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

[madin88]

The beginning of the build. Some things later were changed and improved (controller, battery mount). Pics of the final bike are on page 6.

The first thing was to find a solid DH Frame with the option to mount custom made torque arms. I decided to go with Votec VR 150 DH Frame which is made of 7000AL and has very big upper swingarms (they should handle the torque well).
The Frame is from Germany and costs about 500-600€.
Front shock, brakes, pedals, steerer, headset everything is self chosen and built togehter. I spend a lot of time to find the right parts and fit them together well.
The last thing was the Motor and Rims. Wanted to wait for more infos on cystalyte the Crown TC 80/100 but not much experiences where coming so i decided to order Cromotor and im very hapy with it.
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. (loooots of work!!!). Battery is mounted on the fork in peli 1300 case and its removeable (BIG THX to oanet for this great idea!).

more data:

- 22s9p Sony Konion VTC4, charge with 8A to 90V (4,1v per cell), No balancing needed (the data sheet calaims so)
- Lyen IRFB 4110 18 FET EB 318 controller currently set to 100A phase and 60A battery (its about 5kw)
- CA V3 with expansion
- AWI 5k Thumb throttle
- Cromotor in 16 equavalent bmx rim. bigger phase wires. thermistor added.
- LED 1A for low beam + 2A driven LED for high beam. both with wide angle lens.
- LED turn signals and taillight with brake light function (have to think of how to connect the brake light to my e-brake switch)
- real moped horn^^
- Rock Shoxx boxxer fork
- Shimano Saint brakes
...

speed: 75km/h hot of the charger on flat ground. for me very fast acceleration (its no wheele machine of its only 100A phase / 60A batt)
range: about 50km at 25-30 Wh/km with full speed tested and it should be about 150-200km on 33% controller speedlimit (20km/h).
weight: bike 34kg, battery 12kg = 46kg

very very heavy bike (but very light for a moped)


some pics (no peli 1300 battery case added)

 

[ambroseliao]

Congrats on a beautiful, clean build. You have mad machining skills. Those torque plates/dropouts are gorgeous!

 

[snellemin]

Those torque plates are indeed badass. I really like your dash as well.

 

[madin88]

thx
the torque plates are made of 7000AL (Dural) which has >500N/mm². I wanted to build a strong basis bike which does not wear out if i give the motor more than 100 amps phase. For 200 or more amps such big torque plates are truly necessary believe me :wink: (200amps mean 200N*m torque)
The bad side of this plates is that they narrow the drop out wide from 150mm to 135mm. Because of this brake rotor and chain (chainline) only barely fit...
The front plate, plate for mud guard and stand are hand cutted (filed) and painted with Al spray (its like zinc spray)

 

[samoloh]

Mehn that a good looking bike sweet, upload some vids ASAP

 

[hjns]

very very nice. I am very impressed with this build.

 

[pdf]

Wow. Can we see the battery "under the hood"?

 

[nicobie]

Clean! Nice build.

 

[electr0n]

That is sexy. Very well done. I like how you've got the battery mounted and covered and well everything else too.

 

[zombiess]

ZombieSS looks at his bike with wires everywhere from testing and hangs his head in shame.

You has some skills, very nice build.

 

[Alan B]

Nice build. Make sure to hook up regen with the Cromotor, then you will hardly need that beautiful rear brake.

 

[kfong]

Nice build

 

[LSBW]

Regen hardly worth the trouble.
I would stay with proper braking system.

 

[zombiess]

I love riding with slip charge regen.

 

[e-beach]

Beautifully done! With an artiest's eye!.....So where do you put the battery?

 

[hjns]

I looked more closely at the dropouts. Is it correct that the dropout is now located slightly more to the rear as compared to the original location? Looks like only a couple of inches, but moved all the same. How thick are these dropouts, because at the frame side it looks thinner than at the dropout side? Can you elucidate?

 

[madin88]

Regen hardly worth the trouble.
I would stay with proper braking system.

have enable regen (its the green button) and the braking power is very strong even in the lowest possible controller setting. If i push the button on full speed the tire barely does not stop (controller set to 60amp Batt). Variable regen would be better (if not even necessary) at more amps to prevent a stopping tire, but for now its ok.

ZombieSS looks at his bike with wires everywhere from testing and hangs his head in shame.

You has some skills, very nice build.

thx
a month ago my bike did look like chaos too^^ haha

I love riding with slip charge regen.

will try it out.
i also have to connect and set up your throttle tamer (throttle with an Xie Chang controller is really jerky).

I looked more closely at the dropouts. Is it correct that the dropout is now located slightly more to the rear as compared to the original location? Looks like only a couple of inches, but moved all the same. How thick are these dropouts, because at the frame side it looks thinner than at the dropout side? Can you elucidate?

yes the dropouts move the motor a bit to the back and a bit more to bottom to prevent wheelie and raise up the pedals, but basically they are for a solid motor mount to the frame. where the big M12 screw is, there normal would be the rearaxle of the bicycle. They are 15mm wide on motor side and clamped with M6 screw + 7mm wide at frame side (so dropout for chainline and disc rotor only is 136mm).

 

[Alan B]

I've done both ways - with and without regen, and the regen is much better than heating and wearing out brakes for descents. Variable regen would be better, eventually we'll have controllers with that. The throttle controlled regen is one way to do variable, like engine braking. I have not tried that mode on my bike, I did try on an electric motorcycle. It was not nearly as strong, but was useful.

Regen doesn't help the range much, but it makes the brakes last and stay cool. I've put almost 4,000 miles on and not worn out any pads (though did wear out a rear moped tire at 3K miles). My route has a stop in the midst of a 15% downhill, really hard on brakes.

 

[Emoto]

Real nice and clean, ive also decide on getting a set of boxxers and saint's coming soon i hope.

 

[madin88]

closer look to the dropouts. they are painted with alu spray.

 

[madin88]

Real nice and clean, ive also decide on getting a set of boxxers and saint's coming soon i hope.

thx
the saints are very good but you shoud think of that they have 2-finger levers. If you going to use twist throttle than you may have problems to reach the levers. Thumb throttle can be mounted to the left side of the lever so there is no problem with this type of throttles.

Battery soldering and mounting. 3x 6s and 1x 4s 9p. Big THX to my brother who helped me by this work!
must say i still have some scruples about the klickfix plastic parts, but they are rated for 7kg each so they should hold the bettery well.
there is a screw in the steerer tube which holds the case on the bottom.

 

[Emoto]

Yeah i rode a ebike with small/ short levers with halftwist and noticed the problem, the saints are supposed to have good power are you happy, also do you have a disc to outside of caliper measurement / what size disc spacer did you use, you must have a fine tolerance between caliper and motor housing, im on my swing arm designing/ fabricating stage.

 

[madin88]

today previously i lenghten the fork about 2cm. it now has 15cm of travel before the bumper (on the alu on bottom of the case) hits the forkframe.
some pics with battery added:

 

[madin88]

what size disc spacer did you use, you must have a fine tolerance between caliper and motor housing, im on my swing arm designing/ fabricating stage.

i have used the normal shimano adapter for 203 discs on front and back. the mounting holes for this adapters are standardized (distances fom axle) so it was easy to make them fit on the custom dropout.

the tolerance between caliper and motor is about 3-4mm and 2mm between rotor and dropouts. Should be enough (nothing scrabs for so far)

 

[grindz145]

Gorgeous Build! More like a FAST moped.