new stealthy-ish project

[dylan]

Hello my fellow ES fountains of knowledge, I am about to start another project & would greatly value your expert advice.
My requirements are for a stealthy-ish, fast-ish (close to 30 mph) bike for short range (always <10 miles) & low cost.
I am 80Kgs, normally ride on flat-ish roads or tracks & don't want to peddle too much as the old knees are not what they used to be.

My plan is as follows. Buy from BMSBattery BPM 500W 48v rear kit 328 rpm in a 26" wheel, 12 mosfet controller ($169 USD great price), 48V 10Ah lifepo4 battery (30-60Ah discharge $300 USD) + Freewheel, charger & rear torque arms.
Buy on ebay a used front suspension hardtail mountain bike, that has front & rear disc brake mounting points.
Fit 180mm disc on rear using easily available adapter bracket as this will almost hide the 180mm diameter rear motor,
Mount the battery & controller in a boot bag on homemade rear rack exactly like d8veh did on saneagle's bike (great build btw)
Would also like a switch to select 'slow mode 15mph' & full power mode (possibly joining the white controller wires togeather via a handlebar mounted switch?)

My concerns are:
what motor code should I / will I get. I assume I will get the chrome 8fun motor?
is the 10Ah battery up to the job with a 30 - 60Ah discharge rate, or do I need a 12Ah (bearing in mind short range)
How fast should it go when all done?
your advice would be much appreciated. Thanks all. Dylan

 

[d8veh]

I guess you mean this battery, which can give all the current you need:
http://www.bmsbattery.com/packs/156-48v-10ah-38120-lifepo4-battery-16-cells-ebike-battery-pack.html
They;re relatively heavy, but good batteries. 10aH won't take you far at that speed - probably about 10 to 15 miles. If you need to go further, get a bigger one. This 20aH one is relatively small and light, but can still supply the maximum controller current, so might be a better option. Myself and Saneagle use the 3
36v version, and they've been fine for over a year now.
http://www.bmsbattery.com/48v/249-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

I think the last 48v 32m motor supplied was reported as a code 10, which should give you the speed you want, but it'll probably be the BPM2 with not so easy to unscrew side-plate, but improved inside.

 

[-dg]

I think the last 48v 32m motor supplied was reported as a code 10, which should give you the speed you want, but it'll probably be the BPM2 with not so easy to unscrew side-plate, but improved inside.

Is there any information available about what changes were made to the BPM II over the BPM? I'm considering ordering one to experiment with oil cooling and wonder about what else might be different and which would be better to start with. Thanks.

 

[dylan]

thanks d8veh, good advice. what did you think about the speed selection switch idea using the white controller wires?
also there are a few older posts about people getting caught out with extra import duty payments. is that still happening?

 

[dylan]

just went to place the order for the kit & battery with bmsbattery & they want $189 USD shipping...!
removing the battery from the list & they still want $149 USD shipping...!
is it me or is that outrageous...?
any advice on an alternative place where I can buy a kit & battery at a more reasonable cost?

 

[dogman dan]

That would depend on where you are.

 

[dylan]

hi Dogman. shipping to the UK.

 

[lbz5mc12]

Yeah their shipping is kind of expensive but It usually only takes two weeks to get stuff all the way to me in California. I have the 48V 10A Li-ion and I can squeeze about 10 miles out of it if I average between 20-25 mph.

 

[bowlofsalad]

Cheap, fast, good, pick two.

There are many variables here, are you familiar with 'c rating'? A 1c rating with a 480 watt hour battery pack will be capable of putting out 480 watts comfortably. Have you played with ebikes.ca/simulator?

Choosing who to buy from can be almost as challenging as choosing which chemistry or type of motor to go with. There are places with good reputations such as ping and em3ev, but typically it would seem that you will pay more at those places than you would else where. There is a saying, you get what you pay for. Are various companies just greedy or expecting more? Or are various companies cutting corners/selling inferior product.

 

[dylan]

Well guys I have started this project.
I now have a used, but good condition, Claude Butler alloy hard tail, front suspension & disc, mountain bike (from e-bay for £70).
I have ordered all the kit from BMS Battery.
Now I just have to sit back & wait for it all to arrive.

 

[d8veh]

I must have missed your previous question. We used to get away without having to pay duty, but now you get it nearly every time. Expect to pay about £5 to £10 duty and a handling charge of about £10.

What stuff did you get? Did you get the hidden-wire brake sensors for cable brakes, and a torque arm. If not, add them to your order now before its too late. Just email them, and they'll ask you to send the difference by Paypal, so no extra postage.

 

[Mordan]

your shipping costs are cheap try $431 FEDEX

 

[dylan]

Hi d8veh. good call on the hidden wire brake sensors, I have just added them to my order.
On order I have the BPM bafang 500W kit, rear motor in a 26" wheel, various throttle combinations, front & rear disc set, 6 speed free wheel,
pair of 12mm torque arms, a couple of 3 speed switches & various connectors.
In the end I went for $218 Li-Ion battery 10Ah, max 30Ah discharge 3.5Kgs inc charger.
I don't go far, normally about 3 to 5 miles round trip to pubs by the river, so this should be fine & not too heavy.
(my current front wheel motor set-up uses 3 x 12v SLA's & it's so heavy)

i'm hoping to do something with the 3 speed switch to give the bike a 'slow mode' if possible.
any idea's on the easiest way to achieve this?

 

[dylan]

Well the kit has arrived from BMS battery & I have been busy in the garage. The delivery was fast & everything looks great. Unfortunately I just received an invoice for another £46 duty from FedEx, boo
Fortunately I asked the very helpful man at BMS to provide me with a low cost invoice otherwise it would have been a lot more.
The motor delivered was a code 10 in silver alloy colour (not the chrome shiny one). I spent quiet a while getting the rear new 203 disc aligned with the calliper (went for a 203 rather than a 180mm rotor as it hides the motor better).
I had to gently hammer the inside rear alloy fork leg to get the large disc to clear. Also a fair amount of calliper / bracket grinding to get it all to fit correctly. I have installed both rear torque arms so am happy the rear motor should stay in place when 'I'm giving it the beans'.
I checked all the polarities on battery (48v 10ah 3.5kgs lipo) & charger were correct (which they were), plugged in the thumb throttle, 3 speed switch, motor & hall sensor wires & gave it a 'wheel in the air test'.
Yea, all looking good. I'm just waiting for a new suspension seat post (softer on the old bottom over the pot holes), longer rear disc brake cable & a seat post rack to arrive so I can finished the build.
I have a great little rear rack bag to hold everything neatly.
One thing I did notice is that the position 1 & 2 on the 3 speed switch appear to be the same slow mode, while position 3 is fast mode.
My question is why a 3 speed switch? why not a 2 speed switch? or have I done something wrong.
Hopefully in a few days I'll be doing an 'on the road' shakedown test.
I will temporally tape a satnav to the bike so I can monitor slow & fast mode speeds.
Any guesses what speed she will do in both modes?

 

[bowlofsalad]

While it sounds unlikely, the controller could be programmed to with 1 and 2 to be nearly the same throttle %, but who knows. Do you have something like a cycleanalyst? That'd tell you what you need to know. Is it possible you are simply mistaken on the 3 speed switch? Personally, sometimes I would like a 4 or 5 speed switch.

 

[d8veh]

If you've got the KU123 controller, the 3 speed switch will give three speeds: position one is middle black to blue, which cuts the speed from the throttle down to about 15mph; the middle position has no wires connected, and is normal operation; position three is black to green and does something which nobody seems to be able to answer. It only works with the halls connected. I think it advances the timing a bit. The effect is different with different motors, but it normally gives about 2mph speed increase.

When fitting these motors I usually have to put an extra washer inside the dropout on the disk side to get the right alignment with the disk caliper, otherwise the disk scrapes against the caliper mount. Dishing the wheel is also usually necessary to get the rim central

 

[dylan]

So yesterday I got the bike assembled & had about 10 minutes for a quick first shakedown test. I taped a satnav to the handlebars & gave it the beans. well we have a gravel drive & it did a lovely power slide for about 15 feet (the throttle response was much more instant than my old bike). with a more gentle approach to the throttle I eased it down the road. I still need to adjust both front & back brakes & the gears which I hope to do over the weekend. max no pedalling speed was 28 into a reasonable strong headwind. with the 3 position switch in slow mode it was around 18 - 20. once I have adjusted, fiddled & fettled I will do a longer test, but so far all looks very promising.

 

[Agiator]

Hi Dylan, and thanks for your informative tread. I am looking at a similar set up to yours, but would like to see some photos of the bike and also a little bit more information about how your set up works and if you aresati sfied?
I would have thought that maybe the battery pack with 15 ampsccurrent supply would be a little small for the engine / controller?
Anyone with a similar set up, - please feel free to share your thoughts!

 

[d8veh]

Hi Dylan, and thanks for your informative tread. I am looking at a similar set up to yours, but would like to see some photos of the bike and also a little bit more information about how your set up works and if you aresati sfied?
I would have thought that maybe the battery pack with 15 ampsccurrent supply would be a little small for the engine / controller?
Anyone with a similar set up, - please feel free to share your thoughts!

The BPM kit comes with a 30 amp controller, which is more than enough current, and I think he went for the Headway battery, which can give 60 amps. BMSBattery have now changed the way they sell kits, so you can mix and match components. The controllers with LCD displays (S12S 23 amps and S12P 29 amps) are a much better option than the KU123 because you can use the pedal sensor.

If I wanted a kit with this motor, I'd get the 48v 15 aH shrinktube LiMnNiCo battery, the S12S controller (plus LCD and wheel-speed sensor), torque arms, PAS, Thumb throttle and brake sensors (if cable brakes). The speed would be the same as above, and torque would be a bit less, which is more manageable. For correct gearing, you need a DNP rear gearset with 11T top gear, and a 48T crankset (Shimano M590).

Having said all that, the 500w CST motor is also very attractive and worth the extra money because it takes a standard cassette for much better gearing options. It's a 270 rpm motor, so about 22 mph at 36v and 30mph at 48v.

 

[Agiator]

The BPM kit comes with a 30 amp controller, which is more than enough current, and I think he went for the Headway battery, which can give 60 amps. BMSBattery have now changed the way they sell kits, so you can mix and match components. The controllers with LCD displays (S12S 23 amps and S12P 29 amps) are a much better option than the KU123 because you can use the pedal sensor.

If I wanted a kit with this motor, I'd get the 48v 15 aH shrinktube LiMnNiCo battery, the S12S controller (plus LCD and wheel-speed sensor), torque arms, PAS, Thumb throttle and brake sensors (if cable brakes). The speed would be the same as above, and torque would be a bit less, which is more manageable. For correct gearing, you need a DNP rear gearset with 11T top gear, and a 48T crankset (Shimano M590).

Having said all that, the 500w CST motor is also very attractive and worth the extra money because it takes a standard cassette for much better gearing options. It's a 270 rpm motor, so about 22 mph at 36v and 30mph at 48v.

Hi d8veh, and thank you for your reply! I have probably read 100's of comments from you on ES the last month - so Im Grateful you take your time to look at my setup.

I don't think I am qualified to build my own battery from Headway batteries, I want a safe / stabel option - and good walue pack (2000+ cycles).
At the same time I want a small pack because I want to fit it in the frame of my bike, and have ordered a Nice top-tube bag for light/easy on the eye build.

Im 90 kg, need 25 km range (2x11 km home-work-home route) and want a bike - not a moped Im now and then using the bike I plan to electrify (Hybrid 700c 7 gear aluminium bike) and manages to do one way at ca 25 km/h speed. I've tried the BH-emotions cross (?) With pedal assist up to 30 km/h and a 350 w rear hub (supposed to be "forced" Down to the legal 250w limit...but I dont know if i belive that..... This bike was Nice, - but to slow. The climbing ability was enough as I pedal all the way - and my commute is mostly flat /small hils up and Down. So I need something more powerfull witch can continue to support me a bit longer than the 30 km/h cutoff. How mutch more speed I want is difficult to say - as this is my first build and I hope to avoid regreting going for a to slow/weak build - so I Guess I want an engine that will give med speeds around the 45 km/h + mark... And I would like it to be "stealthy".... be able to Climb a litle bit if needed... and Im on a Budget.... Doable? Easy... straight forward...? Hehe... NO...

All I've acomplished by spending a lot of hours Reading and Reading at this fantastic forum is that I realice you need to know what your doing if you want your first build to be a good one, - and to actually give you the result you pictured when you started up. As a mather a fact Im mutch more insecure of how to do this now than I was before I wisited ES... !!

Well - this was my plan build:
1) Bafang BMP rear 500w/48v 328 RPM engine delivered in a 700c Wheel (I was planning to take the Whole standard kit - price dif is only $25 and I then get the Controller ++) : http://www.bmsbattery.com/ebike-kits/348-bafang-350watts500watts-bpm-motor-e-bike-kit.html
2) The S09P Controller (I dont understand the diference between sinwave or square wave - took the smalest one for easy install)
http://www.bmsbattery.com/controller/553-s06-250w-imitation-torque-square-wave-controller.html
3) The 48v/10ah LiFePO4 Battery at $259. (Its bigger than the $218 48v/10ah Li-Ion - but gives 2000 cycles - better value and still fits my framebag).
http://www.bmsbattery.com/48v/496-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html
(The battery you suggest (48/15 Li-Ion was considered - but because I dont need long range and the Dimensions of the battery are not listed atBMSBattery.com (and only 800 cycles it lost out...) Do you know the Dimensions of this battery?

4)

If I wanted a kit with this motor, I'd get the 48v 15 aH shrinktube LiMnNiCo battery, the S12S controller (plus LCD and wheel-speed sensor), torque arms, PAS, Thumb throttle and brake sensors (if cable brakes). The speed would be the same as above, and torque would be a bit less, which is more manageable. For correct gearing, you need a DNP rear gearset with 11T top gear, and a 48T crankset (Shimano M590).

The plus LCD,wheel-speed, torque arms, PAS (12/10/8/5 poles? - whats the difference - witch is best?) Thumb trottle and brake sensores are in my list to
Also disc-brakes for front and rearwheel, extra battery charger (one at home and one at work just in case...) exstra spokes (12g or 13g)?, extra throtle /PAS and brake sensors. I have also the 7 gear Shimano Freewheel on my list: http://www.bmsbattery.com/ebike-parts/48-14-28-teeth-shimano-freewheel.html

The DNP rear gearset With 11t topgear... or the 48T crankset ..... ?I have absolutely no idea of what this is - or why I need it?

I considered the CST 36v/500w kit - and run it at the 48v pack but, With a fair chance of not knowing what Im talking about I concluded that this is aimed more at "professjonal" bikers that are "hung up" at more Advanced gear-systems than I am... And from the rewievs from other BPM-users, they more or less seemd saisfied...

I have also considered going for CST 36v/500w With 48v bat/con... not because of this gearing-thing - but because I like the 270 RPM "basis" With exstra V....
But the price and Reading somewhere that its more efficient to run 48v at a 48 engine I droped it...

Im also a litle bit conserned about battery 15 amp continius discharge and a 30 amp (KU123) Controller / 23 amp (S09p) Controller... (?)
But I've seen many People using the KU123 at similar battery amps claiming it all Works like a charm...
Am also considereing buying the Speedict / android - thing to monitor/controll current and I love the Panic-button!

Well... a lot of questions here.... Hope to get some good answears.

Thanks - Agiator of Norway

 

[dylan]

hi Guys. Sorry I haven't been online for a while.
I have pretty much finished this project.
I just haven't connected my hidden wire brake switch yet.
very pleased with the overall result, so here are a few of my thoughts.
I went with the cheaper BMS battery 48v 10Ah (15A continuous 30A max) battery 3.5Kgs @ $218
great choice for my short range requirements normally 3 miles round trip (been 8 miles mostly flat out no problems)
max no pedalling speed is 28mph switch position 3
max no pedalling speed is 22mph switch position 1 or 2
would have ideally liked to be able to switch it to 15mph (legal speed) max, so I just go easy on the throttle when I need to
I fitted a small speedo on the handlebars because trying to guess 15mph is very difficult
like most things in life, if you don't draw attention to yourself or ride like an idiot you won't get noticed...!
motor is reasonable quite & pulls strongly getting to top speed rapidly
still get a very slight annoying rub noise from the monster 203mm rear disc on the calliper (I will make a better spacer bracket one day)
bike is light & handles beautifully & I will fit an upgraded 203mm disc on front one day for even better stopping power
Gearing can't keep up with top speed (need an 11T rear cluster) so I pretend to peddle when required
made my own rear rack to my exact requirements (thanks d8veh for the great idea)
bag is bolted to rear rack & couple of cable ties for extra security keeps everything in place
using a domestic light switch in rear bag side pocket for hidden power on/off switch (operates through the fabric of the bag)
battery charging by unzipping a rear bag pocket & pulling out a female kettle socket lead works great
just put slime in both inner tubes after a 'walk home' puncture the other day
here are a couple of pictures

 

[majornelson]

Looks great! What range do you get out of the battery? Do you notice the 7.5 lbs battery on the rack from a handling perspective? And what is the final weight?

Assuming the controller is in the bag?

If you get a CA v3 (or v2, I think) it allows the throttle speeds to be set to the speed you like, I believe. Others can confirm.

Really great setup!

 

[d8veh]

Looks very nice. Getting the battery forward and low like that makes a massive difference to handling. It looks like you got the whole battery in front of the rear axle. Very neat torque arm too.

 

[dylan]

thanks for the favourable comments guys
I am really pleased with the result too
@ majornelson, handles really well, almost don't notice extra weight
don't know total bike weight, & controller is in the bag with battery
I put a fair amount of dense foam padding under & around battery & controller to protect them from vibration & bumps
furthest I have been on one trip was 8 miles going fast, battery was fine
my best guess with a light throttle would be double that
I don't want a cycle analyst as I'm trying to keep it as stealthy as possible
@ d8veh, thanks for your favourable comment, coming from you that's high praise indeed...!

 

[Agiator]

Very nice result Dylan, I hope to have something similar

One week ago I ordered my kit from BMSBattery with the torque - controller and small lcd screen.
With the five level pas control (lcd) I hope to be able to set one of the levels to legal 25 km/T.

Thanks for posting. Sure ain't easy to decide witch kit will suit, but your posting has been helpful. Good luck riding!