finished my build!

[Returnformer]

They restocked sooner than expected, so I went with the ebikeling 48v 1500 watt waterproof kit in the end. also got the headlight/horn kit. horn is good but the light is a bit meh. they said its 1000 lumens, but im also a flashlight buff, and it doesnt seem close. maybe defective? at least i dont have to strap it to my helmet, though.

battery is a 52v 17 ah super shark from em3ev. i went for the higher ah cells, but looking back, theyre not rated for as high continuous amp output, and the controller is 35 amp, so i probably shouldve gone with the lower ah higher amp rated cells, but oh well. hopefully it wont catch fire, just the battery's overall life wont last as long. its rare that i ride more than 15 min at once tho. one question remains regarding this combo, tho. im guessing a 52v battery has a slightly higher min voltage that you should drain it to than a 48v battery. since the kit is intended for a 48v battery, will it drain the 52v battery too much, further reducing life expectancy? or are they close enough that it shouldnt matter?

only had one small ride so far, but performance is what i had hoped. ive gotten up to 33 mph according to the speedometer, which is probably overstated, but ill check that with waze another time. should be at least 30, though, which is exactly what i wanted. I've got a couple more minor mods to make, such as changing to a 203 rotor in the front, but im still waiting on it to come. its basically done, though, and overall im quite pleased with how it turned out so far.

on my previous build i covered the controller and connections with plastic to protect them from the elements. still debating whether to do that on this one...

 

[Balmorhea]

battery is a 52v 17 ah super shark from em3ev. [...] one question remains regarding this combo, tho. im guessing a 52v battery has a slightly higher min voltage that you should drain it to than a 48v battery. since the kit is intended for a 48v battery, will it drain the 52v battery too much, further reducing life expectancy? or are they close enough that it shouldnt matter?

The controller’s minimum voltage is too low for your battery, but that shouldn’t matter because the BMS will intervene first.

Running your battery down until either the controller LVC or the BMS cuts it off reduces the life of the cells, tends to put your battery out of balance, and is best avoided. Set your display to show pack voltage, and recharge before it gets close to cutoff.

 

[Returnformer]

battery is a 52v 17 ah super shark from em3ev. [...] one question remains regarding this combo, tho. im guessing a 52v battery has a slightly higher min voltage that you should drain it to than a 48v battery. since the kit is intended for a 48v battery, will it drain the 52v battery too much, further reducing life expectancy? or are they close enough that it shouldnt matter?

The controller’s minimum voltage is too low for your battery, but that shouldn’t matter because the BMS will intervene first.

Running your battery down until either the controller LVC or the BMS cuts it off reduces the life of the cells, tends to put your battery out of balance, and is best avoided. Set your display to show pack voltage, and recharge before it gets close to cutoff.

im not sure if the display can do that, but whats a good cutoff for a 52v battery? ill take readings manually for a bit to get a feel for how far i can go before it reaches that.

 

[goatman]

I like the rear rack and how it mounts, is it stable?

 

[Balmorhea]

im not sure if the display can do that, but whats a good cutoff for a 52v battery? ill take readings manually for a bit to get a feel for how far i can go before it reaches that.

When the resting cell voltage reaches 3.4V, voltage under load will fall quickly, and there isn't that much energy left anyway. That's 47.6V for a perfectly balanced pack. So it would be good for your battery not to let the resting voltage fall below 48V if you can avoid it. Your BMS won't cut off until the lowest cell drops to 3.0V, if not lower (though that's under load).

The deeper you discharge your battery, the fewer cycles you get out of it.

 

[Returnformer]

I like the rear rack and how it mounts, is it stable?

pretty stable. im not sure if i feel it bouncing around because its unsteady or because of the suspension moving, or both. doesnt move so much when i push on it, but it does move a bit and its only held in place by nylon straps, so i might add hose clamps for reinforcement. overall, its good, if really expensive, the thule pack n pedal. i gotta move my seat up a bit, though, im sitting on the crate a bit, too. gonna have to wait a bit, though, as its pouring right now...

 

[Returnformer]

im not sure if the display can do that, but whats a good cutoff for a 52v battery? ill take readings manually for a bit to get a feel for how far i can go before it reaches that.

When the resting cell voltage reaches 3.4V, voltage under load will fall quickly, and there isn't that much energy left anyway. That's 47.6V for a perfectly balanced pack. So it would be good for your battery not to let the resting voltage fall below 48V if you can avoid it. Your BMS won't cut off until the lowest cell drops to 3.0V, if not lower (though that's under load).

The deeper you discharge your battery, the fewer cycles you get out of it.

ok, thanks. gonna test for a while after each ride to get a feel for volts per mile and then limit based on that.

 

[amberwolf]

FWIW, the design of the rear rack supports is going to allow twisting (yaw) of the rack itself. The more load there is toward the rear of it, the worse this is going to be.

Additionally, the further back the load is, the more it is going to "wag" (yaw) the entire bike around at the rear, and the more it is going to affect the suspension response when you hit bumps.


If I were to add a rack to a bike like that, I would do it along the red lines I added in the attached pic. The front would be secured with a clamp built like a Ubolt around the frame behind the headtube under the downtube, and another around the headtube itself. The rear would be secured with a similar ubolt-like clamp over the toptube in front of the seattube and another around the seattube itself.

Then triangulate across the top of the rack with an X from that point to the rear end of it, to minimize side-to-side sway. Then triangulate from just above the bottom of the seattube (where it meets the other tube) to the rear end of the rack, to minimize vertical sway.

This takes all the weight off the suspension, making it more effective, and gives a stronger rack support with less flex, but still lets you use the milkcrate on there.


For an even better rack, I would create a stiff triangulated frame to either side of the rear wheel and swingarm, that is attached at the top to the rack and at the bottom to another rail that connects to the bike frame at the same seattube bottom point as the lower triangulation member of the rack itself. Then use panniers, either bags or boxes bolted to that side frame, to carry everything.

This would handle much better than sticking the stuff on top of the rack (and also still gives the option of using the top of the rack if you have to>

 

[goatman]

I hung the same 5p pack upside down on my sons bike like yours, hanging 10lbs is kind of hard on those plastic tabs and reinforced with fiberglass and painted black with plasti-dip, it works good.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=103989

 

[Balmorhea]

I hung the same 5p pack upside down on my sons bike like yours, hanging 10lbs is kind of hard on those plastic tabs and reinforced with fiberglass and painted black with plasti-dip, it works good.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=103989

A friend of mine killed two Luna Shark packs in rapid succession by letting them ingest rainwater when mounted in an upside down orientation like that. Water can pool in the battery top cover and cause all kinds of problems. Either drill a drain hole at the low point of the case (mark the spot and remove the top cover first!), or mount it right side up on clamp-on bosses on the top tube.

 

[Returnformer]

FWIW, the design of the rear rack supports is going to allow twisting (yaw) of the rack itself. The more load there is toward the rear of it, the worse this is going to be.

Additionally, the further back the load is, the more it is going to "wag" (yaw) the entire bike around at the rear, and the more it is going to affect the suspension response when you hit bumps.


If I were to add a rack to a bike like that, I would do it along the red lines I added in the attached pic. The front would be secured with a clamp built like a Ubolt around the frame behind the headtube under the downtube, and another around the headtube itself. The rear would be secured with a similar ubolt-like clamp over the toptube in front of the seattube and another around the seattube itself.

Then triangulate across the top of the rack with an X from that point to the rear end of it, to minimize side-to-side sway. Then triangulate from just above the bottom of the seattube (where it meets the other tube) to the rear end of the rack, to minimize vertical sway.

This takes all the weight off the suspension, making it more effective, and gives a stronger rack support with less flex, but still lets you use the milkcrate on there.


For an even better rack, I would create a stiff triangulated frame to either side of the rear wheel and swingarm, that is attached at the top to the rack and at the bottom to another rail that connects to the bike frame at the same seattube bottom point as the lower triangulation member of the rack itself. Then use panniers, either bags or boxes bolted to that side frame, to carry everything.

This would handle much better than sticking the stuff on top of the rack (and also still gives the option of using the top of the rack if you have to>

im not quite sure what youre describing, but i dont plan to put more than 10-15 lbs in the crate, and to try to keep anything heavier more towards the front of it. the rack is only rated to 25 lbs anyway. if i know im going to be getting more than a few things at the store, i bring a trailer for the heavy stuff.

I hung the same 5p pack upside down on my sons bike like yours, hanging 10lbs is kind of hard on those plastic tabs and reinforced with fiberglass and painted black with plasti-dip, it works good.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=103989

ive got the velcro strap for that. i think should at least take excess stress off the tabs, the straps are pretty strong. im not handy enough to put together something like what you did...

I hung the same 5p pack upside down on my sons bike like yours, hanging 10lbs is kind of hard on those plastic tabs and reinforced with fiberglass and painted black with plasti-dip, it works good.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=103989

A friend of mine killed two Luna Shark packs in rapid succession by letting them ingest rainwater when mounted in an upside down orientation like that. Water can pool in the battery top cover and cause all kinds of problems. Either drill a drain hole at the low point of the case (mark the spot and remove the top cover first!), or mount it right side up on clamp-on bosses on the top tube.

im a bit worried about water, but i dont plan on riding in the rain unless i have it coverd with a plastic bag from both below and above.

 

[goatman]

ive actually got 2 holes drilled in the battery case and the fiberglass at the low point, I remember another member had done the same.

 

[Returnformer]

ive actually got 2 holes drilled in the battery case and the fiberglass at the low point, I remember another member had done the same.

holes for drainage? is it ok for some water to get into the case as long as it can get out? i dont want to open the case, but i could use a dremel with a fine sanding point to sand down the edge until it creates a hole. but wouldnt it be better to avoid getting water inside in the first place? or does it not matter as long as it can get out and not pool inside?

 

[Balmorhea]

My experience is that water will find a way in, so you want to make it easy for it to find its way back out. Don't put a drain hole where it receives direct spray, because that's defeating the purpose.

Or you can pot everything in resin, but then there's no fixing it when something goes awry.

 

[goatman]

I put my holes here

1/8 drill bit, drill slowly, theres batteries inside right . you can always duct tape the holes or make a little mud flap

 

[amberwolf]

but i dont plan to put more than 10-15 lbs in the crate, and to try to keep anything heavier more towards the front of it. the rack is only rated to 25 lbs anyway.

And that is really a static, vertical load rating. It doesnt' seem to apply to the side-to-side sway that occurs during riding, or shock loading.

So as long as you don't hit bumps, or sway side to side (which is normal for any bicycle while pedalling), that rating is "true". But when you hit a bump, or a pothole, especialy with an unsuspended rack, it multiplies the weight loading on the rack, by the depth/height of impact and speed and mass on the rack+wheel/etc. ("G-forces", shock loading). And pedalling sways teh bike side to side, and hte mass on teh top of the rack delays the swing of the rack a bit, causing repeated flexing and stress at teh mounting points, etc.



It seems like many racks, even "heavy duty" ones, are only "really" rated for perfectly smooth roads...because their weight ratings don't include shock ratings. The worse the roads are, the more of a problem it is. I started making my own racks (and trailers, and later bikes) because of this, since even small loads (backpack of groceries) in the racks on my unsuspended bikes would over time break the racks at their supports or mounting points, partly from the swaying (which flexes the supports at intersect points with each other or mounting areas, and fatigues them),

YOu may never have problems...I just have a brain that sees potential failure points and thinks of potential solutions. So don't worry about it...but if you do have a problem, keep the above in mind.

im a bit worried about water, but i dont plan on riding in the rain unless i have it coverd with a plastic bag from both below and above.

Since it is difficult (almost impossible) to keep water out of anything, even with bagging, even a tiny hole drilled at the lowest point of the casing when mounted on the bike will help, to let anything that does get in, get out. (same thing with hubmotors, etc)

 

[Returnformer]

It seems like many racks, even "heavy duty" ones, are only "really" rated for perfectly smooth roads...because their weight ratings don't include shock ratings. The worse the roads are, the more of a problem it is.

Definitely true, I had a rack that was supposedly rated for 300 lb eventually fail over time. It couldn't handle the side to side pressure, especially because the main support attached to the seat tube, which is round and therefore that support does little for the sway. But that rack I was loading up with 50-60 lbs. Definitely not going to do that with this one.

im a bit worried about water, but i dont plan on riding in the rain unless i have it coverd with a plastic bag from both below and above.

Since it is difficult (almost impossible) to keep water out of anything, even with bagging, even a tiny hole drilled at the lowest point of the casing when mounted on the bike will help, to let anything that does get in, get out. (same thing with hubmotors, etc)

It feels a bit wrong to go drilling a hole in a brand new battery, but if that's what it needs...

Although bagging was sufficient for my previous battery, I never had an issue with water inside the battery itself, but it was mounted normally, not upside down.

 

[Balmorhea]

I put my holes here

1/8 drill bit, drill slowly, theres batteries inside right . you can always duct tape the holes or make a little mud flap

I took the cover off the pack before I drilled it, so I could chamfer the holes and not leave a burr inside to retain water.

 

[Returnformer]

i decided to take the scenic route on the way home from work today. went about 11.5 miles. i checked with waze on my phone for about half the trip, and the built in speedometer seems pretty accurate. hard to tell for sure unless going a constant speed as the two adjust the speed at different rates, but it seemed pretty accurate, within 1 mph. speed topped out at about 37 mph. mightve gotten a bit faster if i let it, but i let up on the throttle when i saw that. a bit faster than i wanted to go, especially since there were three cops in the next lane over back a bit and i didnt want them to start wondering. luckily they either didnt notice or didnt care. i reduced to level 4 assist after that, which caps at 30 mph, which i rode for most of the rest of the ride, except a 2 mile stretch on the boardwalk, where i reduced to level 1, 11 mph max. battery went from 58.6v when i left work to 51.7v when i got home.

got back a bit ago from another ride, i had to go pick something up from someone. didnt have time to quite fully recharge in between, but it got back up to 57.0v when i left. about 15 miles round trip, pulling a trailer and with some hilly sections, so i reduced to level 3 assist, which caps out at about 25 mph, knowing that i wouldnt make it otherwise. this worked out pretty good, it was down to 47.5 when i got back. probably a bit lower than i should let it get, but hopefully once or twice here and there wont be too bad for it. based on that, id guess i can probably get 10-12 miles out of level 4, especially if not pulling a trailer. i probably wont use full power much unless i feel like really blowing by someone on one of those cheap chinese bikes... 8)

I put my holes here

1/8 drill bit, drill slowly, theres batteries inside right . you can always duct tape the holes or make a little mud flap

yeah, thats where i figured. i would still cover with a bag whenever theres rain/mud so that the battery stays clean. especially on the underside and without a good mud guard.

 

[markz]

i decided to take the scenic route

I ride my ebike different ways home each and every day. Today, I had a great time riding, just like the previous day and the day before that. Everyday is a blast! when you have lots of power at your thumbs fingertip thumb throttle. Been exploring this area of the city lately which takes me a good while to get to, hence why I never been there in all my decades of living here. A few grass fires every year is about all the news it gets. If I did not have an ebike, I would have never ridden Nose Hill Park ever and that is a fact. I wouldnt have ridden it 3 times on 3 different days. Same could be said for countless other area's of the city I visited, countless trails, countless restaraunts, countless roads, countless sidewalks, countless parks, countless communities, thats just the way it is when you ride each and every day. With covid19 I was exploring everyday on my ebike. Riding 40km+ everyday, where no motorcycle could go, where no vehicle could go, but my ebike surely can go anywhere and everywhere. I like the name of ES user Hill Hater, thats the truth I hate hills! I hate pedaling too, but do not be fooled into thinking just because we got power that we are lazy and dont pedal. No no, I still sweat my arse off because I realize I should pedal, also I want more battery juice to go further!

 

[Returnformer]

i decided to take the scenic route

I ride my ebike different ways home each and every day. Today, I had a great time riding, just like the previous day and the day before that. Everyday is a blast! when you have lots of power at your thumbs fingertip thumb throttle. Been exploring this area of the city lately which takes me a good while to get to, hence why I never been there in all my decades of living here. A few grass fires every year is about all the news it gets. If I did not have an ebike, I would have never ridden Nose Hill Park ever and that is a fact. I wouldnt have ridden it 3 times on 3 different days. Same could be said for countless other area's of the city I visited, countless trails, countless restaraunts, countless roads, countless sidewalks, countless parks, countless communities, thats just the way it is when you ride each and every day. With covid19 I was exploring everyday on my ebike. Riding 40km+ everyday, where no motorcycle could go, where no vehicle could go, but my ebike surely can go anywhere and everywhere. I like the name of ES user Hill Hater, thats the truth I hate hills! I hate pedaling too, but do not be fooled into thinking just because we got power that we are lazy and dont pedal. No no, I still sweat my arse off because I realize I should pedal, also I want more battery juice to go further!

thats great. and yeah, having an ebike opens up so much for exploring, i definitely wouldnt have ridden nearly as much today if i had to pedal. (im lazy, i dont really pedal other than a bit to get started... )

 

[markz]

(im lazy, i dont really pedal other than a bit to get started... )

We are all lazy to some extent or another, thats just human nature. I pedal to get going and I pedal on the hills but I also every once in a while fake pedal or some like to call it ghost pedaling. Do it when there are certain people around, or when you get the head turners. I had one today, gazed at me for a good 20+ seconds as I passed from in front of them to behind them about 40' off to the side. Then there are times I say to the other struggling cyclist up a hill "You gotta go electric" as I zoom on by them.

 

[amberwolf]

yeah, thats where i figured. i would still cover with a bag whenever theres rain/mud so that the battery stays clean. especially on the underside and without a good mud guard.

You may also wish to use dieelectric grease (like the packets you get with a new car battery for the terminals) on the contacts where battery case and base mate up. You can use that in all your connections, too, for any that are not already waterproof.

 

[miro13car]

this luggage rack is really high up making whole thing wobbly.
but battery placement is excellent for law center of gravity.

 

[momus3]

I know what you mean about an eBike giveing you the range to explore new parts of the city. I go all over Tucson, which is really spread out, and haven't needed to get on a bus (thank goodness w/ this virus) or call uber to fetch stuff.

You might want to consider one of these Wald baskets like the one below for the rear vs the milk crate. They're built much stronger than the picture indicates. Your local bike shop should have one. I've had mine on two bikes for years and it's shown no sign of wear even though I'm always hanging heavy bags of groceries tied to it's sides when the basket gets full. There's a couple of issues w/ the milk crates. They really get people's attention, while the wire racks essentially are seen through when empty, and they're plastic vs metal. My goal is to not scream EBIKE to the local cops, who may be ok, but no contact is good contact w/ those folks. Anything I can do to not attract their attention is my goal.

The Wald basket will also do a better job of distributing the weight vs where it is now. This model isn't as long as your crate, but it's long enough. You're well past the center of the rear wheel w/ yours. Puts a lot of stress on the rack and will cause some handling issues when fully loaded. They make different sizes, but this one will hold a lot because the sides are a little higher than usual. I took the handle off mine and used hose clamps and wire to secure it. There's 2 bungie cords too that don't actually do anything, but they're there if I need to tie something down.

https://waldsports.com/store/front-baskets/133-quick-release-basket/