guy153

Looks good! 60lbs is a reasonable weight I think. Can you get angle iron and flat iron that thin? I can only get those down to 3mm as it's all "hot-rolled". My only concern would be the two long bits of angle down the sides as angle iron is not at all stiff in torsion. Basically I think the red bits (the tube) are the real structure here (and that looks stiff enough) and everything else is just something to attach the body to, which means you could even use aluminium angle and flat bar for those-- just weld little brackets onto the steel frame to bolt it onto.

MrInitialMan

You are correct--the angle iron is simply there to attach the body to. I THINK I can get it that thin, but I'll have to check with some welding shops to find out for certain.

I don't think I have to worry about torsion as much, since I'll have a suspension system--looking at transverse springs has given me interesting ideas, and I may use those for both front and rear They look simpler than what I had in mind, that's for certain.

That said, the rest of the frame is going to send the weight up (and up and up), so I may have a 100+-lbs monstrosity when all is said and done.

EDIT: I just checked a few sites. It seems 1/8 is the thinnest I can get, which bumps up the floor frame to 65 lbs. That being said, I've seen some mighty thin strips, so I'll have to ask around.

EDIT # 2: Never mind, some companies DO sell stuff that thin: https://www.metalsdepot.com/steel-pr...steel-flat-bar

MrInitialMan

CarCycle Design #3

The plans have been updated, with the nose frame and front suspension support construction, as well as some clarifications on positioning of parts. I'm about to design the front suspension support frame, which will also hold my pedal frame. For the bottom bracket--or whatever it would be called in this contraption--do I need to get something from a bicycle parts dealer, or would a short pipe with a couple of bearings tapped in do the trick? I'm hoping to build it so it can be moved up and down. Because overthinking and all that.

Also, I looked up Rhoades Cars. Their one-person cyclecar weighs 108 lbs. I think my design may hit the 150 mark.

guy153

​​​You need something that's compatible with the chainset and cranks is the thing. Bottom bracket shells from bicycle tubing suppliers don't cost very much and you can get a threaded one (for much less than the taps would cost to make it). Threaded bottom brackets are the most ubiquitous, best standardised and are reliable.

It also might be an idea to cannibalize an old bike frame or two also for some of the parts since other bits might come in useful.

MrInitialMan

Hm, good point. I'll see what I can find, then. Maybe even at the town dump.

wsteve464

These guys carry blank bottom bracket shells in pretty much any standard you want.

https://www.paragonmachineworks.com/...et-shells.html

MrInitialMan

How do you attach them to a frame, though:?

Andrew R Stewart 

Weld, braze, glue depending on the material, joint design and your skill set. Andy

wsteve464

If you do use one I would recommend a BSA threaded shell. The press fit shells require reaming after attaching to make the bearing fit, this allows for distortion from the heat of welding/brazing. The T47 is a new standard and the taps to chase the threads after attaching are probably hard to find at a local shop. The BSA standard has been around forever and a lot of shops have the taps. You need a left and right threaded tap if you do it yourself probably close to $500 for the taps and handles.

MrInitialMan

Hmmm. The company you linked seems to have only T47, English, and PF30 type shells.

wsteve464

English is BSA it's pretty much the standard for threaded BB most Sram Shimano cranks fit BSA BBs

MrInitialMan

Okay, fair enough.

Now, a question I need answered, because I'm really not sure: Is the page I'm creating a useable blueprint?

guy153

Anything can be a usable blueprint from a few scribbles on an envelope up to a full CAD. The design looks fine, but no harm in making it up a bit as you go along as well.

BB shells are thick metal and easy to weld to. Make sure you get it the correct way round-- "English"/"BSA" threaded is lefty-tighty on the right hand side and a regular thread on the left. Fact-check this in case I remembered it wrong. It's something to do with it not coming loose but is counterintuitive.

MrInitialMan

Another question, though this one will sound weird: Is it possible to install the pedals in such a BB "backwards" so the chain ring is on the left?

guy153

I don't see why not if it's a single. If it's a double or a triple it might not shift gears as well the wrong way around as there all sorts of subtle ramps and bits chipped away to make that work. And anyway the front derailleur would be all wrong unless you could get it into the fourth dimension to rotate it and turn it into a mirror image of itself. Unless the chain went forwards of course and you pedalled backwards but under that setup nothing has really changed from the point of view of the drivetrain!

MrInitialMan

Drat, because I was planning on a 2-part drivetrain (the design requires a 90-degree angle)

Andrew R Stewart 

Tandems use a chain on the left side all the time. Cranks can be rethreaded with various inserts to achieve this. (Or just thread lock a good pair of pedals like I've done before). Track bike have been set up this way for decades, though not common.

There's nothing saying that the front rings that also are shifted have to be located at the same crankset that the pedals are. Andy

MrInitialMan

I'll have to look at tandems and see what they've got for cranksets. And good point with the front rings.

In other news... *Whiizzzzzzzzzzzzzzzzzzz* That was the 100-lbs. mark going by. CarCycle Design #3


EDIT: Thanks, Mr. Stewart, for directing me towards tandems!

MrInitialMan

Looking at this for rear suspension. Is a leaf spring like this going to be too stiff?

https://www.etrailer.com/Trailer-Lea...SP-169275.html

guy153

It says it's meant for a 2000lb axle so yes too stiff. You are only planning on using one across the back though so you can halve that, and then you could remove some of the lower elements, one at a time, until you get the spring rate you need. Just the top element on its own might be about right.

squirtdad

IIRC One of several threads, and at least one failed initial build attempt so

also IIRC goal design goals are carry OP (not a small guy per his self description), 300 lbs of cargo, be enclosed, be stable, have suspension/rough roads and ice and no electric boost, and using a lot of on hand steel and other parts

not stated are speed, climbing and braking goals

This is a huge challenge

I have serious concerns that the total weight (700 to 800 lbs or more) would make it impossible to pedal on anything but close to flat and that it would be difficult to control speed (brake) on any down hills, basically an inherently impractical and unsafe setup.

If the OP wants to try just because go for it, but set proper expectations

i would strongly suggest other options, but for any option the KISS Principle should apply Keep it Simple Silly. So relentless focus on low weight, no suspension, if rough use fat tire bikes. Forget 4 wheels go for 3, 4 adds magnitudes of complexity and weight (drive train), Be open to upright seating position, build a bike that could use electric assist legally

10 seconds of google and I found this, which seems could be used as a good base, weather protection could be added

https://www.treehugger.com/buid-your...-cycle-4857433

also instructables of interest

https://www.instructables.com/id/how...-a-cargo-bike/

https://www.instructables.com/id/fai...ed-cargo-bike/

https://www.instructables.com/id/Vel...-Electric-Car/

https://www.instructables.com/id/Facet-V1-Velomobile/


another option would bike and trailer,, bike could be veloize and load in trailer

MrInitialMan

You're more or less right--except I think the 300 lbs included me. If it didn't before, it does now. I'm not likely to be carting around more than me, my instruments, a few groceries, or a few books. (What I do need is cargo ROOM. Two of my instruments are tubas.)

And the failed build attempt was BECAUSE of the steel on hand--I think it was 1/8 inch wall. (The new design uses a lot of 16 gauge steel, less rectangular tubing, and more flat iron.) I'm going to go to Promould--which is a local welding shop--and see other walls are available for the tubing I have in mind. Maybe 18 gauge. (Or even maybe aluminum, if I can afford it)

Right now my biggest challenge is trying to break free of the "sturdiness is everything" mindset my dad instilled in me.



Like I said, the cargo expectations have drastically been reduced. I'm not looking to build a racer by any means--that would suggest I'm some sort of athlete.

...if I've read Alberta's regulations right, legally using electric assist would preclude the bike being enclosed, so it couldn't be a velomobile. Also, aren't fat tires pretty soft, and thus require extra effort to pedal anyways?

Oh, and as for the three vs. four wheels... let's just say one rollover is enough for me, and leave it at that (Also, I already have the differential for the rear.).

I'll have a look at those.

UPDATE: I've found I can get 18-Gauge 1X1 square and 1X2 rectangular tubing. Considering how I've got a bit of a roof frame as well, do you think I can get away with material that light? It's got the current weight down to less than 120 lbs.

guy153

Is 18-gauge about 1mm in surrender units? I would go with 1.6mm if it's mild steel. Also how are you welding it? 1.6mm will be easy to MIG. 1.0mm will be possible though tricky to MIG (you'll probably need to sort of "pulse" it a bit) and better to use the TIG. Either is too thin for stick unless you're very good.

Yes keep the weight as low as possible but if the gears go low enough and you're not in a hurry in theory it's not a problem as you have four wheels so can go as slow as you like.

MrInitialMan

18 Gauge is about 1.2 ,mm. 16 is 1.5 mm.

MrInitialMan

Maybe I should give a rundown of what I'm trying to accomplish. I'm trying to build something that:

• Can go faster than walking speed. If I can get to the nearest town (6 miles away) in less than an hour, I'm good.
• Can support 240 lbs of All-Natural Anthrogenerated Seat Padding (in other words, me.)
• Keep aforementioned oversized mass of Anthrogenerated Seat Padding from being beaten black and blue when the weather (or the town council being cheap--again) results in rough roads.
• Has some cargo space (Bike carts are all nice, but good luck keeping your groceries dry in a rainstorm, and what would I do with my busking equipment?) with the possibility of adding a second seat if I wanted to give someone a ride. Should be large enough to cart my tuba around in as well. (The case is about 40 inches long) or baritone saxophone around--and keep it out of the rain.
• Is nice to look at. I'm sorry, but I find a lot of velomobiles just plain ugly. I know they're very aerodynamic but just... urf. And honestly, having only three wheels is part of that, thus my other reason for wanting four.

For brakes, I intend to have five disk brakes--one on each wheel, and one in the center of my rear axle (my differential allows for this).