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

[samoloh]

I see no problem with the design as long as there will be no balancing issues, I hope u took into consideration that when you move the controller to middle of the frame the peli cases will be lower than they are in the pictures

 

[Emoto]

Im really pleased to hear / see this evolution, and glad you took his advice for sure you will benefit from this move... and you wont have to dial in as much of preload to the boxxers.

If you can lower and further back would also be better, you could also consider moving controller behind your seat if you have to.

 

[madin88]

I hope u took into consideration that when you move the controller to middle of the frame the peli cases will be lower than they are in the pictures

If i mount the 18 Fet Xie Chang vertical and not horizontal under the frame tube it will easily fit between the two cases. The tube of the Votec frame is about 5-6cm wide.

Hope to finish this rebuilding this week (peli cases should arrive thursday). Also will mod my controller to about 100 Amps Batt. Low ESR ceramic and electrolytic caps, bigger cables, better heat foil and paste i have already at my place.

 

[madin88]

have modded my controller and blew it up
I think i tighten the screws for the FETs to much (also changed the thermal foil). Because of this some got contact with the heatsink and so they short circuit.
The curious thing was i checked everything with a multimeter before and it didn't show short circuit between the FETs :?









big hole in the heatsink. there are everywhere little copper bullets lying around on the board.

 

[dotrick]

This week I wanted to modify my controler 12FET... I want to decrease the Rshunt value to increase the current... I think I'm going fishing instead!

How much did you pay your fork? I want to change mine...

 

[madin88]

This week I wanted to modify my controler 12FET... I want to decrease the Rshunt value to increase the current... I think I'm going fishing instead!

How much did you pay your fork? I want to change mine...

yes i better should have done something other too.. Wasted about 50 dollars for the caps etc. You should better safe your money for a torque mode kelly controller or even better a sine wave Adaptto.
These Infineon Controllers are so bad jerky and very uncomfortable. The only good thing is they are cheap, open source and easy to mod (if it doesnt blow up after it haha).

For my RockShox Boxxer i payed about 500-600 Euros. Its a very good Fork with good suspension, but i wish i better had taken one with dual disc brake option.

there is a DNM-USD8 (450$) or a KOWA GF Fork (1500$) on the market with this option :wink:

 

[dotrick]

These Infineon Controllers are so bad jerky and very uncomfortable. The only good thing is they are cheap, open source and easy to mod (if it doesnt blow up after it haha).

I don't know if it's the configuration of my CA, the controler, the TC100, the battery voltage, but for me it is the same thing... Not very confortable at low speed (under 35kph). Between 55 and 75kph it's OK.

It's an open source? I would like to see! It's easier to modify the code source than the Rshunt value!

... i wish i better had taken one with dual disc brake option...

Dual disc brake option is a good solution... Now I have one disc (very cheap) And it's not serious for the speed of my ebike!

 

[madin88]

I don't know if it's the configuration of my CA, the controler, the TC100, the battery voltage, but for me it is the same thing... Not very confortable at low speed (under 35kph). Between 55 and 75kph it's OK.

It's an open source? I would like to see! It's easier to modify the code source than the Rshunt value!

I more mean they are more open and not open source.. The infineons are so jerky because they only control the speed. The kellys having already the more comfortable torque mode (also the small controllers).

I'm now in to order a Adaptto Max-E controller set. Already stay in contact

Dual disc brake option is a good solution... Now I have one disc (very cheap) And it's not serious for the speed of my ebike!

the point is the speed. the more speed the more energy the braking system must absorb. If you ride 70km/h and brake down very fast, a single bicycle disc will begin to fade soon and get much to hot. By this the braking system probably will get damaged too.

 

[briangv99]

I'm now in to order a Adaptto Max-E controller set.

hi, I'm trying to get an adapt to max-e too for my cromotor, but no luck finding them. Can I ask where you ordered from?

 

[Allex]

This is the guy you need to talk with about adaptto
http://endless-sphere.com/forums/viewtopic.php?f=6&t=47970

 

[madin88]

hi, I'm trying to get an adapt to max-e too for my cromotor, but no luck finding them. Can I ask where you ordered from?

Hi, you better direct call the manufacturer E-drives Lab. There is a big russia thread: http://translate.google.com/transla...t.ru/ussr/index.php/board,90.0.html&sandbox=1

the phone number is listed in the first post (in the signature). The guy on the phone spoke english very well. He gave me his email address to make the order.

more infos about the Adaptto Controllers can be found here: http://translate.google.com/transla...t.ru/ussr/index.php/board,90.0.html&sandbox=1

products which are currently available: http://translate.googleusercontent....9de2d1&usg=ALkJrhiGFMwzeETmog2tIWbJ_NySYOq-tw

they are also working on a very compact BMS and a configurable DC-DC converter with - as far as i have read - turn signals, brake light function included

 

[dotrick]

Dual disc brake option is a good solution... Now I have one disc (very cheap) And it's not serious for the speed of my ebike!

the point is the speed. the more speed the more energy the braking system must absorb. If you ride 70km/h and brake down very fast, a single bicycle disc will begin to fade soon and get much to hot. By this the braking system probably will get damaged too.

Today, I did some calculations... I'm little worried about my braking system...
My top speed is 90Kph (25m/s) . The weight of my ebike and me is 100kg. The cinetic energy is e=1/2.m.v^2 = 1/2.100.25^2 = 31KJ.
The steel specific heat is about 0.5KJ/°K/Kg. If you use only the front brake, you have a rise temperature of 310°C for a 200mm rotor of 200g. It's under the maximum rating of 400°C (with an ambient temperature of 30°C).

So, for the temperature, one brake rotor (200g) it's enough... Do you agree with me?

Now, the braking distance. A good distance it's about 40m for 90Kph. For this distance, the braking torque must have greater than 200Nm... Any braking system are able to provide a torque higher than 200Nm?

 

[hjns]

http://www.bikeradar.com/mtb/gear/article/how-we-test-hydraulic-disc-brakes-24345/

 

[madin88]

My top speed is 90Kph (25m/s) . The weight of my ebike and me is 100kg. The cinetic energy is e=1/2.m.v^2 = 1/2.100.25^2 = 31KJ.
The steel specific heat is about 0.5KJ/°K/Kg. If you use only the front brake, you have a rise temperature of 310°C for a 200mm rotor of 200g. It's under the maximum rating of 400°C (with an ambient temperature of 30°C).

this calculation is not right. Primarily the outer part of the rotor must absorb the heat. So its not 200g but more like 100-120g :wink:
Also the piston will get much to hot and can get leaky...

 

[madin88]

Peli 1200 mounted.
I used thread bolts through frame and rubber washer between case. On both sides M6 screws and washer.

New alu bracket.
the tube for turn signals i have a little shortened.

wind casing. lights moved from steerer more down.
its also a good place to hide all the light electronics and cables.

Adaptto Max-E Controller is on its way
will be installed under the frame tube between the cases.
maybe i add one more "s" to my battery to 23s. It would easy fit in the cases. No more battery volts possible because controller will limit, but that is enough speed anyway i think..

 

[trevc2]

How wide is it across those 2 pelican cases + frame? Would love to see a shot from above.

 

[madin88]

How wide is it across those 2 pelican cases + frame? Would love to see a shot from above.

i will make a pic from above. One 1200 case is about 12cm high + frame tube 4cm. Overall its about 28cm (11") wide and on bottom a bit more.
I have to spread my knees a bit but its not uncomfortable. Better this way than one heavy case at the handlebar i think..

 

[chilledoutuk]

In my experience the handling is better at speed when you have some weight on the front wheel steering it makes the bike less twitchy because the weight dampens your steering input.
If you planning however to go off road then the weight makes quick steering inputs difficult.

 

[dotrick]

this calculation is not right. Primarily the outer part of the rotor must absorb the heat. So its not 200g but more like 100-120g :wink:
Also the piston will get much to hot and can get leaky...

Braking S3 disc brake rotors 185mm 163g

Disc brakes
Avid Polygon 160mm rotor 115g
Avid Polygon 185mm rotor 164g
Avid Polygon 203mm rotor 223g

So I think, it's closer 200g than 100-120g for a basic 200mm rotor.

My calculations is the worst case. Piston, brake pads, air flow due to speed help to reduce the heater.

I think a brake system with a 200mm rotor and only 2 pistons is not enough to stop the ebike at high speed... Let's take a look on stealth bomber (one rotor of 200mm with 6 pistons , and 8 in option ) And this ebike goes "only" to 80kph.

What is your best brake stop distance at 30mph/50kph? The braking distance for a car is under 15m.

 

[madin88]

I think a brake system with a 200mm rotor and only 2 pistons is not enough to stop the ebike at high speed...

the number of pistons are not very meaningful. Look at hjns link! The best 203mm brake only has 2 pistons.

Let's take a look on stealth bomber (one rotor of 200mm with 6 pistons , and 8 in option ) And this ebike goes "only" to 80kph.

The 8 piston Gatorbrake from the stealth bomber is not as far as good as it looks. The Shimano Saint 4 Piston which i have is better^^ :wink: (read a few mtb threads before i ordered my braking system).

What is your best brake stop distance at 30mph/50kph? The braking distance for a car is under 15m.

I have not made such a test and now i cannot test it because i'm waiting for the Controller. If the bike is on the road again i will test it. I'm also very interested how it will perform.

 

[madin88]

In my experience the handling is better at speed when you have some weight on the front wheel steering it makes the bike less twitchy because the weight dampens your steering input.
If you planning however to go off road then the weight makes quick steering inputs difficult.

What we need on high speed ebikes is more gyroscopic force. With light bike rims/tires this force is very low.. Because of this i choose heavy 100kmh Motorcycle tires. This makes the bike less twitchy on high speed an you can do also quick steering.

 

[Allex]

Let's take a look on stealth bomber (one rotor of 200mm with 6 pistons , and 8 in option ) And this ebike goes "only" to 80kph.

The 8 piston Gatorbrake from the stealth bomber is not as far as good as it looks. The Shimano Saint 4 Piston which i have is better^^ :wink: (read a few mtb threads before i ordered my braking system).

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/

 

[trevc2]

How wide is it across those 2 pelican cases + frame? Would love to see a shot from above.

i will make a pic from above. One 1200 case is about 12cm high + frame tube 4cm. Overall its about 28cm (11") wide and on bottom a bit more.
I have to spread my knees a bit but its not uncomfortable. Better this way than one heavy case at the handlebar i think..

Thanks.

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)

Might allow decent battery storage, but keep a lower profile and width for pedalling.

 

[trevc2]

Let's take a look on stealth bomber (one rotor of 200mm with 6 pistons , and 8 in option ) And this ebike goes "only" to 80kph.

The 8 piston Gatorbrake from the stealth bomber is not as far as good as it looks. The Shimano Saint 4 Piston which i have is better^^ :wink: (read a few mtb threads before i ordered my braking system).

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/

Forgot to mention, I'm also using the same Saint setup and it's a very good brake. Surprised it's not used more often.

 

[dotrick]

the number of pistons are not very meaningful. Look at hjns link! The best 203mm brake only has 2 pistons.

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:

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.

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