My UC Pro has arrived

[Deacon Blues]

This damn UC Pro.........

Let me explain.
I took my UC Pro on a 55km ride a couple of days ago. I circled a small peninsula, with some mild trail riding.
Most of this road is either going up or going down. Very little of it is flat.
With the power this bike has the hills were like molehills. My pace up the many hills was rapid, but I never went above level 3. A higher level wasn't needed.
The bike even performed very well on the mild trails I rode on. I was surprised, considering the bike's heft. The 3 inch wide tires helped a lot.

The downside?
I rode my Cannondale Topstone Neo Lefty 3 (could this name be any longer?) yesterday on a senior's group ride and the bike felt underpowered, which is weird, because with 85 Nm of torque from the Bosch Gen 4 motor (and it's de-restricted) the bike, in the past, has never felt slow.

I blame it on my UC Pro. This bike has spoiled me. I've experienced 'really fast' and now I'm disappointed with 'quick'.

Damn you UC Pro.

 

[Deacon Blues]

Beauty (sort of) and the beast.

 

[mschwett]

@Deacon Blues why so many unused paintbrushes

 

[Johnny]

which is weird, because with 85 Nm of torque from the Bosch Gen 4 motor (and it's de-restricted) the bike, in the past, has never felt slow.

Physics is physics, the less power you have the slower you go(many of us pointed this out while fanboys were singing a different song). Torque by itself is a meaningless number and it is used for marketing too much. By putting my weight on one pedal I can generate far more torque then 85nm. By playing with the internal gearing, one can have as high torque as it wants.

It is funny to see that in some reviews. expensive bikes that come with that bosch cx mid drive being called an F1 car because of the bike's price. F1 cars don't share the same motor with a toyota corolla.

 

[Johnny]

Yup. "Physics is physics".
When you say "By putting my weight on one pedal I can generate far more torque then 85nm", being just a student you got me thinking and I'm trying to wrap my head around this. Have I erred?
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No doubt some can and maybe do pedal w/ 85nm force, but to generate (lets use) 80nm, one would have to put out 59ft lbs. - per leg, per revolution - only done standing up (all sources I can find say).
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An example came to me:
Cranking @ 80nm will move 30,000lbs one ft. in 254 revolutions.
That 2mins 8secs @ 90rpm cadence is some SERIOUS HUMAN POWER OUTPUT. .... over 9000 Calories in 2mins 8secs ?
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In perspective, if/ when one reaches an insurmountable strength plateau after weight training for years, a simple routine was developed to crush that barrier: Every other week lift 30,000lbs; no rest between sets; two - three people; one always spotting, one lifting.
Deadlift 400 x 5 to get 2k, or bench 250 x 8 to get 2k. (Smith machine) Squat whatever x the reps you so chose to get 2k lbs per set.
No BS like 'clean n' jerk'. This is not a fun routine. Prima Donna's fail quick. Perfect timing = finished in 22 mins for two, 29mins for three. Etiquette is you rotate who picks the exercise and do what they do ( your weight and rep choice).
Working out with Islander Brah's was brutal. Guys benching 450, deadlifting 600+ reps, but he's stuck with 5 reps to exceed 2000lbs, me 8 reps at 250, he lifted 250 lbs more on bench and 400 more D-L'ing to finish with 2000lbs. I'm more conservative knowing 'the end is near'.
Object is to both finish at +30,000lbs, last set of reps. Your not maxing weight - at 2000lbs total per set. It's only 15 sets. Yawn come on, only 6 sets left Big Guy - YOUR SET.
Soon as you get good, add 2000lbs to the routine. Rinse and repeat. A healthy respect for disciplined repetition training schedules, I attained 100,000lbs in -90mins. Takes a few years. Only routine that ever made me take a nap. Caloric intake was insane; 2-3% body fat, my muscles would eat themselves and I'd be weakened in all my lifts for 4 days, then stronger, just a bit, but always stronger.
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Albeit, considering such lifts move the mass roughly two feet, moving 30,000lb = 60,000 ft. lbs./ inputting 80nm for 508 revolutions - without stopping for 4mins 16 secs @90rpm.
I conclude it's near superhuman, unobtainable by the strongest and dedicated, most fit for more than a very short while. No way any man can do it for 10 minutes - and almost no 'street legal' product 'class' bike can either.
It's simply not where the money is and that's where manufacturers want to be, and why I went w/ the WW's Ultra. No problema for a real 160nm - 'cept destroying all the bicycle stuff - that 80nm pumping madmen couldn't break.

Fn'F

Your confusion is, you start with torque which is a measure of rotational force then add rpm into the mix and venture into power. Put rotational speed aside.

A 90kg human being putting all its weight on a pedal of length 17.5cm generates(maybe the word generate is creating this confusion) roughly 150nm of torque. Of course this means nothing. One can stand on that pedal all day long, if the pedal is not turning since that person is not generating any power.

That is why some people are constantly confused about the torque ratings of a motorcycle vs an ebike. The simple difference is while an ebike motor like bosch will give 85 nm only up to a measly 60 rpm at its peak(nominal is much lower than that), a Ducati rated at an almost the same 86nm torque will sustain that torque well over 6000rpm!

This is such an easy value to manipulate and it is used by ebike manufacturers for false marketing.


Power that is turned into motion is what matters. Torque by itself does not give that information, one needs rotational speed too for that.

 

[mschwett]

Power that is turned into motion is what matters. Torque by itself does not give that information, one needs rotational speed too for that.

well put. and assuming the designers of the gearing of the vehicle in question were not dumb or otherwise constrained, the power figure is far more meaningful than torque.

an able amateur human cyclist can generate 1000w of power for short bursts, and perhaps 200w for an extended period. tour de france winning territory is a sustained 350w. this puts the power these small eBike motors put out in perspective!

 

[JRA]

"an able amateur human cyclist can generate 1000w of power for short bursts, and perhaps 200w for an extended period. tour de france winning territory is a sustained 350w. this puts the power these small eBike motors put out in perspective!"

What I would consider to be a sidebar to this is that I find it interesting that the winners or 100mile and plus gravel bike races average 20mph. I find that in order to do this with an ebike even it is a hang on experience that is not all that pleasant.

 

[Fast n' Furious]

Your confusion is, you start with torque which is a measure of rotational force then add rpm into the mix and venture into power. Put rotational speed aside.

A 90kg human being putting all its weight on a pedal of length 17.5cm generates(maybe the word generate is creating this confusion) roughly 150nm of torque. Of course this means nothing. One can stand on that pedal all day long, if the pedal is not turning since that person is not generating any power.

That is why some people are constantly confused about the torque ratings of a motorcycle vs an ebike. The simple difference is while an ebike motor like bosch will give 85 nm only up to a measly 60 rpm at its peak(nominal is much lower than that), a Ducati rated at an almost the same 86nm torque will sustain that torque well over 6000rpm!

This is such an easy value to manipulate and it is used by ebike manufacturers for false marketing.


Power that is turned into motion is what matters. Torque by itself does not give that information, one needs rotational speed too for that.

Static Torque the exception, without rotational speed there is no torque.
A unit of force is equal to a unit of mass times a unit of acceleration. I can stand on a rock all day with all my might and 'generate' zero torque.

Rotational Equilibrium is analogous to translational equilibrium, where the sum of the forces are equal to zero. In rotational equilibrium, the sum of the torques is equal to zero. In other words, there is no net torque on the object.
In imperial units, the 'Foot-pound' being used is confusing because colloquially the pound is sometimes used as a unit of mass and sometimes force. What is meant here is pound-force, the force due to earth gravity on a one-pound object.
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Measuring a static torque in a non-rotating system is usually quite easy, and done by measuring a force. Given the length of the moment arm, the torque can be found directly. Measuring torque in a rotating system is considerably more difficult. One method works by measuring strain within the metal of a drive shaft which is transmitting torque.
There is considerable confusion between torque, power and energy. For example, the torque of an engine is sometimes incorrectly described as its 'turning power'.
Torque and energy have the same dimensions (i.e. they can be written in the same fundamental units), but they are not a measure of the same thing. They differ in that torque is a vector quantity defined only for a rotatable system.
Power however, can be calculated from torque if the rotational speed is known. In fact, the horsepower of an engine is not typically measured directly, but calculated from measured torque and rotational speed.
Peak torque is relevant for generally describing how quickly a vehicle will accelerate and its ability to pull a load. Horsepower (relative to weight) on the other hand is more relevant to the maximum speed of a vehicle.
The SI units of torque, a Newton-metre is also a way of expressing a Joule (the unit for energy). However, torque is not energy. The distinction arises because energy is a scalar quantity, whereas torque is a vector.
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I agree that a lot of folks don't understand the differences, but it's really simple.
Power is how rapidly work is accomplished (Eighteenth-century Scottish inventor James Watt gave us this handy equivalency: one horsepower is the power required to lift 33,000 pounds exactly one foot in one minute.
Energy is the capacity for doing work.
Work is the result of a force acting over some distance.
Torque is a rotating force produced by an engine’s crankshaft.
The more torque an engine produces, the greater its ability to perform work. The measurement is the same as work, but torque is a vector (acting in a certain direction).
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My confusion was the caloric conversion. The table I used was for kilocalories - but used "'c". lol.
On average a human consumes around 2000 kilocalories per day. This converts to roughly 200,0000 calories / 86400 seconds or around 100 joules / second giving roughly 100 watts. Given that, I can see athletes capable of a much larger scale output.
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For us, manufacturer listing torque figures lacking the rotational speed are incomplete, easily manipulated data. I'm partial to GRIN's Motor Simulator.
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The Ducati Monster 821, a 1200cc beast with 109 bhp at 9,250 rpm, 86 Nm (106Nm peak) at at 7,750 rpm.
Great taste in machinery and thanks for the input.


Fn'F

 

[scrambler]

Do not forget that torque / rpm relationship in a combustion engine is different than in a DC motor itself different than in an AC motor...

 

[Jon A]

As for the Olallie trail... it may be nice and sunny but it's cold right now, 16° before windchill at Mt Washington!

It was quite an adventure, but I wasn't ever cold (sweating profusely actually)!

@Jon A my rims actually landed stateside on the 27th! USPS shows estimated arrival the 3rd. I build up my own rims but have the LBS destress & true them, saves me a good bit of money and turn around is much quicker, plus I get back a perfect wheel.

I hear ya. I've got a set of 100mm wide carbons on the way as well, shipped about three weeks ago. Unfortunately, I don't expect them to show up while there's still any hope of good snow riding conditions around here. Oh well, I'll have them for next year. Those are the original boat anchors that came with the bike...it should be against the law to make a wheel that heavy!

 

[Jon A]

Wow, looks like I have some catching up to do in this thread. While so difficult to read I often skip them, this one needs to be addressed.

You lost me with the chaff. What "Standard cranks"? Bafangs? WW's? Miranda's? What "fat cranks"? Bafangs, etc/

If somebody is talking about cranks on Bafang motors, does not specify an aftermarket brand name and model, and shows a picture directly from Bafang of Bafang cranks, it's safe to assume they are talking about Bafang made cranks.

What "my frame"?

I have an E06. I've mentioned it many times in this section.

You know exactly how, again, that "They obviously will fit Deacon's, but that frame won't clear a 5" tire" ?

They obviously fit the fit the frame because he rode the bike with them. He wouldn't have gone very far if they contacted the chainstays.

"I'm not saying there's zero chance the combo would fit, but I'm certainly not going to tell people it will". WTF does that mean?

It's English. I encourage you to learn it. I don't state with certainty parts combos will work together unless I actually have certainty they will. People may buy parts, plan a build and find out things don't fit. I prefer not to be responsible for that. Apparently you don't mind.

"When you include the Christini fat spider in that, its smaller bolt circle makes interference even more likely"
It does not. Not on the topic bikes, our WW 197mm hardtails.

You clearly don't understand the problem--it's not bike specific. This is the problem:

There's a whopping 2mm of clearance there with my BAFANG fat cranks using 3.8mm spacers with the chainring, without spacers it's a whopping 5.8mm. If you look at the picture using your eyeballs, you can see how a spider and chainring with a larger BCD will put that point of interference at a location where the crank has a lot more clearance. Most aftermarket cranks, while certainly not following this geometry exactly, will have more clearance farther along their length than at that location. This is why the Christini is more likely to interfere.

Now, if you have a database of all aftermarket cranks with detailed dimensions showing how much clearance they will have at that location, I stand corrected. You actually do know what you're talking about and have simply not shared that information with the rest of the class. Otherwise, you're making stuff up--guessing.

I don't have details on the cranks Pushkar is using. Do you? We do know he sent a new set of his version of fat cranks to Deacon to use along with the fat spider. What is your evidence he wasted the money and screwed up Deacon's Q factor for no reason at all?

 

[Jon A]

Yikes.

Static Torque the exception, without rotational speed there is no torque.

Uhm, no. That's not how it works. There's no such thing as a "static torque exception" in the Engineering world. Torque is torque. There is no distinction between them. Moving or not it's the same thing. The reaction to it is what determines if there's movement or not.

A unit of force is equal to a unit of mass times a unit of acceleration.

That's a law of motion, not the definition of a force. Not relevant.

I can stand on a rock all day with all my might and 'generate' zero torque.

Assuming the rock is cantilevered somehow (you do realize it's rotational, right?), you are, in fact, applying a torque with the help of gravity and your mass. The rock not moving simply means the structure is sufficient to react it in an equal and opposite way (you know, one of those other laws from Mr. N).

You can, in fact, stand on the pedal of a bike all day and yes, you are creating and applying a torque to the system...which is changed to a linear force in the chain...which is then turned into a torque once again at the cassette. If the bike doesn't move because something is stopping it, it doesn't change the torque you are putting into the system at all. If, for example, you're holding the rear brake that simply means the pads are applying a force to the rotor creating and equal opposite moment about the axle. It doesn't change the force you're putting on the pedal nor the torque that creates.

Torque and energy have the same dimensions (i.e. they can be written in the same fundamental units), but they are not a measure of the same thing.

The units are the same, but the dimensions are not. The distance dimension means something different for each. This should be denoted with the order, but many get them wrong. A ft-lb of energy by definition is a force of one lb applied through a distance of one foot. A lb-ft of torque is a lb of force applied one foot from the point of rotation. Yes, it can cause confusion but saying they're the same "dimensions" only furthers the confusion.

Peak torque is relevant for generally describing how quickly a vehicle will accelerate and its ability to pull a load. Horsepower (relative to weight) on the other hand is more relevant to the maximum speed of a vehicle.

This is not correct. Let me explain why:

While sometimes that seems to be the case in some examples, this is due to execution/implementation/practical limitations that sometimes allow a motor with more torque to have more usable power at lower speeds than another motor that may have more power but require unreasonable gearing, etc, to use it effectively at low speeds.

Because yes, acceleration will be determined by power applied. If you go back to your law of motion equation, you can see the acceleration of a given object is directly proportional to the force applied to it (linear force at the contact patch actually, torque of the motor itself is irrelevant as the relationship between the two can be changed with gearing). That's not the end of the story. As an object accelerates, it changes velocity by definition. Applying a force at a velocity requires power. Velocity is distance per unit time. Force applied through a distance is work. Work per unit time is power. So the force you can apply to a moving object at any given speed is determined by the power the system, not the torque of the motor.

That concept is why this is not correct for many end users:

In fact, the horsepower of an engine is not typically measured directly, but calculated from measured torque and rotational speed.

One of the most popular chassis dynos is the Dynojet inertia-based dyno. Using a drum of a known rotational inertia, the rate of acceleration from the car is tracked. Since this is directly proportional to the force at the contact patch applied to it at speed, the power can be directly calculated. The torque of the engine cannot. The torque of the engine can only be calculated with an additional RPM pickup on a spark plug wire so it knows the RPM of the engine during the run. Then, the torque can be calculated from that and the power the engine was producing at that point in time. Disconnect that and you can measure the engine's power, but not its torque.

Since the faster you go, the more power is required to accelerate at a given rate, power differences become more obvious at higher speeds in the real world. That doesn't mean they aren't still the determining factor for accelerating at lower speeds, just that practical limitations of gearing, etc, sometimes masks what's really going on and causes misconceptions.

 

[Fast n' Furious]

Do not forget that torque / rpm relationship in a combustion engine is different than in a DC motor itself different than in an AC motor...

Ohhhhh gawd ... I'd bite and say 'How is it different?', but respecting the topic - I'll look into that.
Feel free to hint.

Fn'F

Yikes.

Uhm, no. That's not how it works. There's no such thing as a "static torque exception" in the Engineering world. Torque is torque. There is no distinction between them. Moving or not it's the same thing. The reaction to it is what determines if there's movement or not.

That's a law of motion, not the definition of a force. Not relevant.


Assuming the rock is cantilevered somehow (you do realize it's rotational, right?), you are, in fact, applying a torque with the help of gravity and your mass. The rock not moving simply means the structure is sufficient to react it in an equal and opposite way (you know, one of those other laws from Mr. N).

You can, in fact, stand on the pedal of a bike all day and yes, you are creating and applying a torque to the system...which is changed to a linear force in the chain...which is then turned into a torque once again at the cassette. If the bike doesn't move because something is stopping it, it doesn't change the torque you are putting into the system at all. If, for example, you're holding the rear brake that simply means the pads are applying a force to the rotor creating and equal opposite moment about the axle. It doesn't change the force you're putting on the pedal nor the torque that creates.


The units are the same, but the dimensions are not. The distance dimension means something different for each. This should be denoted with the order, but many get them wrong. A ft-lb of energy by definition is a force of one lb applied through a distance of one foot. A lb-ft of torque is a lb of force applied one foot from the point of rotation. Yes, it can cause confusion but saying they're the same "dimensions" only furthers the confusion.


This is not correct. Let me explain why:

While sometimes that seems to be the case in some examples, this is due to execution/implementation/practical limitations that sometimes allow a motor with more torque to have more usable power at lower speeds than another motor that may have more power but require unreasonable gearing, etc, to use it effectively at low speeds.

Because yes, acceleration will be determined by power applied. If you go back to your law of motion equation, you can see the acceleration of a given object is directly proportional to the force applied to it (linear force at the contact patch actually, torque of the motor itself is irrelevant as the relationship between the two can be changed with gearing). That's not the end of the story. As an object accelerates, it changes velocity by definition. Applying a force at a velocity requires power. Velocity is distance per unit time. Force applied through a distance is work. Work per unit time is power. So the force you can apply to a moving object at any given speed is determined by the power the system, not the torque of the motor.

That concept is why this is not correct for many end users:



One of the most popular chassis dynos is the Dynojet inertia-based dyno. Using a drum of a known rotational inertia, the rate of acceleration from the car is tracked. Since this is directly proportional to the force at the contact patch applied to it at speed, the power can be directly calculated. The torque of the engine cannot. The torque of the engine can only be calculated with an additional RPM pickup on a spark plug wire so it knows the RPM of the engine during the run. Then, the torque can be calculated from that and the power the engine was producing at that point in time. Disconnect that and you can measure the engine's power, but not its torque.

Since the faster you go, the more power is required to accelerate at a given rate, power differences become more obvious at higher speeds in the real world. That doesn't mean they aren't still the determining factor for accelerating at lower speeds, just that practical limitations of gearing, etc, sometimes masks what's really going on and causes misconceptions.

"Uhm, no. That's not how it works. There's no such thing as a "static torque exception" in the Engineering world. Torque is torque. There is no distinction between them. Moving or not it's the same thing. The reaction to it is what determines if there's movement or not."
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"Torque can be either static or dynamic. A static torque is one which does not produce an angular acceleration. Someone pushing on a closed door is applying a static torque to the door because the door is not rotating about its hinges, despite the force applied".
https://www.sciencedirect.com/topics/engineering/static-torque
Someone pedaling a bicycle at constant speed is also applying a static torque because they are not accelerating.
The drive shaft in a racing car accelerating from the start line is carrying a dynamic torque because it must be producing an angular acceleration of the wheels given that the car is accelerating along the track.
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Sources flip the output to "watts" - which is a measurement of Lb Ft/ enrgy/ joules, not Ft Lb force, are just as you say 'causing confusion', but
"torque and energy have the same dimensions (i.e. they can be written in the same fundamental units), but they are not a measure of the same thing"; https://www.khanacademy.org/science...d energy have the,only for a rotatable system.
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You replied: "This should be denoted with the order, but many get them wrong. A ft-lb of energy by definition is a force of one lb applied through a distance of one foot. A lb-ft of torque is a lb of force applied one foot from the point of rotation. Yes, it can cause confusion but saying they're the same "dimensions" only furthers the confusion".
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I'd again simply paraphrased Khan Academy. Faster than me explaining. It fits my understanding that one cannot be confused as the base definition is the same for my purposes.
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While "a pound-foot (lbf⋅ft) is a unit of torque representing one pound of force acting at a perpendicular distance of one foot from a pivot point, thus conversely one pound-foot is the moment about an axis that applies one pound-force at a radius of one foot", which is a force of one lb applied through a distance of one foot.
A foot-pound force (symbol: ft⋅lbf, ft⋅lbf, or ft⋅lb ) is a unit of work or energy transferred upon applying a force of one pound-force (lbf) through a linear displacement of one foot and the corresponding SI unit is the joule, transferred upon applying a force of one pound-force.
Regardless of perspective, both above "(can be written in the same fundamental units), but they are not a measure of the same thing".
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However, Mia culpa. As https://en.wikipedia.org/wiki/Pound-foot_(torque) describes I use foot pounds interchangeably.
"Despite this, in practice torque units are commonly called the foot-pound (denoted as either lb-ft or ft-lb) or the inch-pound (denoted as in-lb).[7][8] Practitioners depend on context and the hyphenated abbreviations to know that these refer to neither energy nor moment of mass (as the symbol ft-lb rather than lb-ft would imply).
For me it's a carryover improperly transpose the abbreviation.
[Real world] confusion?
The Oxford (my definitive source for 50 years ) defines foot-pound/ˌfo͝otˈpound/
1. a unit of energy equal to the amount required to raise 1 pound a distance of 1 foot.
2. a unit of torque equal to the force of 1 lb acting perpendicularly to an axis of rotation at a distance of 1 foot.
Made me feel better knowing the most educated folks on the planet screwed it up !!!
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"Peak torque is relevant for generally describing how quickly a vehicle will accelerate and its ability to pull a load. Horsepower (relative to weight) on the other hand is more relevant to the maximum speed of a vehicle."
One of many sources (again why I love this organization and a great place to brush up on physics) https://www.khanacademy.org/science/physics/torque-angular-momentum/torque-tutorial/a/torque states: "Along with horsepower, the peak torque produced by a vehicle engine is an important and commonly quoted specification. Practically speaking, peak torque is relevant for generally describing how quickly a vehicle will accelerate and its ability to pull a load. Horsepower (relative to weight) on the other hand is more relevant to the maximum speed of a vehicle."
It's a pretty common statement and how I visualize it.
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The Dynojet, around since the 70's uses rpm [and known gearing calculations in my day] to measure contact torque at the meats.
Measuring torque at a shaft is another matter - generally extrapolated in other ways - I'm still studying.

Fn'F

 

[Fast n' Furious]

Do not forget that torque / rpm relationship in a combustion engine is different than in a DC motor itself different than in an AC motor...

Ohhhhh gawd ... I'd bite and say 'How is it different?', but respecting the topic - I'll look into that.
Feel free to hint.

Fn'F