Dual "fast wind" mini-motor build
- Thread starter motomech
- Start date
Samd
10 MW
Just re-read this again - great thread.
Are the front forks mag alloy, or are the dropouts steel Motomech?
Are the front forks mag alloy, or are the dropouts steel Motomech?
motomech
10 MW
The forks are Dirt Jumper II's and are alloy.
They seem fine with one torque arm and the MXUS's 800 watt out put.
I've pretty much decided that's about the limit for me, not so much for a drop-out limit, but for control reasons.
They seem fine with one torque arm and the MXUS's 800 watt out put.
I've pretty much decided that's about the limit for me, not so much for a drop-out limit, but for control reasons.
motomech
10 MW
UPDATE:
It's been awhile, so I thought I would do an update.
Still running two throttles, two controllers, two battery systems and dual Q100 (Cute) fast speed (328) motors.
The rear is the CST version that accepts a cassette.
The frame bag contains 10 Ah of 12 S Lipo configured 6S + 6S and 4S + 4S + 4S. A 6S side by side with a 4S makes the perfect width for the frame bag.
On top of the Batteries are the two rather large Elifebike 9-FET 350 Watt controllers. And on top of that, a rat's nest of wires.;
The 5Ah/12S for the frt. motor is still carried in the case below the down tube.
Since I only use 2WD about half the time, so the two battery systems discharge at about the same rate.
I avg. almost 1 1/2 miles per Ah at speed in the middle to high 20's mph.
With the two ELB controllers, two 810 meters are used to turn them on:
From left to right, half-twist left-hand throttle (rear motor}, thumb throttle (frt. motor), 810 meter, airhorn, Luminator from Grin, 810 meter {up-side down) and rear shifter. The frt. shifter has been removed
One of the reasons I like the LED meters is they match up to 12S Lipo (46V nom.)reasonably well.
At full charge-3 of the 4 lights lit.
At half charge-second lite goes out.
At 3.60V (cell)-last lite starts blinking
At 3.5V (cell)-The controller LVC kicks in and shuts down system.
There is a cell low Voltage alarm/meter on the frame behind the steering tube.
A while back, I replaced the org. crankset with a Shimano Claris 50 T gear wheel crankset that came with short 165mm crank arms. This helped to get some more clearance from pedal strikes. This is a good replacement for those with the Octalink system;
http://www.amazon.com/Shimano-FC-2450-Double-8-Speed-Crankset/dp/B00PUDERYW
And since going to 24"wheels, i had enough clearence to use a Sunlite drop rack with a taller bag(for my gal. of milk
Latest upgrade was swapping out the chinese pizza-cutter rims with wider Alex DM 24's.
This required longer spokes and after comparing the Chinese genaric 13 ga. spokes with bicycle size DT Swiss 14 Ga., I went with the latter
The DT Swiss stainless steel spokes seemed as strong or stronger and they won't rust.
Mounting the larger CST 2.4 X 24"Cyclops tires acerbated something I already knew. That is, a single high speed small motor, on a bike with a large rider, is pushing it.
On the flat, no wind, it will slowly lose mph from it's top speed of 23 mph and hills, well, forget it. The controller will heat up like heat lamp and it's efficiency goes all to Hell.
But of course, with two motors splitting the load, it's a different ball game and the bike acts much like a single larger motor on 30 Amps.
But the second motor adds a whooping 4 mph, rather than the usual 2 mph a second identical motor would add. This is because the single tiny motor runs out of power(current), not RPM.
Currently building an extra set of motor/wheels for lite trail riding.
2) Q100H's (260 winds), Alex DM 24 rims and 2.4 X 24" CST Holly Rollers that will be run tubeless.
Edit, later cleaned up the battery compartment;
It's been awhile, so I thought I would do an update.
Still running two throttles, two controllers, two battery systems and dual Q100 (Cute) fast speed (328) motors.
The rear is the CST version that accepts a cassette.
The frame bag contains 10 Ah of 12 S Lipo configured 6S + 6S and 4S + 4S + 4S. A 6S side by side with a 4S makes the perfect width for the frame bag.
On top of the Batteries are the two rather large Elifebike 9-FET 350 Watt controllers. And on top of that, a rat's nest of wires.;
The 5Ah/12S for the frt. motor is still carried in the case below the down tube.
Since I only use 2WD about half the time, so the two battery systems discharge at about the same rate.
I avg. almost 1 1/2 miles per Ah at speed in the middle to high 20's mph.
With the two ELB controllers, two 810 meters are used to turn them on:
From left to right, half-twist left-hand throttle (rear motor}, thumb throttle (frt. motor), 810 meter, airhorn, Luminator from Grin, 810 meter {up-side down) and rear shifter. The frt. shifter has been removed
One of the reasons I like the LED meters is they match up to 12S Lipo (46V nom.)reasonably well.
At full charge-3 of the 4 lights lit.
At half charge-second lite goes out.
At 3.60V (cell)-last lite starts blinking
At 3.5V (cell)-The controller LVC kicks in and shuts down system.
There is a cell low Voltage alarm/meter on the frame behind the steering tube.
A while back, I replaced the org. crankset with a Shimano Claris 50 T gear wheel crankset that came with short 165mm crank arms. This helped to get some more clearance from pedal strikes. This is a good replacement for those with the Octalink system;
http://www.amazon.com/Shimano-FC-2450-Double-8-Speed-Crankset/dp/B00PUDERYW
And since going to 24"wheels, i had enough clearence to use a Sunlite drop rack with a taller bag(for my gal. of milk
Latest upgrade was swapping out the chinese pizza-cutter rims with wider Alex DM 24's.
This required longer spokes and after comparing the Chinese genaric 13 ga. spokes with bicycle size DT Swiss 14 Ga., I went with the latter
The DT Swiss stainless steel spokes seemed as strong or stronger and they won't rust.
Mounting the larger CST 2.4 X 24"Cyclops tires acerbated something I already knew. That is, a single high speed small motor, on a bike with a large rider, is pushing it.
On the flat, no wind, it will slowly lose mph from it's top speed of 23 mph and hills, well, forget it. The controller will heat up like heat lamp and it's efficiency goes all to Hell.
But of course, with two motors splitting the load, it's a different ball game and the bike acts much like a single larger motor on 30 Amps.
But the second motor adds a whooping 4 mph, rather than the usual 2 mph a second identical motor would add. This is because the single tiny motor runs out of power(current), not RPM.
Currently building an extra set of motor/wheels for lite trail riding.
2) Q100H's (260 winds), Alex DM 24 rims and 2.4 X 24" CST Holly Rollers that will be run tubeless.
Edit, later cleaned up the battery compartment;
cwah
100 MW
What's the real benefit over a single motor? I bpm would end up lighter and able to pull the same power.
Is it just traction?
Is it just traction?
motomech
10 MW
How so?
Greenbikelit lists the BPM CST @ 4.5 Kg.
All Cute variants @ 2.2 Kg.(X 2)= 4.4 Kg.
Advantages-2) mini-motors vs. 1) larger geared Motor
Better overall weight balance
Less unsprung weight for better suspension performance
2 minis are more stealthy than one larger motor
Better traction on poor surfaces
Cost-2) Cutes + 2) controllers = $220,...1) BPM CST + 1) controller = $260
Not prone to wheelies
Disadvantages
Can't loft frt. wheel to jump curbs(Something geared motor riders probably shouldn't be doing anyhow)
A single motor on the same Amps/Volts will accelerate faster.
2WD needs space for second controller
To be frank, none of the above is that important to me for street riding.
What really led me down this path is:
The original build was a single mini MXUS on the frt. Later, when I wanted to go faster, I could not safely go back to the original (non-motor) frt. wheel because of the metal that was removed from the drop-outs. I didn't want to have the fork lowers welded or buy new forks.
But I really didn't save any money as I persued the Ebike I wanted.
Adding the Q100 328 fast wind to the MXUS 250 mid wind was not the best match.
Going to two fast wind Cutes got me go 28 mph on 12S, my goal, then...
The CST version of the Cute came out and I thought I had to buy that to dump the the clunky DNP Enoch free wheel.
The Ironic thing is, I don't shift much any more.
I have read about the advantages of 2WD off road, but I haven't tried that yet
I could be that using two throttles off road may be awkward enough (it's easy on the road) as to off-set that advantage.
I'm not trying to convert anyone, but in the end I like this bike alot, it has worked out well for me.
cwah
100 MW
The bpm is about 4.3kg. And I'm quite confident that with the extra wiring, fixing, controller, throttle, connectors, torque arm (yes you need I broke my front fork with Q100H), it'll end up at least 500g more than the BPM.
I also see it as an additional risk of component failure.. although it can also save some hassle if 1 motor fail. But double pain when you have puncture on the front or rear wheel, the additional wiring, routing and part are also a hassle and makes it more visible.
And overall, I'd say that the ebike enemy number one is wear and tear on parts. So double wear with 2 motors so when servicing time arrive... you'll have 2 times more work.
I'm not saying it's bad, but I see it from a maintenance point of view, and no ebike I've own to date have been maintenance free and I've fixed almost any possible part on a bike. So more components, more servicing.
I also see it as an additional risk of component failure.. although it can also save some hassle if 1 motor fail. But double pain when you have puncture on the front or rear wheel, the additional wiring, routing and part are also a hassle and makes it more visible.
And overall, I'd say that the ebike enemy number one is wear and tear on parts. So double wear with 2 motors so when servicing time arrive... you'll have 2 times more work.
I'm not saying it's bad, but I see it from a maintenance point of view, and no ebike I've own to date have been maintenance free and I've fixed almost any possible part on a bike. So more components, more servicing.
motomech
10 MW
I didn't post this update to start it up the 2WD vs one single larger motor debate again.
cwah
100 MW
sorry no offence. just sharing my thoughts
Russell
1 MW
motomech said:
Hmmm...now you've given me an idea how to use my weak-ish front 260 RPM Outrider motor. I could get a 260 RPM rear Cute 100H and run them both on the same bike with 48V/14A KU63 controllers. The peak power would be a little high for my downtube battery pack, which I'd want to use for weight balance, but it worked ok on my Townie/BPM build at 26-27A (Have since switched to high C-rate 36V Battery) so it would probably survive.
About the front forks, I don't believe it's a problem. In fact I had to file the Salsa forks on my Gravity build from around 9.4 mm up to the requisite 10mm and now plan to go to a rear motor with a QR wheel up front. The axle will naturally sit at the bottom of the dropout (er, top with bike upright) and with the QR nice and tight it shouldn't move around.
-R
motomech
10 MW
My thoughts are as follows;Russell said:
The Ebike CA sim shows two Outrider standards on a 48V batt. and in 700 wheels would see 27.5 mph. Add the mph or two you seem to get
, and that would give a good turn of speed. Even with 50T X 11T gearing, I have to drop down to 25 mph to add anything with my legs.But rather than go with the Q100H and the required DNP Enoch freewheel (Which sometimes I thought was ok, but most of the time, hated), I would be inclined to go with the MXUS rear CST;
http://www.aliexpress.com/item/36V-48V-250W-High-Speed-Brushless-Gear-Hub-Cassette-Motor-E-bike-Cassette-Motor-Rear-Wheel/1888675185.html
Dave had several and did a short review:
http://www.pedelecs.co.uk/forum/threads/mxus-motor.15211/
It's somewhat larger than what you need, but the motor speed looks to be a perfect match to the OR, while I think the "H" doesn't spin quite as fast.
If I was starting a 2wd for country riding, I think I would want to go with a PAS only rear, with a throttle on the frt. and controllers with matching 3-speed limiting(the #2 setting giving that good for pedaling 25 mph). I think the perfect controller would be the low power ELB 10 Amp 6-FETs(Which are available on Ebay BTW). Or, if needed the KU63 shunts could be ground down, although the one time I tried that, I didn't clean-up well enough afterwards and a fleck of metal shorted something
Septerate throttles would allow single motor running when it's in the sweet spot, although I don't believe one would see any big increased efficiency over running a single throttle at a reduced setting running two motors.
And I did run one throttle to a pair of KU63's simply joined on a short gnd. It worked ok, but I thought they felt a bit rough, like they were interacting.
It'ds none of my business, but I wouldn't have any problem sending the OR back to the vendor, even if I had to take a credit. They need to know sometime(if they don't already), that they have a, well, if not a lemon, a lime on their hands.
EDIT:
Grin did eventually drop the Outrider and replaced it w/ a Bafang.