First build advice, commuter project

[linkdown]

I've been riding a bofeili mid drive e-bike (details here) for a few months, have racked up about 2200km and I'm itching for a project.

I use my bike to commute about 16km each way every day come rain, wind or whatever. I get an average speed (including lights, etc) of 27-31km/h and I'd like to go faster (surprise) and ride a nicer bike (looks and build quality). I used to bike a lot on reasonably nice bikes and the bike parts of my current ride are really not doing it for me.

I don't really want to travel over 50 - my entire commute is either on 50km/h roads or separated bike path.

There are a few hills on the route but nothing really serious, I think.

I pedal the whole way and rarely use the throttle, current setup is 36V10Ah and according to the display peaks around 640 watts. I like to pedal and would like to use mostly PAS. I currently charge at work and can continue to do this if it's a battery that is safe to charge unattended.

My tentative plan is to start with a new hybrid, like the Kona Dew Plus and install a BBS-02 750W with an appropriate battery, a speedict mercury and rig up some cutoff switches for the brake levers.

Budget is about 1000USD shipped for the electronics, I have reasonable electronics understanding and soldering experience. I'd like this to be as bike like as possible, so no large/heavy DD hub (not this time anyway). Not really that keen on LiFePO4 batteries, any that can handle 25A seem to be 8kg and up.

Wall of questions:
Is a mid drive actually a good choice? I like the idea of retaining QR wheels.
What vendors are good?
How much battery capacity do I need?
if I get a speedict, can I ditch the bafang display and use a cheap android phone?
If I buy 18650s from tumich, they seem to come as 4s2p blocks, can I use these with a BMS (from ????) to make a 14s4p pack with a relatively small amount of soldering?

Thanks all, chasing a new EV grin

 

[dogman dan]

Actually, your existing ride looks damn nice to me.

Hmm, find out if your current mid drive could handle 48v. If so, there's more like 1000w, and various components on the existing bike could be improved, like new brakes, wheels, forks, etc.

$1000 budget barely covers a new bike, if you don't have others handy.

Though you don't seem inclined that way, trying a rear hub, with about 1000-1500w might get you the speed you want. One nice thing about a rear hub, you do get to put the crank you like on the bike, vs being stuck with what comes with the kit.

 

[linkdown]

Actually, your existing ride looks damn nice to me.

Haha, don't say that - I want a project!

Hmm, find out if your current mid drive could handle 48v. If so, there's more like 1000w, and various components on the existing bike could be improved, like new brakes, wheels, forks, etc.

Yeah, I thought about this, the controller is in the bottom of the battery mount, so I guess I could swap in a 48V battery and controller. How would I know if it is likely to work though? I can't find anyone who has messed about with one of these drives. Is there any way to tell from inspecting the internals whether the parts will handle 48V? In that case would my issue be just heat and strength of the gears?

$1000 budget barely covers a new bike, if you don't have others handy.

Though you don't seem inclined that way, trying a rear hub, with about 1000-1500w might get you the speed you want. One nice thing about a rear hub, you do get to put the crank you like on the bike, vs being stuck with what comes with the kit.

$1000 doesn't include the donor bike, I'd buy that from a local shop. A rear hub could work, according to the ebikes.ca calculator a BPM or CST would do the speed I want on 48V. I guess I can fit a MAC into the budget if I DIY a battery pack.

 

[dogman dan]

Want a project? Then no reason not to build a new ebike, pretty much every spring.

I maxed out at 6 ebikes in my garage, ready to ride any moment. Now I have three, and a fourth just waiting on funds to buy a controller. Piles of motors laying around in there, mostly spares, or ones I broke and eventually fixed. A large table full of parts, and a frame graveyard outside.

Always up to something, and it gets even more fun when you get your own welder. 8) Starts with fun modifications, but I will be building frames from scratch one day.

Yesterdays project a nice bike to pedal. A 1970 mixte fame, 70's race wheels, stripped down to be an urban hipster ride.

 

[Drunkskunk]

That looks like a good bike, but I can totaly understand wanting a project. I've also built 6 of them. I haven't built a new one in a couple summers, and the itch has me.

Your budget might be a bit light to build something better. BBS02 aren't cheap, nor are quality safe batteries. EM3ev.com is who I would use for a vendor.

You might consider stripping your existing bike to the frame and motor, then building a new bike with it and quality parts. I have no idea what the upper limits of that motor are, but it might be fun to find them.

 

[linkdown]

Yesterdays project a nice bike to pedal. A 1970 mixte fame, 70's race wheels, stripped down to be an urban hipster ride.

Very nice, will it get a motor? - this is my non electric project just completed

That looks like a good bike, but I can totaly understand wanting a project. I've also built 6 of them. I haven't built a new one in a couple summers, and the itch has me.

Your budget might be a bit light to build something better. BBS02 aren't cheap, nor are quality safe batteries. EM3ev.com is who I would use for a vendor.

You might consider stripping your existing bike to the frame and motor, then building a new bike with it and quality parts. I have no idea what the upper limits of that motor are, but it might be fun to find them.

Yeah, starting to look like I need a few more $$ to make this work the way I want it. I'd totally strip and mess about with the bofeili but right now I need it for the commute, it was gonna be backup while I got the new one ironed out.

Looks like a bbs02 is about $600 shipped (em3ev price). Could I make a 14s4p pack for around 400ish with cells from tumich (about 200ish, nfi on shipping)? I can put a charger in the order from em3ev without blowing out shipping. Otherwise it looks like it would be 1200-1300 shipped for an em3ev kit.

 

[dogman dan]

I was thinking about making a longtail from a mixte frame. But for years I could not find one. So this spring I gave up, and built a new longtail from a regular cruiser frame.



So of course, the mixte frame appears the next month at the bike swap. But it's such a good frame for "Portlandia style" urban bike, I decided to make that from it.

Never happy without a project. Definitely create some funds in your fun budget, and go for it.

 

[linkdown]

Never happy without a project. Definitely create some funds in your fun budget, and go for it.

Yeah, I think I will go back to the drawing board - ride this thing for another 4-5 months to build up some more fun budget and build what I really have in my head.

 

[999zip999]

$

 

[linkdown]

$1300-$1400 should do it, right? donor bike not included.

 

[cycleops612]

Get a better battery -15-20ah lifepo4, and make it 2wd- a 2 speed 250-450watt front hub motor & controller, off the one battery.

your link dont work but this may help

http://suzhoulongyue.en.made-in-china.com/product-group/nbGxNfsDsRkL/Mountain-Electric-bicycle-catalog-1.html

 

[linkdown]

So, I went ahead with a MAC 10T, a 14s6p EM3EV small triangle and a S12SN 40A controller from BMS battery. Designed my own torque arms and had the cut from 8mm stainless steel. Nearly at the end of first part of the build so I thought I'd post up here.

Currently looks something like this.

Part list:
GT Transeo 4.0
Magura MT2 brakes
MAC 10T from em3ev
14s6p small triangle battery, 30Q cells from em3ev
Em3ev triangle bag, temp solution
DIY torque arms
S12SN controller from BMS Battery
Thumb throttle, brake sensors, rear lights from various aliexpress vendors
180mm disc rotors, adapters, etc.

 

[cycleops612]

Re improv torque arms, a natty tip i heard is, use a suitable double ended spanner.

 

[Avitt]

Nice build! I'm sure that you'll be happy with the performance.

 

[linkdown]

Re improv torque arms, a natty tip i heard is, use a suitable double ended spanner.

Got these laser cut from 8mm stainless, attached them with JB weld and an M6 bolt