first electric bike build, lots of questions

General Discussion about electric bicycles.
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Mickey   1 µW

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first electric bike build, lots of questions

Post by Mickey » Apr 26 2019 10:37am

I'm trying to build myself the first bike. I use a xiaomi m365 for traveling now, but it has some drawbacks (i have to stop it before every sidewalk, potholes, the brakes are not the best in the world, it's limited to the city etc)

I'd like something for going to work and go out do some light mountain bike / forest trails etc
I'm interested in reliability of both the motor and the cassette sprocket / chain (i dont want to wear them out every 400km).
I dont need more than 30 mph top speed and i will start easy (20 mph until i get used to it)

Budget is 1500-1800 euro. If I can squeeze everything in 1500, fine.. otherwise.. 1700-1800... i'd go 2000 only if the extra 200 would change things a lot..

i checked the Bosch / Shimano / Yamaha systems on bikes, but I find them quite expensive to purchase, small wattage (and expensive to replace ) batteries, underpowered motors compared to bafang

PS. I read the "guide" made in 2015, does this still apply? "For 90% are more people I'd recommend a 48V 1000W rear direct drive kit."


I read a lot in the three-four weeks but this is pushing me into the summer if I want to get the motor / bike and the more I read, the harder is to make a decision :)

My questions so far:

1) New or second hand bike? Should i get a second hand with a better frame / components or new bike? which one handles better with a motor?
2) What type of motor should I go? TSDZ2 or Bafang? Mid drive or hub? I read more about bafang
3) Should i get less speeds on the cassette sprocket and a thicker chain? 8 instead of 10-11? I saw that with bafang u can't use more than 3-4 "speeds" of the cassete because the chain will be misaligned and you will wear out the chain / cassette)
4) Should I try to find something with 1x10 speeds from the start? If i get mid drive motor
5) What is the minimum shimano level you'd go to? Alivio, Altus, Acera, Deore? Higher? (doesnt have to be Shimano, but it's a system that I understand at this point)
6) How would you budget things? what percentage for the bike and what for the motor / battery? 50-50? get a better bike? get a BBSHD from the start, maybe i'm gonna use it on the next bikes i'm gonna have?
7) I saw some bikes have 73mm bottom braket, others have more.. to be future proof, should i try to buy 68mm or 100mm? i dont like fat bikes, so 120 is out of the question
8 ) MTB or XC or trail bike? I'd go with the first two since in the city i'm gonna be helped by the motor and won't be very inconvenient. Also it's 30 minutes ride to the work on a non electrical bike, i presume it's gonna be even faster with a motor
9) Battery : 48 or 52V? Makes sense to get a 52 and never charge it completely so the batteries last more cycles?

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Re: first electric bike build, lots of questions

Post by markz » Apr 26 2019 6:19pm

1) New or second hand bike? Should i get a second hand with a better frame / components or new bike? which one handles better with a motor? Buy a used bike, its great value because you can spend more on the electrics.

2) What type of motor should I go? TSDZ2 or Bafang? Mid drive or hub? I read more about bafang
Mid drive is for hills and stop and go commuting.

3) Should i get less speeds on the cassette sprocket and a thicker chain? 8 instead of 10-11? I saw that with bafang u can't use more than 3-4 "speeds" of the cassete because the chain will be misaligned and you will wear out the chain / cassette)
Primarily its freewheels but some do come in cassette. Tend to use less gears, so 6 speed is the most you want for a freewheel/cassette.

4) Should I try to find something with 1x10 speeds from the start? If i get mid drive motor
Mid drives stick out to the average person, so only use mid drive if you have lots of hills and some are steep. Other then that, you will be replacing the bottom bracket (crank) to suit the mid drive system, because they are much wider.


5) What is the minimum shimano level you'd go to? Alivio, Altus, Acera, Deore? Higher? (doesnt have to be Shimano, but it's
a system that I understand at this point)
It really does not matter, Tourney, Atlus are the basic, Acera, Alivio are the middle ground, Deore and SLX are better. So I'd go with Acera or Alivio but if the prices are close, then go up.


6) How would you budget things? what percentage for the bike and what for the motor / battery? 50-50? get a better bike? get a BBSHD from the start, maybe i'm gonna use it on the next bikes i'm gonna have?
The battery is the most expensive part of the system, then the motor, then the controller. Battery would be $450-700, but average would be 700-1000. Motor $200-400, controllers $30-$100, Throttle $20, Torque Arms $25, Charger $100.

7) I saw some bikes have 73mm bottom braket, others have more.. to be future proof, should i try to buy 68mm or 100mm? i dont like fat bikes, so 120 is out of the question.
68 is the most common buy that

8 ) MTB or XC or trail bike? I'd go with the first two since in the city i'm gonna be helped by the motor and won't be very inconvenient. Also it's 30 minutes ride to the work on a non electrical bike, i presume it's gonna be even faster with a motor
yeah it will halve your time easily! Go with a full suspension, used 26" bicycle that is a brand name like Specialized, Rocky Mountain, Giant, Trek, Kona. Look on Pinkbike.com, or Kijiji if you are in Canada, USA and the world then Craigslist. I would be hesitant on buying through-axle bikes, tapered headset. Go with cable actuated disc brakes.

9) Battery : 48 or 52V? Makes sense to get a 52 and never charge it completely so the batteries last more cycles?
48V is a good system to get, what you want to be concerned about is the capacity or Ah, thats like your gas tank. Voltage is your speed.

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 26 2019 7:48pm

Mickey wrote:
Apr 26 2019 10:37am
II'd like something for going to work and go out do some light mountain bike / forest trails etc
Hey. Don't listen to me, I'm new. :D

But these two options seem diametrically opposed. Like "I want a car that's good on gas, but does 200 mph"

I have both a 1000W mid drive and a 1500W hub. I'd say the 1500W hub is better for commuting, with a higher top speed and easier to use, while the mid drive is more efficient and more suitable to gearing, with a better center of gravity and handling. (the back wheel with my 100kg ass on it is too much for a hub motor to take even the slightest drop)

If I could be so bold, there's no such thing as "light mountain bike riding". It's subjective. But when you are dealing with such small amounts of power (say 1hp). the difference between riding the road and riding the boulevard is huge.

So I'm new, but I'd say flat road and speed just go with a hub motor. For anything bumpy full suspension and a mid-drive.

A mid drive is more suitable to both but I would lay dollars to donuts it would just result in something disappointing on both fronts; not enough torque to "light trail ride" and not enough hp to commute.

I'm sure those more experienced will chime in, but that's my take after 6 months. Hope this helps.

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Re: first electric bike build, lots of questions

Post by flat tire » Apr 26 2019 8:36pm

You need full suspension, and a hard choice with respect to drivetrain. Hub drive is easier, less expensive, quieter, lower maintenance, better for city riding but sucks offroad.

Full suspension is needed regardless, unless you want to only go very slow speeds or ride on perfectly-smooth surfaces. Your streets are not perfectly smooth.

Mid drive will be much more fun offroad if that criterion is important. I'll leave a particular recommendation of mid-drives to others.

Last, make sure to buy everything you can second-hand. With your budget you will need to save money everywhere possible to end up with a good ebike. And don't worry about "disc" vs "rim" brakes. Good rim brakes on a older full-suspension MTB will be much better than inexpensive, manual-pull disc brakes on a cheap newer bikes.

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 26 2019 10:03pm

flat tire wrote:
Apr 26 2019 8:36pm
And don't worry about "disc" vs "rim" brakes. Good rim brakes on a older full-suspension MTB will be much better than inexpensive, manual-pull disc brakes on a cheap newer bikes.
Good rim brakes will work, but if you commit yourself to rim brakes you lose out and make your future limited. I'd say rim brakes will work but you are further ahead by selecting disc brakes and making that happen.

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Re: first electric bike build, lots of questions

Post by flat tire » Apr 27 2019 3:14am

When you're starting out on a budget you get a lot more bike / $ for old high end mtb with rim brakes. All my bicycles have Magura MT7 and I spent less on a entire bike, a good full suspension MTB than just the brakes alone on my current downhill. Don't go with hydraulic discs until money isn't a issue. The stopping power sucks anyway compared to motorcycle brakes.

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 27 2019 5:00am

I guess they are cheaper here. I picked up a set of Shimano 355's for $30 at a local bike shop. Cheaper than a new set of v-brakes.

Both v-brakes and hydraulics are going to stop the wheel from turning. The difference is with hydraulics I can do it in the rain with a 1 finger pull.

There are very few front shocks out there that don't have disc brake mounts. And most frames made in the last 15 years have IS posts even if they didn't come with discs. Unless it's a Wal-Mart bike any full suspension bike made in the last 20 years is going to be disc brake ready.

Oh, 68mm is going to leave you with way more options in terms of frames. Unless you have a specific frame in mind that requires 100mm stick with 68mm.

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Re: first electric bike build, lots of questions

Post by donn » Apr 27 2019 8:47am

furcifer wrote:
Apr 27 2019 5:00am
I guess they are cheaper here. I picked up a set of Shimano 355's for $30 at a local bike shop. Cheaper than a new set of v-brakes.

Both v-brakes and hydraulics are going to stop the wheel from turning. The difference is with hydraulics I can do it in the rain with a 1 finger pull.
Vs. mechanical disk brake, like Shimano BR-TX805 for example, is I think what he's talking about. Among other virtues, it allows you to use the cable brake levers with a switch for the controller, that come with the hub kit for brake-controlled shutoff/regen.

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 28 2019 8:31pm

donn wrote:
Apr 27 2019 8:47am
furcifer wrote:
Apr 27 2019 5:00am
I guess they are cheaper here. I picked up a set of Shimano 355's for $30 at a local bike shop. Cheaper than a new set of v-brakes.

Both v-brakes and hydraulics are going to stop the wheel from turning. The difference is with hydraulics I can do it in the rain with a 1 finger pull.
Vs. mechanical disk brake, like Shimano BR-TX805 for example, is I think what he's talking about. Among other virtues, it allows you to use the cable brake levers with a switch for the controller, that come with the hub kit for brake-controlled shutoff/regen.
Oh, that's actually a good point. If you want to use the integrated levers you can't use hydraulics.

When I worked in a bike shop we would get in bikes with Tecktro mechanical discs and they were garbage. Less stopping power than a cheap v-brake and they rubbed all the time. I don't know if the new ones are any better but I doubt it.

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Re: first electric bike build, lots of questions

Post by amberwolf » Apr 30 2019 2:22am

furcifer wrote:
Apr 28 2019 8:31pm
If you want to use the integrated levers you can't use hydraulics.
If you mean, levers with switches built in, that's not true. There are hydraulic levers with switches built in (have been some for sale in the ITems For Sale New section of ES, dunno if they still are).

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 30 2019 6:46am

amberwolf wrote:
Apr 30 2019 2:22am
furcifer wrote:
Apr 28 2019 8:31pm
If you want to use the integrated levers you can't use hydraulics.
If you mean, levers with switches built in, that's not true. There are hydraulic levers with switches built in (have been some for sale in the ITems For Sale New section of ES, dunno if they still are).
True, I should say you can't use "most" hydraulics. I have seen identical Shimano 355's with built in switches. But I think 99% of the hydraulic brakes out there require purchasing a sensor and awkwardly gluing a magnet to the lever.

Which sucks. In the motorcycle world most brake levers have a tapped hole for a contact switch. It's extremely simple tech, it just hasn't been necessary on bicycles so it hasn't been incorporated.

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Re: first electric bike build, lots of questions

Post by donn » Apr 30 2019 8:31am

furcifer wrote:
Apr 30 2019 6:46am
True, I should say you can't use "most" hydraulics. I have seen identical Shimano 355's with built in switches. But I think 99% of the hydraulic brakes out there require purchasing a sensor and awkwardly gluing a magnet to the lever.

Which sucks. In the motorcycle world most brake levers have a tapped hole for a contact switch. It's extremely simple tech, it just hasn't been necessary on bicycles so it hasn't been incorporated.
Just guessing, that sounds like it might be the difference between on/off and proportional brake control. Can't imagine that the brake lever that came in the box had any sensors. Personally I only need on/off, anyway ... but I guess I would only need mechanical brakes, so there you go.

The real reason I wished I'd had a disk brake on the rear, when I installed the hub motor, is that it would have added a lot of choices for a rim for wider tires. So many wide rims these days have no brake surface.

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 30 2019 8:46am

donn wrote:
Apr 30 2019 8:31am
So many wide rims these days have no brake surface.
Well yah, if you want strength in the rims and you don't care about weight, disc is the way to go.

To each his own. But I've always given up speed for control and looked for stopping power. I've never had an accident and the only time I dropped a bike was letting out the clutch too fast on a DT400 in the rain.

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Re: first electric bike build, lots of questions

Post by amberwolf » Apr 30 2019 8:13pm

furcifer wrote:
Apr 30 2019 6:46am
True, I should say you can't use "most" hydraulics. I have seen identical Shimano 355's with built in switches. But I think 99% of the hydraulic brakes out there require purchasing a sensor and awkwardly gluing a magnet to the lever.
I think you mean, 99% of the brake *levers*. I expect that many of the various levers should be intercompatible with many of the calipers. (but I don't have direct experience with hydraulics).


donn wrote:
Apr 30 2019 8:31am
Just guessing, that sounds like it might be the difference between on/off and proportional brake control.
The controller has to support that. Most of them seem to only support it via the throttle, so to use it you activate the brake switch, and then the throttle controls braking, instead of acceleration. Seems to work for a lot of people, but I don't like the idea, because it means relearning reflexes that are very important to have be completely automatic.

Some have a separate analog braking input, so you could use some form of analog brake sensor (hall, pot, strain gauge, etc). That's the kind I'd prefer.

Some controllers use a completely throttle-based braking, not requiring any action other than decreasing the throttle in some way.

The SFOC5 by Incememed that I'm testing has settings to give "negative torque" when decreasing the throttle below the torque level presently needed to keep the wheel moving at the present speed (or something like that). For now, this setting appears to be disabled, as it hasn't had any effect on my trike so far (he's probably still working on that part of the firmware), but it should be an easy way to slow quickly that wont' require much in the way of relearning (since the brakes themselves still work nromally, and I'd be letting off throttle during braking anyway).

IIRC, the Phaserunner uses the small voltage range between zero and the usual 0.7-0.8v a throttle starts working at, to control braking. The Cycle Analyst v3 has the option to output a voltage in this range for proportional braking (I forget what input it uses to know what to do).

There's other methods by other controllers, I don't recall which ones do what.

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Re: first electric bike build, lots of questions

Post by E-HP » Apr 30 2019 8:40pm

amberwolf wrote:
Apr 30 2019 8:13pm
There's other methods by other controllers, I don't recall which ones do what.
I noticed that the OpenSource firmware for KT controllers includes a digital (on/off) or analog (variable) regen among the cutomized parameters. I'm going to read the entire thread again then flash mine, since I could go higher with regen without having it hit so abruptly when pulling the brake lever.

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Re: first electric bike build, lots of questions

Post by furcifer » Apr 30 2019 8:42pm

amberwolf wrote:
Apr 30 2019 8:13pm
I think you mean, 99% of the brake *levers*. I expect that many of the various levers should be intercompatible with many of the calipers. (but I don't have direct experience with hydraulics).
Hmm, good question. I don't think that's true though, they all seem to use slightly different plungers. These are the ones I saw:

https://www.amazon.com/SHIMANO-Hydrauli ... B06XCMP6NQ

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Re: first electric bike build, lots of questions

Post by MadRhino » May 01 2019 12:18am

All those different opinions are not making it easy for a newcomer, to build his first bike.

Here is how I see it. Your first should be simple, and reliable. So, forget about mid drives. Driving the chain is making for a lot of maintenance, and much more building problems. You might want to build a mid drive for your second bike, or just be satisfied with a hub motor. The fact is, the hub is simple and low maintenance, and can make more than most are looking for.

It is common to hear that hubs are not good to ride mountain trails, but I never met a nid drive that could follow me in the mountain. I can ride up to 50 mph in most of my trails, and you’d have to spend a fortune on a mid drive to do it. Friends who tried, failed miserably. They are spending more time tempering than riding. The only places where a mid drive is better, are slow rough technical trails where most have no fun to ride anyway, or trails that have jumps higher than 3ft because hubs are not making good jumpers. But, let’s face it, most riders don’t have the balls and skills to speed and jump in mountain trails. I personnally, gave up jumping and chose the reliability of a big hub.

I’d say: if you like trial motorcycles or racing MX, then you will like a mid drive and you’d probably be better buying one specific, for it would be more expansive to build your own. If you are high level Freerider who likes challenging wild terrain and technical mountain trails, then you should build with one of the common BB drive kits. If your trails are nice and maintained enough to speed, then build with a big DD hub and laugh at all those toy sized mid drives.

On the street, a hub is much better. It can last 20,000 miles with minimal maintenance. When you are commuting daily, in the winter especially, a hub is a must.

If you don’t want to spend much, build with an average rear DD hub kit, slow winding in a 24’’ wheel, and upgrade the controller. Then adapt the battery voltage to a top speed 20% higher than the speed you will ride. If your trails are steep, you will need heavier and more powerful than average kits. Build on an old DH bike, make your battery by assembling RC lipo and fit it on the front of the bike.
Make it fool-proof, and I will make a better fool.
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Re: first electric bike build, lots of questions

Post by Thomsontouring » May 03 2019 1:04pm

I wouldn't categorically say that a mid-drive install is more difficult for a first build (provided you have the right tools to remove the crank). My first Bafang BBS02 install took 3 hours and my second one took 2 hours, as did my tenth one. All the electrics are plug-and-play so there's no crimping or soldering. Controller is in the motor so there's no controller to mount. Super shark battery attaches to water bottle mounts. Most of the installation time is tidying up the wires. I buy the complete kit with 52v battery from EM3EV for $1000 delivered to USA.
Here's my fourth one - cost 1500 euros including brand new bike. Good for roads and light trails, up to 30mph. 1350 watts, 8 speed IGH.
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Re: first electric bike build, lots of questions

Post by MadRhino » May 03 2019 2:40pm

Thomsontouring wrote:
May 03 2019 1:04pm
I wouldn't categorically say that a mid-drive install is more difficult...
BB drives are simple. All plug and play as you say.

Bigger, powerful mid drives are a lot of work for most.
Make it fool-proof, and I will make a better fool.
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Re: first electric bike build, lots of questions

Post by wturber » May 04 2019 9:03pm

Mickey wrote:
Apr 26 2019 10:37am
I
8 ) MTB or XC or trail bike? I'd go with the first two since in the city i'm gonna be helped by the motor and won't be very inconvenient. Also it's 30 minutes ride to the work on a non electrical bike, i presume it's gonna be even faster with a motor
How much faster depends a bit on how fit you are and how fast you ride right now. A standard rear hub commuter like mine will give you a comfortably fast cruising speed between 25-28 mph on mild inclines, flats, and downhills. A fairly fit rider on a lightweight road bike probably doesn't fast cruise much faster than 20 mph for very long. Less fit and on a MTB and you are probably fast cruising at well below 20 mph.

I've found that I can make a good and slightly conservative estimate on travel times using Google maps. I choose "cycling" as the transportation mode and modify the route as I see fit to make it cycling friendly. I then take the trip time that Google calculates and multiply it by .60. That gets me pretty close.

I have to deal with hills on my routes. If you are commuting on flat ground, you'll probably go a bit faster.

My typical trip speed averages are between 17 and 20 mph given the delays for traffic lights and stop signs, and having to deal with some 10% and greater hill climbs.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
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