Slag0e

Hey everyone, i recently got an assignment for my engineering class where I have to design an easy to balance bicycle for a local children's rehabilitation center. It can't use training wheels, what they're looking for is something that can progressively transition from self balancing to harder and harder to balance, until a normal bike can be used. Anyone have any ideas on a clever way to do this? Some things i've thought of are:
1. switching out the front wheel with a row of interconnected skateboard/rollerblade wheels (similar to flowboard trucks) that are arranged in a curved U shape, making it easy to balance than a normal wheel, but with a slight challenge
2. having a thick wheel on the front that can either be pulled apart or pushed in to change the thickness, or have it divided into sections that can be taken out.
3. throw on a small cylindrical wheel to the front, which would make it easy to balance but not really challenge the rider

any ideas would be great, thanks
Adam

onetrack

hang a weight from the down tube or bottom bracket. It can't be able to swing in any direction independant of the frame, probably has to be really heavy and low. it wont allow the bicycle to balance on its own, but it'll be super stable. you could adjust height/weight to make balance more chalanging

Tom Stormcrowe

Place a gyro on it?

Slowly cycle down the gyro speed to reduce the Gyro effect toward 0? There one solution.

StephenH

Make a 2-wheeled Big Wheel with training wheels. Arrange the training wheels such that they don't touch the ground in normal operation.

On a normal bike, training wheels don't do much to teach the rider. The problem is that you have to learn to lean IN on a curve, but riding with training wheels, you automatically lean OUT. And then even with training wheels, you're high enough that you can tip over, so it's sort of scary for a little one. And, it's easier to ride fast than it is slow, but if you're afraid of falling over, you hate to ride fast.

By getting the kid right down on the ground, it pretty well eliminates the over-turn fear. Set the training wheels so they prevent overturn, but require a pretty good lean before they come into play.

I haven't tried this, so don't know that it would work, but that's my idea.

The more hi-tech way would be something along the lines of the Segway, but you'd have to make the balancing gizmos control steering, which could be real interesting to say the least.

mastershake916

https://www.thegyrobike.com/
You could either buy one of these when it comes out, or duplicate it.

StephenH

One problem I see with that is that if the flywheel is large enough to add a lot of stability to the bike, it also adds stability in the horizontal plane- meaning it should be noticeably harder to steer.

Slag0e

One of my ideas is replacing the front wheel with a set of multiple wheels like this

https://www.flowboard.com/rider%20sub...-Images/34.jpg
(trucks on a flow-board)

that still make you balance but are wide enough to keep from falling over. The problem is, I need to somehow attach this to the fork of the bicycle. This would mean I need something that extends from the fork to the trucks, because it is much smaller than a normal wheel. Any help on how I can attach it, what material, or where I could get it would be great. Thanks

jimblairo

Discovery Channel had a bit on a University in Holland who are looking at ways to make bicycles more stable. They claim that a bike is self-stable between 14 and 24km/hr and it is the low speed instability they are working on.

zeytoun

https://www.livescience.com/technolog...e_trainer.html

Fast Eddie

this is pretty far out there and would be wicke expensive, but if "hubless wheels" were used, andthe contact betwee rim and "hub" were at the center and bottom of the wheels (if veiwed from the profile) that would take out alot of low speed instability, if that were combined with some of the ideas already presented in this thread you might be able to make a bike that didnt even need a kickstand....suhweet!
fast eddie outty

fuzzbox

Have you ever been on one of those flowboards? I doubt it would work just because if you can't keep the handle bars straight it just doesn't work. And plus they could still fall. Try a fat tire like the back tire of the Schwinn choppers.

redtires

It is totally possible to build a "self-righting" bike, I've done it before, but for less than noble reasons...more just because we were bored and wanted to see how it would work. The design has to incorporate negative trail though and you would need to do something like having multiple forks to change the trail/rake as the rider gets better. I'm not sure if that's exactly what your after, but with a negative trail set-up, the bike will actually stand itself up as it starts to lean over. You literally have to steer it into the ground.

geebee

How about a standard trike layout but setup to allow the back wheels to be moved closer together as the riders confidence grows utill they are basicaly touching.
If you want to simplify it use the pedals to drive the front wheel.

Philatio

if this works (not saying it doesn't, I don't know) it clearly would be the easiest, cheapest, and simplest solution offered so far.

Paramemetic

That gyrobike is really cool, but I wonder if it would fight you on the lean? It seems like if you took a turn at high speed, the front wheel wouldn't correct as it should. Though I admit I don't know the principles being used here, so I can't say.

I would think that rather than designing the bike as a usual bike, use stays and forks that are horizontal to the ground, and attach those to an internal gyro with a heavier weight than the weight of the rider on the bottom. As the bike turns, the weight and rider will still tend to be straight up and down, while the wheels will lean. This will cause some serious weirdness riding, but would remove the problem of balance.

dcb

https://www.tam.cornell.edu/~ad29/JBi...stability.mpeg
If you freeze it, it looks like they just spun the front fork around to increase the trail. Give it a good shove and it goes straight, give it a smack from the side and it straightens up.



Found on: https://en.wikipedia.org/wiki/Bicycle...cycle_dynamics

cerewa

Putting a heavy weight won't add a lot of stability. I just added a 10-lb electric motor mounted low below the bottom bracket of my bike, and the weight of motor doesn't make the bike feel more stable. A razor scooter (either the motorized or nonmotorized kind) has most of its weight within a couple inches of the ground but still falls over easily.

To get this concept to really work, you have to get the weight below the bottoms of the wheels. Put enough weight far enough below, and you have the stability of a suspended roller coaster.

This is a feat that is only possible when riding on a tightrope or some other kind of elevated track.

dcb

If you google for lean steering trikes you might come up with some more ideas as well:

JeanCoutu

Would fluid in the tubes on a regular bike have the same effect?

NoReg

"Hey everyone, i recently got an assignment for my engineering class where I have to design an easy to balance bicycle for a local children's rehabilitation center. It can't use training wheels, what they're looking for is something that can progressively transition from self balancing to harder and harder to balance, until a normal bike can be used."

One way it is being done every day is with the likeabike.com. No pedals so you are walking the bike along, yet you have to ballance it. For little kids, they also have access to trikes, so they learn to spin the pedals, put the two together and you are riding. Something that takes away the need to ballance the bike defeats the purpose of the rehad, though a single vehicle that was progressive in how much it gave or took away would be cool.

Training wheels sorta suck. The kid goes from a trike, where he was master of the universe, to this thing that he doesn't always feel safe on (and some of the TWs these days are really lame looking) as it flops side to side, If there is a divot for the wheel he falls over, and yet he is leaning on the outboard wheel and not learning ballance. It's almost like a system that encourages one to avoid the vertical position where ballance occurs. More vertical adjustment would help with training wheels,

Vissthew

Adding weight to the bottom of the bike would be ineffective, unless it was significant. The idea is to lower the center of gravity- I think that best way to do that would be to somehow lower the rider, and progressively move them higher. Maybe something like a recumbent bike that hinges at the center to then raise the center of gravity. I might have seen a video of this somewhere, but not for this purpose.

Bikes get easier to balance as you speed up because of the gyroscopic motion of the wheels- so if you can duplicate that at lower speeds you'd be in good shape. You could make the wheels really heavy, but that would make it hard to get going (and stop).

PunctualAlex

I was thinking about this earlier (while riding, of course). Training wheels have got to be the worst way to train somebody to ride a bicycle. Every time you turn, your momentum throws you to the outside of the turn, where you rest on the training wheel, which teaches you that you don't have to lean into turns! For that matter, even if you do lean into the turn, you can't lean far enough to balance the force pushing you outward, so you'll swing outward anyway. Sort of makes turning a bicycle into an exercise in futility. Damn.

oldfool

Check with the maker of this bike it seems pretty stable.

https://www.dvorak.org/blog/?p=14935

Sianelle 

That's wot comes from having an electronic bike computer on your bike; - I saw '2001 A Space Odyssey' I know wot happens if you put a computer on a vehicle.....