Help me build e-bike (mtb)

[Smurf2]

For sensor? To be honest - NOT really :lol:

Told me that "this Cut Off Brake Sensor is compatible for 8fun BBS01 BBS02 BBSHD mid motor", and not comp. for rear hub.
I not see reason why not be work. What do you think?

In meantime, today received a battery! It show 47.4v, and when turned OFF, show 3.5v. We can't test mAh, but we will see.

 

[Chalo]

Ok, about cassettes, sellers respond me that I can install 8 cog. Is that possible?

Yes.

So, can I buy used 8 cog cassette?

That's not a good idea. A worn out cassette will wear out your chain, which in turn will wear out your chainrings, derailleur pulleys, etc. If you're going to pedal, I recommend a new cassette and chain.

If you're not going to pedal, then it doesn't matter.

 

[Smurf2]

Ok.

I wonder if my hub motor will work on 48v

I saw some motors for single voltages, and some for 36/48. But my seller not have any data of voltages in description. I hope is not only for 36v ?

 

[E-HP]

Told me that "this Cut Off Brake Sensor is compatible for 8fun BBS01 BBS02 BBSHD mid motor", and not comp. for rear hub.
I not see reason why not be work. What do you think?

Compatible is not a precise term. It can mean whether it's plug n play (or not), since the connectors are different, or that it just won't work with the signal a non-BBSXX controller works with. It doesn't necessarily mean that it can't work with the hub motor controller though. The unit requires 5V in, which normal cutoffs don't require. So it may work if you are able to provide 5V separately (sharing the 5V throttle input for instance) and get it to function correctly. It's not a mid drive vs hub issue, but one controller vs another controller issue.

 

[E-HP]

Ok.

I wonder if my hub motor will work on 48v

I saw some motors for single voltages, and some for 36/48. But my seller not have any data of voltages in description. I hope is not only for 36v ?

Don't worry. Electric motors aren't really rated for voltage, but are rated for power. You could run the motor at 100V, as long as you don't exceed the power rating.

 

[biphaeboh]

I didn't. I did not search only bike with discs. I hope I found mtb carbon "D" frame(with more space inside), Shimano system, M size, 16inch, dicscs, and important to me "Color"! but I not found discs, you can't got all what you want always (except if someone cheat you like previous seller which sold cheap bike with discs someone else!).

Not a big deal; personal preference. Chalo will tell you it's better to use rim brakes than discs.

Depends on the application. If you use 3" or bigger tires, and ride in a slurry of grinding paste, then disc brakes are your thing for sure.

Ride on roads like most of us, in tolerable conditions like most of us, and a two foot disc rotor is better than a six inch inch disc rotor. Duh.

I mostly agree with that. Discs are better in the wet and for big wide tires.
Other than that rim brakes are good. The best brakes I ever had were XTR V brakes on my Thorn Raven Nomad. Better than the Spyke mechanical discs on my Prospector, which are okay but seems to eat brake pads constantly.

I just bought a used bike with hydros. Have to see if I hate them as much as Chalo does.

 

[Smurf2]

Don't worry. Electric motors aren't really rated for voltage, but are rated for power. You could run the motor at 100V, as long as you don't exceed the power rating.

Uh Thanks, I almost collapse
Btw seller confirmed me.

Compatible is not a precise term. It can mean whether it's plug n play (or not), since the connectors are different, or that it just won't work with the signal a non-BBSXX controller works with. It doesn't necessarily mean that it can't work with the hub motor controller though. The unit requires 5V in, which normal cutoffs don't require. So it may work if you are able to provide 5V separately (sharing the 5V throttle input for instance) and get it to function correctly. It's not a mid drive vs hub issue, but one controller vs another controller issue.

Yeah, I thought that signal is main, not the type of motor. It is not too expencive, I can try that sensors (anyway I will got brake levers in kit).

Have to see if I hate them as much as Chalo does.

LoL :lol:

 

[Smurf2]

Ok, I opening a new theme, which make me nerves about - down to hill with brushless motor.

When I was e-skating, I got spark on ESC connectors (connectors was black), and it is good that fire no start. What I was doing yes that I run it (pushing skate by leg) when battery was empty. Not sure do I spark then, or when was turned off and run.

So, I am afraid of that and need clear suggestions what don't to do in future

1)When drive ebike downhill the road, speed sometimes will be faster than hub motor speed, can I burn it in that way?

2) when I will out of battery, I will shut off bike battery and pedaling, will I burn hub like that? Or not turn it off?

If yes, please suggest me how prevent that.

 

[E-HP]

Ok, I opening a new theme, which make me nerves about - down to hill with brushless motor.

When I was e-skating, I got spark on ESC connectors (connectors was black), and it is good that fire no start. What I was doing yes that I run it (pushing skate by leg) when battery was empty. Not sure do I spark then, or when was turned off and run.

So, I am afraid of that and need clear suggestions what don't to do in future

1)When drive ebike downhill the road, speed sometimes will be faster than hub motor speed, can I burn it in that way?

2) when I will out of battery, I will shut off bike battery and pedaling, will I burn hub like that? Or not turn it off?

If yes, please suggest me how prevent that.

Neither will damage the motor based on the scenarios you described. If the motor was direct drive, and you were engaging regen on the downhill, then there would be a low chance of overheating the motor, since regen creates some heat, but even that would be an extreme case and very unlikely.

 

[Smurf2]

Hi. I got kit today.

Case one. On mounting cassette, it fit very well. Is it gap on 1c/1d normal? I repeat, it sits nice. Only I can try fit one by one cog, but think will not help.

Don't know is it result of that gap on picture 1e/1f, or maybe that normal too?

Third case, the worst one, on picture 2 you see that frame is touching cassette lock ring. I tried to tighten with a wrench like that, but only like 60%, just to see would be stick, and it is.
Very sorry for that, it is very bad idea, and I hops that I not broke a lock ring. It seems fine for now

So, do I need place in that some screw, or two, which will be touching frame?

Edit: got this set of washers and half-washers too.

 

[E-HP]

You need additional washers on the cassette side, on the inside of the dropout to keep the dropout from interfering with the cassette.

 

[99t4]

You can get the axle to fit deeper into the dropouts (more secure) if you carefully open the radius a bit with a round file, areas shown in red:

Don't use a flat file or leave any sharp edges or corners.

 

[calab]

I ran into that issue with the mxus 3kw, had to cut down washers and spread the dropouts a m.m. or 2. Not worth it, just need 4 gears, 11, xx, xx, 36 and 2 crank gears 36 and 54. Be sweet, tack on 1000 extra watts, to 2800w peak, f/s, them boys would be happy.

Nice, shiny, perfectly shaped threads on that axle there, me jealous. Mines red'ish now

Helpful tip, rotate the axle back and forth by placing a wrench on the axle flats and moving it back and forth.
Little on the side of the road, changing tires tip for ya. I carry along an adjustable wrench big enough for the big hub motor nuts, so I just change its size to fit the axle flats to rotate it, sometimes stuff in the way, tires, rear rack, no shade sun glare, whatever. Trust me we all half assed it in times of rushed tiredness and it bit us in the ass, or better yet how many close calls. Felt that rear tire felts a bit low around that corner, nope gotta get going.

I am finding it hard to find axle bolts, both times they gave me the wrong ones. Third times the charm.

You need additional washers on the cassette side, on the inside of the dropout to keep the dropout from interfering with the cassette.

 

[Smurf2]

You can get the axle to fit deeper into the dropouts (more secure) if you carefully open the radius a bit with a round file, areas shown in red:

Thanks guys.
Ok, I can do that.
But first I can try with hammer, with little force  
off course, be careful to not damage the thread.

You need additional washers on the cassette side, on the inside of the dropout to keep the dropout from interfering with the cassette.

Can you give me please some picture or link, is that normal washers or some special?
It must be installed more washer it seems,.because they are tiny.

Also I prefear something from home or local store, because not waiting shipping, for the quick solve.

(Also I am not forgot Torque Arm. It is on the way).

 

[E-HP]

You need additional washers on the cassette side, on the inside of the dropout to keep the dropout from interfering with the cassette.

Can you give me please some picture or link, is that normal washers or some special?
It must be installed more washer it seems,.because they are tiny.

 

[Smurf2]

But I can with normal one? Just find washer which go inside hub hole and if is washer hole to small, just drill it on center.

Found something:
https://youtu.be/KPk7SqgiuV8

 

[E-HP]

But I can with normal one? Just find washer which go inside hub hole and if is washer hole to small, just drill it on center.

Found something:
https://youtu.be/KPk7SqgiuV8

Sure

 

[99t4]

But first I can try with hammer, with little force  
off course, be careful to not damage the thread.

Hold on a second-- just to make sure (maybe my description was unclear)-- you file the dropout to open up the radius, not the axle.

That way the shape at the bottom of the dropout more closely matches the shape of the axle so the axle can fit deeper and more securely in the dropout.

 

[Smurf2]

I solve one side! It was too easy. After I searched many washers and pipes, I remembered that I have original washers for that, which I post in above! haha ! Used 1 rounded and 1 lock washer, which now nicely fit.

B U T

Then I saw other side of wheel. Please tell me that is factory made and don't must nothing do here. You see how little peace hold bike fork there, like about 2mm. But not see any way that insert something in that space (blue). Think that I can't install washer there because all part rotate. I tighten and holding.. What do you think?

 

[E-HP]

I solve one side! It was too easy. After I searched many washers and pipes, I remembered that I have original washers for that, which I post in above! haha ! Used 1 rounded and 1 lock washer, which now nicely fit.

B U T

Then I saw other side of wheel. Please tell me that is factory made and don't must nothing do here. You see how little peace hold bike fork there, like about 2mm. But not see any way that insert something in that space (blue). Think that I can't install washer there because all part rotate. I tighten and holding.. What do you think?

You always need a washer on the inside of the dropout, so you need to move one of the washers inside the dropout on the other side.

 

[Smurf2]

Oh, did you mean like that?
That fit nice now.

Tomorrow must expend holes, and would be it.

 

[E-HP]

Oh, did you mean like that?
That fit nice now.

Tomorrow must expend holes, and would be it.

 

[Smurf2]

I filed with dad help, which insist that must fill only 1 side, not both (in this case front). On pictures it is very hard to see, but in real it looks better. I assure you that we try put a niddle bellow the axle, and we can't put it that black color on picture don't must be gap. What you mean?

 

[99t4]

You need to file the "corners" to open up the rounded part.
In my primitive drawing the original is in black pencil. File away the area shown as green, to get the final shape shown in red. Both sides.

 

[Smurf2]

Thank you for your precise drawing.

I filed now both corners. You can't see good on picture.

Please someone check videos I made. My father and brothers said it is ready to go!

Right side

Left side