Help. Ebike conversion

Nealh

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Aug 7, 2014
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One will have to be very careful on the drive side, there is little material to play with. As one mills out deeper then the likely hood of a stress fracture occurring increases, the two tapped holes marked (one the gear hanger) will end up with less material between them and the d/o seat cut. Stress fractures may occur in the area where I have arrowed.

It is often better to source a better frame to adapt with a better meatier d/o area with so many tapped holes nearby.

drop out_LI.jpg
 
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slowbutsure1936

Pedelecer
Mar 28, 2022
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At all costs avoid securing a torque arm using the hose clip method, a secure fixing via a threaded bolt hole or a through hole with a snug bolt and nut fixing.

Both sides of the d/o'd need to be milled out equally so the axle sits horizontal, don't rush the job. Better to take a little at a time out then go mad.
not using a hose clip would mean making your own torque arm I’m guessing?
 

slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
One will have to be very careful on the drive side, there is little material to play with. As one mills out deeper then the likely hood of a stress fracture occurring increases, the two tapped holes marked (one the gear hanger) will end up with less material between them and the d/o seat cut. Stress fractures may occur in the area where I have arrowed.

It is often better to source a better frame to adapt with a better meatier d/o area with so many tapped holes nearby.

View attachment 46567
thats an interesting observation. One thought. The motor is switchable between 250w & 1000w. When it was in 250w mode the wheel stayed in places, it only pops out in 1000w mode. I’m just wondering if I could fit two torque arms and not grind out the drop outs, might that safely solve the problem?
 

Nealh

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not using a hose clip would mean making your own torque arm I’m guessing?
No one can buy a two piece torque arm and use a secure fixing for it, a hose clamp is not the answer.
 

slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
Excellent Photos and very clear, many thanks.
I am reminded of the saying that a "picture is worth a 1000 words!"
The fork looks tiny to me personally, and I am not surprised that you are having problems.
But I am also interested in opinions of other here too.
My only thought, but not easy to achieve, but how I would go about it, would be to generously cut off the same piece from a scrap bike, and weld it securely and accurately in place of what you have now.
Or find another frame, and scrap the one you have now......
I am sorry for you that you have such a problem, hopefully someone here knows a proper fix.
Best wishes and happy Easter to all Pedelecers.
Andy
I'm still also wondering about buying some new drop outs like these below, grinding them and then glueing them on. Would gluing them on be strong enough? some kind of epoxy resign im guessing, or metal glue. Any idea what I would use for that?

 
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Nealh

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Andy-Mat

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I'm still also wondering about buying some new drop outs like these below, grinding them and then glueing them on. Would gluing them on be strong enough? some kind of epoxy resign im guessing, or metal glue. Any idea what I would use for that?

Glueing, when done correctly, can often be better than welding. You only have to slightly rough up all the areas to be glued, then clean "intimately", using Meths and throwaway plastic gloves (get at least a dozen or more), as fingerprints are detrimental to the quality of the "hold"!
Make the glueing area as large as you can, to increase the holding power. Once fully cured, wrap & support with either Fiber glass fine weave (car repairs!) bandage, or carbon fiber bandage, if you can get it!
Do "soak" the bandage well to leave no voids.
Maybe try first on some bits of metal that are unimportant, then attempt to break them apart.
The quick hardening versions of Fiber Glass Resin, I would not recommend, even though they have got much stronger over the years, they may harden faster than you can work, and that might make for a messy joint.
Remember, you need Methylated spirits for cleaning, for 3 reasons:-
1) Cleaning of glueing surfaces before applying resin
2) Cleaning of skin, but BEFORE THE RESIN HARDENS!
3) Cleaning of metal surfaces that have collected too much glue, but again, before it hardens only.
After it hardens, you will need files and a grinder!

Look around on the internet for good infos, YouTube especially.
Treat all gluing as if you were a emergency room nurse, sterilising a wound before bandaging, "cleanliness is next to Godliness!".

Many here will say, without have the slightest inkling of how a proper repair, made with Epoxy (no other fiber glass resins please! For instance not Polyester please as it is difficult to work with for a beginner, and is ALWAYS repaired with Epoxy once hard anyway!!), can be really fantastic. Ask instead car builders and repairers, boat builders and sailors, fisherman and their fiber glass rods, usually made with carbon fiber nowadays, but I still have a 6ft 2 piece Spinning rod, made from a £3.00 Kit, over 60 years ago (I was 13), which still sees occasional usage when fishing! I could beat someone to death with it and only need to wipe off the blood stains!

If you DO decide to have a go, as I said before, get used to the materials first.

The really good and strongest Epoxy glues need at least 24 hours, in a normal warm room, to harden. And a further 2 - 4 days, to "cure" to full strength. Givng you a lot of time to get it right....... Do read the instructions first!

Getting the mix correct with resin and hardner is MOST IMPORTANT.

Best wishes and a good dose of luck, if you do it.

regards
Andy
 
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slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
Glueing, when done correctly, can often be better than welding. You only have to slightly rough up all the areas to be glued, then clean "intimately", using Meths and throwaway plastic gloves (get at least a dozen or more), as fingerprints are detrimental to the quality of the "hold"!
Make the glueing area as large as you can, to increase the holding power. Once fully cured, wrap & support with either Fiber glass fine weave (car repairs!) bandage, or carbon fiber bandage, if you can get it!
Do "soak" the bandage well to leave no voids.
Maybe try first on some bits of metal that are unimportant, then attempt to break them apart.
The quick hardening versions of Fiber Glass Resin, I would not recommend, even though they have got much stronger over the years, they may harden faster than you can work, and that might make for a messy joint.
Remember, you need Methylated spirits for cleaning, for 3 reasons:-
1) Cleaning of glueing surfaces before applying resin
2) Cleaning of skin, but BEFORE THE RESIN HARDENS!
3) Cleaning of metal surfaces that have collected too much glue, but again, before it hardens only.
After it hardens, you will need files and a grinder!

Look around on the internet for good infos, YouTube especially.
Treat all gluing as if you were a emergency room nurse, sterilising a wound before bandaging, "cleanliness is next to Godliness!".

Many here will say, without have the slightest inkling of how a proper repair, made with Epoxy (no other fiber glass resins please! For instance not Polyester please as it is difficult to work with for a beginner, and is ALWAYS repaired with Epoxy once hard anyway!!), can be really fantastic. Ask instead car builders and repairers, boat builders and sailors, fisherman and their fiber glass rods, usually made with carbon fiber nowadays, but I still have a 6ft 2 piece Spinning rod, made from a £3.00 Kit, over 60 years ago (I was 13), which still sees occasional usage when fishing! I could beat someone to death with it and only need to wipe off the blood stains!

If you DO decide to have a go, as I said before, get used to the materials first.

The really good and strongest Epoxy glues need at least 24 hours, in a normal warm room, to harden. And a further 2 - 4 days, to "cure" to full strength. Givng you a lot of time to get it right....... Do read the instructions first!

Getting the mix correct with resin and hardner is MOST IMPORTANT.

Best wishes and a good dose of luck, if you do it.

regards
Andy
Thanks, thats really helpful.
 

slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
One will have to be very careful on the drive side, there is little material to play with. As one mills out deeper then the likely hood of a stress fracture occurring increases, the two tapped holes marked (one the gear hanger) will end up with less material between them and the d/o seat cut. Stress fractures may occur in the area where I have arrowed.

It is often better to source a better frame to adapt with a better meatier d/o area with so many tapped holes nearby.

View attachment 46567
A new frame would be my last option, I think. I would like to make it work on this one. But your points are well taken and leaning me toward gluing new steel drop outs on that can be ground.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
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Thanks, thats really helpful.
I am surprised that nobody else here, up to now anyway, has not made similar, or even better tips on glueing for you, as once you understand the points I just made, you are a KING!
regards and I wish you a happy Easter for you and yours
Andy
PS. If you decide not to do it, that is still your prerogative as well!
 

slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
I am surprised that nobody else here, up to now anyway, has not made similar, or even better tips on glueing for you, as once you understand the points I just made, you are a KING!
regards and I wish you a happy Easter for you and yours
Andy
PS. If you decide not to do it, that is still your prerogative as well!
Thanks, as a Christian minister I will have a great Easter :). Hope you and yours do too.
 

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
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431
Though filing isn't mentioned the Grin page diagrams shows the axle filly in the d/o with the flats of the axle well covered by the d/o, ali can and will over time spread/wear if no torque arm/s are used to counter the rotation. No standard bike frame will have drops outs that deep whereby no milling/filing is required, most are to accommodate 9mm axles.

Rear ali d/o's are better for fitting then front ali for d/o's which have little strength in them.
The reason for the axle flat to sit in well is to prevent the roll out effect if not done so, given the chance the roll effect will cause miute spread and fracture of the ali d/o.
The images I see for the torque arm don't show the axle fitted but show the torque arm being designed to tightly hold the axle in the axle hole of the torque arm. However on the dropout of the Subway on the driveside there are two holes close to where the metal will be filed out in order to deepen the dropout. It doesn't have this issue on the non-drive side. It seems to me a very difficult situation where filing too deep could compromise the dropout on that side but as you say not filing it out could allow the axle to twist but the aluminium is soft anyway and part of the dropout shape is the gear hanger which is ultra soft with very little strength at all. The main material that will stop the axle twisting will be the torque arms won't it? I'm writing this with Zero experience of installing a hub motor into aluminium dropouts but have to say that dropout design does worry me a bit. They have reinforced that dropout with extra material and a percentage of that will be removed close to where the holes are.

I just wonder if there is a position where you don't file out quite as much material and still have a decent grip of the axle but still maintain a little more distance to the other holes in the dropout and rely on the two torque arms a little more. I wonder how other Carrera ebike conversions have done this, fully filed the dropouts or slightly less and relied on the torque arm. I definitely feel I wouldn't run that ebike kit at full 1000W mode.

 

slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
The images I see for the torque arm don't show the axle fitted but show the torque arm being designed to tightly hold the axle in the axle hole of the torque arm. However on the dropout of the Subway on the driveside there are two holes close to where the metal will be filed out in order to deepen the dropout. It doesn't have this issue on the non-drive side. It seems to me a very difficult situation where filing too deep could compromise the dropout on that side but as you say not filing it out could allow the axle to twist but the aluminium is soft anyway and part of the dropout shape is the gear hanger which is ultra soft with very little strength at all. The main material that will stop the axle twisting will be the torque arms won't it? I'm writing this with Zero experience of installing a hub motor into aluminium dropouts but have to say that dropout design does worry me a bit. They have reinforced that dropout with extra material and a percentage of that will be removed close to where the holes are.

I just wonder if there is a position where you don't file out quite as much material and still have a decent grip of the axle but still maintain a little more distance to the other holes in the dropout and rely on the two torque arms a little more. I wonder how other Carrera ebike conversions have done this, fully filed the dropouts or slightly less and relied on the torque arm. I definitely feel I wouldn't run that ebike kit at full 1000W mode.

That sounds like an interesting compromise. Perhaps grind out 2mm and use two torque arms. The wheel stayed in fine when using 250w, it only popped out at 1000w. I am also still toying with the idea of buying two new steel drop outs, grinding them out, and fixing them to the existing ones with a strong metal weld compound.
 

slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
Question. Can the torque arm go on the inside of the forks instead of outside? On the non-geared side I don't have much room to put the arm, but on the inside I could replace a spacer with it.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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On the inside one needs a spacer washer usually to prevent hub/cassette rub on the drop out, a torque arm is more then a spacer/washer in size so even on the inside needs a washer between it and the motor.
 
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slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
Update on this. I filed down the forks and used the torque bracket and it’s working great. Thanks for everyone’s help.

Another question. I have a 48v battery and want to connect lights to it. Anyone done this, any thoughts on how to do it?

thanks.
 

guerney

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Sep 7, 2021
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Another question. I have a 48v battery and want to connect lights to it. Anyone done this, any thoughts on how to do it?

thanks.
I got good advice from this forum about this. Where the battery normally connected to the controller, I cut off the bullet connectors, wove the strands together and then wove in strands of another pair of wires (T-shaped) for the headlights, and soldered it all together using acid-free flux, a 100W cheapo silverline soldering iron and leaded solder.... then covered those wires with self-amalgamating rubber tape. I then soldered a 5A miniblade inline fuse on the red wire, just in case. Then I soldered on a waterproof handlebar switch. Wherever possible, I also used self-adhesive 4:1 marine heat shrink. Covered the miniblade fuse with self-amalgamating rubber tape, for extra waterproofing. Below is a link to one of the 1800LM 12V-80V lights I installed. Works brilliantly, is brilliant. I'm considering adding another, if I can make room on my handlebars. Just one is plenty bright, but two would be 3600LM of visibility on the road - without the need for separate bike light batteries, and having to remember to charge them.

Not recommending any particular seller:





 
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slowbutsure1936

Pedelecer
Mar 28, 2022
43
4
I got good advice from this forum about this. Where the battery normally connected to the controller, I cut off the bullet connectors, wove the strands together and then wove in strands of another pair of wires (T-shaped) for the headlights, and soldered it all together using acid-free flux, a 100W cheapo silverline soldering iron and leaded solder.... then covered those wires with self-amalgamating rubber tape. I then soldered a 5A miniblade inline fuse on the red wire, just in case. Then I soldered on a waterproof handlebar switch. Wherever possible, I also used self-adhesive 4:1 marine heat shrink, and covered the miniblade fuse with self-amalgamating rubber tape. Here's one of the 12V-80V lights I installed. Works brilliantly, is brilliant. I'm considering adding another, if I can make room on my handlebars. Just one is plenty bright, but two would be 3600LM of visibility on the road - without the need for separate bike light batteries, and having to remember to charge them.

Not recommending any particular seller:





Excellent thanks. Sounds like a good plan.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,112
8,219
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West Sx RH
I use to use wired in lghts but for less wires I now simply use good usb lights.