My Cromotor E-Bike Build -> more like a moped

Allex said:

Actually, the stock Bomber comes with Magura MT2, one piston brake and they are quite good, enough for me. 8 piston brakes are marketing bullshit.
Take a look at this chart, the formula R0 with one piston delivers 124Nm in breaking power, best in the test.
http://www.bikeradar.com/mtb/gear/article/how-we-test-hydraulic-disc-brakes-24345/

Click to expand...

Can you do a braking test (50kph to 0) for us? If you can measure the temperature of your disc after the test, It will be perfect... I tried to measure with a laser sensor but it didn't work and with my finger, the measure is not precise... :?

If the braking torque with Magura MT2 is really 103Nm, I think it's not enough to have a very goog braking. The weight of bomber is about 53Kg. If your weight is about 70Kg, you need between 250-300Nm to lock the front wheel (dry condition).

What is your top speed with your Bomber? Have you ever tried to do an emergency braking at the top speed?

Stealth bomber, I like it!

dotrick said:

Allex said:

Actually, the stock Bomber comes with Magura MT2, one piston brake and they are quite good, enough for me. 8 piston brakes are marketing bullshit.
Take a look at this chart, the formula R0 with one piston delivers 124Nm in breaking power, best in the test.
http://www.bikeradar.com/mtb/gear/article/how-we-test-hydraulic-disc-brakes-24345/

Click to expand...

Can you do a braking test (50kph to 0) for us? If you can measure the temperature of your disc after the test, It will be perfect... I tried to measure with a laser sensor but it didn't work and with my finger, the measure is not precise... :?

If the braking torque with Magura MT2 is really 103Nm, I think it's not enough to have a very goog braking. The weight of bomber is about 53Kg. If your weight is about 70Kg, you need between 250-300Nm to lock the front wheel (dry condition).

Click to expand...

I don't care about the theoretics on technicalities because a LOT of that is marketing lingo. All I care about is test results in a standardized setting that are as close to real life as possible. Bikeradar test is just that. Based on that test, I bought the Formula R0.

My bike used to be around 40kg incl a 10kg Cromotor and 10kg of batteries. I am 70kg, so total weight was 110kg. Tires were 2.7" DH from Maxxis on SAS HALO rims. Front fork was a Fox 40 single crown. Going downhill, max speed I once achieved was 90kmh. My experience (done only once) on tarmac with this bike with my Formula R0 ("only" 124Nm) with 210mm in front and 203mm in the rear is that I could come to a stop from 70kmh/45mph within ~30m/100ft with my stomach on the saddle and my behind located some mm above the rear wheel. The 10kg rear hubmotor was hanging in the air for a couple of meters, front fork dived a lot.

Note that this really took a lot of modulation from my brakes, because you really do NOT want to lock the front wheel at that speed!!!!

trevc2 said:

Did you consider the Pelican 1170? It'll fit 4 of the 8000mah nanotech 6s packs. Internal dimensions are:
10.54" x 6.04" x 3.16" (26.8 x 15.3 x 8 cm)

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Yes, but because my current battery wouldn't have fit in there i decided to take the 1200 case (its 1300 size only lower in height).
If i had not yet build my battery i would have take the 1170 for sure.

I'm not very interested in Lipos. I more look to self balancing Konion Cells or A123. These Cells have much higher lifespan and are not that dangerous.

With the cases on the frame i can clasp my knees around them and this gives a more stable seat position Pedaling is also no problem..

dotrick said:

No, No More you have surface more you have pressure on the rotor by the pads. Four pistons of surface S is better than two pistons of surface S/2 Take a look here It's the law of fluid mecanic. :wink:

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No, there are much more other important things than only surface area.

Tonight, I did 3 tests of braking at 50kph to 0 : 1st :14-16m , 2nd 20-22m :? , 3rd 24-26m
Probably during the first test, the Rotor/Pad heat was too high and they didn't appreciate... My braking system is a cheap system. A rotor of 160mm and no hydraulic system.

Click to expand...

thats called brake fading and happens when your braking system get to hot :wink:

I'm looking forward to see your test with your Shimano Saint 4 Piston. I think it will be good!

Click to expand...

My 203mm SM-RT99 rotor with alu cooling fins does emit heat very fast, but its very thin and i think it will wear down fast. If the rotor is done i will test the Formula 203mm centerlock which should be the same as in the R0 braking system.

I would do that for sure but the weather is so darn cold right now around +2°C and rainy so I just want to stay in the house as much as possible
I can say that MT2 performs at 100% when I do emergency brakes(without regen), so yes I would like to have better brakes on the bike eventually. But I am only 60Kg so they do fine for me. If I pinch hard enough I lock up the front wheel on the paved road.
The bike have regen so most of the time I just use that and brake only when regen does not have any(or very little) effect, below 20km/h.
And when I do emergency brake I use regen+front+rear brakes so it is very efficient.

dotrick said:

Allex said:

Actually, the stock Bomber comes with Magura MT2, one piston brake and they are quite good, enough for me. 8 piston brakes are marketing bullshit.
Take a look at this chart, the formula R0 with one piston delivers 124Nm in breaking power, best in the test.
http://www.bikeradar.com/mtb/gear/article/how-we-test-hydraulic-disc-brakes-24345/

Click to expand...

Can you do a braking test (50kph to 0) for us? If you can measure the temperature of your disc after the test, It will be perfect... I tried to measure with a laser sensor but it didn't work and with my finger, the measure is not precise... :?

If the braking torque with Magura MT2 is really 103Nm, I think it's not enough to have a very goog braking. The weight of bomber is about 53Kg. If your weight is about 70Kg, you need between 250-300Nm to lock the front wheel (dry condition).

What is your top speed with your Bomber? Have you ever tried to do an emergency braking at the top speed?

Stealth bomber, I like it!

Click to expand...

The Adaptto unit sould arrive at least in 1 or 2 weeks. Can't wait to get it and test it / play with settings..

some more pics from building:



brake rotor and screws i had to file down to fit:





stand:



thermistor added on windings:



holder for turn signals and rear light (its a part from mud fender):

Allex said:

I would do that for sure but the weather is so darn cold right now around +2°C and rainy so I just want to stay in the house as much as possible

Click to expand...

Pfff... you are a chicken!

more pics. Maybe somebody can take out inspiration for own bike buils. Thats why i do this.
Everyone learn from somebody other. I did so too here in ES.

rim centering:



dropouts:



bolts for cases:



little work on cases:



battery. The cells i only sticked together with CA.
on top and bottom 1,5mm gfk plates sticked on. Double 4mm² wire and 5,5mm bullets.
surrrounded with self sticking foam to absorb impacts and good fit in case:











charger from BMS-Battery:

Today the postman delivered me a parcel.

that was in there:









comparison with CA V3 and Lyen 18FET:

Is that the sine wave controller?! looks pretty sweet. Is that other part it came with similar to the CA? How much did it cost? I am sure more people would want these for smooth power output and efficiency.

Ebikebert said:

Is that the sine wave controller?! looks pretty sweet. Is that other part it came with similar to the CA? How much did it cost? I am sure more people would want these for smooth power output and efficiency.

Click to expand...

Yes this is the Adaptto sine wave controller. There are lots of options to set up and configuration can be done without the need of a computer.
The Display only works with this controller. Its a complete unit. The power for this little size is awesome. The current price is about 24000 russian Rouble.

more infos can be found here: http://endless-sphere.com/forums/viewtopic.php?f=3&t=37377

or here in russia forum: http://translate.google.com/transla...t.ru/ussr/index.php/board,90.0.html&sandbox=1

At the moment i solder hall wires, throttle, e-brake wires to the connectors. Tomorrow i will install it on my bike and try it out.

I really like this controller. Have fun!

Max-E: Peak power 12kW

Let me know how it works!

What is that you used for your rear mud guard?

QuestionMan said:

What is that you used for your rear mud guard?

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this Mudguard Set is from Manufacturer SKS calles "Rowdy" and fits 20-24" Wheels.
I bought it two times. One for regual use and the other for the rear light / turn signal holder. To make the rear mud guard a bit longer towards the bottom, i cut down the part from the second set and mounted it reversed to it.

Today i did a test ride with the Adaptto Max.
First the controller showed !THR! which means the throttle puts out to much volts. After throttle calibration with some gaps (free travel) it started working.
There is no need to connect Halls, Phase wires the correct way. The controller has a function called "autodetect". If the wheel runs in the wrong direction you have only to reverse it (care should be taken because pedals also will turn backwards).
Autodetect takes about 2-3min and also calibrates hall angel offset and some other things.
After this procedure the controller is set up and ready to go.
There are three profiles (eco, normal, boost). In every profile you can set different batt amps, phase amps, brake amps, speed limit and acceleration rise.

Now some words to the comfort/performance/efficiency:

comfort:

The sine wave torque mode throttle is loooooots!! more comfortable according to my previous speed based Infineon. No more rough jerking if i shake throttle at middle speed.
The motor is very silent. There is no clattering at take off - it only produces some buzzing niose which is very silent.

performance:

The performance is really awesome for this little size. In boost mode (no acceleration delay) with 100A batt 200A phase the bike will now do a wheelie if i don't lean over the steerer
The first range test was not so good. With my Infineon and CA i needed about 30Wh/km (very steep hill up and down. about 10km). The Adaptto showed me about 40Wh/km but with much higher Amp settings.
For better comparison i will do a test with same amp settings as i used with Infineon.
The topspeed seems to be lower. It's now about only 64kmh on flat ground according to 73kmh with Infineon. Up the steep hill with Infineon about 60kmh and Adaptto 55kmh (at least the speedo says this. didnt test with gps)
Have to look closer to the settings if there is something adjust... Speedo settings seems to be correct.

efficiency:

My previous 18FET got a lot hotter. Especially at hill climbing when not full throttle used the Adaptto stays a lot cooler. It only got slightly warm not more (and there are no cooling fins on the case). I think thats the benefit of sine wave.
The Cromotor was quite hot after the ride. At high phase amps efficieny drops down and i think the additional 10Wh/km are mostly converted into heat (did lots of stop and go on the test ride).

keep you informed

Disclaimer: I don't know if adeppo does this, but they should. (and it is probably an option).

A BLDC motor being run as a PMSM will have a lower top speed. Can't remember the number, but I think it was between 8 to 13% lower top speed. To fix this; Once the limit is reached with sine control, the controller should go into trapezoidal control, to push the speed to the limit. After that, field weakening is needed to increase speed.

People are freaked out by my controller, once it transistions into trapezoidal (around 60km/h) - it starts making noise. As it is virtually silent up until this, the normal reaction is "something is wrong!" xD

As far as i know the Adaptto don't do so.
I can change manually to trapezoidal mode in menu. Will test it out how top speed rises.

You say you have a own controller which does this automatically? Tell us more

I've prototyped inverters for about 3 years. Latest controller uses Texas instruments instaspin FOC chip - but with additional AVR's for some functions.

Experiences with cooling mosfets and building layouts hopefully will culminate in a nice controller. Working hard on it

Madin, your speed sounds low, didn't andreym get over 100 kph with max-e, 18S lipo and cromotor in a 24" wheel? I think that was with field weakening but still. GCinDC reported also he's getting more speed with his mini-e than with his previous infineon comtroller.

Do you know of an existing thread about sine wave controller for an e-bike? Maybe I need one...
Is it possible to change the program of the infineon controller for a sine wave controler? Maybe the PWM is too slow to do this...

gua_rana said:

Madin, your speed sounds low, didn't andreym get over 100 kph with max-e, 18S lipo and cromotor in a 24" wheel? I think that was with field weakening but still. GCinDC reported also he's getting more speed with his mini-e than with his previous infineon comtroller.

Click to expand...

You are right. I stay in contact with andrey because i bought Max controller from him. I told him about my speed issue and he sent me the specific settings for cromotor.
After new setup and test ride im very happy with it

With this setttings the speed is about 3-4kmh faster than Infineon and this with sine wave mode (he said there is no need to switch to trapezoidal).
For the tests i have set up the Adaptto to the same settings as i used with Infineon (60A batt, 100A phase). With this i get about the same Wh/km (<30) but with more speed -> Adaptto seems to be more efficient.
It looks like sine wave is more efficient at take off from dead stop and square wave maybe is more efficient on high speed but i dont know for sure. Will do some more range tests at different speeds soon.

@ dotrick:

i only know about the Sabvoton controller thread and some other chinese controller for lower power. Sine wave controllers are very new on the market.
Infineon controller cannot set to sine wave. I already would be happy if they would have torque mode throttle like kelly controller...

Now, lets kill some myths before they get the chance to thrive.

1. Running a BLDC as a PMSM won't give you better efficiency. It will, however, reduce noise substantially.

2. A "sine wave controller" can be FOC, SMO, "timer-estimator" or different. Don't get lost in marketing lingo. With FOC, as Adeppo employs, you need to sample phase currents. This enables torque control easily, in comparison to speed control.

3. BLDC controllers come in many flavours, Infineons are good as they have decent software compensation while running single shunt. Other cheapo controllers let the phase currents go incredibly high.

I do not want to speak badly about Infineon. These are good and cheap controllers but not very comfortable because of the speed mode throttle.

As i said with the Adaptto and special cromotor settings i get about 3-4kmh more topspeed on flat ground and even more on steep hill climbing with almost equally power consumption (same amp settings).
To be fair i must say before i put my bike on the road i did some tests with the wheel spinning freely off the ground. Because of this the consumption probably will rise a bit... The next tests will make it clearer.

The wheels are double wall cross lacing 20" BMX rims with 2,5 / 16" Moped tires. Spokes are 13ga front and 12ga at the back -ordered from Holmes Hobbies. The back rim is custom drilled to make the steep spoke angle possible.

-the winter is coming and I have now some time for my motor, spokes and so on...

some questions to you:

-please send the type of the 20" BMX rim GS....
-please send the lenght of the spokes
-12ga is 2,05mm is this right? I think not, or?
-the nippels are 4,0mm diameter and you drill the rim with 5mm?