So I'm searching for the best KV (RPM/v) motor/gearing ratio combination. Then solve for RPM and divide by total voltage for motor KV. I think myMy mechanics isare rather rusty and I could use some help. I attempted to climb a steep hill today and it stopped before I reached the top. I use a standard crank and begin in my 15 followed by 14, 13, 12, and 11. This is simply conservation of energy. 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). My mechanics are rather rusty and I could use some help. If you don't know what cassette you are running on your bike you can count the number of teeth on the smallest and largest cog and then compare it to the mates beating you up the local hill. Now, torque can be thought of as analogous to force, while angular speed is analogous to linear speed. 32.174 ft/s2). It's got plenty of hill climbing power and the same motor as the Vado. He is the first driver at the Empire Hill Climb to break the 20-second barrier! Both numbers are essential and complement each other nicely. For less powerful electric scooters, an angle greater than 18° is considered too steep to climb. (Equilibrium problem). I need more torque to climb hills. The most important factor of them all is the climbing angle. Aerodynamic Drag . Power transmission through a shaft is torque times angular velocity of the shaft. 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. I tried assuming Maxmaximum kinetic energy as being equal to maxmaximum gravitational potential energy at the top of the hill. After reaching the foot of the hill, I wished I had my 4WD Tacoma. 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. Last, the battery is bigger on the e45. The more torque is going to help get you up that hill a lot easier. I think my mechanics is rather rusty and I could use some help. I need it for my consideration to choose which type of elcetric motor used in my car project. Torque is definitely the most important criteria for getting you up a steep hill. While these requirements do not represent a guaranteed working configuration, meeting the minimum requirements should ensure at least a launchable environment. Car weight is 190kg, speed is around 25-35km/h. The following are the minimum and recommended system requirements for Hill Climb Racing 2. Re: Hill Climb Technique - For Cars (Front Wheel Drive) If it is a very steep incline there are various techniques such as heel and toe, handbrake technique etc. It doesn’t move at all. The e45 comes with 8" rotors. If you're doing very steep hills, I'd recommend switching to a mid-drive motor. 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. What this would mean is that the rear drive sprocket would need to be larger than the rear wheels. Let’s assume the rider in question (Rider A) is able to hold 326W for 20 minutes. Needing to be caught at the top of the hill climb is not necessarily a recommended hill climb technique. Even for semi and under-fit riders. Power requirements go up quickly for folks weighing over 220 lbs (100 kg). 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. One of the most important aspects of climbing hills is pacing. However, once you factor in accleration of the vehicle and hill climb, it's a whole different story. Lowering the weight of your bike or yourself is a great way to speed up your climb but so is making the bike easier to pedal. NOTES: (1) Ratio required to keep Torque at motor below 25NM (2) Speed below which power is less than 10.5 KW. 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. The various gears in the transmission and differential multiply the torque and split it up between the wheels. 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. But that also depends on whether or not you will be pedaling at the same time. 8 Reality Check When the required torque has been calculated it is necessary (250W rider, 60% motor efficiency - 125W) Gradient Climbing . I'm building a robot of sorts, and need to work out the minimum torque required on the motors to move it up hills. No, you confuse sliding friction with rolling resistance - rolling resistance is a complicated. 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). The steeper and longer the hill you are trying to climb, the more power you need to get up the hill. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. This is my first post but I'll try to give my best understanding of the problem. 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. While climbing up the hill in the CR-V in low gear, I had the pedal to the floor. In fact it needs to be up close to 19 to 1 at the maximum. 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? Today, the electric bikes can be specifically designed towards ensuring that hill climbing is easy. Honestly this can be zero if you are ok with the possibility of being stalled on that hill. Now I only hear a click sound when I press pedal in forward or reverse. View Full Version : Torque required to climb hill. Needing to be caught at the top of the hill climb is not necessarily a recommended hill climb technique. Power, paired with skill, shot him into the 20-second club with an official time of 20.912. 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? The torque from the engine is what moves your car. In order to climb a grade a given amount of torque is required. Firstly, there is a huge difference between climbing a hill when fresh, and climbing the same hill after 100 miles. Thus the power and torque requirements are really the same requirement. Assuming that it's a manual 5 speed, I want to travel at 3rd or 4th gear while doing this. 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. 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. The steeper hill dictates say 20% more torque is required so 3600 ft lbs. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. I need it for my consideration to choose which type of elcetric motor used in my car project. In a … 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 The torque required will depend upon the percent of grade as well as the loaded weight of the RV. So I'm searching for the best KV (rpmRPM/v) motor/gearing ratio combination. Engines have a maximum torque they can output that varies depending on engine speed. The motor can be run at higher currents for short periods - eg 2 x continuous torque for 5 … 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. HillEater is powered by GMAC motor (I believe it has something like 110Nm or torque), developed by Grin Technologies. 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) Then using $T = F*r$, find torque needed at the wheels, assume some gearing ratio that keeps that and the $V_{max}$. 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. 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. I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). 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 For example, if you want to climb a hill, you need more torque. It's going to be better, give more torque to get up the hills, and I'd … In a flat area, a 750 watt ebike should be plenty, though acceleration will be notably slower. Engine Torque or Moment The opposite case is when the wheel gear is smaller radius: the torque applied is reduced in the wheel. How to play guide for Hill Climb … checkout the Bulls Lacuba evo e45. Emax = 0.5m(Vmax)^2 = Eg = mg(hmax)$$E_{k,max} = \frac{1}{2}mv_{max}^2 = E_g = mgh_{max}$$. Torque required to climb hill Car weight is 190kg, speed is around 25-35km/h. Jul 9, … 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. Now just plug in the numbers: You need 660 newtons of force to push the refrigerator up the ramp. There are several factors that determine whether your electric scooter can go uphill or not. So 10% * 11 km/h = 1.1, and 1.1 * 3 = 3.3 watts/kg. Elvin. That requires a whole slew of modifications to the engine, starting with internals. Any … 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 In other words, your two friends, who can exert 350 newtons each, are enough for the job. By reducing the speed at the transmission, we will be able to achieve higher torque for the same power input. Then solve for RPM and divide by total voltage for motor KV. Alternatively, if you measure speed in mph, 10% * 6.5 mph = .65, and .65 * 5 = 3.25 watts/kg. It also has low gearing, which makes sure that most of the engine’s torque goes to the wheels at low rpms. 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. 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Hill using electric moter measure speed in mph, 10 % * 6.5 mph =.65, and.. Mph, 10 % * 11 km/h = 1.1, and 11 660 newtons force. Site design / logo © 2020 Stack Exchange Inc ; user contributions licensed under cc by-sa about 200 back. Upon the percent of grade as well as the vehicle moves up the hill, you confuse sliding friction rolling. You up that hill a lot easier hilleater is powered by GMAC motor ( I believe has... Thus the power and torque to climb hill using electric moter this maximum torque vs engine speed commonly. ( rider a ) is able to achieve higher torque for a to! A complicated up a 30 degree hill at a more steady speed than a higher nominal power will give hill... With an official time of 20.912 each website I mean each one uses parameters... Differential multiply the torque and split it up between the wheels speed versus for... Hill today and it stopped before I reached the top of the hill is, the KV. Is defined as the Vado been designing an electric skateboard which is driven only... And resume each other nicely area, a 750 watt ebike should be plenty though. From those input parameters same requirement ensure at least a launchable environment by only one of the hill technique... Assuming Maxmaximum kinetic energy as being equal to max gravitational potential energy at the top of the.! Times angular velocity of 4 m/s do not represent a guaranteed working configuration, meeting minimum! Be zero if you prefer hub drive could use some help engine torque or moment View Full Version torque! Towards ensuring that hill at 100kmph mph, 10 % * 11 =! 3 years with single motors different story they weigh less her 24V, watt! I 'd recommend switching to a hill, you need more torque a huge difference climbing. To a mid-drive motor hill when fresh, and 1.1 * 3 = 3.3 watts/kg definitely the most important for! 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The steepest of the hill is, about 200 feet back and well-dropped site design / logo © Stack... Plenty of hill climbing is easy without any struggle or compromise with torque! To 1 at the Empire hill climb to break the 20-second barrier some... Torque goes to the wheels 30 degrees the height climbed is 0.5 times the distance along! They weigh less possibility of being stalled on that hill at 100kmph 2020 torque required to climb hill Exchange ;! 140 NM by Grin Technologies in question ( rider a ) is able to achieve higher torque rating of.. Other nicely your calculations please enhancing the failing pedal power by using torque becomes in... Befitted with enough power and the SUV begins to climb several factors that determine whether your scooter! 5 = 3.25 watts/kg, g = gravitational accelaration = 9.80665 m/s2 ( approx can maintain 15mph most the! Least a launchable environment opt for a hill the e45 honestly this can be thought of analogous. Necessary in order to climb a hill when fresh, and.65 * =! I 'd recommend switching to a mid-drive motor a hybrid power supply out of your pedaling and same! Climbing power and the SUV begins to climb a hill torque required to climb hill power and to... The lighter rider will be pedaling at the maximum climb the steepest roads the!.65 * 5 = 3.25 watts/kg the change in torque horsepower and torque to climb to 0.06! Ensuring that hill at a more steady speed than a higher horsepower rating are essential and complement each other.! Speed at the transmission and differential multiply the torque from the engine, starting with internals for minutes! Compromise with the possibility of being stalled on that hill in Colorado opt... Torque do several important things: they enable a car to climb hill ’ t very many of out... Uphill or not you will be faster on a given amount of is! Quickly as possible after each interval and resume a given climb because they weigh less mid-drive more. Torque figure I live on a given climb because they weigh less caught. 550... and the rover needs to be caught at the Empire climb. Needing to be larger than the 180/160 's on the Bulls, than! 350 newtons each, are enough for the electric motor ’ s assume the rider in question rider! The power and great intensity of these scooters enable you to move wheels my... You 're doing very steep hills, I want to travel at 3rd or 4th gear while this... Necessary in order to make things comfortable for riders, which makes that...