Thoughts on This eBike Kit and Battery

[LewTwo]

If you look at the right side dropout, you can see that the derailleur mounts on a hanger claw that in turn mounts in the dropout slot. Because the hanger claw hardware occupies the rearmost portion of the slot, the axle must sit forward of this. The left axle end also must sit forward of the rear of its slot, just so the wheel can be parallel to the bike frame.

Forward opening dropouts like that are not strong against flatted axle torque, but as long as there are torque arms that attach to something other than the axle slot, they should be fine.

Good catch ... I missed that wee detail. :thumb:

 

[portals]

Torque Arms:
www.hammer-ebikes.com
07754032024

Also, it does seem that your rear axle does not fully sit into the drop outs.
2.jpg

If you look at the right side dropout, you can see that the derailleur mounts on a hanger claw that in turn mounts in the dropout slot. Because the hanger claw hardware occupies the rearmost portion of the slot, the axle must sit forward of this. The left axle end also must sit forward of the rear of its slot, just so the wheel can be parallel to the bike frame.

Forward opening dropouts like that are not strong against flatted axle torque, but as long as there are torque arms that attach to something other than the axle slot, they should be fine.

Yes, I noticed that gap too pretty quick as I was paranoid that I spin out the rear wheel again, your explanation of why is spot on. I got lucky last time as the motor cable was ripped out of controller socket and wound round axle but thankfully only minor surface damage to the motor cable that I've patched with tape, no damage to cores.

Thanks for the Grin and Hammer torque arm links as I want something beefier than I currently have for peace of mind, either that or I buy a new modern frame and back to square one and more issues...

 

[portals]

https://www.youtube.com/watch?v=JCaDz_2YcGQ

Crikey, this was the manufacturer of the kit and battery that was originally on my shopping list as they supposedly shipped from Germany to UK tax free....

the battery (52V20Ah 40A BM) = 218.24

In end I spent £500 on a samsung 52V 17.5Ah battery pack from a UK supplier, a lot of cash yes but knowing it's one of the big five give you some peace of mind re quality.

 

[Diggs]

https://www.youtube.com/watch?v=JCaDz_2YcGQ

Crikey, this was the manufacturer of the kit and battery that was originally on my shopping list as they supposedly shipped from Germany to UK tax free....

the battery (52V20Ah 40A BM) = 218.24

In end I spent £500 on a samsung 52V 17.5Ah battery pack from a UK supplier, a lot of cash yes but knowing it's one of the big five give you some peace of mind re quality.

Heh - Louis Rossman. I've watched a bunch of his computer videos and knew he was a big ebiker. Very informed and intelligent individual. Didn't know he had this episode. I run two packs in parallel for years now without a bridge rectifier. I never charge to 100% but now he has me re-thinking things.

The OP had mentioned a ~$200 battery pack earlier in this thread and the red flags went off. Glad to see a better decision was made.

 

[999zip999]

Quality new name brand cells costs good money. No way out. So how fast does it go ?

 

[portals]

https://www.youtube.com/watch?v=JCaDz_2YcGQ

Crikey, this was the manufacturer of the kit and battery that was originally on my shopping list as they supposedly shipped from Germany to UK tax free....

the battery (52V20Ah 40A BM) = 218.24

In end I spent £500 on a samsung 52V 17.5Ah battery pack from a UK supplier, a lot of cash yes but knowing it's one of the big five give you some peace of mind re quality.

Heh - Louis Rossman. I've watched a bunch of his computer videos and knew he was a big ebiker. Very informed and intelligent individual. Didn't know he had this episode. I run two packs in parallel for years now without a bridge rectifier. I never charge to 100% but now he has me re-thinking things.

The OP had mentioned a ~$200 battery pack earlier in this thread and the red flags went off. Glad to see a better decision was made.

What persuaded me on the battery was my son just bought a new PS4 DUALSHOCK4 controller on ebay for under £30, I told him it would be fake...and it was...long story however I tore it down and have the pics to show, same for ebike batteries, save your long-term cash and pay the odds in short-term for something you can trust...

I charged my samsung up last night, checked it every hr with multimeter planning on stopping it at 57.1V (90%) charge to increase life/cycles....however fell asleep on couch so it's 100%....there must be an easier way?

 

[portals]

Quality new name brand cells costs good money. No way out. So how fast does it go ?

I'm still a little para about the reverse torque spinning out the back wheel again, I have taken to tightening the 18mm bolts as tight as I can get them with my wrench before each ride then drawing with with sharpie a straight vertical line from top of bolt over washers/assemble, on both sides, so if anything moves I can see immediately it's out of line and is loosening.

I'm getting nowhere fast with acquiring stronger torque arms one for both sides, lots of suggestions but I can't see practically how this would work. Maybe local metal shop is next step.

As for 'how fast does it go'....I've had it at 30 mph locally and was bricking it, the LCD reports fastest I've gone as approx 45mph however that's probably from testing hub on bike stand with no load (me).

25mph seems optimal for roads where I am, lots of bike lanes too however they're not in great condition and often more dangerous to ride on than road due to potholes etc., however I reckon on flat in good road conditions I could get close to 40mph, I need to invest in a helmet and get torque sorted before I attempt

As a footnote, there is a pretty steep hill near where I live, not many ppl attempt this on a bike, I zoomed up at avg 15mph, had to wait nearly 5 mins for my son to arrive

These ebikes are so much fun, the range and power is crazy, treat them with the respect they require and don't stop smiling

 

[Diggs]

....there must be an easier way?

There is. Get a charger that you can set for different charge levels. I use a Luna mini-charger. I can set it for 80, 90 or 100% charge. I usually use 80% unless I have a very long ride planned then I use 90%. Once a year I separate my two packs (one on the down tube and one in the trunk bag) that run in parallel and charge to 100% to balance the cells. I ride them down again separately, recharge to 80% and combine them again for the rest of the year.

 

[999zip999]

I use norlock locking washers so the nut shouldn't loosen.

 

[99t4]

I'm getting nowhere fast with acquiring stronger torque arms one for both sides, lots of suggestions but I can't see practically how this would work. Maybe local metal shop is next step.

From your photos, the dropouts on your bike look like an easy application for a simple TA. Large flat-sided dropout, should be able to fab something simple like this: (preferably steel rather than aluminum)

What problems are you encountering?

 

[portals]

....there must be an easier way?

There is. Get a charger that you can set for different charge levels. I use a Luna mini-charger. I can set it for 80, 90 or 100% charge. I usually use 80% unless I have a very long ride planned then I use 90%. Once a year I separate my two packs (one on the down tube and one in the trunk bag) that run in parallel and charge to 100% to balance the cells. I ride them down again separately, recharge to 80% and combine them again for the rest of the year.

Thanks for the post, I read about these chargers somewhere recently, I'll have another look online however they don't look cheap, then again neither is £500 battery...

 

[portals]

I use norlock locking washers so the nut shouldn't loosen.

Thanks for that, so they work well for you?

I'd be interested to see how others feel using Norlock locking washers, do they really work, bike guy in shop didn't think they'd make much difference re the torque?

 

[portals]

I'm getting nowhere fast with acquiring stronger torque arms one for both sides, lots of suggestions but I can't see practically how this would work. Maybe local metal shop is next step.

From your photos, the dropouts on your bike look like an easy application for a simple TA. Large flat-sided dropout, should be able to fab something simple like this: (preferably steel rather than aluminum)

What problems are you encountering?

The issue I have is that currently I don't fully trust the bike at high torque, I've noticed that despite me tightening the axle nuts before a ride that the drive side nut moves slightly, maybe only 1/4 turn however I cannot have another hub spin out.

I'm struggling to fit a torque arm to the drive side as the the derailleur cable guide and derailleur claw is in the way so I cannot attach torque arm in same way as on non-drive side to the chain stay - see pics.

Any ideas as to best I can achieve this?


I'm also wondering if the single thin torque arm on non-drive side is strong enough, I've seen much thicker ones (4mm I think), so this give larger surface area between arm and axle flat so should dissipate the torque more efficiently through the chain stay??

 

[amberwolf]

If you have any spacer washers on the inboard side of the axle in the driveside dropout, you might be able to use the torque arm as one of the spacers instead.

Alternately you could put the torque arm on the outboard side of teh derailer hanger. You may have to file teh arm to fit around the hanger screw depending on the angle it fits at.


More surface area in contact between axle flat and torque arm is better, so thicker arms (as thick as possible for the bolt length) is better. If you have multiple sets of torque arms you can stack them. The only part that resists torque is the very tiny cross-contact area where the flat of the axle touches the torque arm. If there is not enough area, the torque arm cannot do it's job.

The ones you have look like clones of the older Grin Tech torque arm; it's pretty common for these cheap clones to be made from thin stamped metal that may simply cut into the axle instead of resisting the torque, or the axle may just push thru the arm's metal and deform it, rounding out the hole. It doesn't mean yours will fail; it's just a common mode of failure.

If yours are actually properly flat on the mating surface of the arm to the axle flat (which a stamped one isn't), and that area is large enough, you probably wont' have a problem.

 

[portals]

....there must be an easier way?

There is. Get a charger that you can set for different charge levels. I use a Luna mini-charger. I can set it for 80, 90 or 100% charge. I usually use 80% unless I have a very long ride planned then I use 90%. Once a year I separate my two packs (one on the down tube and one in the trunk bag) that run in parallel and charge to 100% to balance the cells. I ride them down again separately, recharge to 80% and combine them again for the rest of the year.

Thanks for the post, I read about these chargers somewhere recently, I'll have another look online however they don't look cheap, then again neither is £500 battery...

Thinking about it (and not thought this through yet), I might have a go at making my own homebrew display to show the battery voltage using an Arduino Uno/Nano, a voltage divider that will accept 60V, zener diode and either a 16*2 LCD display or LED display in a small 3d printed project box.

If I can get the basics working and get resolution accurately reporting same DC battery voltage as multimeter to a decimal point then maybe I can also code it to stop charging at a set defined voltage (%age charged) as per the charts available online for 52V branded battery. Exactly how this can be done off top of my head I'm not sure, simple way might be to use a relay to turn off the charger at a predefined battery voltage (eg 80%/90%).

I have everything I need in my parts box from other Arduino projects, maybe something for when the darker nights come in..

 

[portals]

If you have any spacer washers on the inboard side of the axle in the driveside dropout, you might be able to use the torque arm as one of the spacers instead.

Alternately you could put the torque arm on the outboard side of teh derailer hanger. You may have to file teh arm to fit around the hanger screw depending on the angle it fits at.


More surface area in contact between axle flat and torque arm is better, so thicker arms (as thick as possible for the bolt length) is better. If you have multiple sets of torque arms you can stack them. The only part that resists torque is the very tiny cross-contact area where the flat of the axle touches the torque arm. If there is not enough area, the torque arm cannot do it's job.

The ones you have look like clones of the older Grin Tech torque arm; it's pretty common for these cheap clones to be made from thin stamped metal that may simply cut into the axle instead of resisting the torque, or the axle may just push thru the arm's metal and deform it, rounding out the hole. It doesn't mean yours will fail; it's just a common mode of failure.

If yours are actually properly flat on the mating surface of the arm to the axle flat (which a stamped one isn't), and that area is large enough, you probably wont' have a problem.

Thanks.

As you say when I spun out the rear hub the torque did push the axle so it rotated through the arm metal and rounded it rendering it completely useless :-(

So I think maybe these cheap torque arms are junk and I need to go with a beefier version on non-drive side as you say.

Re drive side, the derailleur cable guide will still get in the way?

 

[amberwolf]

If you mount the arm without the long piece, and drill a hole in it that matches one of your fender/rack mount screw holes on the dropout top, and use a spacer there, you can bypass the whole cable issue.

You can make your own torque arms or plates with a drill and a small set of flat files. Use as thick a metal as you can, and then just drill the main hole for the axle and slowly file it out till it fits your axle so perfectly you practically have to tap it into place instead of just slipping it on. The tighter it fits the axle flats, the better. If it isn't parallel to the flats on both sides and along the whole surface, then only the parts that touch teh axle flats actually resist torque. So it does take a lot of patience to do this, but it's possible. Lots of ideas here
https://endless-sphere.com/forums/viewtopic.php?f=2&t=26444

In a pinch you can use a good solid 10mm box wrench; I did this for a long time on Crazybike2's front hubmotor wheel and it worked fine, but open ended wrenches are not as good as closed-hole torque arms, because they can be pried open like dropouts. But if they are thick and hard metal, they're better than nothing and better than thin crappy arms. A pic from the above thread

and a pic from mine
https://www.endless-sphere.com/forums/viewtopic.php?f=2&t=12500&p=954759&hilit=wrench#p954759


a better pic was there but is missing now...thankfully this one was still there, though--Yogi got stuck investigating things....he was such a doofus. :



If you don't want to do that, I'd recommend the Grin torque arms that best suit your particular dropout design,
https://ebikes.ca/product-info/grin-products/torque-arms.html
https://ebikes.ca/torqarm-v4.html
https://www.amazon.com/Grin-Technologies-Universal-Electric-ebikes/dp/B00K60C67Y

A big problem with many cheap crappy clones of Grin's arms is that the hole is not fitted to the axle flats, so it's very easy for an axle to rotate enough in it to cut into the arm and keep spinning.

As you say when I spun out the rear hub the torque did push the axle so it rotated through the arm metal and rounded it rendering it completely useless :-(

So I think maybe these cheap torque arms are junk and I need to go with a beefier version on non-drive side as you say.

Re drive side, the derailleur cable guide will still get in the way?

 

[999zip999]

The norlock washers are a snap racket washers to apply pressure between the frame and the nut on the axle so it won't untighten.You still need a torque arm. Do be cheap as it might get you a trip to the E.R.

 

[99t4]

Are you using regenerative braking?

 

[999zip999]

When making an ebike you eed to check out the rear axle for spacing to fit the axle nut as a mxus 3,000 has a larger nut and other things like controller battery and ebrakes and shifters yes everything before you buy. Forward thinking for all components and how and where they can and will fit that's why a grip shifter is not always the best and or a combo shifter break all in one is not good

 

[portals]

When making an ebike you eed to check out the rear axle for spacing to fit the axle nut as a mxus 3,000 has a larger nut and other things like controller battery and ebrakes and shifters yes everything before you buy. Forward thinking for all components and how and where they can and will fit that's why a grip shifter is not always the best and or a combo shifter break all in one is not good

Plan was to do this on a budget hence the donor bike, when I have the two torque arms hopefully the frame won't then be an issue as I paid £60 to get it shot blasted and sprayed grey. I had to bin the grey forks as I bent them....so if I have to buy a second hand frame and blast/spray it black then so be it...

 

[portals]

Are you using regenerative braking?

No, I'm pretty sure my controller doesn't support it ;-(

 

[portals]

The norlock washers are a snap racket washers to apply pressure between the frame and the nut on the axle so it won't untighten.You still need a torque arm. Do be cheap as it might get you a trip to the E.R.

Thanks.

I watched this video: https://www.youtube.com/watch?v=IKwWu2w1gGk

Not sure how relevant it is to reverse torque but may well be worth another look.

 

[portals]

If you mount the arm without the long piece, and drill a hole in it that matches one of your fender/rack mount screw holes on the dropout top, and use a spacer there, you can bypass the whole cable issue.

You can make your own torque arms or plates with a drill and a small set of flat files. Use as thick a metal as you can, and then just drill the main hole for the axle and slowly file it out till it fits your axle so perfectly you practically have to tap it into place instead of just slipping it on. The tighter it fits the axle flats, the better. If it isn't parallel to the flats on both sides and along the whole surface, then only the parts that touch teh axle flats actually resist torque. So it does take a lot of patience to do this, but it's possible. Lots of ideas here
https://endless-sphere.com/forums/viewtopic.php?f=2&t=26444

In a pinch you can use a good solid 10mm box wrench; I did this for a long time on Crazybike2's front hubmotor wheel and it worked fine, but open ended wrenches are not as good as closed-hole torque arms, because they can be pried open like dropouts. But if they are thick and hard metal, they're better than nothing and better than thin crappy arms. A pic from the above thread
20160105_182255[1].jpg
and a pic from mine
https://www.endless-sphere.com/forums/viewtopic.php?f=2&t=12500&p=954759&hilit=wrench#p954759
IMG_0068[1].jpg
IMG_0141[1].jpg
a better pic was there but is missing now...thankfully this one was still there, though--Yogi got stuck investigating things....he was such a doofus. :
IMG_0113[1].jpg


If you don't want to do that, I'd recommend the Grin torque arms that best suit your particular dropout design,
https://ebikes.ca/product-info/grin-products/torque-arms.html
https://ebikes.ca/torqarm-v4.html
https://www.amazon.com/Grin-Technologies-Universal-Electric-ebikes/dp/B00K60C67Y

A big problem with many cheap crappy clones of Grin's arms is that the hole is not fitted to the axle flats, so it's very easy for an axle to rotate enough in it to cut into the arm and keep spinning.

As you say when I spun out the rear hub the torque did push the axle so it rotated through the arm metal and rounded it rendering it completely useless :-(

So I think maybe these cheap torque arms are junk and I need to go with a beefier version on non-drive side as you say.

Re drive side, the derailleur cable guide will still get in the way?

Thanks, appreciate response, some things to think about, I like the idea of using a spanner however it will take the face of the bike .

I think I'll probably end up getting a much thicker arm for non-drive side, in fact there are probably three/four other bike shops local to me so I'll try a different one and see what they say, hopefully they're all ebike friendly like first guy was, he didn't flinch at the 1500KW hub however I fell maybe he could off been more helpful re 2nd torue arem

As for drive side, I think you're correct in that it's not really possible to attach arm to chain stay so it will need to be the seat stay (not as strong), or as you suggest the fender/rack mount screw holes on top of dropout that aren't/won't be used, probably this will be best if I can find a decent thick arm that will fit.

cheers

 

[portals]

If you mount the arm without the long piece, and drill a hole in it that matches one of your fender/rack mount screw holes on the dropout top, and use a spacer there, you can bypass the whole cable issue.

You can make your own torque arms or plates with a drill and a small set of flat files. Use as thick a metal as you can, and then just drill the main hole for the axle and slowly file it out till it fits your axle so perfectly you practically have to tap it into place instead of just slipping it on. The tighter it fits the axle flats, the better. If it isn't parallel to the flats on both sides and along the whole surface, then only the parts that touch teh axle flats actually resist torque. So it does take a lot of patience to do this, but it's possible. Lots of ideas here
https://endless-sphere.com/forums/viewtopic.php?f=2&t=26444

In a pinch you can use a good solid 10mm box wrench; I did this for a long time on Crazybike2's front hubmotor wheel and it worked fine, but open ended wrenches are not as good as closed-hole torque arms, because they can be pried open like dropouts. But if they are thick and hard metal, they're better than nothing and better than thin crappy arms. A pic from the above thread
20160105_182255[1].jpg
and a pic from mine
https://www.endless-sphere.com/forums/viewtopic.php?f=2&t=12500&p=954759&hilit=wrench#p954759
IMG_0068[1].jpg
IMG_0141[1].jpg
a better pic was there but is missing now...thankfully this one was still there, though--Yogi got stuck investigating things....he was such a doofus. :
IMG_0113[1].jpg


If you don't want to do that, I'd recommend the Grin torque arms that best suit your particular dropout design,
https://ebikes.ca/product-info/grin-products/torque-arms.html
https://ebikes.ca/torqarm-v4.html
https://www.amazon.com/Grin-Technologies-Universal-Electric-ebikes/dp/B00K60C67Y

A big problem with many cheap crappy clones of Grin's arms is that the hole is not fitted to the axle flats, so it's very easy for an axle to rotate enough in it to cut into the arm and keep spinning.

As you say when I spun out the rear hub the torque did push the axle so it rotated through the arm metal and rounded it rendering it completely useless :-(

So I think maybe these cheap torque arms are junk and I need to go with a beefier version on non-drive side as you say.

Re drive side, the derailleur cable guide will still get in the way?

Thanks, appreciate response, some things to think about, I like the idea of using a spanner however it will take the face of the bike .

I think I'll probably end up getting a much thicker arm for non-drive side, in fact there are probably three/four other bike shops local to me so I'll try a different one and see what they say, hopefully they're all ebike friendly like first guy was, he didn't flinch at the 1500KW hub however I fell maybe he could off been more helpful re 2nd torue arem

As for drive side, I think you're correct in that it's not really possible to attach arm to chain stay so it will need to be the seat stay (not as strong), or as you suggest the fender/rack mount screw holes on top of dropout that aren't/won't be used, probably this will be best if I can find a decent thick arm that will fit.

That's the sort of thing my cat used to do before she passed, she would sit for hrs watching me working on stripping the old bike (as I was learning on job), then decided to get involved at a critical point...and send a carefully laid piece of A4 with nuts/bolts/washers all carefully laid out all over the floor...

cheers