Standard hill-climbing test suggestion

[pdf]

In my application, I am more interested in the ability of a particular set-up to climb a hill than its top speed. I would like to suggest the following standard test:

Start up a hill at 20 km/hr (12 mph), not pedaling. Place controller/CA/battery/BMS combination at highest continuous rating setting. Allow adequate time for the speed to reach an equilibrium value, say a minute, if the hill is sufficiently long (not a problem in my case). Record the % grade, current, voltage, power, ambient temp, and if outfitted, max temp of motor and how measured. For the set-up, record the bike wheel size, gearing (if working through gears), motor model, the controller model and current rating, the nominal battery voltage and charge state, capacity (Ah), continuous and maximum discharge rating (or the battery setup and let the reader determine the relevant design info), and, if equipped with the ability to limit current with another device (i.e. a Cycle Analyst), the current or power limit setting.

If you have a selection of different hills, attempt to find the highest grade hill it can climb in this manner, motor only, and reach an equilibrium speed. That is, on a 0% grade, the equilibrium speed will be the top speed you reported. At some grade, the motor will not be able to go up the hill. So presumably, there is a grade below which a motor will reach an equilibrium speed and not slow down but above which it will continue to slow until it stops.

I have seen a lot of posts quantifying top speed, but I can't remember one that quantifies the ability of a setup to climb a hill. Regardless of how much or little you intend to pedal, it would help people to have some idea of how a given set-up handles elevation changes. I have not had any luck with simulators in this regard, so in the absence of a good model, we will have to resort to an empirical approach.

The suggested experiment is more involved than measuring the top speed but will be more useful to those of us in the "hill country". For all-in-one set-ups, the test will be easy. For example, the owner of a Magic Pie setup just needs to get the bike speed to 20 km/hr, point it up the hill, and hit the throttle. As the controller is built in anyone looking at this setup will know what they can expect.

For cutom set-ups the result will be highly dependent on what system component is the limiting component, but at least people would know, for a given set-up, what they could expect. Right now, all I've seen are qualitative comparisons and manufacturers claims that a particular set up is "great for climbing hills". Since my idea of what is great could be different from the manufacturer's, it would be nice to be able to extrapolate performance based on a qualitative assessment.

Feel free to suggest a different approach and feel free to post the results of your own tests here.

 

[deardancer3]

PDF,
my thoughts:

Some interesting work.

May I add to record bike and load weight, and wind speed.

For mandatory pedal pedalec prebuilts, I use a heart rate monitor ( dont want to help one a lot more than another)

To me this is important to many ebike users, 1) as hill climbing ability is a big reason people buy ebikes, 2) a big place where power cutouts and failures occur.

I use to always test on my hill from a standing start, pedalling as hard as I could with the Throttle at full on and check for quickest 1/4 mile time. Best was a crystalyte 4011/408 at 48v. 325lb total load, 7% grade. 360w cyclone close 2nd.
but since I was pedaling, I had to also factor in what gears to use, and then it got real complicated with chain drives and me pedalling. then multiple tries and my recovery time.

My wife on the new 250w bionx flys up this hill from a rolling start, but she is lighter and the bike is too small for me to ride, so, no apples to apples comparison.

Your method gives more of an apple to apples comparison. And gives both performance and reliability info.

If done, a potential buyer could determine if a certain configuration would work well for them, and after purchase, could determine if they had parts working to benchmarks.

This might also be good for dealers in getting customers on the right ride, handling customer performance discussions.
Might be a little too good for internet dealers, not so good for bricks and mortor dealers.

Do you have an example of what you did?
d

 

[dogman dan]

Must not have read any of my motor reviews.

My standard hill is about a mile long, mostly 5% but with a good stretch of 6% in the middle. It's part of my regular commute. Since I'm not doing an " I intend to kill my motor test" I do pedal in an appropriate gear but not enough to get winded, no standing on the pedals, etc. It's pretty hard to have everybody have a standard hill, but I do my best by taking as many motors as I can get my hands on up this hill. Because of a busy street, the test allways begins while stopped, and a good deal of the evaluation is how it handles the first few feet, that are up a driveway that is about 7%.

Even with pedaling, a wimpy motor and controller quickly shows itself on this hill. A decent motor will keep me going at least 15 mph or more all the way up, while lower wattage ,or less efficient setups struggle to maintain 10 mph. One time up the hill tells me nothing, only when I have many repeated trips do I have the real answer.

There is a place where I can test a 13% grade, but none of the motors I have had handle it well. Gearmotors get up it ok, but overheat really fast.


I do agree though, that there are way too many vague evaluations of hill climbing performance out there. All of them that don't take motor heat into consideraton are pretty worthless. Any motor can be overvolted to sprint up a hill as it destroys itself.

 

[pdf]

PDF,
my thoughts:

Some interesting work.

May I add to record bike and load weight, and wind speed.....

Do you have an example of what you did?

Ah yes, weight would be an important variable for hill climbing!!! Thanks. Wind speed should be recorded as well for completeness.

If I can gauge that there is sufficient interest, I'd be willing to try to compile any data as long as it is gathered in a consistent manner so it is apples-to-apples.

What I did: well, I have been trying to determine what system to buy. I have vaccillated about as far each way as can be done: jumbo hub motor, geared hub motor, "cyclone" motor, you name it. I finally found the bike simulation programs I'm sure you've seen, and I began my "virtual quest" for the ideal ebike using the forum reviews and the simulation programs. Then, when I had compiled a list of likely candidates, I visited a place where I could test ride several. In short, the simulators predicted that the setups I rode should have easily done a 6% grade motor-only but that was not what happened. Only one setup was able to reach an equilibrium speed up the relatively modest hill and it was not even one on my short list because it was a through-the-gears bike setup and I had only considered the simpler hub motor setups.

While the ability to predict behavior with a simulator would be preferable, in the absence of that option, we have to fall back on empirical evidence. At any rate, empirical evidence will be required to validate any models.

I have read several accounts by users here with their first ebike setups who are disappointed with the hill climbing ability. I would really like to see ebikes take off as a commuting option. But if people who buy them at pretty significant expense are disappointed and the bike goes right back in the garage, they will not catch on and will remain a fringe application. In addition, I am hoping that if people submit their trials as a reply here, a trend will evolve so that I can make a more informed purchase myself and avoid experimentation-by-checkbook. Manufacturers are not likely to provide this data unless it is favorable to them and even so, it is not likely to be provided in a consistent way so that any two options can be compared.

 

[deardancer3]

I forgot about something; what about our different frontal areas as defined by our bikes, posture and body size/shape?

I think this is a miniscule effect at 5mph, but as we get up towards 15mph could this skew results?

I know that a 6ft 2" 230 lb guy weighs more than average, but he also has some extra wind drag too.

Maybe one of the science/physics folks can tell us.


In the meantime, if a few folks could do a practice run we could see how the info would compare.

Soo, when the snow melts, I guess we will giv it a try with the Cyclone and the Bionx(wife)

Got instructions and form to fill out?

d

 

[pdf]

I forgot about something; what about our different frontal areas as defined by our bikes, posture and body size/shape?
I think this is a miniscule effect at 5mph, but as we get up towards 15mph could this skew results?
I know that a 6ft 2" 230 lb guy weighs more than average, but he also has some extra wind drag too.
Maybe one of the science/physics folks can tell us.

In the meantime, if a few folks could do a practice run we could see how the info would compare.
Soo, when the snow melts, I guess we will giv it a try with the Cyclone and the Bionx(wife)
Got instructions and form to fill out?

Wind resistance is a factor. However, even on a modest 5% incline, the power required to overcome gravity is about 3 times the the power required to overcome air resistance. This depends on rider weight, frontal area, etc. of course. So while wind would be a significant factor, it is not the primary factor. None-the-less, if a hill-climbing test occurs in a hurricane, it would be best to note that.

Will put together a form today, in hopes that people contribute.

 

[dogman dan]

Another issue is people don't know the grade they are climbing. I thought my hill was 10%, based on readings I took with an aircraft altimiter. But I calculated wrong. The hill is mostly 5% with some 6% in the middle section. It's the length of it that makes this hill tough.

You see people say, my bike zoomed right up a steep hill, but then later they say, Map my ride says it's only 4%, only a moderate hill. Then you have the pedaling effort thing. I don't pedal hard, to me. But to a guy just taking up the bike again after 20 years my wattage at easy, is more than he can do.

So yeah, some kind of calibrated hill, and riding to a dead stop would be a good test. Problem is, its a good way to pop your controller, stalling the bike like that. So I won't be doing that test myself. Mabye distance ridden till the bike to slows to 7mph? From a start up the hill at 10 mph?

One test I do to compare bikes is a very steep but very short hill on my bike path. I hit it at full speed, 20-25 mph and see how fast I travel at the top with no pedaling. My aotema starts out at 25 mph and can still be doing 10 mph at the top. My fusin will start at about 22 mph and be going less than 5 mph at the top. No suprise, though the fusin has gear advantage, it's only 350 watts vs the aotemas 750.

The other gorilla in the room is motor heating. My fusin will grind right up 13% grade, though slowly. But it will overheat in about 2 or 3 miles. A real hill motor would have the heat shedding ability and wattage of an x5, along with unbreakable planetary gears. Others report nice climbing with the higher wattage bmc's but they do get hot quickly when climbing non stop.

 

[pdf]

All: Below is what I would consider a reasonable hill-climbing test. Please read and suggest changes. I propose people simply reply here and after the responses fall off (if there are any) I will compile in a table. Sorry the list of desired info is so long, but the setups vary so much, a lot of info is needed to know what to make of the results.

Preamble: In an effort to quantify the hill-climbing performance of various e-bike setups, I have defined the following Standard Hill-climbing Test. It is designed to safely and quantifiably determine the ability of a given e-bike to mount a hill. The test is designed to be performed with the motor only supplying power. If you think performing this test will cause equipment failure or injury of any kind, do not perform this test. Post data by replying to this thread in endless-sphere, quoting this message.

Standard Hill-climbing Test:
Reach a speed of 20 km/hr (12.4 mph) up a hill of known grade (pedaling allowed). If pedaling, stop pedaling, set throttle to maximum, and start timer. If speed is DECREASING, let speed decrease to 10 km/hr (6.2 mph) and stop timer. If speed is INCREASING or STABLE, record speed after 10 seconds. If a parameter or data value is unknown or not applicable, indicate this with UNKNOWN or NA, respectively.

SECTION 1: SYSTEM PARAMETERS

Motor
-manufacturer and model:

Battery
-nominal volts:
-actual volts at time of test:
-chemistry (LiFePO4, NiMH, etc.):
-lower voltage cutoff of BMS:

Controller
-manufacturer and model:
-current limit:

Bike setup:
-total weight of rider and bike:
-wheel size:

External gearing
-total ratio from the motor output shaft to the wheel (not including gearing internal to motor, such as planetary gears):

Power monitor (Watts up, CA, etc.)
-current limit:

Environmental conditions
-%grade of hill and how determined:
-wind speed and direction relative to bike (headwind, tailwind, etc):

SECTION 2: DATA TO RECORD

-speed decreasing: Time from 20 km/hr (12.4 mph) to 10 km/hr (6.2 mph):
-speed increasing or stable: Speed after 10 sec.:
-electrical power (if equipped with power monitor):
-current (if equipped with power monitor):
-any relevant comments:

 

[Russell]

While it would be nice to have a standardized hill-climbing test for all of the motors available it’s also quite impossible for E-S members to do collectively because there are far too many variables involved. Look at this test of the BMC-T&S motors by the gals at Cycle9 and you can see how just a small weight difference can make a big difference out on the road.

http://endless-sphere.com/forums/viewtopic.php?f=3&t=7524&p=122174#p122174

In practice the no-pedaling performance of a motor up a grade also doesn’t mean a great deal unless of course you can’t pedal at all. For example I have a 250W 36V Bafang geared motor on a 700C wheel with a big 50mm tire powered by a 48V/10Ah battery using a 15A controller; most people would say this is not a “climber” and they’d be right…to a point. All by itself the little motor in the big wheel can’t sustain a reasonable speed up a steep grade. I tested this today on a few hills on my normal route for the first time really (I and the bike have a combined weight of 250 lbs). Up a 7% grade the motor would slow to as little as 6 mph with the amps peaked at just under 15A. On the steepest hill on this ride, approximately an 8% grade, I approached the base of the hill at a normal speed (high teens) then proceeded up the hill on the motor only at full throttle. My speed slowed to 5 mph. It’s under these conditions that the motor is running extremely inefficiently with much of the 700W be drawn from the battery being wasted as heat in the motor. I don’t know if the motor was going to stall but I figured I’d stop torturing the little guy and pedal. All it took was a quick spin in a lower gear to get the motor back into its “happy zone” and the speed to 13 mph and all it took was some very easy pedaling to keep it above 12 mph. I can’t stress this enough because it really did take little pressure to stay at 12 mph with vigorous pedaling not getting me much more speed, around 14 mph. So far the steepest grade of any length I’ve gone up is about 12% and the little Bafang has yet to let me down. Sure if I had mountains to climb I’d want a motor which could handle more power over a continuous period but I think my example shows how when rider and motor work together the result is far better than either one acting alone.

-R

PS, Change any variable such as rider weight, wheel size, controller current and the result on the motor only would be different, change them all and the results for the same motor up the same grade would be very different.

 

[dogman dan]

PDF does have a point though, I'll be doing some testing similar to what he suggests very soon. I can compare a 350 watt fusin gearmotor, an Aotema 750 watt, and an E-BikeKit (one version of the 9 cont). All will use the same 36v pingbattery.

I don't have a good way to measue amps or watts. But I can report controller size, battery type, etc, and give a report on climbing performance pedaling and not pedaling on a 5% hill or so. I'll do several runs of each type, dead start, starting at 10 mph, etc. Distance might be better than measuring time. I may post results here, and again on another thread so the seach engine can find it easier for folks later. Finding a hill that has a very constant slope is the hardest part of standardizing a test. My commute hill has pretty constant slope for the first 1/3 of a mile or so.

 

[pdf]

Well, it was worth a try. I thought such a test would allow people in the market for a system to climb a hill would find quantitative information useful at least as a point of reference. Apparently, there is little interest.

My advice is: If you are in the market for a system to be used in hilly areas and use simulator results to determine likely performance on the bike, it may not match the results of actual bike trials. I suggest that before buying, you test-ride several systems of all types (hub, geared hub, bottom-bracket, etc.) and see what each system offers. They each have positive and negative points and my personal experience has been that when used to predict low speed, high torque performance on hub motor-equipped bikes, simulators significantly overpredict climbing speed on grades. If anyone can verify that an eZee 26" (26" wheel, 48V 10Ahr battery, 215 lbs rider and bike, 20 amp controller) will accelerate from a standing start to 7 mph in 20 sec. up a 15% grade, I'll stand corrected; this is what a simulator predicts. It is very possible I did something wrong when I tested this and other set-ups. (If you actually try this, I suspect it will be trouble for the controller, so do so at your own risk).

I'd just add as an analogy that all commerical and military aircraft (I worked to develop simulators in these areas) are now designed in-silico prior to any testing and it would not be acceptable to conclude, after spending billions of dollars to develop and build a new aircraft to say, "Well, I didn't expect it to actually FLY. The motor is just there to help keep me in the air. If I want to go UP, I need to flap my arms a bit."

Just my 2 cents. It's worth what you paid for it.


EDIT: Well, Dogman has chimed in. I will not lose hope yet.

 

[Russell]

PDF does have a point though, I'll be doing some testing similar to what he suggests very soon. I can compare a 350 watt fusin gearmotor, an Aotema 750 watt, and an E-BikeKit (one version of the 9 cont). All will use the same 36v pingbattery.

I don't have a good way to measue amps or watts. But I can report controller size, battery type, etc, and give a report on climbing performance pedaling and not pedaling on a 5% hill or so. I'll do several runs of each type, dead start, starting at 10 mph, etc. Distance might be better than measuring time. I may post results here, and again on another thread so the seach engine can find it easier for folks later. Finding a hill that has a very constant slope is the hardest part of standardizing a test. My commute hill has pretty constant slope for the first 1/3 of a mile or so.

That's what is really needed, one person testing as many different motors as possible up a nice steady known percentage grade. On a hill climb you're likely to be running at the peak current for the controller so maybe a meter isn't necessary but I find a wattmeter to be an invaluable tool and as cheap as this one is there's little reason not to get one.

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10080&Product_Name=Turnigy_Watt_Meter_and_power_Analyzer

-R

 

[deardancer3]

My opinion:

Any numbers on hill climbing ebike selection would be very helfpful to buyers;

Initially;
Knowing that 250lb ebike #1 will not climb a 7% grade over 8mph without pedaling $1.5k
220lb ebike #2 will not climb a 6% grade over 8mph without pedaling $1.3k
300lb ebike #3 will climb a 7% grade at 9mph without pedaling $2k

although the data is not identical, it is tested by honest people trying to give real data, and would be quite helpful to dealers and buyers alike. much better than only having the manufactures hype we have now.

After we get some initial data , yeah we may come down to "find a 7% grade, approach it at 15mph, floor it no pedalling, and record how far you get before you drop to 10mph"; Tell us the distance and weight.

To me---- this thread, and people hearing that some light pedalling is enough to make a significant difference to a hill climbing is quite valuable. Dealers, knowing that hardly any system can do big hill climbs without assistance, this is good to tell buyers, and good for them to test. If a dealer knows this is risky but probable use, they had better make sure that the controller protects itself against the customer that will certainly try to climb the 'hill from hell' with no assist.

 

[pdf]

Knowing that 250lb ebike #1 will not climb a 7% grade over 8mph without pedaling $1.5k
220lb ebike #2 will not climb a 6% grade over 8mph without pedaling $1.3k
300lb ebike #3 will climb a 7% grade at 9mph without pedaling $2k

What was the setup for bike #3, just out of curiousity.

 

[dogman dan]

Well, we allready know a few things. such as.

500-700 watt direct drive motors don't zoom up 7% grade hills at 20 mph no pedaling with 36v. My experience up the hill on my commute no pedaling is more like 8-10 mph. That is with both brushed and brushless versions of Aotema, with a 36v pingbattery. 36v 22 amp controller With pedaling I climb the hill at 15-18 mph.

Using my fusin gearmotor, and the same battery, this 350 watt motor really slows down, but can't be stalled like a dd motor. It'll climb the same hill at more like 5 mph no pedaling. 36v 15 amp controller. With pedaling, this motor climbs the hill at about 13 mph. Climbing no pedaling, it gets hot really fast so for serious hillclimbing I wouldn't recomend it. The smaller gearmotors like bafangs and fusin just can't shed the heat good enough.

I weigh 180 pounds, and the bike about 85 pounds.

Finding a good hill for the test is a definite problem. My big hill on the commute for instance has lots of grade changes. Over a mile and a half I climb 600 feet of vertical. It has steep sections and flat parts, and averages 5-6%. There are a few spots that are 7% and today looking at it 1/4 mile at a time, map my ride shows a short spot of 11%. Wow, no wonder the bike slows down there so much, but to the eye it looks all pretty similar.

I did finally locate a suitable hill with about .8 of a mile of 6 and 7% grade that is pretty consistent. It's on Augustine pass and fairly near my home. Too windy for any testing today though, with the bad weather blowing through. Ebikes really climb great with a 30 mph tailwind.

 

[Drunkskunk]

I like the Idea of the test, but the method is such that it would be difficult for a large bunch of people to reproduce close enough to get meaningfull data from it.

part of the problem is a suitable hill. here in Texas, we have hills. usualy the size of something dropped out of the back of a dump truck. Real hills are few and far between, and far too short to get real numbers from. I have a driveway thats probably 8 to 10% grade, but it's 25 feet long. thats the steepest hill I encounter. I can terll you my 9C pulls up it at 36 volts better than my 408 at 36 volts, but I doubt i could get any meaningfull data from a short test except to say one's better than the other.

WHats needed is whats been talked about before. Some kind of Dyno thats easy and cheap to assemble, we can all build and test with.

 

[deardancer3]

Knowing that 250lb ebike #1 will not climb a 7% grade over 8mph without pedaling $1.5k
220lb ebike #2 will not climb a 6% grade over 8mph without pedaling $1.3k
300lb ebike #3 will climb a 7% grade at 9mph without pedaling $2k

What was the setup for bike #3, just out of curiousity.

(weights above total ebike and rider weight)

Probably a 500w cyclone nicad with a 32 tooth rear gear on a 20" wheel.

d

 

[dogman dan]

Ok, well, weather conditions were not so great today either but I went out and found a hill in Organ NM about .2 long and showing on map my ride as 5% with some 4% at the very top. It's really hard to get a consistent grade, one spot where a flat spot is caused by a street intersection shows 13% after you cross for a few feet. Weather was pretty breezy, and I forgot to carry my anemometer. But I estimated the wind at about 10 mph tailwind. So this test will show some exaggerated performance. Guesstimating, from 5000 miles commuting experience, in no wind speeds would have been about 2mph slower at least.

To keep it simple, I just rode the .2 mile several times both from a standing start, and from a 12 mph start, and took note of the approximate average top speed. This is equilibrium speed.

From a standing start, the highest speed 13 mph on the steeper 5% grade part. It took about .1 mile to reach 13 mph. At the top, the grade is only 4% and on that part the speed increased to 14 mph.

From a rolling start at 12 mph, the highest speed was 15 mph, but dropped to 14 mph by the top. I am going to assume that if more 5% grade had been avaliable, the bike would have slowed to 13 mph.

This speed at the top was the same as the previous test, so I am going to say the top sustainable speed at 5% was 13 mph and at 4% the top sustainable speed was 14 mph.

Both tests were at full throttle, Aotema front hub motor on 26" wheel. 22 amp controller. Kit sourced at High Tech Bikes. Battery was a fully charged 36v 20 ah pingbattery lifepo4. Rider weight 180 pounds. Bike weight about 85-90 pounds. No pedaling at all on the standing start test, on the starting from 12 mph test, it was about three cranks of the pedals to reach 12 mph.

For now that's the olny test on the aotema, I want to get the new E-BikeKit motor on the bike this weekend.

 

[pdf]

Ok, well, weather conditions were not so great today either but I went out and found a hill in Organ NM about .2 long and showing on map my ride as 5% with some 4% at the very top. It's really hard to get a consistent grade, one spot where a flat spot is caused by a street intersection shows 13% after you cross for a few feet. Weather was pretty breezy, and I forgot to carry my anemometer. But I estimated the wind at about 10 mph tailwind. So this test will show some exaggerated performance. Guesstimating, from 5000 miles commuting experience, in no wind speeds would have been about 2mph slower at least.

To keep it simple, I just rode the .2 mile several times both from a standing start, and from a 12 mph start, and took note of the approximate average top speed. This is equilibrium speed.

From a standing start, the highest speed 13 mph on the steeper 5% grade part. It took about .1 mile to reach 13 mph. At the top, the grade is only 4% and on that part the speed increased to 14 mph.

From a rolling start at 12 mph, the highest speed was 15 mph, but dropped to 14 mph by the top. I am going to assume that if more 5% grade had been avaliable, the bike would have slowed to 13 mph.

This speed at the top was the same as the previous test, so I am going to say the top sustainable speed at 5% was 13 mph and at 4% the top sustainable speed was 14 mph.

Both tests were at full throttle, Aotema front hub motor on 26" wheel. 22 amp controller. Kit sourced at High Tech Bikes. Battery was a fully charged 36v 20 ah pingbattery lifepo4. Rider weight 180 pounds. Bike weight about 85-90 pounds. No pedaling at all on the standing start test, on the starting from 12 mph test, it was about three cranks of the pedals to reach 12 mph.

For now that's the olny test on the aotema, I want to get the new E-BikeKit motor on the bike this weekend.

This sounds pretty good to me. It is better than my experience at 48V ona simimlar grade The aotema is DD, correct?

 

[dogman dan]

Yes the aotema from high tech bikes Terry. Similar motors are sold under the WE brand. It's a Direct Drive motor, with what looked to me like 7 windings when I opened it up. It's flat land top speed is about 24 mph. It's less windy today so I am going to go out in a few minuites and try the test again on some steeper slopes. Yesterday I was trying to find a hill with less wind. On the steeper bits of my commute hill I remember it being slower. So today I want to see what it can do on 7%. I may have had more tailwind than I thought, so I need to do it again.

 

[dogman dan]

Ok here's the results. The hill is pretty steady grade, starting out 5% then going to 7%. On direct drive motors I have had, I don't want to test any steeper because experience tells me that 7% is about the limit for 500-700 watt direct drives. 10% stalls the mid size direct drives unless you pedal.

Ambient temp 66F, wind calm, with some 3mph gusts. Tailwind in the gusts. No pedaling at all. Rider weight 180 lbs, bike weight 85 lbs. Bike is a tall "comfort style" setup with horrible aerodynamics. Aotema 750 watt direct drive front hub and 22 amp controller from High Tech Bikes. 36v 20 ah lifepo4 battery from Pingbattery, fully charged.

So the hill is about 450 feet of climb, over 1.5 miles. From a standing start, the 5% grade goes at 13 to 13.5 mph As the hill steepens, speed dropped to 11.5 to 12.5 mph. At the very top where the hill is a solid 7% for the last half mile, speed dropped to 10.5 mph. Motor temp at the top of the 1.5 mile ride was 160F.

Here is a screen shot of the Map My Ride page, showing the grades.

As I said in a previous post, without the motor heat considered, hill performance is meaningless, Without pedaling, this motor went from 66F to 160F in a mile and a half. I consider above 160F overheating the motor. The rapid overheating shows the importance of helping a motor climb the hill by pedaling.

 

[deardancer3]

Raleigh Gruv with 360w cyclone, 24v 20 ah Headway LiFePO4 pack, 26" tires comfort feet forward bike. 6 ft 1" rider, normal bike clothes. BMS used for charging only, not for load. Left Pannier removed, battery in Right rear basket.

305 lb total load 8% grade. Pack fresh from charger.

No watt/amp meter installed.

this is a stock cyclone motor with internal controller, 14tooth drive on cyclone, internal ~10:1 step down gearbox.
Cyclone motor is installed on the bottom chain line between crank and rear cluster.

Outside temp 55F, slight cross breeze.

start speed 12 mph bike stabilized at 9.5 mph no pedaling; identical results in 2nd (28tooth) and 3rd (24 tooth) rear gears; no red or yellow lights.

In first gear (32 tooth), speed dropped below 7 mph after 400 feet, quit test

<10F rise in motor after 1/4 mile; Pack measured 26.6 v after testing and 15 minute rest.

dick


edit... did a calibrate on the speedo, its 9.3 mph today at 65F degrees, and the motor went up 15 degrees after ,25 miles

 

[dogman dan]

Cyclones have a blower to cool the motor don't they? Likely to beat the pants off hub motors for staying cool on a long climb if so. I'd like to see a 24v hub motor climb at that speed too! 8% is serious steep too. I'll take 7mph sustained, no pedaling , up 8% any day. In second that motor kicks ass!

 

[deardancer3]

Thanks. Normally I pedal to help. No blower on the cyclone.

I was impressed too. But, this ebike never did that till I got the new batteries. Before that, I got a yellow light on the 13ah NIMH if I did not help. wish I had my CA on there so I could know more about minimum battery requirements- 20ah might be overkill. never take a charger though.

Hopefully this info can help people.

Thats 8% not 8 degrees. its 5 degrees on my $10 HARBOR FREIGHT inclinometer.

d

 

[dogman dan]

That's still an impressive climb for a sealed motor to only heat that much. Direct drive motors make a lot of heat when ridden less than 15 mph. I'd like to see an ebike with a blower cooled motor. In the mountains I rely on sloooow riding, pedaling hard, and lots of stops to cool the hub. That test I did was the first one for a direct drive motor with no pedaling I've done that was that long. 100 degrees rise in heat for 1.5 miles of riding is getting hot fast! The heat measurements are accurate, on that motor I have a sensor inside the hub, right next to the windings. I try to never exceed 170F. Above 160 on a hill, it's time to stop.

I get a real laugh when I hear people talk about riding roads that are 10 degrees. I did find one close to that in NM, crossing a pass, the sign said steep hill 15%. Dang glad I was going down that side. The side I climbed was only about 5%.