Never too much torque

[EdC]

When I was in my 20s, before there were cellphones, computers and electric bike, the mantra for my generation was “ You can never have enough horsepower.” Fast forward 54 years and the mantra for the ebike generation is” You can never have enough torque.” When I was in my 20s my cars had far more horsepower than I ever could use safely and used more gas than I could afford. What I want to buy a new electric bike I tried hard got to get a bike with more torque than I actually needed and that wouldn’t run my battery down before I completed my ride. I know there are exceptions to my thinking. Back in my day a lot of horsepower was very important to a drag racer and today a lot of torque is very important to a mountain bike or down hill rider. But what about the rest of us? My best guesstimate is that 30 Newton meters of torque for people who do most of their riding on flat terrain and 50 Newton meters of torque for the rest of ebike riders. What do you think? Ed

 

[indianajo]

When I was younger I always pulled the axle forwards in the frame and made the tire rub on the struts. I had to weld nuts on the frame and install axle push bolts to stop this. In those days I could lift the front of the MTB with my legs and ride dozens of feet.
Now I let the motor do that. The hub drive axle nuts came unscrewed last month despite the use of blue loktite, and the only thing holding it in place were the two torque arms. Thank the forums for good planning. I have torque arms to the struts on both sides.
I start from a dead stop on 15% grades with the 1000 w hub motor at gross weight 330 lb. that requires 52.2 ft lb on a 14" radius wheel, or for you Europhiles, 70 NM.

 

[AHicks]

Ed, came for a similar background. I participated in more unofficial street racing during the 60's and early 70's than a body has a right to and came out reasonably unscathed. I worked as a heavy mechanic at a Chevy dealership in the very heart of Motor City's hottest activity, which included full on factory participation at times - Friday nights on Woodward (US1)...

Anyway, that experience definitely had an effect on me when picking my bike, which was given a top to bottom overhaul withing weeks of the time it was purchased new, resulting in twice the original power with all new electronics I could set up MY way. This resulted in a bike that was WAY faster than practical, but left me with a respectable amount of torque to allow me to cross a busy street safely.

When left to full potential (1500w), it is capable of gobbling up quite a bit of power (battery life) doing something over 40 mph, something I have reigned in using a setup function allowing me to set max power avilable to the motor of only about 1000-1100 watts. That's been working pretty good as far as battery life as the bike is set to never exceed about 20 mph.

Now, never satisfied, I'm considering replacing the current 1500w direct drive rear hub with a hub that should work better (from a performnce perspective) at speeds under my self imposed 20 mph speed limit. This will be a gear driven rear hub (probably the 1200w MAC 12t), which should offer much better acceleration and hill climbing done with authority - while using no more power than I am now. This due to the 5:1 gears.

A big factor is this bike is often used in a coastal area with sometimes pretty big rolling hills that can challenge the current direct drive setup. It will always make it, but it's using GOBS of power doing it. My thought is the 5:1 gears will make this job much easier, making it possible to reach the top with much less of the battery's capacity used. No downside to the gears (other than some noise maybe) as the bike will still be able to run 20 mph easily.

Is it the right call for everyone? Nope. Total overkill for people riding on level paved surfaces. How right it is for you will depend on how often you find yourself riding areas that aren't so level. That's my thinking anyway. -Al

 

[indianajo]

Speed is horsepower or kilowatts. Starting ability on a grade is torque. Speed can be limited on an electric bike by the nanny controller, or by battery limitation. My kitbike only limits to 26 A.
I have a car that will run 105 mph all day without overheating, but the only place I can do that is W. Texas Arizona N. Mexico. And there only uphill. It hasn't been out there since 1997.
The e-bike is about stretching my physical ability on the days when mother nature is fighting me tooth & nail. No headwind, I am the engine! About 200 W if I am average- for 3 1/2 hours. Waaay above average for 68 year olds. Guys my age are dropping like flies due to mismanagement of the body.

 

[Roxlimn]

I'm using the Yamaha PWX motor right now that tops at 80 Nm of torque supposedly. I almost never use that much, but I do occasionally use it on insanely steep uphill climbs. These would be climbs that no sane person would attempt on an unpowered bike, and at that point, the main problem isn't more torque but more grip. It's quite a feat to keep the back wheel from spinning out without lifting the front. For application on-road with sane gradients, 50 Nm seems plenty.

 

[PDoz]

The fastest motorbike rider I've had the privelledge of sharing the dirt with was aboard a ktm 125, I was chugging along on my xr600 as he blasted past ( on the back wheel and waving)

Give me control over power any day.

 

[ez3putt]

I can't have too much torque. 98% of my riding is on hard flat surfaces, but having extra torque and not needing it is way better than needing it and not having it. It is my understanding that speed and torque tend to be inversely proportional in ebikes. I really don't care about speed when I need to pull a loaded cart uphill or have to start a steep uphill climb from a dead stop.

 

[JRA]

Sach’s Mobility’s entry into the mid drive market https://ebike-mtb.com/en/first-ride-sachs-rs/

High torque at low cadence seems tailor made for loaded and eMtbs.

 

[Roxlimn]

Yamaha puts 80Nm for an ebike? I just don't understand why ebikes need more torque if you want to go faster.
Haibike now has 120Nm... maybe the power is what ebikes need.

The torque is probably measured at the crank-arm before it's delivered to the transmission. From experience, the value is greatest at low speed and low cadences on the Yamaha motors, so they're really putting that much torque into the motor in order to assist with extremely steep hill starts. It's not for high-speed applications. I don't know that it makes sense to compare the torque output of a motorcycle to an ebike because I'm fairly sure they're measuring forces at different points.

 

[AHicks]

Regarding motorcycle abilities compared to bikes/ebikes, not finding much useful relevance there myself.

 

[Off road all day]

When I was younger I always pulled the axle forwards in the frame and made the tire rub on the struts. I had to weld nuts on the frame and install axle push bolts to stop this. In those days I could lift the front of the MTB with my legs and ride dozens of feet.
Now I let the motor do that. The hub drive axle nuts came unscrewed last month despite the use of blue loktite, and the only thing holding it in place were the two torque arms. Thank the forums for good planning. I have torque arms to the struts on both sides.
I start from a dead stop on 15% grades with the 1000 w hub motor at gross weight 330 lb. that requires 52.2 ft lb on a 14" radius wheel, or for you Europhiles, 70 NM.

Try red locktight

 

[Off road all day]

When I was in my 20s, before there were cellphones, computers and electric bike, the mantra for my generation was “ You can never have enough horsepower.” Fast forward 54 years and the mantra for the ebike generation is” You can never have enough torque.” When I was in my 20s my cars had far more horsepower than I ever could use safely and used more gas than I could afford. What I want to buy a new electric bike I tried hard got to get a bike with more torque than I actually needed and that wouldn’t run my battery down before I completed my ride. I know there are exceptions to my thinking. Back in my day a lot of horsepower was very important to a drag racer and today a lot of torque is very important to a mountain bike or down hill rider. But what about the rest of us? My best guesstimate is that 30 Newton meters of torque for people who do most of their riding on flat terrain and 50 Newton meters of torque for the rest of ebike riders. What do you think? Ed

Yah throw a 401 into my 73 Gremlin. I'm with you EDC, it took me a year of trial and error to get the gear thing right. mine is a frame mounted motor but i had different gears for the rear. I started with a motor 12 tooth gear and rear 16 tooth gear. Changed to a 22 tooth rear gear, basically lite peddling from that point but i'm draining power. 6 of one, half dozen of another but peddling is all good at this point.

 

[ejr4578]

Errr... the bike I just bought online comes 155 nm torque... 5000w 72v 40ah batt w sine wave controller... I’m guessing this must be a lot? Lol

 

[harryS]

Ha ha. I knew an engineer at work in the early 70's. From Kenosha, home of American Motors. He owned an AMC sleeper and would tell us stories, win or lose, about weekend street racing for money,

In the ebike world, it's the battery that pushes you. More volts. More power til everything quietly goes silent. A kaboom would be nice.

 

[AHicks]

Ha ha. I knew an engineer at work in the early 70's. From Kenosha, home of American Motors. He owned an AMC sleeper and would tell us stories, win or lose, about weekend street racing for money,

In the ebike world, it's the battery that pushes you. More volts. More power til everything quietly goes silent. A kaboom would be nice.

Unfortunately, stuff like that just usually just lets the smoke out signalling it's demise. Rarely too spectacular. Not like the big BANG, followed by silence, that you get with a connecting rod coming out through an oil pan......

 

[AHicks]

E-bike torque is measured at the rear wheel. I say that because having the advantage of the bike's gear set is the ONLY way they're going to see some of the torque values advertised with the mid drives.....

 

[Manu]

I'm using the Yamaha PWX motor right now that tops at 80 Nm of torque supposedly. I almost never use that much, but I do occasionally use it on insanely steep uphill climbs. These would be climbs that no sane person would attempt on an unpowered bike, and at that point, the main problem isn't more torque but more grip. It's quite a feat to keep the back wheel from spinning out without lifting the front. For application on-road with sane gradients, 50 Nm seems plenty.

Mountain bike climbing specialists lower tire pressure to 1 bar.

 

[AHicks]

I doubt it.

For example, BBSHD is always 120Nm, Bafang Ultra is always 160Nm.
They do not change torque figure bike to bike.

Because what you're suggesting is, ebike manufactures will install their motors, and put it on dyno to see how much torque it is creating at specific setup.

I've seen several motorcycle guys putting ebikes on dyno on YouTube, but I think they were doing it just for the heck of it.
I think ebikes companies just put torque spec advertised by Bafang, Shengyi, or whatever motor manufactures say.

If for no other reason than the physical size of those motors, we'll need to agree to disagree.

 

[Ravi Kempaiah]

Honda Fit has 153Nm of torque and it weighs 2,568 lbs.
Ebikes have 160Nm of torque and they weigh 60 lbs or so.

@Timpo ,

It's called marketing.
After a while, you become adept at separating wheat from the chaff.
Numbers don't mean much unless you have seen the actual test data and the process.

 

[Marcela]

Torque is a static measurement, with no time involved, and is used in the definition of power. Power takes into consideration the duration or amount of time involved to perform the operation.

So torque by itself can have no meaning, but when inserted into the formula for power, then it becomes useful.

You can have gargantuan amounts of torque, but if there is no power you will be disappointed.