guy153

There's a sort of general principle/rule of thumb that things can get a bit too floppy if the diameter is more than 50x the wall thickness. So 2 inches and 1.2mm should be just about OK.

MrInitialMan

I've been looking at recumbent tadpole trikes, and wondering who makes the spindles for the front wheels. It's GOT to be better than, say, building front forks--which was my original design.

squirtdad

(Bike carts are all nice, but good luck keeping your groceries dry in a rainstorm, and what would I do with my busking equipment?)
what would keep you from making cover/enclosure for a trailer to protect groceries, instruments, and other items/ This is not a different problem than how do do the same if cargo is on board your velo (not sure what else you use for busking.....any videos? )

possibility of adding a second seat if I wanted to give someone a ride.
again big design variable and added complications from one person to maybe 2 one person 240 lbs, 100 cargo, 100 frame is 440 so assuming your biggest friend is 200 you for from 440 to 640 load and probably more like 660 to 700 for building a stronger frame...side by side seatoig means much wider velo or front and back is longer.

intend to have five disk brakes--one on each wheel, and one in the center of my rear axle (my differential allows for
what is the plan for ensuring braking consistency.both right and left and or fore and aft...Hydraulic? I know there are levers that allow 2 cabled brakes to be pulled by a single lever but have no idea if that is possible with hydraulic

MrInitialMan

Sadly, no videos or pictures, but it's generally me, a hat/instrument case/ice cream pail for people to toss change into, my instrument (usually a saxophone), a stool, and a cushion. And I guess I could build a covered cart... Which would look like trying to tow a horse trailer for Clydesdales with a smart car...

Yeah, I'll have to think about that. I dunno if I'll actually have a two-seater (it would be a tandem if so). But the second seat would be RIGHT over the rear suspension, which is reinforced anyways.

To simplify my rear setup (yes, I'm actually simplifying things. That burning smell is my brain grinding gears from doing something so unnatural for me) I'm skipping the fifth disc in the middle of the axle. But yes, it IS possible with hydraulic--you just need a bigger master cylinder, apparently, so I'm thinking of using three splitters--first between front and rear, then one for left front/right front, and one for left rear/right rear.

On the braking, I'm going to seriously splurge--I'm going to take my idea into a bike shop and hash things out with them and probably even get them to set things up. Like you said, braking is a serious issue.




I dunno, maybe something's just wrong with my mindset when it comes to this whole thing.

squirtdad

absolutely no help at all, but I am getting visions of a gypsy decorated busking-mobile

MrInitialMan

I'll worry about the paint job when I get to it. Though I have thought of (once it's done) taking it to a paintball field, providing proof I own it, and telling the players to have fun.




Now, back to being serious, I'm beginning to think there is something fundamentally wrong with the way I'm approaching this, beyond my insistence of it being four wheeled (I do want the stability of four wheels). But I'm not sure what it is.

MrInitialMan

I'm going to start a fourth design. I'm thinking of narrowing the frame (34" should give me enough elbow room if I use a steering wheel, right?), and I've done some measurements on my bathtub of all things (since I can sit in that comfortably) to see where 46"-56" from the pedals puts the back of the seat (which will be adjustable), which should tell me how much trunk space I have.

Trevtassie

If I were you, I'd start looking at stressed skin construction for the chassis. Basically like an aircraft wing, where the skin is most of the strength and the structure is there to keep the skins apart. Even foam will serve as the separator. The tricky bit is the interface between the axles and the structure. I'd ditch the suspension, and instead rely on balloon tyres and a swing front axle to remove the torsion factor of the equation. Basically if you take torsion (chassis twist) out of the equation you can go a lot lighter. But this will mean you would need to be more interactive weight wise in cornering to not have too much body roll

MrInitialMan

1) I do NOT have the engineering skill to do stressed skin construction, unfortunately. I wouldn't know where to begin.

2) I've seen balloon tyres before--wouldn't something that soft be hard to pedal?
3) Swing front axle? You mean the kind seen on old carriages where the whole thing pivots? That sounds REALLY unstable.


Anyways, update: I've narrowed the design by 2 inches and shortened it by 10 inches so that should save some weight.

Trevtassie

Not pivoting in the horizontal plane but the vertical. You still have a tie rod and ackerman steering, but with a centre pivot. 4 wheel, but with the physics of 3 wheels. Alternatively you could make the rear axle pivot, which would handle better, but might give you some issues with the drive train. Either way it removes most of the need for suspension
I'm only talking tires like 2.4-2.6" wide.
You can do stressed skin, even using your current welded steel frame, but by lightening the steel then riveting and glueing a skin on the top and bottom of the chassis with foam in between the frame members. The example I like to use is hollow core doors. they are very light, made with honeycomb cardboard and thin plywood, but you can support them on either end and stand in the middle.

MrInitialMan

What would you use for a skin, though? I just planned on riviting plywood to the steel and calling it a day.

As for swing axles, what I'm seeing is something SORT of like double wish bone--but there's only one "axle" so to speak, and the wheel pivots with it instead of being held up and down. Is that what's meant?

MrInitialMan

One major problem I'm having is finding suppliers for what I want. Can you even get 18-gauge angle iron?

wsteve464

Take 18 gauge sheet metal to a metal working shop and ask them to cut/shear it and bend 90 degrees

MrInitialMan

That's true.

Anyways, I'll have to talk to local welding shops to see what is available. I've been looking online, but maybe they have sources I don't.

squirtdad

I still don't get the 4 wheel insistence.... if you do something like a recumbent trike I can't see anything that would tip that that wouldn't tip a 4 wheeler (note the upright 3 wheelers which are driven on one side only are a whole different story
I do think you complicate things ie. suspension, having a steering wheel in ways that add weight
Plywood riveted is going to add up in weight really fast. Coroplast maybe or even fabric that is then sealed with polyurethane (used for skins on skin on frame kayaks)
Problems finding suppliers is going to make things cost more fast

do you have budget? what is more important to you doing the build and solving solutions and challenges or getting a functional solution faster/cheaper? not a right or wrong but what you want

I am still of the opinion that doing a recumbent trike and trailer set up would be a better way to go..... you could focus on building the fairings/weather protections to meet you needs (check out the fabric/urethane)

MrInitialMan

Sorry I took so long to reply. I wasn't ignoring your question, I was thinking (and if you got an email about a reply earlier, that was me, late at night, with loads of late-at-night thoughts).

I've tried those recumbent trikes (there's a place called Bentley Cycle west of Red Deer, Alberta, Canada). Yes, they're nice and light and a blast to ride but I find them quite difficult to get out of afterwards (whether this is due to actual leg strength or it's something psychological I don't know, but I really do have a time getting out from a seat that low).. My hope is to build something that rides as high as my office chair or thereabouts, so stability is a bit more of an issue.

I also want something with a floor. Puddles are a serious problem in spring, and I don't want to be splashed from below--especially not in near-freezing weather. (I'm Albrrrta--er, Albertan. It's a bit chillier up here than it is in California).

Also--it's been planned as a quad since the beginning (joke thread about a decacycle notwithstanding; if I built one of those, it would be a parade piece). I did consider a trike, but... I just don't like three-wheelers with bodies for some reason. Something just looks... off about them.

I know. >_< I complicate EVERYTHING, it's one of my biggest hangups. (If you think I'm making this complicated; you should see the way I do my website.)

The reason for the suspension is (like I said) roads get kind of ugly up here. I live in a rural area, so roads are sometimes not plowed or even properly maintained. (Heaven help you if local chuckleheads in lifted trucks have had some fun with a gravel or dirt road recently).

And I thought of having underseat steering, but I won't have the room with the body (only 32" on the inside, 34" outside, and this limitation is based on my rear axle.)

Can Coroplast stand up to a downpour? Can it stand up to about a foot of snow? A foot of wet snow? Can it to pea-sized hail? How brittle does it get when it's so cold Celsius and Fahrenheit snuggle up for warmth (-40)? Basically, what I'm asking is... can Coroplast stand up to Canadian weather--which can get downright stereotypical or worse?


Which is why I'm designing with what I CAN find (I have been able to find 16-gauge 1"x1" angle iron, for example. Industrial Metal Supply has them). And I'm going to talk to some welding shops about what's available.

Haven't worked out a budget yet, sadly. I do have a number of the bike parts I want, though--Samaga rear end differential and hubs, for example.

And what's important to me? Partially being able to say "Well, it's mine, warts and all", partially having something that I can cycle for about 5-15 miles in a stretch (Work is about 6 miles, my busking spot is about 10), and partially having something that won't fritter away gas, and partially something I don't need to beg/pray for/curse at/pop the hood and fiddle around to start when I need to get to work.

I'm not building a long-distance tourer--I'm not in good enough shape to even warrant one. I'm not building a racing bike--I'm no athlete. I'm just trying to build something to get me from Point A to Point B, basically. And have some cargo space (but I will look into the cart idea. If I go that route, I'll base the size of that around my sousaphone case).


UPDATE: @squirtdad, I took one of your implied suggestions, removed the cargo space and based the length on what I, personally, would take up.

...

CycleVan Design (Short Bodied)

...

I'm sorry! The mental image I'm getting from something this... this... stumpy is just ridiculous! I'd feel like I'm taking the short bus every time I drove it! Maybe it's just me, but this thing looks so ludicrous!


--------------------------

Update No. 2 : Redid the smaller design concept based on what I could theoretically fit into. CycleVan Design (Short Bodied Take 2) It looks almost too small to get my fat rear end in and out of, but that's probably my overbuilding mind talking.

MrInitialMan

I've got a general size I think I can work with: CycleVan Design

Still looks a bit stubby and goofy in my opinion, but what do you think? (Total length: ~7ft)

guy153

Looks good! Nothing wrong with looking stubby and goofy. Interesting comment I saw in this video from about 1:47 about the idea of using aluminium for the chassis on this kind of thing:
btw for the suspension you could maybe pick up some ideas from these YouTubers who make buggies and go-karts and things. They often seem to get their suspension parts from somewhere called "GoPower Sports" who usually sponsor their videos. They all have engines but many of the principles are the same.

MrInitialMan

The cops would have a LONG talk with me if I went 80 miles an hour, though. First off, that's almost 130 kmh (na$ty ticket), then there's the issue that I would most certainly have to have a motor. As it's designed to have four wheels, that would make it a passenger car. I'd never be able to get it insured (na$tier ticket) or registered (VERY na$ty ticket--and towed!!$!). If it had three wheels--well, I don't have a motorcycle license...


This thing's probably going to go somewhere in the vicinity of 20, though--downhill.

I do have an idea for building the 12-footer, though--I'd put a nice bench seat in the back so I could take my parents--who are quite elderly and infirm and so will NOT be pedalling--for a ride. But that will be for another day. I think THIS is the size I'll go with. I took some measurements, I take up about 5' of room, and this will give me 2' for cargo.

MrInitialMan

I've decided on a final length of 90 inches even (I may lengthen it by extending the front and back wedges) and 34 inches wide. The floor frame currently weighs less than 40 lbs. I still have plenty of cargo space, but if I need more, I can come up with a cart.

Still will be a four-wheeler. With transverse spring suspension. And a steering wheel, because I need SOMETHING to be stubborn about.


I think I realized what was wrong with my original design--I was overestimating what I'd need. Um... is that a common foulup for first-time builders?

squirtdad

this may be of interest

I still am of the opinion that the design goals are so broad (hail resistance, floor for protection, handling rutted roads, high center of gravity, etc) that the end result may do nothing well and it will be heavy

you would probably better served with a good clothes, a good mountain bike and a trailer.....but it is is your build, I am just devils advocate

as to durability of a skin on frame fabric coated cover, they are used for kayaks and would show less damage from hail than plywood

also to note, though my current address is sunny warm california........ I grew up in Chinook, MT watch Canadian TV from Lethbridge, I know what type of hail you are talking about and what 40 below zero feells like and gravel roads that get rough with spring mud and 4x4s

MrInitialMan

I did see that.


"I remember, back in Holland, your grandpa--my dad--would load the full milk cans into his cargo bike and take them into town." That's as close as I can quote my dad. You may have seen milk cans in museums or perhaps as some cartoonish or stylized farm scene? Dear old Dad can remember them being used. That's why at first I didn't really consider weight.

I'm aware this might be a bit on the hefty side--but like I said earlier, I chopped off over 4' from my original design--from 12' to 7'6"

And in a downpour?

I shall look into that.

Ah, so you know the weather I intend to ride this through.

MrInitialMan

I also had an exchange of comments with the gentleman who built this: He told me he used 40X40mm square tubing with ~1.5mm wall--a quick conversion suggested to me that's 1.5X1.5 16 gauge steel. And here I thought I needed 2X2!

squirtdad

pretty cool.....some good ideas for you I would suspect

MrInitialMan

Indeed it did! I'm trying to get in contact with some leaf spring companies to see what I can get for leaf springs. (Like I mentioned above, I'm using transverse leaf springs, so I only need one set per axle). Hopefully I can source some that are only an inch and a half across.