Motorized bikes: technical & theoretical

[.Froomestrong.]

Re: Mechanical doping: first rider caught

Ive built batteries for a hidden motor bike, based on a Carerra from 2013. We used a bottle to house the battery.
Ill get some pics later next week if the bike is still in the shop.

 

[jyl]

Re: Re:

Daaang, look at those pencil-thin stays. Nothing to work with there. And wide rims aren't in fashion, so there's that. http://cdn.media.cyclingnews.com/2016/02/12/2/img_9910_670.jpg

John Swanson

Yeah, but they are building an aweful lot of space around the bottom bracket these days......no doubt just a coincidence?

JS was being sarcastic.

Here is a picture showing the seatstays of that bike (2016 Madone).

http://pelotonmagazine.com/wp-content/uploads/2015/07/MadoneHero.jpg

Eyeballing it, I'd say the seatstay where it crosses the rim is about 10-15 mm thick (right to left dimension), about 25 mm wide (front to back dimension), and there is about 20-25 mm of gap between inside surface of stay and outer surface of rim. The stay and rim have to be strong enough to do their day jobs, so you can't use the entire dimension for a coil and/or metal inserts - there has to be enough carbon fiber for structural strength, to be a brake track, etc.

So that stay can possibly fit a coil at most 15-20 mm outside diameter and 10 mm length. The end of the coil will be about 25 mm distance from any metal insert you place in the rim.

You will not get a useful amount of force tangent to the rim, with such a coil.

If that is incorrect, I'd be very interested to know the specifications of the coil (dimensions, turns, wire gauge, core material, current, voltage).

 

[GJB123]

Re:

The argument that "no one is checking for motor doping, so the motors don't actually have to be undetectable" makes no sense.

If you actually think that are no bike checks (the tablets are dummies, xray machines not plugged in, everyone just pretends to remove bottom brackets, all the motor checks are just a big sham) then there is no reason to develop a rim drive or a hub drive.

Just use the existing crank drives with motor in the seat post, they are proven, inexpensive, and work well with plenty of power and no mythical skunk works with "hundreds of millions of dollars" of cutting edge R&D needed.

This exactly! I have said the exact same thing some pages back but naturally this will be overlooked again because it doesn't fit the narrative that Hesjedal was already racing a rim motor.

 

[Hawkwood]

Re: Re:

[/quote]Here is a picture showing the seatstays of that bike (2016 Madone).

http://pelotonmagazine.com/wp-content/uploads/2015/07/MadoneHero.jpg

Eyeballing it, I'd say the seatstay where it crosses the rim is about 10-15 mm thick (right to left dimension), about 25 mm wide (front to back dimension), and there is about 20-25 mm of gap between inside surface of stay and outer surface of rim. The stay and rim have to be strong enough to do their day jobs, so you can't use the entire dimension for a coil and/or metal inserts - there has to be enough carbon fiber for structural strength, to be a brake track, etc.

So that stay can possibly fit a coil at most 15-20 mm outside diameter and 10 mm length. The end of the coil will be about 25 mm distance from any metal insert you place in the rim.

You will not get a useful amount of force tangent to the rim, with such a coil.

If that is incorrect, I'd be very interested to know the specifications of the coil (dimensions, turns, wire gauge, core material, current, voltage).[/quote]

So in order to do this there would have to be major redesigns/rebuilds of the frames, it's not just a matter of taking a Colnago frame, drilling some holes in it, inserting a couple of magnets, and you're good to go. So if this rim drive idea is actually being carried out at what point do manufacturers such as Colnago, Trek, Pinarello, Specialized, Canyon etc have to be brought in and asked to radically change their designs, and insert all manner of things in their frames? Sounds like an awful lot of people would be in the know, not a couple of mechanics per team.

 

[sniper]

Re: Re:

The argument that "no one is checking for motor doping, so the motors don't actually have to be undetectable" makes no sense.

If you actually think that are no bike checks (the tablets are dummies, xray machines not plugged in, everyone just pretends to remove bottom brackets, all the motor checks are just a big sham) then there is no reason to develop a rim drive or a hub drive.

Just use the existing crank drives with motor in the seat post, they are proven, inexpensive, and work well with plenty of power and no mythical skunk works with "hundreds of millions of dollars" of cutting edge R&D needed.

This exactly! I have said the exact same thing some pages back but naturally this will be overlooked again because fit the narrative that Hesjedal was already racing a rim motor.

the only narrative is that it should not be discarded just because you can't get your head around the technology.

 

[Hawkwood]

Re: Re:

The argument that "no one is checking for motor doping, so the motors don't actually have to be undetectable" makes no sense.

If you actually think that are no bike checks (the tablets are dummies, xray machines not plugged in, everyone just pretends to remove bottom brackets, all the motor checks are just a big sham) then there is no reason to develop a rim drive or a hub drive.

Just use the existing crank drives with motor in the seat post, they are proven, inexpensive, and work well with plenty of power and no mythical skunk works with "hundreds of millions of dollars" of cutting edge R&D needed.

This exactly! I have said the exact same thing some pages back but naturally this will be overlooked again because fit the narrative that Hesjedal was already racing a rim motor.

the only narrative is that it should not be discarded just because you can't get your head around the technology.

Can you tell us what the technology is then? It appears that to make a rim drive system work you'd need to make major and very apparent changes to the frame.

 

[Cloxxki]

In a rim you could have a tubular channel all the way around. In this tube, a radial piston could be placed. This piston could also be a floating stator running on the rim's built-in magnetic track.
Say, you manage to drive 2kg mass it keeps itself at 90º (3 o'clock) inside the rim, at 30cm from the hub.
What's that, 6Nm of torque?
At 36kph nearly 100W, 54kph 150W? Fuzzy math, looked up some formulae that seemed right.

 

[poupou]

Hi Cloxxki,

Can you draw it on a paper, and put here a picture? Thanks a lot.

I imagine that it could be possible to have a " magnet wheel" inside the wheel. The magnet wheel is moved by a rotating magnetic field created by coils piloted. That means that the battery is inside the wheel, and a mechanical reduction system is needed to transmit torque. Only valid for lenticular wheels.

 

[Cloxxki]

Re:

Hi Cloxxki,

Can you draw it on a paper, and put here a picture? Thanks a lot.

Wheel is rolling right. Rim on the right side is moving down, and the red mass is crawling up the lila magnet track at the inverse rate, keeping it at the 3 o'clock position. Effectively a (2kg) weight is always pulling on the bike nearly at tire level. for easy of calc we'll presure leverage optimal.
I am struggling to make it a correct power assist figure. Intuitively I'd say it's the same as having a weight on a rope over the edge of a cliff helping you go faster. Mass is doing work by falling as fast as the bike is moving.

V= 10m/s = 36kph as an easy figure.
m= 2 kg
t= 1 second

Kinetic Energy added every second:
KE=1/2 * m * V²
KM= 100 Joules
P= E/t
P= 100W

The weight could just be a battery pack and motor on a magnet infested rail, or better: maglev.
The location of the weight relative to the axle would determin work that could be done by a given active mass.
Stuck at the bottom of the wheel no work work be done, but it would be overcoming friction, else it would become a drag. During hard braking the system would be put to the test, to release quick enough. If it doesn't, and makes its way to the other side of the wheel, regeneratve braking would come in play, I just realize.

Easily detected, but it would not require a special torque arm or frame modifications.

 

[jyl]

Re:

In a rim you could have a tubular channel all the way around. In this tube, a radial piston could be placed. This piston could also be a floating stator running on the rim's built-in magnetic track.
Say, you manage to drive 2kg mass it keeps itself at 90º (3 o'clock) inside the rim, at 30cm from the hub.
What's that, 6Nm of torque?
At 36kph nearly 100W, 54kph 150W? Fuzzy math, looked up some formulae that seemed right.

Why would the mass (sliding piston) "keep itself" at 3 o'clock? Instead of traveling around the rim?. The system is going to take the path of least resistance. Since it will be easier to lift a 2 kg piston against gravity from 3 oclock to 12 oclock than to accelerate 80 kg of rider up a 10% grade, why won't the piston displace, rather than the rider?

When the drive is off, how do you ride with a 2 kg / 4.4 lb slider in the rim? Without the drive pushing the piston around the rim, won't the piston tend to stay at one point on the rim?. Won't this make the rear wheel incredibly unbalanced, so that the bike shakes and jumps?. Seems like it would be obvious at moderate speeds and uncontrollable at higher speeds.

Will a racer willingly lug around 2 kg of piston, some kg of magnets in the rim, some more kg of battery and controller - sounds like the bike would end up weighing 11 kg?

Where is the battery? If in the frame, how do you get current from the frame to the rim, and then to the sliding piston?.

Would this light up the UCI's magnetometer?. They are checking wheels, not just seat tubes.

 

[Cloxxki]

Re: Re:

In a rim you could have a tubular channel all the way around. In this tube, a radial piston could be placed. This piston could also be a floating stator running on the rim's built-in magnetic track.
Say, you manage to drive 2kg mass it keeps itself at 90º (3 o'clock) inside the rim, at 30cm from the hub.
What's that, 6Nm of torque?
At 36kph nearly 100W, 54kph 150W? Fuzzy math, looked up some formulae that seemed right.

Why would the mass (sliding piston) "keep itself" at 3 o'clock? Instead of traveling around the rim?. The system is going to take the path of least resistance. Since it will be easier to lift a 2 kg piston against gravity from 3 oclock to 12 oclock than to accelerate 80 kg of rider up a 10% grade, why won't the piston displace, rather than the rider?

When the drive is off, how do you ride with a 2 kg / 4.4 lb slider in the rim? Without the drive pushing the piston around the rim, won't the piston tend to stay at one point on the rim?. Won't this make the rear wheel incredibly unbalanced, so that the bike shakes and jumps?. Seems like it would be obvious at moderate speeds and uncontrollable at higher speeds.

Will a racer willingly lug around 2 kg of piston, some kg of magnets in the rim, some more kg of battery and controller - sounds like the bike would end up weighing 11 kg?

Where is the battery? If in the frame, how do you get current from the frame to the rim, and then to the sliding piston?.

Would this light up the UCI's magnetometer?. They are checking wheels, not just seat tubes.

I said, easily detectable.

If sit on your bike, flat surface and someone sticks a 2kg mass to your front wheel, you'll start rolling.
If the mass is actively working its way up, this input does not stop by reaching the bottom side of the wheel.
Why? It has electronics, knows where it is and what is asked of it.
The mass IS the battery pack. All the tech that can be on the mass itself is reduced loss.
What you are not understanding is that the mass acts like a car with unlimited traction using the wheel as its road. By staying at 3 o'clock it can give most gravity converted torque to the bike. Think of a monkey climbing up your front wheel just quick enough to not be overridden.

If there is really low friction, when "off" or out of battery power, it will sit at the bottom and not do much. Its friction inside the rim is added to the bike's rolling resistance.

I've once taken a ride with 3.4kg in water in my rear innertube. Very random, but not making me acutely slow or anything. The water distributes over the innertube, depending on speed. A lot speed, it will sit at the bottom, slosh around a bit. A high speed, almost uniformly distributed, sitting relatively still, merely adding mass to the wheel. It got weird for a moment when having a conbination of decend angle change, velocity change, and direction change at the same time. Over over a little bride, braking into a sharp turn.
But a clever rotating piston motor would be very easy to live with. Especially when there is still power left in the battery.

Sorry for the off-topic. Just coming up with a propulsion system difficult to see with the naked eye.

 

[blackcat]

Re:

The argument that "no one is checking for motor doping, so the motors don't actually have to be undetectable" makes no sense.

If you actually think that are no bike checks (the tablets are dummies, xray machines not plugged in, everyone just pretends to remove bottom brackets, all the motor checks are just a big sham) then there is no reason to develop a rim drive or a hub drive.

Just use the existing crank drives with motor in the seat post, they are proven, inexpensive, and work well with plenty of power and no mythical skunk works with "hundreds of millions of dollars" of cutting edge R&D needed.

yeah, there sorta would be motive to develop

if, i say if, cos I am merely on the highly skeptical of spartacus, I am not 100% convinced...

if like FreddytheFrog recalls and Levi and Levi's crew, just wait a sec, how absurd does that sound? "Levi's crew". does Levi really have a crew? FreddytheFrog, are you sure, this sounds like a logical fallacy, <Levi + crew>

however, I digress. lets assume for the purpose of this post, Levi does indeed have a crew, not matter how unfathomable it is, and whatever Odessa machine Gunn saw in him to marry the little hobbit from Peter Jackson middle earth central casting and he could be Frodo Cavendish' brother by another mother...

where was I?

oh yeah, if Levi and his crew, lets call them the Leipheimer entourage, if they were at the Tour of California speaking to Spartacus about his motor, this makes the whole motor charade more plausible...

now, if there were motors...

there would be motivation to develop new motor tecnology,
for
i) to stay ahead of the game
ii) to defend against the internal enforcement politics from the Leipheimer entourage, aka Levi's crew.

It is like Alan Turing law of technology, I think it was Turing the cryptographer/mathematician, coulda been someone else... but whatever you can think or imagine to invent, will be possible.

you stay ahead of the game, you neutralise the internal rules and politics from the peloton, you can still successfully cheat, you are just not assisted by internet2.0Gruber

 

[jyl]

Re: Re:

In a rim you could have a tubular channel all the way around. In this tube, a radial piston could be placed. This piston could also be a floating stator running on the rim's built-in magnetic track.
Say, you manage to drive 2kg mass it keeps itself at 90º (3 o'clock) inside the rim, at 30cm from the hub.
What's that, 6Nm of torque?
At 36kph nearly 100W, 54kph 150W? Fuzzy math, looked up some formulae that seemed right.

Why would the mass (sliding piston) "keep itself" at 3 o'clock? Instead of traveling around the rim?. The system is going to take the path of least resistance. Since it will be easier to lift a 2 kg piston against gravity from 3 oclock to 12 oclock than to accelerate 80 kg of rider up a 10% grade, why won't the piston displace, rather than the rider?

When the drive is off, how do you ride with a 2 kg / 4.4 lb slider in the rim? Without the drive pushing the piston around the rim, won't the piston tend to stay at one point on the rim?. Won't this make the rear wheel incredibly unbalanced, so that the bike shakes and jumps?. Seems like it would be obvious at moderate speeds and uncontrollable at higher speeds.

Will a racer willingly lug around 2 kg of piston, some kg of magnets in the rim, some more kg of battery and controller - sounds like the bike would end up weighing 11 kg?

Where is the battery? If in the frame, how do you get current from the frame to the rim, and then to the sliding piston?.

Would this light up the UCI's magnetometer?. They are checking wheels, not just seat tubes.

I said, easily detectable.

If sit on your bike, flat surface and someone sticks a 2kg mass to your front wheel, you'll start rolling.
If the mass is actively working its way up, this input does not stop by reaching the bottom side of the wheel.
Why? It has electronics, knows where it is and what is asked of it.
The mass IS the battery pack. All the tech that can be on the mass itself is reduced loss.
What you are not understanding is that the mass acts like a car with unlimited traction using the wheel as its road. By staying at 3 o'clock it can give most gravity converted torque to the bike. Think of a monkey climbing up your front wheel just quick enough to not be overridden.

If there is really low friction, when "off" or out of battery power, it will sit at the bottom and not do much. Its friction inside the rim is added to the bike's rolling resistance.

I've once taken a ride with 3.4kg in water in my rear innertube. Very random, but not making me acutely slow or anything. The water distributes over the innertube, depending on speed. A lot speed, it will sit at the bottom, slosh around a bit. A high speed, almost uniformly distributed, sitting relatively still, merely adding mass to the wheel. It got weird for a moment when having a conbination of decend angle change, velocity change, and direction change at the same time. Over over a little bride, braking into a sharp turn.
But a clever rotating piston motor would be very easy to live with. Especially when there is still power left in the battery.

Sorry for the off-topic. Just coming up with a propulsion system difficult to see with the naked eye.

See emphasis added to your quote, above: "flat surface". Yes, on a flat surface (and no rolling resistance and no air resistance) this will work. But this 2 kg weight attached to the rim will not propel your bike plus you up a grade steeper than about 1.3 degrees.

Gravity acting on the 2 kg rim weight causes a 2 * 9.8 = 19.6 kg*m/s^2 force vector on the rim, direction straight down. The geometry of the wheel and the friction between tire and road translates this to a 19.6 kg*m/s^2 force vector on the bike, direction to the right (uphill) and tangent to the road. Meanwhile gravity acting on the 85 kg of rider and bike causes a 85 * 9.8 = 833 kg*m/s^2 force vector on bike, direction straight down. The component of that force vector that is direction left (downhill) and tangent to the road is 833 * sin (A) kg*m/s^2 where A is the angle of the road.

At A = 0 degrees (flat road), the direction left force vector is zero, so the direction right force vector is larger, and the bike will roll forward.

At A = 1.34 degrees, the two force vectors equal in magnitude, because sin (1.34 deg) = 19.6/833, and the 2 kg weight can hold you stationary on this extremely slight hill.

At A > 1.34 degrees, the direction left force vector is larger, and the bike rolls backwards, downhill.

Gravity acting on the 2 kg weight doesn't generate enough force to be useful.

The same problem applies to the rim drive you described.

I also suggest that a wheel with a tire full of water was not an imbalanced wheel, because the water was distributed uniformly around the tire. If all 3.4 kg of water were in a milk jug tied to the spokes at one point on the rim, that would have been an imbalanced wheel. I think it is pretty obvious that riding that wheel at high speed would be a bad thing. Calculate the centripetal force of 3.4 kg rotating at a 0.3 m radius at tangential speed 60 km/h . . .

So the drive you described would have to be turned "on" at all times, or the bike would buck and hop at racing speeds.

 

[jyl]

Re: Re:

Hi Cloxxki,

Can you draw it on a paper, and put here a picture? Thanks a lot.

Wheel is rolling right. Rim on the right side is moving down, and the red mass is crawling up the lila magnet track at the inverse rate, keeping it at the 3 o'clock position. Effectively a (2kg) weight is always pulling on the bike nearly at tire level. for easy of calc we'll presure leverage optimal.
I am struggling to make it a correct power assist figure. Intuitively I'd say it's the same as having a weight on a rope over the edge of a cliff helping you go faster. Mass is doing work by falling as fast as the bike is moving.

V= 10m/s = 36kph as an easy figure.
m= 2 kg
t= 1 second

Kinetic Energy added every second:
KE=1/2 * m * V²
KM= 100 Joules
P= E/t
P= 100W

The weight could just be a battery pack and motor on a magnet infested rail, or better: maglev.
The location of the weight relative to the axle would determin work that could be done by a given active mass.
Stuck at the bottom of the wheel no work work be done, but it would be overcoming friction, else it would become a drag. During hard braking the system would be put to the test, to release quick enough. If it doesn't, and makes its way to the other side of the wheel, regeneratve braking would come in play, I just realize.

Easily detected, but it would not require a special torque arm or frame modifications.

The weight stays in a constant position relative to the bike. If the bike is moving at a constant speed, the weight is also moving at a constant speed. Zero acceleration, therefore the kinetic energy is constant. The drive does not "add" more kinetic energy every second.

The drive is actually working on potential energy. The 2 kg weight at 3 oclock has a potential energy PE = m * g * h = 2 kg * 9.8 m/s^2 * 0.3 m = 5.9 kg*m^2/s^2, assuming the weight is 0.3 meters above the road. Which is not much.

Yes, it is sort of a "pulley problem". Basically there is a rope tied to the front of the bike, going over a pulley, the other end of the rope is tied to a hanging 2 kg weight. Gravity pulls the weight down with force 2 * 9.8 kg*m/s^2. That force pulls the bike forward. Unfortunately, that is not much force - not a useful amount of force.

 

[sniper]

Re:

............what is the likelihood of detecting a hidden motor......just by tapping the frame?

Mark L

between IOC and UCI, who's gonna do the bike testing at the Olympics?

cheaters better watch out!

 

[sniper]

great posts, cloxxki. certainly not off topic.
as libertine seguros suggested in the mods thread, it would perhaps be good to separate the theoretical/technical discussion from the Femke discussion to get a better focus on both topics.

 

[Cloxxki]

I agree that there should be a separate thread for (theoretical) mech fraud systems.

I did not emphasize, but my little fraud seems to be very much speed dependent for power assist. If I am right, it could (if powerful enough to maintain 3 oçlock 90º optimum) only produce good power at high speeds. There is no gear reduction. No, it will not be like a motorbike up a hill where you can just coast. It's a mass on a lever.
I can think of ways to boost the output (inner rim spinning faster) but then you need to involve the hub as a gear. What i have here is a rim motor that doesn't need interaction with coils or magnets on the frame. This wheel would go all by itself. And it would GO. Imagine a 4kg wheel of which 2kg is moving inside the rim. It would get up to pretty nice speeds by itself. And as said at higher speed be able tooffer more power. Just a diminishing percentage of leg power (on flat road).

 

[jyl]

Re:

I agree that there should be a separate thread for (theoretical) mech fraud systems.

I did not emphasize, but my little fraud seems to be very much speed dependent for power assist. If I am right, it could (if powerful enough to maintain 3 oçlock 90º optimum) only produce good power at high speeds. There is no gear reduction. No, it will not be like a motorbike up a hill where you can just coast. It's a mass on a lever.
I can think of ways to boost the output (inner rim spinning faster) but then you need to involve the hub as a gear. What i have here is a rim motor that doesn't need interaction with coils or magnets on the frame. This wheel would go all by itself. And it would GO. Imagine a 4kg wheel of which 2kg is moving inside the rim. It would get up to pretty nice speeds by itself. And as said at higher speed be able tooffer more power. Just a diminishing percentage of leg power (on flat road).

Is your drive merely propelling a 4 kg wheel? Very little power required. Or a 85 kg bike and rider? Far more power required, which your drive can't provide.

I encourage you to fasten a 2 kg weight to your wheel (just tie some lead weights, or even a couple of hammers, to some spokes), position yourself facing uphill on a very modest hill, place the weight at 3 oclock, and see what happens. It is an easy experiment, just try it.

 

[Cloxxki]

Re: Re:

I encourage you to fasten a 2 kg weight to your wheel (just tie some lead weights, or even a couple of hammers, to some spokes), position yourself facing uphill on a very modest hill, place the weight at 3 oclock, and see what happens. It is an easy experiment, just try it.

Why do you try to dispute what I did not claim? Don't I sufficiently demonstrate to understand how the motor I invented operates? Don't underestimate fellow posters so easily. Read better. Your response is quite offensive as you imply that I'm stupid after I've just shared a wheel motor design that can offer assist regardless of frame or hub used. Bad form. Were you raised that way?

Don't be so lazy if you're so smart. Do the experiment yourself and do the scientific thing. Measure the pull a rider+bike have while on this incline required to remain stationary (simple digital fish scale aligned with the road does the trick), with and without 2kg on the wheel at 3 o'clock. I bet you the added weight on the front of a wheel makes you lighter. And if you pedal hard enough to achieve forward movement, the assist will start to register as power. Want more assist? >> get a heavier/more potent weight, or pedal harder.

 

[GJB123]

Re: Re:

I encourage you to fasten a 2 kg weight to your wheel (just tie some lead weights, or even a couple of hammers, to some spokes), position yourself facing uphill on a very modest hill, place the weight at 3 oclock, and see what happens. It is an easy experiment, just try it.

Why do you try to dispute what I did not claim? Don't I sufficiently demonstrate to understand how the motor I invented operates? Don't underestimate fellow posters so easily. Read better. Your response is quite offensive as you imply that I'm stupid after I've just shared a wheel motor design that can offer assist regardless of frame or hub used. Bad form. Were you raised that way?

Don't be so lazy if you're so smart. Do the experiment yourself and do the scientific thing. Measure the pull a rider+bike have while on this incline required to remain stationary (simple digital fish scale aligned with the road does the trick), with and without 2kg on the wheel at 3 o'clock. I bet you the added weight on the front of a wheel makes you lighter. And if you pedal hard enough to achieve forward movement, the assist will start to register as power. Want more assist? >> get a heavier/more potent weight, or pedal harder.

I can see nothing wrong with the style of his reply. He replied a few times providing elaborate calculations and arguments why your design wouldn't work, all of which you conveniently ignored. As soon as he makes a somewhat sarcastic jibe in his third or fourth reeky you pounce on the perceived sarcasm yet you provide no counter arguments to earlier replies. Were you raised that way? (which is much more an ad hominem than his reply).

The fun part is that jyl provided his arguments and calculations already so as long as you don't show where he got it wrong the onus of the proof (i.e. scientific experiment) is on you .

 

[jyl]

Re: Re:

I encourage you to fasten a 2 kg weight to your wheel (just tie some lead weights, or even a couple of hammers, to some spokes), position yourself facing uphill on a very modest hill, place the weight at 3 oclock, and see what happens. It is an easy experiment, just try it.

Why do you try to dispute what I did not claim? Don't I sufficiently demonstrate to understand how the motor I invented operates? Don't underestimate fellow posters so easily. Read better. Your response is quite offensive as you imply that I'm stupid after I've just shared a wheel motor design that can offer assist regardless of frame or hub used. Bad form. Were you raised that way?

Don't be so lazy if you're so smart. Do the experiment yourself and do the scientific thing. Measure the pull a rider+bike have while on this incline required to remain stationary (simple digital fish scale aligned with the road does the trick), with and without 2kg on the wheel at 3 o'clock. I bet you the added weight on the front of a wheel makes you lighter. And if you pedal hard enough to achieve forward movement, the assist will start to register as power. Want more assist? >> get a heavier/more potent weight, or pedal harder.

Don't get emotional. This is your design, so it is up to you to show that it will work. Either by correct calculation, or by experiment.

I did the calculation for you. This is equivalent to a pulley problem. Your rim weight will try to pull the bike up the incline with the force of gravity times 2 kg = 2 x 9.8 = 19.6 kg*m/s^2. That is a very little amount of force, compared to the force of gravity pulling 85 kg of bike and rider down the incline. Assuming a 5% grade, which is a 2.9 degree angle, that force is 85 x 9.8 x sin (2.9 deg) = 42 kg*m/s^2. The bike will roll backwards.

It doesn't matter how fast the wheel is rotating. Assuming the rim weight has no friction against the rim, the force required to hold the weight at 3 oclock remains 2 kg x gravity (9.8 m/s^2), and that is the opposite (reaction) force applied to the rim and thus pulling the bike up the incline.

If you increase the weight, then it will pull the bike up the incline with more force. Looks like you'd need a 5 kg (10 lb) weight just to hold the bike stationary on that 5% grade. To pull the bike up the incline with enough force to be useful in a racing situation would require a much heavier weight. Concealing a 20+ kg weight inside a normal looking rim is impractical, and riding with 20 kg additional weight on the rim is also impractical.

 

[sniper]

lol at gjb123 lecturing others on adhoms.

say i'm Sky's director of technological development. (crazy, i know)
say there's a vacancy, the tech team needs a new member to inspire the tech team and bring in new ideas that could give Sky an edge over other new-age scientifically oriented cycling teams. Marginal gains.
Cloxxki would be my guy.

the mindset of "impractical, detectable, nah, not gonna work", that's not the proper mindset for technological advancement in the world of procycling.
If you wanna find that one marginal technical gain, you gotta explore all the possibilities, exploit all the holes in the system, think outside the box.
If i had a big budget and needed to bring in people to give me that brilliant idea, Cloxxki would be my guy.

 

[Cloxxki]

Re: Re:

I encourage you to fasten a 2 kg weight to your wheel (just tie some lead weights, or even a couple of hammers, to some spokes), position yourself facing uphill on a very modest hill, place the weight at 3 oclock, and see what happens. It is an easy experiment, just try it.

Why do you try to dispute what I did not claim? Don't I sufficiently demonstrate to understand how the motor I invented operates? Don't underestimate fellow posters so easily. Read better. Your response is quite offensive as you imply that I'm stupid after I've just shared a wheel motor design that can offer assist regardless of frame or hub used. Bad form. Were you raised that way?

Don't be so lazy if you're so smart. Do the experiment yourself and do the scientific thing. Measure the pull a rider+bike have while on this incline required to remain stationary (simple digital fish scale aligned with the road does the trick), with and without 2kg on the wheel at 3 o'clock. I bet you the added weight on the front of a wheel makes you lighter. And if you pedal hard enough to achieve forward movement, the assist will start to register as power. Want more assist? >> get a heavier/more potent weight, or pedal harder.

Don't get emotional. This is your design, so it is up to you to show that it will work. Either by correct calculation, or by experiment.

I did the calculation for you. This is equivalent to a pulley problem. Your rim weight will try to pull the bike up the incline with the force of gravity times 2 kg = 2 x 9.8 = 19.6 kg*m/s^2. That is a very little amount of force, compared to the force of gravity pulling 85 kg of bike and rider down the incline. Assuming a 5% grade, which is a 2.9 degree angle, that force is 85 x 9.8 x sin (2.9 deg) = 42 kg*m/s^2. The bike will roll backwards.

It doesn't matter how fast the wheel is rotating. Assuming the rim weight has no friction against the rim, the force required to hold the weight at 3 oclock remains 2 kg x gravity (9.8 m/s^2), and that is the opposite (reaction) force applied to the rim and thus pulling the bike up the incline.

If you increase the weight, then it will pull the bike up the incline with more force. Looks like you'd need a 5 kg (10 lb) weight just to hold the bike stationary on that 5% grade. To pull the bike up the incline with enough force to be useful in a racing situation would require a much heavier weight. Concealing a 20+ kg weight inside a normal looking rim is impractical, and riding with 20 kg additional weight on the rim is also impractical.

I never claimed the wheel would drive up an incline with rider sitting back. It's a hidden bike motor, who would seriously expect that? Also the calcs you offer don't seem particularly helpful.
Could a commercial hidden BB motor drive me up that 5% incline in 53x11 from standstill anyway?

If you are going 10m/s (36kph), doesn't the weight give up more potential energy per second than at 5m/s?
I applied this following formula. I could very well be mistaken in thinking that it applies http://planetcalc.com/1908/

Then what IS the correct formula for power assist provided?
If it takes for instance 250W at the wheel to go 10m/s = 36kph, how much weight on a pulley would achieve that terminal velocity?

 

[Hawkwood]

Re: Re:

Hi Cloxxki,

Can you draw it on a paper, and put here a picture? Thanks a lot.

Wheel is rolling right. Rim on the right side is moving down, and the red mass is crawling up the lila magnet track at the inverse rate, keeping it at the 3 o'clock position. Effectively a (2kg) weight is always pulling on the bike nearly at tire level. for easy of calc we'll presure leverage optimal.
I am struggling to make it a correct power assist figure. Intuitively I'd say it's the same as having a weight on a rope over the edge of a cliff helping you go faster. Mass is doing work by falling as fast as the bike is moving.

V= 10m/s = 36kph as an easy figure.
m= 2 kg
t= 1 second

Kinetic Energy added every second:
KE=1/2 * m * V²
KM= 100 Joules
P= E/t
P= 100W

The weight could just be a battery pack and motor on a magnet infested rail, or better: maglev.
The location of the weight relative to the axle would determin work that could be done by a given active mass.
Stuck at the bottom of the wheel no work work be done, but it would be overcoming friction, else it would become a drag. During hard braking the system would be put to the test, to release quick enough. If it doesn't, and makes its way to the other side of the wheel, regeneratve braking would come in play, I just realize.

Easily detected, but it would not require a special torque arm or frame modifications.

Where does the tyre valve go in this design?

 

[Cloxxki]

Re: Re:

Where does the tyre valve go in this design?

Good one.
If you still insist on using pneumatic tires, I suppose since disc brakes are becoming the norm, it could be just onder the beads off to the side.If the motor is to be sneaky, a dummy valve stem will need to be added