheaper than buying (Ive spent about £750 so far, including electrics), and more sayisfying too! I have a build thread here and on AZ if you're interested. Look for White Warrior.

[sn0wchyld]

.......................Atomic Zombie, and would reccomend it to anyone. If you check out the AZ forum, have a look at Spinners Warrior. It's amazing, he did a really good job with it. Much cheaper than buying (Ive spent about £750 so far, including electrics), and more sayisfying too! I have a build thread here and on AZ if you're interested. Look for White Warrior.

will do mate. thanks for the tips.
do you know what your cost is just for the trike? (ie no welder, electrics etc, I already own that stuff )... thanks!

[Xanda2260]

.......................Atomic Zombie, and would reccomend it to anyone. If you check out the AZ forum, have a look at Spinners Warrior. It's amazing, he did a really good job with it. Much cheaper than buying (Ive spent about £750 so far, including electrics), and more sayisfying too! I have a build thread here and on AZ if you're interested. Look for White Warrior.

will do mate. thanks for the tips.
do you know what your cost is just for the trike? (ie no welder, electrics etc, I already own that stuff )... thanks!

Erm, let me do the maths here...

Steel £20
Front wheels £200 ( had to get em shipped from terratrike cos no lbs would make them. Import taxes suck)
Brakes + levers £60
Tyres £90
Seat £80
Various fastenings, pulleys etc. Maybe £50

So about £500 all told. If you're in the US you can knock off £140 from the front wheels.

Hope that helps!

Edit : just seen you're in Aus. If you can find some decent hubs (20mm hollow axle) and get em built locally they'll be cheaper than I paid. Bitex hubs are popular, they go for about £60 a pair. Then add rims, spokes, labour etc.

Edit 2 : also just rwalised that my figure of £750 was before I upgraded from a weak 20 amp controller and lead, to a lyen 12 fet and lipo so its more like a grnd now!

[Goped ESR750]

My trike uses kingpins I made for tapered roller bearings. I cant remove either bearing as they need to be locked against each other to work. I included a picture of the kingpins assemblies I machined, they obviously have all the rest of the steering hardware welded to them now.

The steel I used for this is 50mm square box section with a 3mm wall. The actual frame is not hugely weighty, the wheels double the initial frame weight I would of thought.

There was an upgrade package for the kmx trike seat. I bought it, and made it fit my trike. I decided I didn't like it, although it was comfortable it certainly was not weather proof. I decided to make a bucket sort of seat which comes out the frame using 40mm x 3mm flat bar. Will add weather proof padding where necessary. The only bit of padding I feel I need is on the rear shock support for my back. The rest feels really comfortable for me, and keeps me in one place without risk of falling out in a corner. Others who have tried preferred the kmx seat, guess this happens when you make it fit one person

Few pictures of where I at.

[BATFINK]

Really looks the part with the seat there. What sort of motor are you going to power this with?

[Goped ESR750]

Really looks the part with the seat there. What sort of motor are you going to power this with?

Planning on using an Etek motor with this build. I already have it handy.

[pelle242]

Really looks the part with the seat there. What sort of motor are you going to power this with?

Planning on using an Etek motor with this build. I already have it handy.

What kind of reduction are you planning?

[Goped ESR750]

Really looks the part with the seat there. What sort of motor are you going to power this with?

Planning on using an Etek motor with this build. I already have it handy.

What kind of reduction are you planning?

I have no plan as of yet, but am aiming for at least 40mph. I know the max rpm of the motor is around 4000rpm at the voltage I intend to use so will back work the ratio from this.

[Goped ESR750]

Been working on the steering assembly. Made few bits to weld together tomorrow. Made the notch in the handlebar support box section and steering link pin bracket using a hole saw. Put the hole saw in the mill, worked very well especially seeing as I don't have a collet large enough to fit a 50mm end mill. Used very slow rpm and very slow feed, and was constantly applying cutting compound with a brush. Few pics of what I been working on.

[Xanda2260]

Beautiful work dude, I wish I had your skills

[docnjoj]

That is some nice metal work there goped! Great!
otherDoc

[Goped ESR750]

Thanks. Glad your liking the build.

Bent up some handlebars, and been working on the steering linkages. Think I got the ackerman compensation about right, although I think the proportional steering might require some final adjustment.

Few pictures of where I at.

[Goped ESR750]

Ground off the linkage on the steering tube, wasn't happy with the proportional steering. Found the linkage works best welded closer in. Steering alot better now.

Few pictures of where I am at.

[sn0wchyld]

this thing's gonna be crazy. how much does it weigh so far?

[llile]

My trike uses kingpins I made for tapered roller bearings. I cant remove either bearing as they need to be locked against each other to work. I included a picture of the kingpins assemblies I machined, they obviously have all the rest of the steering hardware welded to them now.

The steel I used for this is 50mm square box section with a 3mm wall. The actual frame is not hugely weighty, the wheels double the initial frame weight I would of thought.

There was an upgrade package for the kmx trike seat. I bought it, and made it fit my trike. I decided I didn't like it, although it was comfortable it certainly was not weather proof. I decided to make a bucket sort of seat which comes out the frame using 40mm x 3mm flat bar. Will add weather proof padding where necessary. The only bit of padding I feel I need is on the rear shock support for my back. The rest feels really comfortable for me, and keeps me in one place without risk of falling out in a corner. Others who have tried preferred the kmx seat, guess this happens when you make it fit one person

Few pictures of where I at.

I am real curious about the seat. I have had more trouble with seats than any other part of a recumbent. Here are some of the issues:

If you are sitting a little upright, as many recumbents do, and your weight is just in front of your sitz-bones, your legs will go to sleep. There is a nerve or a blood vessel or something right there. Getting weight onto your back ala' cattrike helps this effect, as does getting rid of any part of the seat in front of your sitz-bones. Those are actually meant to sit on, you know.

I have a friend who used 6" of good quality upholstery foam for his seat, and it works will. I don't like all that squish, so my seats are usually thinner. My current seat is a standard big-butt bike seat, turned around backwards, so I sit right on the edge, with the "horn" toward the back. I customized it to fit my butt by grinding out the foam just so, and adding a waterproof cover. The back support is two tubes that run along my spine, covered in thick foam pads bought from a company that sells gym equipment. It is really lightweight, and small, but strong. I also made it adjustable, instead of trying to adjust the pedal boom, so taller riders can use the bike.

A thin seat means that road bumps hammer your back unmercifully. Even with that big shock absorber, I predict you'll get a wallopping every once in a while.

I haven't had any luck making seats out of fabric or mesh, or lawn chair webbing, although I have tried all that stuff. I suppose one could just buy a seat from Rans or Burley or one of those guys. What have other folks done for recumbent seats? Had any struggles?

[biohazardman]

Looks BEEEEFY !!! Probly is going to need one of the GM motors Luke used on his "reasonable man's bike" or the new 4" Astro with sensors, Matt has just come up with, to reach it's full potential? I love it.


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[cbr shadow]

Looking forward to updates! VERY COOL!

[sk8norcal]

hey Goped, what happened to ur goped build? still working on it?

[Goped ESR750]

Thanks for the replies.

I have no idea of the weight. I have to take the wheels of the trike to fit it in the shed, I can lift the frame without the wheels including the shock. It is starting to feel heavy though, it is not meant as a light weight thing. This probably going to get abused so the bigger the better.

I still have the goped project sidelined. I was working with a frame builder but he was taking so long, so I started the trike. I am going to now weld up my own scooter frame, once the trike frame is out for powder coat. I also have a few other projects in the sideline.

I am not really sure if I can help you much with the seat. It's probably not going to be the most comfortable. I will probably change things as I go along. I like to make things anyway to progress and then come back to them if they cause an issue later. At the moment the seat I am happy with, but I can't guarantee it will be the final seat.

Since I had the steering completed, I have been focusing now on getting the drive system on the scooter. I started with the pedal side as I already know where the front pedals are this will be the datum for my rear cassette and an ideal place to start.

I had a handy new 7 gear free wheel from a previous project. The thread on it was something particularly awkward, being a 35mm 24tpi thread. Had to machine a small weld on hub. Wasn't going to even bother looking for a die, just screw cut the thread on the lathe.

I then bored the hub to 20mm. Slid a shaft through and welded. I really filled it up with weld, which enable me to nicely machine it back again. Can't tell it was ever 2 pieces.

The idea of the drive system is the pedals run to a shaft behind the back of the seat. On one side is the free wheel on the other the sprocket for the rear wheel. In the middle between the two pillow blocks will be the pulley for the motor to drive off. The sprocket and pulley will be use taper lock bushes, so I got a couple key ways to machine on the shaft yet. I needed to use the shaft for alignment so will machine them later.

Here is a few pictures of where I am at.

[TopCat]

Any updates on the PHOENIX....thats my name for this beast of a machine

Regards
Tom

[Goped ESR750]

Been difficult finding a break in the weather to get the trike out to work on. It's too big to put together in my shed and I needed to assemble to align the pillow block.

Managed to get the mounts welded on today. I have decided I need to remake the shaft to take a flexible couple past the bicycle free wheel. So I can mount the motor on the other end of the shaft. Need to get a flexible coupling before I make the motor mount, as will use it to align the motor then make the mount to fit. Also need to make a bracket to take the derailleur. Should hopefully have some nice weather so should be able to get rolling on this project again. Few pictures of where I am at.