BO15 WAHA-SEDB-3 (TRIKE-TOR...2nd Place)

[MazdaFlyer]

ROUGH Visual Mock-up, again I repeat rough and tentative. Trying to see the scale and where I might want to cut. Axle held in place at present with wire ties. Sitting here thinking through my steering control. Probably going to jump ahead to the wheel spindle phase which will require braces back to frame I think. I still may try the solid axle with a pivot just to see what the effect is.

Post thought. I need to notch the rear of the hood to mesh it with the frame. That will lower it a few inches. Then I need to work out support structure for the front or get a skyhook. My original thought was to let it turn with the wheel. That was going to require sectioning the hood.

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[horsefarmer]

Cool, looks like one of those old midget race cars!

 

[order99]

That simple Pivot joint just might work IF it was flexible enough. Some of the early Cyclecars of the 20th century had a single-point steering setup and i'm told that they worked well enough....

I imagine there was a little 'bump-steer' at high speeds (45+ MPH)but the Falcon and similar Cyclecars were competitive with their multi-point articulation brothers for several years....

 

[handyandy1100]

Looking forward to seeing this one built. Been waiting a long time for the DB hood to finally show up in a build-off,
Big knobby tires to make the front look more like the walk behind tractor?

 

[MazdaFlyer]

Been waiting for this hood to get built for a while, those classic tractors are an underappreciated area in the gearhead world. As an Ontario boy, gotta share the local brand. I give you a splendid example of Cockshutt, manufactured in Brantford ont
View attachment 118317

I’ve always been a tractor fan, and ancestors were farmers. If I had more space tractor collecting would probably be a problem with me. There was a good band called “The Tractors” a few years ago. They produced some great albums but some of the members didn’t want to road trip so they stayed local in Oklahoma.

 

[MazdaFlyer]

Cool, looks like one of those old midget race cars!

When I saw one of these the first time I was drawn to the streamline Art Deco look. I’m liking the look, I’m supposing I’m probably in the minority though. Old school.

That simple Pivot joint just might work IF it was flexible enough. Some of the early Cyclecars of the 20th century had a single-point steering setup and i'm told that they worked well enough....View attachment 118372

I imagine there was a little 'bump-steer' at high speeds (45+ MPH)but the Falcon and similar Cyclecars were competitive with their multi-point articulation brothers for several years....

Thanks for the example!
That’s kind of what I had in mind, to get some flex I’m thinking it needs an elastomer or spring involved. Again trial and error. With a fixed setup the frame leans out the curve instead of into it. Somewhat one the the reverse steer bikes. Thus the bike tries to through you off or over. @GuitarCarl is certainly correct. Trial and error.

Looking forward to seeing this one built. Been waiting a long time for the DB hood to finally show up in a build-off,
Big knobby tires to make the front look more like the walk behind tractor?

Thanks!!!
Yes I was going to try this last year, but the old Schwinn Motobike popped up and it had me hooked on rebuilding it. So .I saved the hoods for BO15.

With the little bit of work I did with it today, I’m seeing there are a few more obstacles to overcome than I originally imagined. There’s some attachment stuff I need to work out. The goal is to do this mechanical without welding or cutting up frame or fork. Some welds would simplify things. Then I guess it would go to Class 2.

If this project can be made mechanically stable and rideable then I’ll decide on finish or lack of. After seeing the stance today I’m thinking the rear tire could be beefier and needs some kind of fender. I also have an old tractor seat that could get an audition.

I started with the brick tread tires on the front thinking they would have less turning resistance. I did some research on available 24” tires with a beefy tread. There are a few choices out there. 26” has more options.

 

[The Renaissance Man]

Just a thought: You might get more favorable results with your original concept by simply reversing the fork (bork). Maybe even flip the whole drawing. By doing so the trail would be moved back which is what I think will give you problems.

 

[MazdaFlyer]

Just a thought: You might get more favorable results with your original concept by simply reversing the fork (bork). Maybe even flip the whole drawing. By doing so the trail would be moved back which is what I think will give you problems.

That’s pretty easy to check, I can just rotate the fork tomorrow and check the turning action. That does seem to make sense. The rough mock-up today definitely showed the problem with the fixed axle. Flipping the fork Walmart style reduces the wheelbase, but shouldn’t create wheel overlap with the dual wheels.
Thanks for the suggestion.

 

[kingfish254]

Awesome mock up visually!!!!! I'm sure you'll figure out the engineering for the steering.

 

[furyus]

Agreed, looks extremely cool. You have to get the steering sorted.

furyus

 

[The Renaissance Man]

The rough mock-up today definitely showed the problem with the fixed axle.

Yeah, you'll definitely have to incorporate some type of pivot to have any hope at all of getting it to turn with the stock rake on the head tube.

 

[SpikeFC]

Now this is the thing I wanna see

 

[horsefarmer]

Might want to check out rope or cable steering used on soap box derby cars. Maybe a more robust system, small boat steering, or chain and sprocket could "lean" you into a corner as well?

 

[Captain Awesome]

Might want to check out rope or cable steering used on soap box derby cars. Maybe a more robust system, small boat steering, or chain and sprocket could "lean" you into a corner as well?
View attachment 118462View attachment 118463

I used a chain and sprockets setup On an old plywood kneeler boat we built. Used spring returns to help with centering

Doesn't tackle the leaning side of the dilemna, but it's a stout system

 

[MazdaFlyer]

Per RM suggestion I flipped the fork 180 degrees. That reduces the lean but tires hit down tube.

So now you know if you didn’t already. I moved on to rough out the pivot mounting.


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[MazdaFlyer]

Started roughing out the axle and fork mount pieces. 1/8”x1-1/4x1-1/4 and 1/4x3x3 angles for a start. I’d purchased a cut off tool last BO that never used. I’d thought it would make quick work of the angles, not so. The 3” wheel doesn’t work well with the cut length. Would be good for sheet metal, bolts and maybe round stock.
I ended up breaking out my trusty old hacksaw, had it for years and years. Not exactly the way to get fast clean straight cuts though.

I’m going to source some hardware an drill some holes.
The hood is going to limit the turning radius some so hoping the pivot may workout. If not, I guess the steering knuckles/spindles are the next resort.
This is sort of an exercise in futility so far.


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[hamqqea]

Hi MazdaFlyer,

I recognize your dilemma, as some have already mentioned rake angle.
See you posted images of joints? Perhaps you can in some fashion make the fork static and run a shaft through the fork's steering tube to connect with a rod at one end and your steering wheel at the other.

Searching for parts I stumbled upon an example you and others my find of use.
Ackermann steering geometry.

 

[SpikeFC]

A few years back I bought this (eyup, still sits in my garage waiting for it's turn). The front "suspension" is a simmilar design as in a tractor (the front axle pivots in the centre). Since it's a 1-1 turning ratio on the steering wheel I was planning to use this:

It's a steering gear used in Trabant car. And since I had a box of them it was a natural choice

My best idea to make a front suspension the easy way would be in this matter - a car steering gear & a tractor-like suspension.

Hope it kinda helps

 

[OddJob]

Per RM suggestion I flipped the fork 180 degrees. That reduces the lean but tires hit down tube.

So now you know if you didn’t already. I moved on to rough out the pivot mounting.


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What about a straight BMX or mtb style fork. It will have enough offset /rake for good steering, but little flop or lean compared to the vintage fork.

 

[OddJob]

Ed, this is really cool! As previously mentioned, I would go with as beefy and 'knobby' a tire as you can find. Something that screams "TRACTOR"!
T-RacT-or oN~!