Might be an odd question but how are the wheels held on for a trike or 4 wheeled bike? I’m having a hell of a time visualizing it and google doesn’t have close up pictures. I want to build a trike or 4 wheeled bike and that’s the hardest part for me right now. I was thinking doing drop downs but instead of them perpendicular to the road making them parallel. But that would be ugly as far as I’m concerned.
Trikes and wheels
- Thread starter Jayw900
- Start date
There are quite a few ways, depending on the design of the trike, and what kind of drivetrain it uses.Jayw900 said:
Some are double-ended axles, some are single-ended.
Some use flatted axle holes (or something similar) that locks the wheel to the axle) and a live axle or other driveshaft to the wheel, so that the drivetrain can drive the wheel directly thru the axle. (methods of driving the axle vary as well).
Some use wheels with round axle holes on bearings just like regular bike wheels, and some form of washer/spacer on the axle and a nut or pin on the end of the axle to keep the wheel on, but the wheel rolls on the axle and is not driven at all.
Some use the above method except they use "rear" wheels with drive sprockets, and use a chain drive to the wheel.
Some use hubmotors, with either single or doulbe ended axles. Mine uses two regular MXUS 450x hubmotors on the rear, and a regular bike wheel up front for now. My brother's trike uses three regular bike wheels (now with two geared hubmotors in the rear instead), wiht the rear wheels tilted at an angle to give a wider track (stability) without making the trike quite as wide as with vertical wheels.
Some use regular hubs with bolt on wheels lke cars, trucks, etc., although they are usually much smaller and ligther hubs and wheels.
Etc.
Lots of ways to do it.
I recommend looking at images of various trikes, and trike wheels, like in this search
https://www.google.com/search?q=trike+wheels+-motorcycle+-drift&btnG=Search&newwindow=1&client=firefox-b-1&tbm=isch
Or other similar searches.
Also look around at the build threads of variosu types of trike here on ES (and elsewhere), like my SB Cruiser and Raine Trike threads, or the various KMX trikes and various custom builds, delta trikes, tadpole trikes, etc.
What does "drop downs" mean?
Dauntless
100 TW
Handle bars? I assume known by such names as wrap around, etc. Boy, I'm sure we could see names put up here.
wturber
1 MW
In most locations, a four wheeled "bike" will not be legally classifiable as a bicycle while a three wheeled bike can be. So be sure to check that out if having the bike legally classified as a bicycle is important to you.
Yeah, we had that discussion with him in his first thread here. 
Chalo
100 TW
Jayw900 said:
Maybe you should have a look at a trike for yourself?
The standard for pedicab trikes is keyed round axles. Most are 1" or 25mm in diameter. Most granny trikes use 15mm or 5/8" axles, and industrial trikes usually have 7/8" axles. There's no consensus about torque transmitting features.
You can buy a keyed 1" axle with differential, plus hubs to fit it, from pedicab.com . I'm not affiliated with that business; in fact I work for a competitor. But if you're building a 3- or 4-wheeled vehicle with a gross weight of over 400 pounds, that's a good place to start.
flangefrog
1 kW
Have a look at these: http://www.sturmey-archer.com/en/products/sd-hubs
Chalo
100 TW
flangefrog said:
Those are really nice, but they have axles only 12mm in diameter. They're not good to carry very much weight. Also, any wheel with one of those hubs has no drive interface for a motor or pedals. (You could use friction drive, I guess.) That's why they're called front hubs even though there's no reason they can't be used on the rear (with drive wheels in front).
With four of those hubs, what you'd have is the makings of a deluxe soapbox derby car.
At the moment, without a response from the OP as to what *kind* of trike they're considering, and to what uses it will be put, suggesting specific parts is kind of pointless.
Chalo
100 TW
Note also that four wheeled cycles must have articulated frames to keep all four wheels on the ground. Trikes can keep all their wheels down with a nice rigid one-piece frame.
Bikes can do it with a nice rigid one-piece frame, and stay upright as they traverse nonlevel surfaces.
There's probably a corollary principle in here for unicycles, but we try to observe some standards of decency on this forum.
Bikes can do it with a nice rigid one-piece frame, and stay upright as they traverse nonlevel surfaces.
There's probably a corollary principle in here for unicycles, but we try to observe some standards of decency on this forum.
