Has anyone made a 2 wheel drive bike?

HeadSmess

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May 17, 2010
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Found this research paper that conducted a stress analysis of a harbor freight 4-1/2" angle grinder. The grinder operates at 11,000 rpms and has a rating of 3/4 of a horsepower. A Rockwell Hardness analysis was conducted on the pinion spiral bevel gear. After a conversion was completed, it was estimated that the pinion gear had Tensile Strength of approximately 106,000 psi. Probably what to expect from other replacement grinder spiral bevel gears. My hunch is that the original equipment gears will be of better quality with the name brand grinders. Dewalt makes angle grinders with ratings of 5.3hp.

Considering that the Honda GHX50 output is approximately 2.1 hp and that approximately 1 hp will be split between the front and rear drives, I think the grinder spiral bevel gears will be O.K. Also consider that the gears won't be spinning at 11,000 rpms like the angle grinder.

http://www.ewp.rpi.edu/hartford/~ernesto/SPR/Zouhri-FinalReport.pdf

Chris
AKA: BigBlue
just had to shoot this lil arrow at your ballooon :(

chains and gears power rating INCREASES with speed. gears for very low speeds have to be a lot stronger than high speed ones. to do with strength of individual teeth, torque requirements, and that transmitted power is a function of rpm and torque.

say it takes a newton of force to bust 10mm of steel. you could either run a tooth thats 11mm thick with one newton and be safe, or spread the load over 11 teeth, all of 1mm... the finer teeth, of course, have to pass each other in the same time as the single fat tooth. each one will also only be loaded to 1/11 of a newton.

now, if you produced 11 newtons of torque in every revolution... and had 11 fat teeth, or 121 fine teeth, all would be well.

double the speed, but retain the same torque over time (power) and the load on each tooth is HALVED.


or , retain the initial tooth loading, and DOUBLE the power rating!

fine teeth make less noise.


cutting 121 teeth is going to cost a lot more than 11 teeth and requires more accuracy... noise versus cost versus speed versus load.

yeah yeah, over technical lecture.

all i can say in favour, is... i havent blown the gears on a grinder yet...and in my work, we replace the brushes every month, a grinder lasts 6 months, tops.


gunna be fun machining the crown gear! they are HARD!
 


IbedaYank

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Jul 12, 2011
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454
everything is impossible. everything.

at first i was going to say, "nice model A pic" but then...the model A ford has the front brake actuator feeding down through the kingpin! so, other than it being old, whatever... its irrelevant :)

sorry. i wouldnt have mentioned it if i hadnt seen the actual device, as attached to a ford 2120 tractor. i believe theyre also marketed as "new holland".

View attachment 51179

patented idea... http://www.google.com/patents/US2306958


http://www.google.com.mx/patents/US4301886

http://www.google.nl/patents/US4613011



well, maybe im dreaming again...but it seems at least someone worked out how to get a drive down through the kingpin...
thats funny looks OFFSET to me so it does not go through the kingpin now does it???
 

HeadSmess

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thats funny looks OFFSET to me so it does not go through the kingpin now does it???
tried turning your head 90 degrees? reading the description? learning how to read diagrams? doofus :)


http://www.google.com/patents/US2306958

lets see now...

the parts that are "offset" happen to be input and output shaft.

the "rod" passing through at a slight angle is the kingpin. the angle is there to provide kingpin inclination.

i guess a person like yourself would think kingpin inclination is simply camber. so i wont burst that bubble on you just yet.

the hub rotates on a stub axle, as per normal.

25 rides on 22 via parts 23 and 24.

32 is bolted to 25.

32, a bevel gear, engages with part 34, also a bevel gear.

34 is splined to shaft, 40. this is the kingpin or pivot rod, call it what you will. in this case, it also serves as a drive shaft.

40 is splined to part 44, which then engages part 45.

45 is part of part 46 (or 52? not sure if 52 is just the splines, i havent read the description yet. why should i?)

52 is splined to 53, the main drive axle from differential, via coupling 54.

please refer to description, and correct any errors in my understanding of this device.

oh, and the patent is dated as published in 1942. its not exactly "new".

here, i read a few paragraphs... direct quote so you get all the typos, too.

A further object of the invention is to provide in a front wheel ydrivi-ng mechanism of the type above referred to, a steering Wheel mounting structure having a king pin formed to serve either as a driving ele-ment or vas a housing therefor, the pin, at the same time, serving effectively as a means for supporting the wheel spindle for steering movement in themanner now commonly employed.
 

BigBlue

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Dec 1, 2011
Messages
515
Thanks for the information. That's why I post here to get others input. I still have an interest in developing a proof of concept and if it pans out, I'll invest in some higher grade spiral bevel gears. This is of course a long term project since I need to finish my current build. In addition, I need to purchase some more tools that I can use now and later for a 2wd project.

I am going to start my own thread on this idea and your more than welcomed to offer constructive input.

Chris
AKA: BigBlue
 

HeadSmess

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3,007
:) i think ive thrown in everything i can think of :)

all too familiar with long term projects. i had these grinders lying around for a few years now, wanted the gears to make a diff. one for my lil lathe that doesnt have a reverse on the lead screw, one for a heavy duty trike build.

CNC will fix the lathe, and 1:5 RC parts will do the trike...


load rating? it struck me then...look at a hand drill!

anyway! the only two things i think to really consider with a 2WD setup, is going to be spreading the drive between front and back. there does need to be a differential. ride through a puddle and take a few turns, measure the distance the front travels in relation to the rear.

and, with bevel drives, such as that kingpin idea...if you get the ratios wrong, the wheel tends to try and rotate, as the steering is turned. set the gears up to rotate the wrong way and steering will be a nightmare as the wheel fights back against you... its ok for a tractor, not so good on a high speed all wheel drive... one reason they arent used on, say, subaru.

just thinking, that on a pushy...it would tend to make you move forwards or backwards depending on which way you turn... or have a steering lock when not moving! depends on the orientation of crown and pinions...

if you can live with restricted steering, and who really needs to be able to turn the front wheel back on itself anyway, then some type of CV joint may be better. uni joints really should only be used in pairs where both are at the same but opposite angles. once again...1:5 RC may be the source...

you have to allow room for adjustment for bevel gears to get em meshing correctly.

im currently racking my brain over the best setup.

therefore, i currently hate you. i got other things to think of, you know! :giggle: this is why i never get anything done!


(just had a super scary thought, what with load ratings and then doubling up on shafts...

dual parallel tubes, with internal driveshafts, driving the front wheel with a hypocycloid bevel either side, and also forming swingarm suspension with hub/centre steering...


man, if i had a super rich japanese business person that wanted a concept vehicle and would pay up front...:devilish:)
 
Last edited:

loquin

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Jan 11, 2008
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The Rokon 2WD motorcycle has been around since the late 50's. Originally built with a West Bend 2 stroke, they've shifted to Honda with a CVT, then through a three-speed range-selector gearbox. They're the ultimate off-road machine. (U.S. Special Forces have used them on some missions.) When equipped with hollow aluminum wheels, they can be used as flotation, and to store extra fuel, or water. If both are filled with gas, you could run one of these bikes for roughly 30 hours before needing to refuel.
MouseOver_Trailbreaker.jpg

mouserover_ranger.jpg

Now, here's another approach that looks like a backwards half-track (Why the French thought they needed a front-track-drive for military use, I don't know. Maybe to get messages to Maginot Line positions in all weather...)
trackedmotorcycle_resized.jpg

Although this one is front wheel drive, it would be fairly easy to run a chain back to the rear wheel.

With the motor & tank up high, though, it would be a bear to balance though.
 

grinningremlin

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Jul 30, 2012
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607
The Rokon's remind me of the pre-internet ad's in mags such as "American Survivalist" "American Firearms" that displayed what looked like an old ATC with two wheels & 2WD (fatcat?), promoted toward hunters, supposedly went up the side of hills at 1 to 3mph like a billy goat.
 

Fabian

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man, if i had a super rich japanese business person that wanted a concept vehicle and would pay up front...:devilish:)
It's quite easy to have all of that, but unfortunately you were born with the wrong gender and without model good looks; both of which are a prerequisite for landing a super rich japanese business person that would grant your every wish.
 

HeadSmess

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May 17, 2010
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if i was into hello kitty and flashy iphones, i wouldnt be into mechanical stuff!

though cute japanese girls do make very good mechanics what with these lil hands that can get places no hand has ever been before :eek:

rokon is from the 50's? i guess it could be, i always thought late 60's. never really looked into them. but very typical of the era, that frame style...popular mechanics plans with a twist!

pscovertrackedmotorcycle.jpg

the front track? yeah, balance looks like it could be an issue. hope those castings are in alloy!

trackedmotorcycle2.jpg

but i doubt it could be as hard as this one...

hyanide.jpg


then i found this one... looks like you dont have to be japanese, just super rich :)

kickboxer-diesel-awd-rf.jpg


oh. wait. maybe you need to be both to OWN one.

pretty good CAD modelling ;)
 
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