Single speed ebike build

[Vagos]

This is my ebike build.
I bought a 36v 250w geared front hub motor kit, with the 36v 10.4ah battery included.
I used a steel frame single speed, because the road bike i had wasn't suitable for the project.
I had a little problem with the PAS ( not enough space for both magnets and sensor in the crankset), but i solved it with a small mod.
For the excess cables i used tyre tubing for protection.
I wanted to make it as clean as possible, what do you think?

 

[Nealh]

Nice job as it looks quite tidy not always easy on a minimalist bike style.
Which hub and controller did you use ?

 

[Vagos]

Thanks, it was hard to hide the cables and i know it is not the best solution to have the controller in a plastic box, but i drilled holes for ventilation. I bought the kit from a local shop, but it didn't have a branding on, just some numbers. SY73626OL0517S1, that's on the motor. The controller is a generic 36v.
Forgot to mention that the bikes weight is now 17.7kg ( before was 10.5kg).

 

[Deleted member 4366]

SY is Shengyi:
http://www.syimotor.com/

 

[Vagos]

SY is Shengyi:
http://www.syimotor.com/

Wow, thank you! Is that a good thing?

 

[Deleted member 4366]

Wow, thank you! Is that a good thing?

probably. It's a standard Chinese motor from a long-established company. On the whole, they're pretty reliable.

 

[Vagos]

Had to change the freewheel from 20 to 16 teeth, because at 30kph the pedals were going to fast. Now the cadence is way better, but after 31-32 kph i notice that the motor kind of stop working, is that normal? Probably due to lack of power?

 

[anotherkiwi]

That is the top speed of your motor, above that you are on your own.

 

[Nealh]

32 km/h is it's optimal speed rating, which would suggest the hub is wound for about 260 - 280 rpm.

 

[Vagos]

Ah ok then. It's not a big deal, i new that was going to be the motors max speed. I wish i could go faster though, but you get what you pay for.

 

[Nealh]

It will go a bit faster with 12s but to use 48v proper as 13s a new 48v controller will be needed you will then get up to 25% more speed..

 

[Vagos]

It will go a bit faster with 12s but to use 48v proper as 13s a new 48v controller will be needed you will then get up to 25% more speed..

Maybe in the future, when the 36v battery gives up, i will upgrade, thanks.
I will try to make a video while driving and post it, cheers!

 

[Vagos]

I have a heatsink laying around. If i cut a small piece of the plastic box that holds the controller inside and use paste to join the heatsink with the controller, will that make any difference in heat chanelling?

 

[Nealh]

Yes it should do as the heat sink will be in open air and have a bit of air flow over it when some of the plastic case is cut away, if the cut out is facing the seat tube then airflow will be more direct.

 

[anotherkiwi]

I have a heatsink laying around. If i cut a small piece of the plastic box that holds the controller inside and use paste to join the heatsink with the controller, will that make any difference in heat chanelling?

Great minds think alike... I am going to do this to my controller too. I will grind the fins off the controller and use thermal paste to have better conducting of heat.

 

[Andy-of-Leicester]

A small suggestion, for aesthetics, remove the pedal sensor from its metal ring. I'm sure you can make or find some part to attach it to the frame and it will look a lot better.

 

[Vagos]

@Nealh , yeaaah, the cut out will be facing backwards, so not so much airflow, but i guess better than the closed box...
@anotherkiwi , i will use some thermal sticker, but the heatsink wont stay on the controller. I may have to use zipties, or drill a small hole on the controller and bolt the heatsink on.
@Andy-of-Leicester , i want to take that ugly thing of, but i have to find an alternative way to fit the sensor.

 

[Nealh]

I got a small tube of silicone thermal paste off ebay for about a £1.50, smear it all over and plonk the heat sink on it agitating the heat sink for adhesion. When you ride next the heat from the controller aids the adhesion.

 

[Nealh]

@Nealh , yeaaah, the cut out will be facing backwards, so not so much airflow, but i guess better than the closed box...

Even rear wards air will cool the sink as airflow will probably cause a little unstable air behind you.

 

[Vagos]

Just ordered one, thank you!