Bafang rear+ DIY battery+central battery+ DIY Computer

[spuzzete]

It looks like a regular BPM to me. Code 13 should be great for hill climbing. Try it on 36V first, but you may want to eventually go for 48V. There are speed switch connections on the BMSbattery controllers to reduce power/speed. I have a switch that i can flick from low/med/high power. Works great, and so does the cruise control. Low is around 22mph, med 24mph and high is 30mph. Mine is a code10 though

Wow that's interesting news!

I have the 3speed switch . I ordered a bunch of stuff so I don't have to order again from them (I hope ).
I can't wait to test this motor but I have to finish to build the battery first, maybe it's a good thing that it's raining at the moment


I just ordered the 201rpm 26 inches rear kit, I didn't ask for any code because I don't really know what the code means.

[Wurly]

I don't think BMSBattery know either.
Rule of thumb, higher the code number slower speed more torque. But they are torquey anyway being 5:1 geared. Best way of increasing speed is with voltage, hence i think going for 48V might be better considering you are at a descision stage.

[spuzzete]

I got a surprise today.

I was about to take the bike for a ride when I noticed a strange ticking coming from the wheel.

This is what I found:

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Another spoke ready to give in.


I am taking the wheel to a local bike shop tomorrow to get it fixed. Any suggestion on what else should I get checked while there?

[dnmun]

if it is ticking, the nipple is still inside the double wall. you can take the tire off and shake the nipple down to where it falls out and then screw it back onto the end of the spoke and tighten and true the wheel and then put the tire back on. add a tire liner too if not there already. jmho

[spuzzete]

if it is ticking, the nipple is still inside the double wall. you can take the tire off and shake the nipple down to where it falls out and then screw it back onto the end of the spoke and tighten and true the wheel and then put the tire back on. add a tire liner too if not there already. jmho

Thanks for the advice!

I had some time today and got it fixed. I found the nipple inside the double wall as you said. A bit expensive ($19) but at least they were quick (15 minutes).

[d8veh]

Did the shop check and tension all the spokes or just the two that were loose? !5 mins seems a bit quick. BMSBattery wheels always seem to have loose spokes, so you need to check them all, You'll know if you have koose spokes because they make creaking noises when you ride your bike.

[Racer_X]

+1

BMSBattery wheels always seem to have loose spokes, so you need to check them all

They are made in an assembly line.

[spuzzete]

They checked all the spokes.I took only the bare wheel with me (no tire no tube) to the shop.

I hope I will not have any other problems with the rim

[spuzzete]

An update.

I have been working a lot on the battery. I finally finished the build and you can see it here: viewtopic.php?f=3&t=26383&start=375#p578094 . I am going to test it tomorrow!

The rest of the bike:

Motor Controller in the tackle box.

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Layer of metal + plastic sheet to make a nice & smooth surface for the battery.

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Handlebar mount for the Watt & Amp meter :)

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[d8veh]

Very neat, but that's a lot of weight on the back of your bike. It'll work, but you might get unstable handling when you ride it. Is there any way to shift that box forward on your rack. I know you need to open it to get access to the battery, but if you had something like a quick release seat-post, you could lift the seat to open it. Ideally you need to get the centre of gravity of that box in front of the axle. Try putting a couple of bricks or something else equivalent to the weight of the battery and try riding it. Then you'll know whethher the handling's OK

[spuzzete]

Very neat, but that's a lot of weight on the back of your bike. It'll work, but you might get unstable handling when you ride it. Is there any way to shift that box forward on your rack. I know you need to open it to get access to the battery, but if you had something like a quick release seat-post, you could lift the seat to open it. Ideally you need to get the centre of gravity of that box in front of the axle. Try putting a couple of bricks or something else equivalent to the weight of the battery and try riding it. Then you'll know whethher the handling's OK

Thanks D8veh!

I am a bit worried that the weight is going to affect the balance on the bike too. The box cannot be shifted forward closer to the saddle, that was the initial plan, but then I found out I could not open it.

In the future I would like to put the batteries in between the frame tubes to have more balance. I cannot weld and I would like to do it without welding, I have an idea of what I would do but do you have any suggestion or point me to other threads?

Thanks,

S.

[d8veh]

You should try it first because it might just be OK, but it doesn't look too good.

What I was thinking was that you could use a quick release bolt like this on the seat-post. Then, you would be able to flip the bolt and slide up the seat to open the box. the box could then br re-positioned right up against the seat-post, which I think would be a lot better.
http://www.ebay.co.uk/itm/New-Bike-Bicy ... 3f0413dcc7
The only other option that I can think of would be to get one of those triangular bags that fit in the frame triangle as long as your battery isn't too wide.

[spuzzete]

You should try it first because it might just be OK, but it doesn't look too good.

What I was thinking was that you could use a quick release bolt like this on the seat-post. Then, you would be able to flip the bolt and slide up the seat to open the box. the box could then br re-positioned right up against the seat-post, which I think would be a lot better.
http://www.ebay.co.uk/itm/New-Bike-Bicy ... 3f0413dcc7
The only other option that I can think of would be to get one of those triangular bags that fit in the frame triangle as long as your battery isn't too wide.

I finally finished the bike today!

I just tried it and the box holds ok, so it's not too bad. When the road is bumpy there are a lot of vibrations though, and it worries me. I just had a short ride around the block. Of course I try not to "bend" the on turns,I can feel all the weight in the back! The motor runs really smoothly, I like it! And if I run out of battery I can pedal with reasonable effort

Your solution will be better, thank you for the idea, I will try it as soon as I can!Thanks!


Here some photos:

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[spuzzete]

Today I had my first "real" ride.

The trip was 11km and I used about 135Wh. Not bad! The top speed is about 30-32kph with this motor on a flat road. I am pretty happy with that. I pedalled a bit because the wind was very strong. I guess the top speed using a 48v battery will be about 40-42kph. I am pretty happy also with the tackle box, as long as I don't hit any bump it feels safe and stable.

The peaks were 1153W and 32.3A just for less than 5 seconds. I guess I need to train myself with trottle usage

I tracked the ride with a smartphone app:

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[spuzzete]

I had a few rides with the bike now and I am pretty happy with the performance!

Here is some data (tracked with gps and turnigy watt meter):

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I can ride at least 50km at full trottle!Average speed WOT is about 30-32kph depending on voltage.


I don't like the tackle box in the back, so I am working on a little frame box:

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Probably not the best job I ever done with wood but it seems solid. I am going to change the shape of the battery to fit the frame.
I am still working on the frame to improve it.

[spuzzete]

Work in progress today :

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Fits nicely and doesn't move.

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The "derailleur" for the front gears can move freely.

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I only fixed one screw for now, and is the one that was already there for the bottle holder.

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Top view, I have to centre the wooden frame .

[spuzzete]

Some more photos, hopefully I will finish it in a few days:

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I just need to secure the batteries and solder a few cables. I am also planning to transfer the controller inside the frame.

[spuzzete]

It's getting crowded in the box:

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[spuzzete]

Finally the first road test!

It's a mess with all those wires but I'm going to clean it up

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I also put a key switch so it feel like running an electric motorbike or scooter.

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I had a ride only around the block and the battery is very stable. I hit a couple of bumps and nothing moved!With the previous setting the battery would have jumped into the box. Also when I turn I don't have to worry about the weight shifting on the side.

Now it's time to shorten some wires and tidy up the settings.

[spuzzete]

Ok, the box is finished and I rode to the grocery store today to test it. It's just a couple of km for the whole trip but I had some great feelings. No more noises on any bump. Very good balance! The bike driving is definitely improved. I also feel more comfortable leaving the bike parked (and locked) outside the grocery store. I think it looks more stealth (less wires visible) and less "strange".
Anyway I am pretty happy also about the key switch! I feel like I'm riding a motorbike

Some more photos:

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This is a temporary closure of the side. I am going to put a lock as soon as I figure out the best way to do it.

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Lifting the panel for inspection and/or recharge.

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Top view. Even with the keys inserted I can pedal without hurting my legs or touching the wood frame.


Next additions: External jst cable to connect 1-8s alarms outside the box (i am waiting for the cables/connector to arrive in my mailbox), a lock and more "reinforcement" to keep the frame into place.

[Memran]

Looking very nice and neat! Not a lot of people use wood/mdf, but it is a very easy material to work with.

How is the low speed torque on this motor @ 36v? Could it handle 30% hills?
I'm running a clyte 408, but it has no grunt for off road riding, and is only useful for cruising on the level.

[spuzzete]

Looking very nice and neat! Not a lot of people use wood/mdf, but it is a very easy material to work with.

How is the low speed torque on this motor @ 36v? Could it handle 30% hills?
I'm running a clyte 408, but it has no grunt for off road riding, and is only useful for cruising on the level.

Thanks!

On steep hills (i don't know the grade) at 36v you need to assist, a 48v or more setup will be better for a 30% incline. Also my controller is limited to 30A, I think 50A would be best for very steep hills.
I don't know if this motor will last a long time though if you put 2-2.5kw in it constantly.

[spuzzete]

An update on the bike.

I am working with Arduino to build a bicycle computer, so far the result is pretty interesting!

Arduino Bicycle Computer

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You can follow the project on my website: http://www.jacopo.tk

[spuzzete]

Here an update on the Arduino-based computer:

Now I can see data on the lcd screen and save the distance and the Ah used in the eeprom, pushing a button I can see the maximum values of some of the data and pushing another button I can erase the eeprom.

Functions:

+Battery voltage
+Battery temperature
+Amps
+Watts
+Ah used (stored in eeprom)
+Speed in Kph
+Distance in Km (stored in eeprom)
+Km left with the current battery.

Little video:

[chisixer6]

good job, I like your wooden box for the batteries instead of the tackle box. don't you need to have the controller exposed to the cool air? otherwise it will probably get very warm in the box.