8 Fun bike kit conversion, also, controller limiting?

[lotrwiz]

Hey guys, I finally bought my ebike kit!
Its an 8fun 250w 36v front brushless geared bafang hub motor.
Here's the link http://www.8funbike.com/detail.asp/sku=8F26F36B
I've got it on a 26 inch steel MTB frame, and I'm in the UK, so sadly 250w is the limit, but, the motor is NOT giving all it can, after 2/3 of the throttle, nothing else happens... does anyone know how to un-limit the controller (I've narrowed it down to the controller)
By the way I'm talking about speed here, does it require me buying a new controller?
thanks guys, thats all!
oh, and also, I'm loving the kit, really helps with the hills, and the battery lasts for a good 15-20 miles on throttle only!
It came with a pedelec sensor, but I prefer the feel of only using the thumb throttle, which sadly sticks a little.
I'd say theres also too much cabling I had to have spaghetti cable tied to my bike but...oh well.
thats the end now, bye for real!

 

[lotrwiz]

anybody? ;(

 

[dogman dan]

Perhaps your bike is just hitting an speed limiter in the controller. Open it up, and take clear photographs of the circuitry. I bet there is a wire in there, that if you snip it, it will remove the amp limiter. In the US, controllers are sold with this amp limiting circuit routed outside the box to a plug. Plug on wire into the other, and you get amp limiting. Yours is likely there, but still inside the controller.

With a good picture, the smarter guys here can tell you which wire to cut.

The speed limiter may be why your throttle seems funny.

 

[lotrwiz]

Hey thanks a lot dogman! unfortunately mt controller seems to be glued shut, don't know if this is for water resistance or what though, what do you propose?

 

[dogman dan]

Unglue it, or just buy a controller without amp limiting engaged. Straight from china, the same controller would do.

 

[lotrwiz]

Any ideas as to how to identify it, there's no model number?
I might just contact 8fun and ask, tell them its for offroad (which is true)

 

[d8veh]

Hey guys, I finally bought my ebike kit!
Its an 8fun 250w 36v front brushless geared bafang hub motor.
Here's the link http://www.8funbike.com/detail.asp/sku=8F26F36B
I've got it on a 26 inch steel MTB frame, and I'm in the UK, so sadly 250w is the limit, but, the motor is NOT giving all it can, after 2/3 of the throttle, nothing else happens... does anyone know how to un-limit the controller (I've narrowed it down to the controller)
By the way I'm talking about speed here, does it require me buying a new controller?
thanks guys, thats all!
oh, and also, I'm loving the kit, really helps with the hills, and the battery lasts for a good 15-20 miles on throttle only!
It came with a pedelec sensor, but I prefer the feel of only using the thumb throttle, which sadly sticks a little.
I'd say theres also too much cabling I had to have spaghetti cable tied to my bike but...oh well.
thats the end now, bye for real!

The 8Fun kit is not particularly fast. don't think that it's speed limited by the controller. Instead, it's limited by the motor winding that you can't change. The only way to get more speed is with a higher voltage battery. You didn't say how fast yours goes.

 

[lotrwiz]

Hey guys, I finally bought my ebike kit!
Its an 8fun 250w 36v front brushless geared bafang hub motor.
Here's the link http://www.8funbike.com/detail.asp/sku=8F26F36B
I've got it on a 26 inch steel MTB frame, and I'm in the UK, so sadly 250w is the limit, but, the motor is NOT giving all it can, after 2/3 of the throttle, nothing else happens... does anyone know how to un-limit the controller (I've narrowed it down to the controller)
By the way I'm talking about speed here, does it require me buying a new controller?
thanks guys, thats all!
oh, and also, I'm loving the kit, really helps with the hills, and the battery lasts for a good 15-20 miles on throttle only!
It came with a pedelec sensor, but I prefer the feel of only using the thumb throttle, which sadly sticks a little.
I'd say theres also too much cabling I had to have spaghetti cable tied to my bike but...oh well.
thats the end now, bye for real!

The 8Fun kit is not particularly fast. don't think that it's speed limited by the controller. Instead, it's limited by the motor winding that you can't change. The only way to get more speed is with a higher voltage battery. You didn't say how fast yours goes.

well it feels like the throttle doesn't do anything past 60 percent, so I feel like theres more it can give? and 15.5 MPH highest, motor only, with me on it.

 

[d8veh]

well it feels like the throttle doesn't do anything past 60 percent, so I feel like theres more it can give? and 15.5 MPH highest, motor only, with me on it.

You can easily determine if you have an active speed limit. Lift the motor wheel off the ground and give it full throttle. If the power cuts in and out at 15mph, you have an speed limit. If the motor just runs up to maximum speed with no cutting in and out, you're limited by the motor winding. It's best if you can measure the wheel speed with a cycle computer, so that you can determine the motor no-load speed.

 

[lotrwiz]

Oh, It runs up to 18 with no load (mph)

 

[dnmun]

look for the speed limiter connecting wires on the controller. usually two white wires coem out and connect to each other in a black plug.

you have no pictures here in your thread to explain your problem. take a picture of the controller leads and post up.

 

[dogman dan]

Yes, if you have a single wire exiting the controller, plugged into another going back in, unplug it.

250w won't get you much, 20 mph with a person on the bike takes 300-400w. By design, that motor is not a hot rod.

It's still possible that your throttle is wonky. not so much not giving 100%, but giving it at 3/4 rotation. Trying a new throttle is affordable.

 

[-dg]

Here's the link http://www.8funbike.com/detail.asp/sku=8F26F36B
I've got it on a 26 inch steel MTB frame, and I'm in the UK, so sadly 250w is the limit, but, the motor is NOT giving all it can, after 2/3 of the throttle, nothing else happens... does anyone know how to un-limit the controller (I've narrowed it down to the controller)

That is a very nice motor and quite capable. I run mine on 48 volts and get 27 mph no load speed and 23-24 on the road. It also seems to cope with 20 amps and climbs well.

The controller you have is the bafang controller and seems nicely integrated, it may even be sine wave (quieter) drive. It is intended for restricted markets. Unless you an get into it I don't see changing the internals. I think that motor should give you about 17 mph on the road and 20 no-load at 36 volts so it does perhaps it is limited by the controller. The controller (display panel) should have a setup screen where you can tell it what size wheels you have. Try telling it 20" instead of 26" and that should fool it into going faster before hitting the limit.

 

[d8veh]

Oh, It runs up to 18 with no load (mph)

That's it I'm afraid. You're limited by motor winding. A couple of guys on the UK Pedelecs forum have added three cell booster batteries to their main ones. to take them up to 13S. This gives a 30% increase in no-load speed, so you should see about 20 mph on the road. It involves a bit of messing about because you have to charge them with a lipo charger and keep a careful eye on cell voltages. The best way is to cut one of the main battery wires and add a connector. You can then fix a wire link to its mating connector and your booster battery to another. Then you can run with or without your booster battery.

We know that the controller can take an additional 3S. It might manage 4S, but I haven't heard anybody try that.

Here's a link to the two recent threads on Pedelecs forum. Note that the first guy didn't monitor his booster pack properly. which killed some cells. You need a lipo alarm or similar:
http://www.pedelecs.co.uk/forum/electric-bicycles/14618-booster-battery-experiment-2.html
http://www.pedelecs.co.uk/forum/electric-bicycles/14841-8fun-kit-mod-48v.html

 

[melodious]

From the moment I saw this post rear it's ugly head I thought for sure it was a troll post to get a rise out of members. I'm still not sure. :wink:

 

[lotrwiz]

Thanks so much for all your replies guys, I appreciate your time and what you all have to say, i may post pictures up soon, if I have the time, very busy with uni at the moment though so we'll see!