MXUS Xf15 front (5:1 geared) at 65nm available . Full kit about £164 from pswpower delivered to UK. Will it fit your forks? I have the rear version and it runs very cool on hills.
60 or 80Nm front hub motor
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Oh I don't know, my gear sensor makes riding over hills relaxing, nearly 100% flawless no-brainer gear changes, though must be said gear sensors don't appear to work on many other people's BBSXX(X) converted bikes quite as well. I can't imagine how hub motored hill climbs could be more relaxing, having never used one. There's a dude selling an entire new looking 16" conversion kit near me for peanuts, but I can't see any reason to buy it. I'd discard everything but the motor if I did, and go KT all over the place, see what the fuss is about.
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Yes - but I was thinking about the traction and handling issue in a more powerful FRONT hub motor.
Cheers.
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Climbing a hill, using a powerful FRONT wheel hub motor, doesn't sound that relaxing. The weight distribution in that case makes wheel spin likely. Everything is wrong with it really. A powerful rear hub is a different world. All the weight is in the right place on climbing a steep hill. With a front hub, in the wet or on a less than great surface, it isn't.
I don't have motor cut outs on my mid drive bike. I just pause the motor for half a second when changing gear, except when I mess up very occasionally, but that is so rare as to be not worth worrying about.
The only set of circumstances when my gear sensor doesn't execute a perfectly timed motor pause, is when I'm climbing a steep hill in heavy rain, when it takes a fraction of a second longer than usual, causing a crunch. Other than that, as I said nearly 100% flawless no-brainer and zero stress. There's no emoji denoting relaxed hill climbs with a gear sensored mid-drive motor converted 20" wheeled folding bike, unfortunately.
Thanks for pointing that kit out and writing about your experience - I hadn't considered MXUS. That's a very good price, for if I ever feel compelled to convert my 26" Dahon Espresso folder with a rear hub motor.
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A 'flight data recorder' monitoring voltage and current at the motor, rpm, and motor temperature inside and out for that hill would answer many people's questions!
In particular the data for that steep bit.
I sense an Arduino project here. Couldn't execute it myself, but I can imagine it. I can see how to do the hardware, but the code is not my thing at all. Variables would be 'time', 'voltage', 'current'. Then you could cross link with the data Peter has on his graphs. Do they show time? No - just checked, it is mileage on the base line of his graph. You could note the time of special events like hill climbs though and work out the current and voltage drops from there.
Simplest no-code way to monitor and record internal motor temperature, would be to slip the temperature sensor of the STC-1000 into the motor via the cable, mount the unit on the handlebar and record the display (and a phone display showing hill climb progress) with an action camera while climbing the hill. Or @thelarkbox's brewing mates could advise how to interface a more expensive genuine STC-1000 with other systems monitoring the rest.
Here's the cheapo knockoff I use for my battery charge overheat alarm AKA Home Ruination by Ebike Battery Fire Expulserating PreTerminator™®©℠!!!
STC-1000 Digital LED Temperature Controller Heating Cooling Centigrade Thermostat 2 Relays Output with NTC Sensor Probe 12v 24v - AliExpress 1420
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So when I originally got the e-bike kit (Bafang G020 rear hub 26" wheel ) it came with a 48v 18 amp speed based controller. I went up that hill many times with no problems. I fitted a torque sensor and it came with a smaller 36/48 v 15 amp 6 mosfet power based controller. On hot summer days, it would sometimes cut out on that steepest section, would work again after a couple of minutes. I replaced that with a larger 9 mosfet KT controller and cadence sensor (max 48v 22 amps -which I since reduced to 18 amps using C5). I can get up that hill in the height of Summer with no problem again.
As long as no real time output to display is needed.
Very little coding if none at all required to capture data and broadcast it with existing tech frameworks.
there are a few configurable f/w systems for popular esp8266/32 socs. Im most familiar with tasmota which will host a web server of config pages so you can configure h/w like temp sensors etc and dictate where and at what frequency logs should be sent in the json/mqtt format over wifi. (other logging available such as *nix syslog..)
A further capture and record device hosting a mqtt broker with storage would be needed (your fone?), though i would use a PI-zero-W to host a wifi network to recieve the mqtt or syslog broadcasts and format the useful data accordingly (i would probably use node red - gui - easy) total cost circa £25-30 + sensors ( asuming you have a powerbank/5v feed available to power the pi-zero.. more otherwise.
( there are <5 client mqtt brokers that can run on an esp8266 but would require coding and h/w to log to storage)
Check tasmota wiki for supported h/w -sensors for input if not there you would need to add to the sources and recompile ( real programming) but not impossible. there are quite a few though..
Alternatively if you find cheap off the shelf ble sensors you can accomplish pretty much the same with the OMG project- Open Mqtt Gateway f/w for an esp32..
- I had plans... but the frequency my back box has been knocked off my bike has slowed my pace asI had planned to house my 'bike brain' within the gap of 2x stacked boxes at the rear.
** MQTT is a messaging protocol that can handle long text strings great for mark up languages like xml json...
A Broker is required to receive and repost mqtt messages, without one your literally whistling into the wind, data gets lost. Its a whole thing worth the 10 mins or so to swallow the basics might take a couple of sessions for it to sink in??
Mosquitto is the broker i employ on the same h/w above , Pi-0-W(v1).
Node Red is a Gui tool accessed via a web interface that is MESSAGE based, create flows that manipulate and change the message as it passes through the flow, THIS IS A PARADIGM SHIFT from traditional coding, but once the penny drops.. its easy/powerful, took me a bit of time tbh tho flow #1 was a monster and about 90% the way through I though hang on .. and reduced it to a handful of nodes..
what i mean to say-- not that tricky and if you want a hand to get going im happy to point..
In the early days of my solar trips I measured, displayed but did not record voltages, currents and Wh for solar generation and solar and non-solar battery consumption.
Fairly soon realised it worked, and keeping on top of the solar battery voltage was all I needed to do.
Arduino nano.
YEL(low) is solar gen, PUR(ple) is solar battery consumption. Middle number is timestamp, seconds since reset. Below I have used a bit more than I have generated, voltage is satisfactory, sky is fairly clear.
Fairly soon realised it worked, and keeping on top of the solar battery voltage was all I needed to do.
Arduino nano.
YEL(low) is solar gen, PUR(ple) is solar battery consumption. Middle number is timestamp, seconds since reset. Below I have used a bit more than I have generated, voltage is satisfactory, sky is fairly clear.
We used to have Speedict device that did all that. It was really good, but I think the guy has stopped selling them now. I still have a couple somewhere. You can see the constant current in each level of the KT controller in post #28 here:
(27) Speedict Power/bike computer | Pedelecs - Electric Bike Community
I've never really got into understanding how BLDC motors work and compare, beyond the basics and until recently I've only ridden the TSDZ2 where in my 'research' such as it was, I just settled for people's experiences of the motor and a subjective estimation of whether it would give me what I was looking for.
This leads me on to asking how the average persons is supposed look at specs and make an informed decision when choose 'suitable' motors?
Thanks.
Righty ho, I get that.
Now this is not something I've spotted and taking the AKM 100SX specs HERE and the G370 specs HERE, there are max torque given in both specs with only the G370 mentioning 'nominal voltage' - neither mention current that I could see, let along maximum current.
This leads me on to asking how the average persons is supposed look at specs and make an informed decision when choose 'suitable' motors?
Thanks.
Many thanks for taking that time to explain, but though I am quite technically adept with hardware and no stranger to building things and repairing them, that looks like a very steep learning curve for me, and it isn't me who needs it. I was simply responding to someone else's issue regarding the current draw of a stalling hub motor on a steep incline.
Thanks for the pointers and the effort to make them.
Read that thread you referenced and it would do exactly what would be required to see how much current was being drawn and data log it for later reference. Perfect solution if anyone needed to see that stuff like the chap who asked above.
OK, I see the confusion. You can't go by the figures in the listing. You need to see the actual test data sheet. as an example of why you can't use the listing, look at the G370. It says max speed 25km/hr. How fast does it actually go?
Let's look at it another way. if you had a KT 15A controller and used it with a 260 rpm Q100, then swapped the motor for a G370 or a 260 rpm Bafang BPM (massive), you'd get the same hill climbing ability, since you're giving all the motors the same power and they all do the same max speed and all have the approximately the same efficiency.
The difference is that the most power you can run the Q100 at is 20A at 36v = 720w from the battery. the BMP can run at 48v and 30 amps = 1440w from the battery, so you get double the power. Power = torque x speed, so if both bikes are running at the same speed, the BPM would give double the torque.
In other words, if you want more torque from any motor, you can increase the current as far as the motor can deal with it. If you were to ru a Q100 with 30A and 48v, the gears would strip instantly.
Motors overheat when they can't shed the heat generated in them. generally, a bigger motor can store and shed more heat; however, if you filled a Q100 full of oil and changed the gears for steel ones, you could run it at 48v and maybe 25A. In that case, it would make a lot of torque and power.
Look here to see a motor's actual test data sheet. At the top are the lines of data that show max power, max efficiency, max torque, etc. on each line you can see how all the other properties/characteristics. parameters vary with the highlighted characteristics. The headings are a few lines down. It's the Xiongda 2-speed motor, so one table for each gear:
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What are you using to generate these graphs, I would like to see some of mine in this format.
As d8veh has said modify the hub a little and it can take a lot more power.
Somewhere on the pedelecs .de forum is case point , a tame 250w Bafang swxh/k hub with steel gears and ferro fluid taking over 2000w at 60v.
Somewhere on the pedelecs .de forum is case point , a tame 250w Bafang swxh/k hub with steel gears and ferro fluid taking over 2000w at 60v.
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Mapometer, and tick the tick boxes for gradient and elevation
This is Ingleby Incline (which is off road track) that I've only done on my mid drive bike
Eta. The other climb I referenced that I use my rear hub bike for was Carlton Bank
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