Building my first e-bike, questions

[s-petersen]

I'm building my first e-bike, and I am looking for better solutions.
Here is the battery, it is 36v 10AH A123 ANR26659M1B LiFeP04 3.3v 2500mAh in a Server Pack
The battery is larger than most, but it will not burst into flames. The only place on the frame it fits is on the front of the down tube, or if there is some kind of rear rack that fits my bike.This is the bike: My legs are not long enough to have the seat any higher than the lowest setting, so a rear rack is not easy to find. The kit is a 1000w Voilamart front hub motor. I will not be going much over 20mph, and the paths are black top, so no severe riding, I'm just riding for being outdoors, and some exercise, with some help om hills. I know there are some out there that will say because it is not a high dollar bike, it is junk, but it is what I have. I am looking for suggestions for a back rack for the battery, or if I mount it on the front a slide mount for the battery that can be latched so the battery does not fall off. I also need a shifter control for the handlebar for 7 speeds, currently the left and right shifter controls are a twist type and the right one will have to be changed to a thumb type because the motor throttle will have to replace it. and the last question the crank has to come apart to add a pedal sensor, can it come apart without special tools, or do I need a puller of some kind? I bought this bike 25 years ago, and rode it a few times, but things changed, and opportunities to ride no longer happened, I just retired, and now have time to start riding again, I am really out of shape, and the 350w e-bike I fixed does not have enough power for the worst hills, the ones I need help for.

 

[docw009]

BCH says the battery is unuseable but cells are good? Have you received it already? Does it work? Will you need to replace the BMS on top to make it work? How about the other ebike? Does it have a battery that you can move to the project bike? Don't have no experience with Voilamart direct drives. I suppose they can run off that battery, but maybe not to 20 mph. Beats me.

Most racks for a suspension bike that clamp to the seat post might snap off. The A123 cell is 76 grams, so call it 8 lbs for the cells and a pound for the enclosure. You could devise a way to clamp a rack to the rear swing arm only, and keep it from tipping backwards. I did that with a rear suspension bike, but it already had the forward holes in the swing arm for a rack

A rear derailleur trigger shifter is under 20 bucks, Easy to install. A pedal puller is 10-12 bucks, often less for the basic models. You probably want a chain breaker tool too, to adjust the chain with more or less links. Also inexpensive,

 

[s-petersen]

The reason they say they the pack is unusable is the BMS has not been decoded for output, The BMS works as is for charging through the output terminals fine, The cells seem balanced when I check, and I will monitor the voltage while riding (the controller also has a low voltage cutoff that I think is adjustable) it will be fused with a 30 amp fuse. I have not used it yet on a bike, but the voltage measurements and balance seems fine.
I made a mistake with one (I bought 2) in that I removed a plug from the BMS, so it is in some kind of mode which is causing it to discharge slowly, so I an recharging it once a week until I install a new BMS and active balancer

I was thinking of using the BCH pack on the original bike, but I would have to modify the battery case to make it fit,
and the bike motor does not have enough power to help me up the hills, so i will sell it in the spring. Depending on this build. The battery is about the same length as the BCH one and Li-on instead of LiFepo4, so no real benefit in moving it

 

[Hwy89]

I don’t think you will have enough clearance between the down tube and the front tire for the battery. Even if your weight doesn’t fully compress the front suspension in normal riding at some point you will hit a bump, curb or pothole that will bottom out the front fork and even a tiny bit of frame flex causing the front tire to impact the battery will toss you over the bars. I know this from experience.
All of the rear racks that I’ve seen will add at least an inch to the lowest seat height. It is possible that you might be able to get a bracket engineered that would attach to the outside of the frame below where the seat tube inserts that would support a rear rack.
On several of the bikes I’ve built I switched the rear index shifter to the left side of the bars the cable exit direction is a little wonky and the numbers are upside down but you get used to it.

 

[fill]

Perhaps look at a higher amp and if necessary a higher drain capacity battery to handle the extra demand for your current 350w bike.. Suspension and cable routing limitations of the proposed donor/base bike above would require a higher mount than optimal for any battery and raise the bikes centre of gravity effecting the handling and ride detrimentally.

detail the hills (gradient/distance) giving you jip atm and just how the 350w bike fails to meet your expectations, chances are addressing that could be a lot cheaper/quicker?

 

[E-HP]

the last question the crank has to come apart to add a pedal sensor, can it come apart without special tools, or do I need a puller of some kind?

You can get a split ring sensor so you don’t need to remove the cranks

Amazon.com

 

[s-petersen]

Perhaps look at a higher amp and if necessary a higher drain capacity battery to handle the extra demand for your current 350w bike.. Suspension and cable routing limitations of the proposed donor/base bike above would require a higher mount than optimal for any battery and raise the bikes centre of gravity effecting the handling and ride detrimentally.

detail the hills (gradient/distance) giving you jip atm and just how the 350w bike fails to meet your expectations, chances are addressing that could be a lot cheaper/quicker?

I don't know how to judge the gradient of the hill it is likely a 30-40 ft rise over 400-500ft? I could be off and the other side is 200ft rise over 2000 ft? The battery does not drop enough voltage to be the issue, unless the there is less motor power than I found (it is unmarked, and the is conflicting data in the web) it is a geared hub motor. on a Liberty mountain bike, old, but still rides decent for a newbie like me.

 

[s-petersen]

You can get a split ring sensor so you don’t need to remove the cranks

Amazon.com

Cool!, I have to find out if my controller is compatible! Thanks!

 

[s-petersen]

I don’t think you will have enough clearance between the down tube and the front tire for the battery. Even if your weight doesn’t fully compress the front suspension in normal riding at some point you will hit a bump, curb or pothole that will bottom out the front fork and even a tiny bit of frame flex causing the front tire to impact the battery will toss you over the bars. I know this from experience.
All of the rear racks that I’ve seen will add at least an inch to the lowest seat height. It is possible that you might be able to get a bracket engineered that would attach to the outside of the frame below where the seat tube inserts that would support a rear rack.
On several of the bikes I’ve built I switched the rear index shifter to the left side of the bars the cable exit direction is a little wonky and the numbers are upside down but you get used to it.

I was worried that might be the case, still looking into it, I like the frame, as it's suspension seems to work nice for the roads and bike paths

 

[docw009]

A crank puller is probably cheaper than a split ring sensor. The problem with any new sensor is whether they used the same pin out in the connector,

 

[Chalo]

The bike will let you down over and over again until you give up. There are plenty of free or very very cheap bikes that aren't nearly as wretched as that one. Don't judge by paint conditions; the very worst bikes are painted "nicely" (probably the most expensive feature of the whole bike) to draw your attention away from its many shortcomings. Signs of use are usually signs that it worked long enough to accumulate some scuffs.

That bike will never work worth a damn, and it will deteriorate immediately and quickly no matter what painstaking setup you do.

 

[BiggKidd]

I'm building my first e-bike, and I am looking for better solutions.
Here is the battery, it is 36v 10AH A123 ANR26659M1B LiFeP04 3.3v 2500mAh in a Server Pack
The battery is larger than most, but it will not burst into flames. The only place on the frame it fits is on the front of the down tube, or if there is some kind of rear rack that fits my bike.This is the bike: My legs are not long enough to have the seat any higher than the lowest setting, so a rear rack is not easy to find. The kit is a 1000w Voilamart front hub motor. I will not be going much over 20mph, and the paths are black top, so no severe riding, I'm just riding for being outdoors, and some exercise, with some help om hills. I know there are some out there that will say because it is not a high dollar bike, it is junk, but it is what I have. I am looking for suggestions for a back rack for the battery, or if I mount it on the front a slide mount for the battery that can be latched so the battery does not fall off. I also need a shifter control for the handlebar for 7 speeds, currently the left and right shifter controls are a twist type and the right one will have to be changed to a thumb type because the motor throttle will have to replace it. and the last question the crank has to come apart to add a pedal sensor, can it come apart without special tools, or do I need a puller of some kind? I bought this bike 25 years ago, and rode it a few times, but things changed, and opportunities to ride no longer happened, I just retired, and now have time to start riding again, I am really out of shape, and the 350w e-bike I fixed does not have enough power for the worst hills, the ones I need help for.
View attachment 362701

I can't even come close to reaching the ground from my seat. I highly doubt anyone with a good leg geometry for pedaling can. The leg geometry is MUCH more important than being able to touch the ground from the seat!

Thinking outside the box I would consider a front rack to put the battery in. I know most others will disagree but bikes never have much weight up on the front wheel.

If that bike is actually made by Honda I would think it would be a damn good bike regardless of what anyone else thinks. I have yet to see Honda put out a truly bad product or even put their name on one!

 

[Chalo]

I can't even come close to reaching the ground from my seat. [...] The leg geometry is MUCH more important than being able to touch the ground from the seat!

This. If you can put your feet flat on the ground on a normal bike, you're cheating yourself out of proper pedaling.

If that bike is actually made by Honda I would think it would be a damn good bike regardless of what anyone else thinks.

IT IS NOT MADE BY HONDA. Almost no bikes branded as cars have anything to do with the car manufacturer. They're horribly cheap, horribly crappy department store bikes for clueless chumps to buy and put in their garages without ever actually riding.

 

[s-petersen]

This. If you can put your feet flat on the ground on a normal bike, you're cheating yourself out of proper pedaling.



IT IS NOT MADE BY HONDA. Almost no bikes branded as cars have anything to do with the car manufacturer. They're horribly cheap, horribly crappy department store bikes for clueless chumps to buy and put in their garages without ever actually riding.

I know it's not made by Honda, and I know it is not a true mountain bike, I am almost 65, and I will not be going on trails, when seated,I can just barely touch both toes on the ground. The bike will not see rough service, and if i really get into it, I can buy a better one. As I stated in the first post, I'm just getting a feeling if his will be for me, and getting exercise in the process.

 

[fill]

I don't know how to judge the gradient of the hill it is likely a 30-40 ft rise over 400-500ft? I could be off and the other side is 200ft rise over 2000 ft? The battery does not drop enough voltage to be the issue, unless the there is less motor power than I found (it is unmarked, and the is conflicting data in the web) it is a geared hub motor. on a Liberty mountain bike, old, but still rides decent for a newbie like me.

Some pedal input will be required to climb but with an ebike you can remain comfortably in the saddle and just add to the effort


The 350w geared motor when supplied with sufficient power would have a better chance of climbing hills than the 1000w direct drive imho. What battery voltage? and whats the controller max current draw/motor supply currently used? If currently employing a 36v battery/controller, upgrading to a 48v system will add circa 30% more torque and speed out of the gate. and a controller with a higher capacity can provide more amps to sustain the output uphill.

Im far from expert but think there is more millage in getting your existing bike upto the job than starting again.

 

[gromike]

I've have used that battery you linked on several builds. I put a 30 amp bms from battery hookup inside the case, and sawed the handles off the case. It has worked well in my limited testing.
Putting a 1000w front hub motor on the bike you pictured is a recipe for disaster. The forks will fail. You could do it by relacing the front fork with a non suspension one. Steel is best. Then you might be able to mount the battery under the downtube.
The best route is to find a more suitable donor bike.

 

[Zambam]

I'd skip the PAS since it could get dicy in tight spots on a front hub.

 

[s-petersen]

Some pedal input will be required to climb but with an ebike you can remain comfortably in the saddle and just add to the effort


The 350w geared motor when supplied with sufficient power would have a better chance of climbing hills than the 1000w direct drive imho. What battery voltage? and whats the controller max current draw/motor supply currently used? If currently employing a 36v battery/controller, upgrading to a 48v system will add circa 30% more torque and speed out of the gate. and a controller with a higher capacity can provide more amps to sustain the output uphill.

Im far from expert but think there is more millage in getting your existing bike upto the job than starting again.

The controller is not in hand yet, but it is either 25 or 30 amps per the kit info. My battery is 36v, but the kit also supports 48v

 

[s-petersen]

I've have used that battery you linked on several builds. I put a 30 amp bms from battery hookup inside the case, and sawed the handles off the case. It has worked well in my limited testing.
Putting a 1000w front hub motor on the bike you pictured is a recipe for disaster. The forks will fail. You could do it by relacing the front fork with a non suspension one. Steel is best. Then you might be able to mount the battery under the downtube.
The best route is to find a more suitable donor bike.

How does the fork fail? The motor will likely put out less than 1000w with 36v

 

[gromike]

You might want to read this thread:
Disadvantages of front wheel drive for ebike?

 

[Chalo]

How does the fork fail? The motor will likely put out less than 1000w with 36v

Even a high quality, expensive suspension fork quickly becomes sloppy and worn out from dragging the bike around by the front axle with a hub motor (this is apart from the tendency of hub motors to break the fork tips and dump out the front wheel, ouch).

If you want a front hub motor, use a rigid steel fork with reasonably thick forged or cut plate dropouts.

 

[docw009]

If you really like that bike, buy a rear motor. New builders often fear the complexities of adjusting the gears on a rear hub motor without knowing the risks of a sloppy front motor install.

 

[e-beach]

I have run a front hub motor since I joined this board. I have gone through 3 sets of forks. The first one was a rigid steel fork that was so uncomfortable to ride I went to an inexpensive suspension fork. Over some time 3000 miles maybe, that fork got sloppy when the arch brace cracked and both sides of the forks started moving independently of each other. So then I got another inexpensive Suntour suspension fork. That ran for a while, 5000 miles maybe, until on one very cold night the front half of the left dropout cracked off. Fortunately my home made dropout design worked perfectly and the wheel stayed in place. As an experiment, I have been running that bike with a dropout that falls into pieces when I take the wheel off just to see how effective my dropout design is. At this point it needs 2 new spokes and is probably time to rebuild that rim, and, get a new inexpensive suspension fork. Probably a $100 Suntour since I know what I get.

Caviots: 1) I only do city riding with that my front wheel setup. 2) when the motor is running the forks are pulled forward in a way that reduces the effectiveness of the suspension. 3) you will need dropouts on both sides to prevent the wheel from falling out of a broken dropout when that occurs.

IMO, if I had to do it all again I would go with a mid drive option first, rear wheel motor second, and a front wheel motor third.

 

[s-petersen]

Unfortunately, the front motor was already shipped2 days ago,($130) I had concerns about the gearing and derailleur being compatible in the rear hub motor, that's why I ordered it, The Pedelco e-bike (another old one) has front motor so I thought it didn't matter so much, which I chose.
I will have to see how it goes and I'll report what fails

 

[s-petersen]

I have run a front hub motor since I joined this board. I have gone through 3 sets of forks. The first one was a rigid steel fork that was so uncomfortable to ride I went to an inexpensive suspension fork. Over some time 3000 miles maybe, that fork got sloppy when the arch brace cracked and both sides of the forks started moving independently of each other. So then I got another inexpensive Suntour suspension fork. That ran for a while, 5000 miles maybe, until on one very cold night the front half of the left dropout cracked off. Fortunately my home made dropout design worked perfectly and the wheel stayed in place. As an experiment, I have been running that bike with a dropout that falls into pieces when I take the wheel off just to see how effective my dropout design is. At this point it needs 2 new spokes and is probably time to rebuild that rim, and, get a new inexpensive suspension fork. Probably a $100 Suntour since I know what I get.

Caviots: 1) I only do city riding with that my front wheel setup. 2) when the motor is running the forks are pulled forward in a way that reduces the effectiveness of the suspension. 3) you will need dropouts on both sides to prevent the wheel from falling out of a broken dropout when that occurs.

IMO, if I had to do it all again I would go with a mid drive option first, rear wheel motor second, and a front wheel motor third.

The dropout is that the same as a torque arm? I have 2 of them also in transit.