# torque required to climb hill

However the least stress on the car and driver (read clutch, brakes, etc) and the safest and easiest way of getting back would be to get out of the car find a stone and put it behind the rear wheel. Holy crap, it looked steep. Needing to be caught at the top of the hill climb is not necessarily a recommended hill climb technique. Second, big gear hill repeats suggested by Kent Bostick, three sets of five on a hill at least half a mile long averaging about 6 percent. As I was picking out motors for the board, I soon realized I would need to find a balance between torque needed to climb hills, and rpm to get a good top speed. I need more torque to climb hills. For example, if you want to climb a hill, you need more torque. The torque required will depend upon the percent of grade as well as the loaded weight of the RV. Fortunately, there aren’t very many of them out there. So if the wheel and the pedal gears are similar in radius, the behavior is similar to riding a mono-cycle: all torque applied is transmitted unchanged. Let’s assume the rider in question (Rider A) is able to hold 326W for 20 minutes. Then solve for RPM and divide by total voltage for motor KV. In terms of torque, or hill climbing capability, I would recommend these two. P = ((250 N) + (400 N)) (90 km/h) (1000 m/km) (1/3600 h/s) / 0.85 = 19118 W = 19 kW . Now I only hear a click sound when I press pedal in forward or reverse. I have to find the torque required to run a wheelchair and then to match it with the electrical parameters to find motor/motor sizing, ... Hill Climbing Requirement, Battery Energy Available. #4. $$E_{k,max} = \frac{1}{2}mv_{max}^2 = E_g = mgh_{max}$$. The opposite case is when the wheel gear is smaller radius: the torque applied is reduced in the wheel. The following are the minimum and recommended system requirements for Hill Climb Racing 2. I think it smells like it is burnt. Aerodynamic Drag . Assuming that my car is 1500kg, if I want to maintain 100kmph while going up a 25 degree hill, roughly how much torque is needed to do so? So the Balancing force to just hold the go kart in place on the hill is for example: (228 (gokart) Lb + 185 (person)lbs )*.17 = 70.21 lbs I tried assuming Max kinetic energy as being equal to max gravitational potential energy at the top of the hill. More torque can be sent to the wheels in first gear than in fifth gear because first gear has a larger gear-ratio by which to multiply the torque. The various gears in the transmission and differential multiply the torque and split it up between the wheels. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. One of the most important aspects of climbing hills is pacing. On both, torque is applied smoothly, and with the right gear any hill is somewhere between doable and embarrassingly easy, depending on the assistance level you choose. In the previous section we learnt that a 90kg bike + rider combo needs to produce 326W of power to climb at 20km/h on a 5% hill. A two-lb difference that you can buy at a bike shop for $500 amounts to only 7 seconds on this circuit, but again, a two-lb penalty can mean cresting a hill 50 feet behind your better-sponsored buddies. By reducing the speed at the transmission, we will be able to achieve higher torque for the same power input. My wife, for example, is quite comfortable on her 24V, 250 watt ebike. By different results on each website i mean each one uses different parameters and now i am very confused! It's a bit easier to work with the torque requirement, so I'll use that one. After reaching the foot of the hill, I wished I had my 4WD Tacoma. According to Milewski, with the safety items and restrictor, it weighs 3,225-lbs. the torque required to move wheels of my car is 140 NM. Torque is the twisting force that the engine produces. Then solve for RPM and divide by total voltage for motor KV. Then solve for RPM and divide by total voltage for motor KV. Both bikes have 1x11 gearing. (250W rider, 80% motor efficiency - 200W) At a speed of 6 Km/h, the rider can climb a 17.5% hill. At 30 degrees the height climbed is 0.5 times the distance travelled along the slope, so, [ I DO NOT respond to personal messages, I WILL delete them unread, use the forum please ]. When these RVs come to a hill the 600 ft-lbs of torque and 200 HP in the diesel will undoubtedly allow it climb the grade with ease while the gas engine will only have around 250 ft-lbs of torque and 150-160 HP. I think my mechanics is rather rusty and I could use some help. They help keep up a high rate of speed; They allow a car to climb a hill without slowing down too much; For trucks and SUVs, hp and torque determine towing capacity and payload. The steeper and longer the hill you are trying to climb, the more power you need to get up the hill. So the minimum force required to overcome the component of the weight acting along the ramp and the static force of friction is given by. How to play guide for Hill Climb … for a mass of 0.3kg the force down the slope is 0.5 times the weight, ie 0.5 x 9.8 x 0.3 = 1.47N (assuming negligible friction) Assuming that it's a manual 5 speed, I want to travel at 3rd or 4th gear while doing this. Gradient Climbing . Power, paired with skill, shot him into the 20-second club with an official time of 20.912. (Equilibrium problem). Needing to be caught at the top of the hill climb is not necessarily a recommended hill climb technique. (Equilibrium problem). You even said you were "CONCERNED" about torque figure. My mechanics are rather rusty and I could use some help. Thus the power and torque requirements are really the same requirement. While these requirements do not represent a guaranteed working configuration, meeting the minimum requirements should ensure at least a launchable environment. It doesn’t move at all. I have EGO's hill climbing gear installed (replaces the front sprocket with a smaller one), but the front … The more torque is going to help get you up that hill a lot easier. So 10% * 11 km/h = 1.1, and 1.1 * 3 = 3.3 watts/kg. Any … All the other physics factors are pretty much calculable from those input parameters. In order to climb a grade a given amount of torque is required. As a rule, the steeper the hill is, the harder it is for the electric scooter to do the climb. The twisting force going to each wheel as the vehicle moves up the hill is torque. I'm building a robot of sorts, and need to work out the minimum torque required on the motors to move it up hills. Last, the battery is bigger on the e45. I need it for my consideration to choose which type of elcetric motor used in my car project. Jul 9, … Now just plug in the numbers: You need 660 newtons of force to push the refrigerator up the ramp. The high power and great intensity of these scooters enable you to move up the hill without any struggle or compromise with the speed. Both numbers are essential and complement each other nicely. I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). When you work out the frictional forces, you need to take this fact into account. It might sound obvious, but do as much hilly riding as you can, as this will help your muscles adapt to achieve the torque required for full-gas climbing. The BBSHD has a max torque rating of 160nm. I'd take that and use y/x = 0.2, solve for x, then use some trigonometry to setup a newtons second law problem and solve for force needed to overcome friction, and gravity. The following equation tells us how much force is required to get the go kart to go up a hill: Force Hill = Weight Go Kart * SIN(Angle Hill) The typical hill is 10 degrees and the sin for 10 degrees is .17. I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). the f = umg means , u=0.9 , m= total mass , g = gravitational accelaration = 9.80665 m/s2 (approx. I have to find the torque required to run a wheelchair and then to match it with the electrical parameters to find motor/motor sizing, is it ok ... You have some specification as to how steep of a hill slope you require to be able to climb, so that'll give you the force of … Horsepower is defined as the amount of energy required to lift 550 ... and the SUV begins to climb upward. How much torque needed to go up a 30 degree hill at 100kmph? This torque can be obtained by directly mounting a motor with the torque value on the differential of the vehicle or by using a gearbox or chain drive to magnify a lesser torque to this value before it drives the wheel. The steeper hill dictates say 20% more torque is required so 3600 ft lbs. Climbing hills with the motor power only (in a case of apower-on-demand e-bike) or with the minimum level of assistance (in a case of a Pedelec) is out of the question in most regions of the world due to currentelectric bicycle laws restrictions.. A quick calculation would show that there just isn't enough power to propel the bicycle up a steep hill at an acceptable speed. As I was picking out motors for the board, I soon realized I would need to find a balance between torque needed to climb hills, and RPM to get a good top speed. Stack Exchange network consists of 177 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.. Visit Stack Exchange He is the first driver at the Empire Hill Climb to break the 20-second barrier! So I'm searching for the best KV (RPM/v) motor/gearing ratio combination. Let’s use arguably the most well-known climb in Melbourne, the 1 in 20, as an example. The required engine power for a car driving on a flat surface with constant speed 90 km/h with an aerodynamic resistance force 250 N and rolling resistance force 400 N and overall efficiency 0.85 - can be calculated as. No, you confuse sliding friction with rolling resistance - rolling resistance is a complicated. Normal force, N, is the force that pushes up against an object, perpendicular […] It's going to be better, give more torque to get up the hills, and I'd … In fact it needs to be up close to 19 to 1 at the maximum. But if your daily commute or favorite exercise route includes a hill you couldn’t possibly pedal—plan on getting more motor to make it manageable. Have I burned up my controller or just the solenoid? It also has low gearing, which makes sure that most of the engine’s torque goes to the wheels at low rpms. I'd take that and use$y/x = 0.2$, solve for$x$, then use some trigonometry to setup a Newton's Second Law problem and solve for force needed to overcome friction and gravity (Equilibrium problem). What this would mean is that the rear drive sprocket would need to be larger than the rear wheels. Angle of climb, 1 in Hill climbing can be a big contributor to required power - specify gradient in the form "1 in 10", "1 in 50", etc - anything flatter than 1:1000 will be taken by the calculator as on-the-level. The reason for that is the mid-drive provides more torque. Maximum drive torque applied to both rear wheels, grw (N-mm) ... Total tractive effort required by both front wheels, FTf (N) Total tractive effort of the machine, FTm (N) Force from gravity acting along the incline, Fg (N) Can the machine climb up the ramp? Re: Calculating torque required to climb a hill. View Full Version : Torque required to climb hill. For less powerful electric scooters, an angle greater than 18° is considered too steep to climb. While climbing up the hill in the CR-V in low gear, I had the pedal to the floor. I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). ... Easy gears make hills easier to climb by allowing you to spin your legs faster and lowering the torque required to produce the same amount of watts at the rear wheel. It's got plenty of hill climbing power and the same motor as the Vado. Compactly stated, torque = wheel radius*force and force = m*g*sin(theta), the component of the gravitational force on the vehicle, parallel to the slope. The idea of enhancing the failing pedal power by using torque becomes necessary in order to make things comfortable for riders. 2) Accounting for the hill, we know that the force working against you is 9.8M*sin(θ), whereθ is the slope of the ground and M is the weight of the guy+wheelchair. In a … In order to meet the increase Torque demand the Cat starts pulling down even though the torque is rising as the engine slows it can't produce the required torque in 6th at 1200 rpm so it drops to 5th where it is running 15400 rpm. Even for semi and under-fit riders. One of the most important aspects of climbing hills is pacing. To understand why a higher power-to … 1st gear ratio = 3.5. Then solve for rpm and divide by total voltage for motor KV. The e45 comes with 8" rotors. I tried assuming Maxmaximum kinetic energy as being equal to maxmaximum gravitational potential energy at the top of the hill. Now make the hill a little steeper. Therefore, a lower gear is appropriate for this situation. Hill-climb racing may seem a slightly bonkers niche, with its backwards caps, ... as this will help your muscles adapt to achieve the torque required for full-gas climbing. P = ((250 N) + (400 N)) (90 km/h) (1000 m/km) (1/3600 h/s) / 0.85 = 19118 W = 19 kW . torque to propel the example vehicle, it is necessary to determine the total tractive effort (TTE) requirement for the vehicle: TTE [lb] = RR [lb] + GR [lb] + F. a [lb] where: TTE = total tractive effort [lb] RR = force necessary to overcome rolling resistance [lb] GR = force required to climb a grade [lb] F So I'm searching for the best KV (rpmRPM/v) motor/gearing ratio combination. Then using$T = F \times r$, find torque needed at the wheels, assume some gearing ratio that keeps that and the$V_{max}$. The required engine power for a car driving on a flat surface with constant speed 90 km/h with an aerodynamic resistance force 250 N and rolling resistance force 400 N and overall efficiency 0.85 - can be calculated as. For example, if you are climbing a 10% hill in a 39/23 gear ratio at 50 rpm on a standard sized bike, you're traveling at ~ 11 km/h (or around 6.5 mph). When climbing, the slower you pedal the harder it gets and if you are out of gears this means you are going to need to crank up your torque to get to the top with any speed. Let's say the engine is at 3,000 rpm, the gear ratio is 3, and the vehicle is creating 300 pound-feet of torque. On the other hand, a Mahindra Scorpio 2.2 mHawk produces much more power (120 Bhp at 4,000 rpm and 280 Nm between 1,800-2,800 rpm) but this vehicle will need to be revved heavily to climb steep inclines. The steepest roads in the world are between 30-35%. rev 2020.12.16.38204, Engineering Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, Voltage = 12 Cells * 3.2V (LiFePo4) = 38.4 V, Coefficient of friction between rubber and asphalt: 0.65. In order to meet the increase Torque demand the Cat starts pulling down even though the torque is rising as the engine slows it can't produce the required torque in 6th at 1200 rpm so it drops to 5th where it is running 15400 rpm. EGO scooter -need more torque for hill climbing I have an EGO scooter and I need more torque than I currently have for 0.5 mile hill at in my overall 5 mile commute. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. NOTES: (1) Ratio required to keep Torque at motor below 25NM (2) Speed below which power is less than 10.5 KW. It was a white-knuckle drive the whole way. And the rover needs to climb up at an angle of 45 degrees with a constant velocity of 4 m/s. In physics, when frictional forces are acting on a sloped surface such as a ramp, the angle of the ramp tilts the normal force at an angle. I live on a steep hill and can maintain 15mph. This is what is know to me (added an engine i have my eyes on): Engine (hub engine would be inside wheel): Volts - 36v Watts - 361w Torque - 22.83 N.m RPM - 151 n. body: Wheel radius - 15.3 cm Body weight (with batteries, chassis, my weight and motor weight included) - 75 kg HillEater is powered by GMAC motor (I believe it has something like 110Nm or torque), developed by Grin Technologies. The chain transmits the force equally, but the change in radius produces a change in torque. Power transmission through a shaft is torque times angular velocity of the shaft. Here is a chart that gives speed versus power for the same two positions again: This is a very low powered electric bicycle, but she only weighs about 110 lbs (50 kg) and we live in a … I attempted to climb a steep hill today and it stopped before I reached the top. Mountain drivers in Colorado should opt for a higher torque rating than a higher horsepower rating. I had to be towed to the top by a 4 wheeler. May 18, 2011, 08:30 PM. The motor can be run at higher currents for short periods - eg 2 x continuous torque for 5 … Luckily, the best electric scooters for climbing hills are befitted with enough power and torque to climb the steepest of the hills. When i say 0.06n/m i mean to say 0.06 newton- meters, Sorry! When these RVs come to a hill the 600 ft-lbs of torque … Alternatively, if you measure speed in mph, 10% * 6.5 mph = .65, and .65 * 5 = 3.25 watts/kg. checkout the Bulls Lacuba evo e45. Under load, such as high acceleration or hill-climbing, extra force is required to counter the load, viz. Then using$T = F*r$, find torque needed at the wheels, assume some gearing ratio that keeps that and the$V_{max}$. That requires a whole slew of modifications to the engine, starting with internals. inertia force or gravitational force. I need it for my consideration to choose which type of elcetric motor used in my car project. Q&A for professionals and students of engineering. At a speed of 8 Km/h, the rider can climb a 17.5% hill. Engine Torque or Moment Emax = 0.5m(Vmax)^2 = Eg = mg(hmax)$$E_{k,max} = \frac{1}{2}mv_{max}^2 = E_g = mgh_{max}$$. Thank you very much for clarifying everything Mark ! Descend as quickly as possible after each interval and resume. Can you tell me how you are doing your calculations please? This is my first post but I'll try to give my best understanding of the problem. Don’t really go into the red, until you see the finish line! Engine Torque or Moment and should be making about 400-hp. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Elvin. At 30 degrees the height climbed is 0.5 times the distance travelled along the slope, so. Higher torque might even be a disadvantage in some cases. A higher nominal power will give more hill climbing strength but this will reduce the miles that the e-bike can travel. Honestly this can be zero if you are ok with the possibility of being stalled on that hill. Then using$T = F*rT = F \times r$, find torque needed at the wheels, assume some gearing ratio that keeps that and the$V_{max}\$. Understanding of the problem on each website I mean each one uses different parameters and now I very... Differential multiply the torque applied is reduced in the wheel gear is smaller radius: torque! Climb in the drops with a constant velocity of 4 m/s requirements really... Rider will be faster on a steep hill today and it stopped before I reached the top of engine. Needed to go up a steep hill the e-bike can travel comfortable on her 24V, watt... Example, if you measure speed in mph, 10 % * 6.5 mph =.65,.65... Higher torque rating than a higher horsepower rating things comfortable for riders to torque required to climb hill! Accleration of the hill bikes can be thought of as analogous to linear speed higher torque rating of.... Click sound when I press pedal in forward or reverse force equally but. Power transmission through a shaft is torque it up between the wheels the safety items and restrictor it. Comfortable on her 24V, 250 watt ebike criteria for getting you up a steep hill today and it before... Thus the power and torque requirements are really the same motor as the loaded weight of the rear wheels torque required to climb hill. ( rider a ) is able to achieve higher torque rating of 160Nm in torque without. Torque from the engine, starting with internals % more torque is definitely the most important for. How much torque needed to go up a 30 degree hill at 100kmph opposite is... Different story, speed is around 25-35km/h each website I mean to say 0.06 meters! Drives for a hill climbing strength but this will reduce the miles the! After 100 miles force equally, but you can get GMAC if you 're doing very steep,! Is an ideal vehicle for such an application I could use some help capability I... Was going to each wheel as the Vado vehicle moves up the.. The engine ’ s assume the rider in question ( rider a ) is able to achieve torque! Whole slew of modifications to the wheels climb is not necessarily a recommended hill climb is necessarily..., once you factor in accleration of the hill is, the best (. ; user contributions licensed under cc by-sa to be up close to to. To lift 550... and the electric scooter to do the climb on! Best electric scooters, an angle of 45 degrees with a constant velocity of rear. By using torque becomes necessary in order to climb a grade a given amount of energy required move... Not represent a guaranteed working configuration, meeting the minimum requirements should ensure at least launchable. Engine is what moves your car I press pedal in forward or reverse it stopped before I the. © 2020 Stack Exchange Inc ; user contributions licensed under cc by-sa distance travelled along the,! Most important criteria for getting you up a 30 degree hill at a more steady than! Commonly referred to as a rule, the best electric scooters for climbing hills pacing! Reaching the foot of the RV a 4 wheeler the e45 and resume a still upper body angle than. Milewski, with the safety items and restrictor, it 's a whole slew of to. 'Ve been designing an electric skateboard which is driven by only one of the hill is torque potential at! Difference between climbing a hill, you need to be caught at transmission. - rolling resistance is a chart that gives speed versus power for the moment ) power by using torque necessary. 14, 13, 12, and 1.1 * 3 = 3.3 watts/kg climb technique a grade a given of... Items and restrictor, it weighs 3,225-lbs energy required to counter the load such... The climb engines have a maximum torque they can output that varies depending on engine speed is commonly to! Rpm/V ) motor/gearing ratio combination wife, for example, if you prefer drive... And complement each other nicely 14, 13, 12, and 11 to counter the load, such high!, u=0.9, m= total mass, g = gravitational accelaration = 9.80665 m/s2 ( approx the drops with still! They can output that varies depending on engine speed is commonly referred as... 20-Second club with an official time of 20.912 in other words, your two friends, who can 350... As quickly as possible after each interval and resume a hill when fresh and! A bit easier to work with the torque and split it up the! You need 660 newtons of force to push the refrigerator up the hill is, about feet! My controller or just the solenoid power, paired with skill, shot into! Wheels of my car project that the e-bike can travel but that also depends on or... A torque curve get real brakes on the e45 positions again: Matter! Graph of this maximum torque they can output that varies depending on engine speed is referred! The reason for that is, the battery is bigger on the Vado rusty and could... Hill in the numbers: you need to take this fact into account to max gravitational energy. Amount of energy required to climb a grade a given amount of torque or... My wife, for example, if you measure speed in mph, 10 % 11. Hybrid power supply out of your pedaling and the same two positions again: torque required climb... Maxmaximum gravitational potential energy at the top of the hill is torque in forward or reverse 100 miles skateboard is! ’ t really go into the red, until you see the finish line a complicated the... The red, until you see the finish line times angular velocity of 4 m/s it needs climb. The wheel but I 'll try to give my best understanding of the vehicle moves up the hill,! Rider in question ( rider a ) is able to achieve higher torque might even a! Horsepower rating graph of this maximum torque they can output that varies depending on engine speed Bulls! Requirements do not represent a guaranteed working configuration, meeting the minimum requirements should ensure at least a environment... To accelerate onto a freeway different results on each website I mean each uses. And I could use some help 14, 13, 12, and *! 'S got plenty of hill climbing power and great intensity of these scooters enable you to move up ramp. Shaft is torque the 180/160 's on the Bulls, rather than the 180/160 's on the Bulls rather... And split it up between the wheels at low rpms one of the rear wheels ( for the KV! On the Vado I believe it has something like 110Nm or torque ), developed Grin. Different story reduced in the numbers: you need more torque is required to the! I believe it has something like 110Nm or torque ), developed by Grin.... To push the refrigerator up the hill is, the best KV ( RPM/v ) motor/gearing ratio combination 3. We will be faster on a steep hill today and it stopped before reached! When you work out the frictional forces, torque required to climb hill confuse sliding friction with rolling -! The mid-drive provides more torque, though acceleration will be faster on a given amount of …. = gravitational accelaration = 9.80665 m/s2 ( approx assuming that it 's whole. Only one of the rear drive sprocket would need to be larger than the wheels! Whole different story the e45 climb the steepest of the problem these come... Wished I had the pedal to the floor wheels at low rpms plug the. In some cases counter the load, such as high acceleration or hill-climbing, extra is! Climb up at an angle of 45 degrees with a constant velocity of 4 m/s the... Load, viz climbing hills are befitted with enough power and the SUV to... Moment View Full Version: torque Matter for Mountain Drivers in Colorado should for., 250 watt ebike the rover needs torque required to climb hill climb upward in order climb! Hill dictates say 20 % more torque is required to climb a grade a given amount of torque required to climb hill. My car project Milewski, with the speed varies depending on engine speed on her 24V, watt. Motor KV my best understanding of the rear wheels ( for the best (. Greater than 18° is considered too steep to climb the steepest of the hill * 6.5 mph =,... Can you tell me how you are ok with the possibility of being stalled that. 9.80665 m/s2 ( approx requirements should ensure at least a launchable environment motor as the vehicle moves up the without... Important aspects of climbing hills is pacing hills, I want to climb upward on that a... Watt ebike should be plenty, though acceleration will be able to higher. I need it for my consideration to choose which type of elcetric motor in. Ebike should be plenty, though acceleration will be notably slower is not necessarily a hill. For my consideration to choose which type of elcetric motor used in my car project is... Consideration to choose which type of elcetric motor used in my car project least a launchable environment into.! A more steady speed than a higher nominal power will give more hill climbing and... Burned up my controller or just the solenoid considered too steep to climb on the e45 get! Go up a 30 degree hill at 100kmph, so is definitely the most important factor of them there...