72v Build help…

[portals]

Yes, most definitely you should have torque arms on drive and non-drive side for the power you have, I have 1500W 52V 17.Ah and have already spun out rear wheel once with just basic torque arm on non-drive side.

Regarding the Grin V4 on your drive side, I was looking at that too however LBS put me off saying the jubilee / hose clips shouldn't be attached to seat stay as they are simply not designed for this and may get damaged under heavy torque as the guy above mentioned, they should always go on to the chain stay as the bracket is strongest part of bike.

As I have an old frame LBS wasn;t convinced it would fit, I have two holes available on my old MTB that the derailleur used to be in (in a claw now), I am currently designing my own torque arem in Tinkercad and 3D printing it to test sizes before getting local metal shop to make me one, still WIP...

 

[Comrade]

getting local metal shop to make me one

Doesn't look like you need to machine that part. You could make it out of 2 pieces of laser cut plate steel, and the 2 bolts will hold it together.

 

[LewTwo]

It’s on Alibaba app this is the best I can do. It seemed the same as a Amazon motor but cheaper… that’s not the actual price bit for the 1500w one. reviews seemed good so we will see.

https://www.aliexpress.com/i/2251832781030870.html?gatewayAdapt=4itemAdapt

Looks like there may been an actual Manufacturer's lable on it ...

 

[portals]

getting local metal shop to make me one

Doesn't look like you need to machine that part. You could make it out of 2 pieces of laser cut plate steel, and the 2 bolts will hold it together.

That's a great idea, I haven't spoken to any local metal guys yet (and know little about metalwork type stuff), I'm assuming from your comment that laser cut plate steel will be cheaper to make as opposed to machining one from scratch from my design?

Thank you for the suggestion, I will report back.

 

[LewTwo]

getting local metal shop to make me one

Doesn't look like you need to machine that part. You could make it out of 2 pieces of laser cut plate steel, and the 2 bolts will hold it together.

That's a great idea, I haven't spoken to any local metal guys yet (and no little about metalwork type stuff), I'm assuming from your comment that laser cut plate steel will be cheaper to make as opposed to machining one from scratch from my design?

Thank you for the suggestion, I will report back.

I used these folks (thanks to PapaSteve for the recommendation): https://sendcutsend.com/
Quick turn around, precision made to your drawing, $30 minimum order.
Free, online estimate. This was a $30 order (Aluminum and SST) I got from them (7 days)

Similar problem. The pieces parts were stacked together (two M6 bolts) to make rear disk caliper mount for my Giant Revive.
https://endless-sphere.com/forums/viewtopic.php?f=6&t=117124

 

[portals]

getting local metal shop to make me one

Doesn't look like you need to machine that part. You could make it out of 2 pieces of laser cut plate steel, and the 2 bolts will hold it together.

That's a great idea, I haven't spoken to any local metal guys yet (and no little about metalwork type stuff), I'm assuming from your comment that laser cut plate steel will be cheaper to make as opposed to machining one from scratch from my design?

Thank you for the suggestion, I will report back.

I used these folks (thanks to PapaSteve for the recommendation): https://sendcutsend.com/
Quick turn around, precision made to your drawing, $30 minimum order.
Free, online estimate. This was a $30 order (Aluminum and SST) I got from them (7 days)

Similar problem. The pieces parts were stacked together (two M6 bolts) to make rear disk caliper mount for my Giant Revive.
https://endless-sphere.com/forums/viewtopic.php?f=6&t=117124

These look great, thanks for posting.

I'm in Glasgow, Scotland though so shipping might be an issue

 

[LewTwo]

I'm in Glasgow, Scotland though so shipping might be an issue

OH ... you might want to consider updating your profile to include location information.

I spent some time in Aberdeen and practically lived on "fish and chips" (as well as the occasional Single Malt).
Nothing I have tried in the US compares ... of course in Aberdeen the fish was really, really fresh.

 

[sweettrade324]

So I think I got in over my head. I got talked into a 72v (19.2ah allegedly) UPP battery and a 2000w 45a motor by the sales people assuring me this was the way to go. I built it on a 29” Schwinn Axum bike. I posted on electricbikereview forums and they sent me here. I see the controller on 25a and I do my best to keep the watts to under 1500-2000. Max speed is generally 25-30. I recently hid the wires in a bag as someone suggested for protection and looks but then was told this is a no no. Any advice would be greatly appreciated! I’m wondering if I should try to sell this and get a 52v battery if I can afford it. I’m not worried about longevity over 8-12 months at this point bebaust by then I’ll have a car again and this is my transport for now. My commute is between 3.1-5 miles depending if I’m going to work or the store.
I realize I probably made a mistake but am trying to salvage all I can.

What doesn't work in your system, or what doesn't it do that you want it to do, that you want to change?

If you can tell us that, we can tell you what to do to achieve that.

The system works great for me right now. I just posted this on another forum and got a ton of negative posts on how I shouldn’t of done that or this… how the battery is terrible, wie too small, telling me it will all catch fire and I got nervous so I came over here for a better opinion. Thank you everyone! I’m feeling much better.

 

[sweettrade324]

It’s on Alibaba app this is the best I can do. It seemed the same as a Amazon motor but cheaper… that’s not the actual price bit for the 1500w one. reviews seemed good so we will see.

https://www.aliexpress.com/i/2251832781030870.html?gatewayAdapt=4itemAdapt

Looks like there may been an actual Manufacturer's lable on it ...What Does That Say.png

Did this help?

 

[amberwolf]

The system works great for me right now. I just posted this on another forum and got a ton of negative posts on how I shouldn’t of done that or this… how the battery is terrible, wie too small, telling me it will all catch fire and I got nervous so I came over here for a better opinion.

Well, I can't say anything specific about the battery without knowing how it's built inside, what specific cells and interconnect materials and methods were used, what BMS and how it works / what functions it has / limits are set in it, etc. Most likely it's good enough, but:

In general UPP has a mixed reputation, as there are known fires in some of their packs that dont' appear to be caused by abuse of them, but the actual cause is very hard to determine after a fire destroys most of the evidence.

One of the problems may be that they don't always use balancing BMS, and they have different "grades" of cells they use, which behave differently. The problems this can cause are that cells that are different from each other become more different on each usage cycle, especially if the pack is used hard and from full to empty a lot. If the BMS correctly operates and shuts off at it's correct limits, this isn't an issue other than that it will have less and less usable capacity every cycle, and will perform less and less well (because some cells will be closer and closer to their empty state to start with, where there is often more voltage drop under load, so you get less total power (watts) out of the whole system).

If the BMS does not correctly operate, you can end up with cells that are above HVC (overcharged) or below LVC (overdischarged), and at some point the amount by which they exceed the limits could be enough to cause damage that can lead to a fire.

All those things can happen in *any* battery...it's just less likely with a well-built battery made with quality well-matched cells and a well-designed BMS....none of which you usually get in cheaper packs (though high cost is not a guarantee of high quality, low cost is much more likely to be a guarantee of poor quality).


If the battery works, and exhibits no problems, and is used well within it's limits, it's likely to be fine. If it begins showing problems (loss of capacity, not charging to full, losing voltage just sitting there, cutouts while riding, etc.), then it's time to check it out.

 

[portals]

I'm in Glasgow, Scotland though so shipping might be an issue

OH ... you might want to consider updating your profile to include location information.

I spent some time in Aberdeen and practically lived on "fish and chips" (as well as the occasional Single Malt).
Nothing I have tried in the US compares ... of course in Aberdeen the fish was really, really fresh.

I have updated my profile.

The world has gone mad, fish (cod) and chips here is now almost as expensive as steak....!!!11?????

 

[amberwolf]

The controller will be ok if it gets wet?

Keep in mind that none of this ebike stuff is waterproof--even if it says it is, it probably isn't. It may be water *resistant*, but under various conditions water will still get in there, even if it's just as humid air that later condenses into moisture.

Often enough the waterproofing is enough to keep what water does get into it inside where it makes more damage than if it had been left without that. :/ You can see this happen on some displays, where they get "dew" behind the plastic screen cover under some conditions. (the same thing can happen inside "sealed" motors and controllers too; you just cant' see it).

Most of the time it's not a problem. If you ride enough in heavy rain, or thru high waters, it can become a problem. My SB Cruiser trike has most of the wiring and electronics underneath the deck; nothing special done to seal anything up, but it has been thru flashflood waters at least twice, all of the stuff submerged for minutes, with no failures from that. I think I had to clean and dry some connectors, and I think the first time water got into the underseat cargo box, where the battery is, and got that wet, so I had to take it apart and dry it out as it has no casing around it to even make it water-resistant. But the two controllers, motors, etc., were ok.

 

[sweettrade324]

35mm or 45mm magnets ?

35mm… is this bad?

 

[portals]

So I think I got in over my head. I got talked into a 72v (19.2ah allegedly) UPP battery and a 2000w 45a motor by the sales people assuring me this was the way to go. I built it on a 29” Schwinn Axum bike. I posted on electricbikereview forums and they sent me here. I see the controller on 25a and I do my best to keep the watts to under 1500-2000. Max speed is generally 25-30. I recently hid the wires in a bag as someone suggested for protection and looks but then was told this is a no no. Any advice would be greatly appreciated! I’m wondering if I should try to sell this and get a 52v battery if I can afford it. I’m not worried about longevity over 8-12 months at this point bebaust by then I’ll have a car again and this is my transport for now. My commute is between 3.1-5 miles depending if I’m going to work or the store.
I realize I probably made a mistake but am trying to salvage all I can.

Well my wires aren't even in a 'bag', the controller is but not the wiring mess, my 'nest' is currently wrapped in a bin bag in case it rains...it sits in front of the controller bag, I think I will buy some velcro, cut to size and just wrap the bin bag so it looks tidier...



And ignore the haters...

 

[sweettrade324]

The system works great for me right now. I just posted this on another forum and got a ton of negative posts on how I shouldn’t of done that or this… how the battery is terrible, wie too small, telling me it will all catch fire and I got nervous so I came over here for a better opinion.

Well, I can't say anything specific about the battery without knowing how it's built inside, what specific cells and interconnect materials and methods were used, what BMS and how it works / what functions it has / limits are set in it, etc. Most likely it's good enough, but:

In general UPP has a mixed reputation, as there are known fires in some of their packs that dont' appear to be caused by abuse of them, but the actual cause is very hard to determine after a fire destroys most of the evidence.

One of the problems may be that they don't always use balancing BMS, and they have different "grades" of cells they use, which behave differently. The problems this can cause are that cells that are different from each other become more different on each usage cycle, especially if the pack is used hard and from full to empty a lot. If the BMS correctly operates and shuts off at it's correct limits, this isn't an issue other than that it will have less and less usable capacity every cycle, and will perform less and less well (because some cells will be closer and closer to their empty state to start with, where there is often more voltage drop under load, so you get less total power (watts) out of the whole system).

If the BMS does not correctly operate, you can end up with cells that are above HVC (overcharged) or below LVC (overdischarged), and at some point the amount by which they exceed the limits could be enough to cause damage that can lead to a fire.

All those things can happen in *any* battery...it's just less likely with a well-built battery made with quality well-matched cells and a well-designed BMS....none of which you usually get in cheaper packs (though high cost is not a guarantee of high quality, low cost is much more likely to be a guarantee of poor quality).


If the battery works, and exhibits no problems, and is used well within it's limits, it's likely to be fine. If it begins showing problems (loss of capacity, not charging to full, losing voltage just sitting there, cutouts while riding, etc.), then it's time to check it out.

Thank you for the useful information! I appreciate if greatly, learning everything I come here instead of people nay saying with no explanation!

 

[sweettrade324]

How else could I mount it? Or should I find a different type?

Unbolt the second part of the torque arm that's under the metal band clamps, and swing the part that's on the axle until it hits the frame? It's tough to see from a 2D picture how well the frame will keep it from spinning in the direction of the red arrows. Might need to get rid of the kickstand.

I would have designed my own. Something like this. Laser metal cutting is so cheap, that you could cut a dozen custom ones for the price of one Grin.

custom_torque_arm.png

Would it be possible to use foam to make a impression and then send it somewhere to be made? No place near me can do it.

 

[portals]

I recently hid the wires in a bag as someone suggested for protection and looks but then was told this is a no no.

Why did they think hiding wires in a bag is a no no.....?

What else can you do unless you start shortening the connector cables which no sane person would bother to do?

 

[portals]

Would it be possible to use foam to make a impression and then send it somewhere to be made? No place near me can do it.

I would attempt to do the 3D design yourself, if you're PC literate then you can learn Tinkercad (free for personal use and runs in browser), in 1/2 hr by following the built in tutorials to learn basics, here you don't draw 2D shape then extrude it out like Fusion 360 but you make shapes and cut other shapes out of them then group together for final part.

Or you might now someone who has a 3D printer and some 3D design skills, print prototypes in plastic to get measurements all bang on.

Something basic like this might fit the bill...you get the idea as you have a spare M6 hole?

You'd probably need a second design for the drive side?

 

[sweettrade324]

I would attempt to do the 3D design yourself, if you're PC literate then you can learn Tinkercad (free for personal use and runs in browser), in 1/2 hr by following the built in tutorials to learn basics, here you don't draw 2D shape then extrude it out like Fusion 360 but you make shapes and cut other shapes out of them then group together for final part.

Or you might now someone who has a 3D printer and some 3D design skills, print prototypes in plastic to get measurements all bang on.

Something basic like this might fit the bill...you get the idea as you have a spare M6 hole?

You'd probably need a second design for the drive side?

torque arem endess sphere.png

This looks good also. I will play around with Tinkercad and see what I can do. I went to a local metal shop and they said they could do it but it would cost a couple hundred dollars!!! So I went with a second Grin v4 for now. I definitely want to custom make one maybe to the M6 hole or as the other design shows and to the kick stand holes on the other.
I also talked to the guys at Grin tech and they suggested a custom one also, if I’m not able them at least a second v4 which I did.
Thank you everyone.

 

[portals]

I would attempt to do the 3D design yourself, if you're PC literate then you can learn Tinkercad (free for personal use and runs in browser), in 1/2 hr by following the built in tutorials to learn basics, here you don't draw 2D shape then extrude it out like Fusion 360 but you make shapes and cut other shapes out of them then group together for final part.

Or you might now someone who has a 3D printer and some 3D design skills, print prototypes in plastic to get measurements all bang on.

Something basic like this might fit the bill...you get the idea as you have a spare M6 hole?

You'd probably need a second design for the drive side?

torque arem endess sphere.png

This looks good also. I will play around with Tinkercad and see what I can do. I went to a local metal shop and they said they could do it but it would cost a couple hundred dollars!!! So I went with a second Grin v4 for now. I definitely want to custom make one maybe to the M6 hole or as the other design shows and to the kick stand holes on the other.
I also talked to the guys at Grin tech and they suggested a custom one also, if I’m not able them at least a second v4 which I did.
Thank you everyone. 5E5176C2-5FAE-4028-9A56-C7D9B21C6475.jpeg

Lol, cpl hundred $$$...find another local metal shop...

Not sure if you could laser cut suggested design as it's kind back to front from my design for my ebike earlier in thread, not a metal work guy but given the Grins are what £50, i"d pay that for a custom one that gives me piece of mind that under torque I won't lose the back wheel....

Looks like you could actually use same design mirrored for drive side.

cheers

 

[tomjasz]

I recently hid the wires in a bag as someone suggested for protection and looks but then was told this is a no no.

Why did they think hiding wires in a bag is a no no.....?

What else can you do unless you start shortening the connector cables which no sane person would bother to do?

The battery is questionable. A UPP budget build. Budget featureless BMS ans all nickel coated steel connections. Likely generic no name cells too. The wiring was sloppy in pictures and we simply questioned his choice in AWG. Suggesting he review it. Jumping blindly into a 72V first build and asking for help, after the issues probably isn’t the best route for someone totally new.

Explanations nearly matching amberwolfs were given.

But I saw where it was going and suggested he’d do better here and link with Amberwolf and more experienced high power builders. I’m the first to admit I dislike and am negative about 72V powerful builds on low priced bikes and budget battery builds without appropriate brakes and torque arms X 2.

Electricbikereview has few builders posting. Several of us often send n00bs here. A better forum for builders.

https://electricbikereview.com/forums/threads/my-new-build-72v-2000w.50747/#post-564054

 

[sweettrade324]

I recently hid the wires in a bag as someone suggested for protection and looks but then was told this is a no no.

Why did they think hiding wires in a bag is a no no.....?

What else can you do unless you start shortening the connector cables which no sane person would bother to do?

The battery is questionable. A UPP budget build. Budget featureless BMS ans all nickel coated steel connections. Likely generic no name cells too. The wiring was sloppy in pictures and we simply questioned his choice in AWG. Suggesting he review it. Jumping blindly into a 72V first build and asking for help, after the issues probably isn’t the best route for someone totally new.

Explanations nearly matching amberwolfs were given.

But I saw where it was going and suggested he’d do better here and link with Amberwolf and more experienced high power builders. I’m the first to admit I dislike and am negative about 72V powerful builds on low priced bikes and budget battery builds without appropriate brakes and torque arms X 2.

Electricbikereview has few builders posting. Several of us often send n00bs here. A better forum for builders.

https://electricbikereview.com/forums/threads/my-new-build-72v-2000w.50747/#post-564054

Thank you for your help in sending me here and the information. I appreciate it. If I could go back I might do a 52v but as I am stuck with this for now I guess. I am looking into the torque arm issue now, I found someone who is going to try to help me build some. Also I have hydraulic brakes coming.

 

[portals]

I recently hid the wires in a bag as someone suggested for protection and looks but then was told this is a no no.

Why did they think hiding wires in a bag is a no no.....?

What else can you do unless you start shortening the connector cables which no sane person would bother to do?

The battery is questionable. A UPP budget build. Budget featureless BMS ans all nickel coated steel connections. Likely generic no name cells too. The wiring was sloppy in pictures and we simply questioned his choice in AWG. Suggesting he review it. Jumping blindly into a 72V first build and asking for help, after the issues probably isn’t the best route for someone totally new.

Explanations nearly matching amberwolfs were given.

But I saw where it was going and suggested he’d do better here and link with Amberwolf and more experienced high power builders. I’m the first to admit I dislike and am negative about 72V powerful builds on low priced bikes and budget battery builds without appropriate brakes and torque arms X 2.

Electricbikereview has few builders posting. Several of us often send n00bs here. A better forum for builders.

https://electricbikereview.com/forums/threads/my-new-build-72v-2000w.50747/#post-564054

Ah, OK, I get you, great advice to come here where people tend not to judge you (like they do on other sites like pedelecs), and I see you point on the OPs wiring and choice of AWG gauge, way to light for the amperage involved.

 

[sweettrade324]

I am second guessing my Juin Tech m1 brakes I purchased and wanted some opinions. They are line pulling hydraulic dual piston. I am thinking now I should go full hydraulic. Any suggestions on finding a pair with the cut off? I don’t have the round connectors but the others with the male end. Number 4 in the photo. Unless you think the Juan tech are good enough?

 

[99t4]

I am thinking now I should go full hydraulic. Any suggestions on finding a pair with the cut off?

I would prefer not to open up the sealed hydraulic system (entails PIA bleeding procedure) to change out the brake levers. Why not simply add magnetic reed switch to the levers?

Forum member E-HP recently bought some https://www.amazon.com/dp/B07RYCSDMK?psc=1&ref=ppx_yo2ov_dt_b_product_details, look in his build post https://www.endless-sphere.com/forums/viewtopic.php?f=6&t=97945&start=250#p1733223.

You most likely will need to splice in matching connectors, to mate with the existing on your controller, or vice-versa.