Torque arms help

[Audisport09]

Hello I'm trying to increase my torque arms from from 10mm wide to 12mm axle flats. What would be the best method. I've got a drill and angle grinder. This is the original drawing, I didn't create it, found it on here. How hard would it be to change? or would you have to start over.

 

[e-beach]

When you say you are trying to increase the width of your torque arms, do you mean increase the width of your existing bicycle dropouts?

What material is you torque arms? Steel?

It would be eaisier if you showed us photographs of what you have.

I tend to use my Dremel tool and hand files when I expand the dropouts on my frames.

 

[RTLSHIP]

By grinding down (unknown quality metal) the inner flats, you will create space for the 12 mm. But you are likely going to have a weaker torque arm. Pony up and buy a 12mm flat torque arm. This seems like the safe and easy way. Online you can get one for maybe $20 or 25 and have it by March 1 or 2. Oddly, I bought a 10 mm torque arm on ebay last year and it apparently came from Ukraine I recall. It was about $15 free shipping and I waited 6 weeks. It is a cheaper quality steel mixture but works fine.

 

[Audisport09]

When you say you are trying to increase the width of your torque arms, do you mean increase the width of your existing bicycle dropouts?

What material is you torque arms? Steel?

It would be eaisier if you showed us photographs of what you have.

I tend to use my Dremel tool and hand files when I expand the dropouts on my frames.

Hello, I want to change from QS205 = 10mm to QS273 = 12mm flats


I guess what I was wondering was how hard would it be to change the drawing so that I can get it cut. I don't know how to do CAD work.

 

[Audisport09]

By grinding down (unknown quality metal) the inner flats, you will create space for the 12 mm. But you are likely going to have a weaker torque arm. Pony up and buy a 12mm flat torque arm. This seems like the safe and easy way. Online you can get one for maybe $20 or 25 and have it by March 1 or 2. Oddly, I bought a 10 mm torque arm on ebay last year and it apparently came from Ukraine I recall. It was about $15 free shipping and I waited 6 weeks. It is a cheaper quality steel mixture but works fine.

Ideally I want the same shape torque arm but bigger. Any one know anything about cad?

 

[E-HP]

Hello, I want to change from QS205 = 10mm to QS273 = 12mm flats
f9aa45d1d14dd07c29c1ffe2228e0fd9.jpg

I guess what I was wondering was how hard would it be to change the drawing so that I can get it cut. I don't know how to do CAD work.

In the pic, the "torque arms" actually appear to be functioning as dropouts, since the dropouts appear to have been sheared off of the frame. Is this also the case for your bike, or are they purely being used as torque arms? (if so, you'll need more fasteners to bolt them to the frame).

 

[Audisport09]

Hello, I want to change from QS205 = 10mm to QS273 = 12mm flats
f9aa45d1d14dd07c29c1ffe2228e0fd9.jpg

I guess what I was wondering was how hard would it be to change the drawing so that I can get it cut. I don't know how to do CAD work.

In the pic, the "torque arms" actually appear to be functioning as dropouts, since the dropouts appear to have been sheared off of the frame. Is this also the case for your bike, or are they purely being used as torque arms? (if so, you'll need more fasteners to bolt them to the frame).

No that is not the case for my bike. My dropouts are intact. Is it a case of 10 to a 12? Or does the length 17 also needs to change

 

[e-beach]

The specs I have looked at say 16mm x 12mm. I believe that to mean a 16mm axle radius that has been reduced to 12mm on the flats. Since the system you want to use will have lots of torque, your dropouts need to fit pretty much dead on. Sloppy cutting on it will only let the axle rock back and forth causing things like nut loosening.

If you don't have the motor, wait until you get it to double check the radius and then use files to carefully and patiently file to the proper size.

 

[E-HP]

The specs I have looked at say 16mm x 12mm. I believe that to mean a 16mm axle radius that has been reduced to 12mm on the flats.

In addition to filing the dropouts to accommodate the wider flats, this also introduces a decision on whether to retain the same axle centerline as the TA in the diagram, which would require filing the dropout 1mm deeper than with the 14mm axle. The TA axle hole is already wide enough for the 16mm axle, so only needs touching up with a flat file to widen it to 12mm.

In a nutshell, file the dropouts to be 2mm wider (1mm on each side), from 10mm to 12mm, and 1mm deeper, assuming the current depth accommodates a 14mm axle; then file the TA to be 2mm wider, 1mm from each side.

 

[RTLSHIP]

that fork drop out appears to be aluminum. It looks cracked off. Steel doesn't crack or break off like that. I recommend better forks first and foremost. If those forks are indeed aluminum, then you are going against the rules whether written or unwritten. And the alum.fork body can crack in half despite a steel torque arm.

 

[Chalo]

I want to change from QS205 = 10mm to QS273 = 12mm flats
f9aa45d1d14dd07c29c1ffe2228e0fd9.jpg

It looks like you already used a hub motor to break your frame, and now you want a heavier more powerful motor. If that's true, the best advice is don't do it.

 

[Audisport09]

Sorry just to clarify, non of the pictures in this thread are mine. I just copied the torque arm design. Thanks for the help guys. Trying to hunt down an appropriate size file. They never state the width, just length.

 

[Chalo]

Sorry just to clarify, non of the pictures in this thread are mine. I just copied the torque arm design. Thanks for the help guys. Trying to hunt down an appropriate size file. They never state the width, just length.

If this is the motor you're discussing, the axle is 14mm thread with 10mm flats.

 

[LewTwo]

Ideally I want the same shape torque arm but bigger. Any one know anything about cad?

Yes. That is a bloody awful drawing. Color choices alone should get someone horsewhipped.
Here is what I think it is supposed to be. I had to guess at the inside radius's of the cutouts.

From what I can guess, you have two control points shown in yellow.
The dimensions for those are in red.
The orange dimensions are reference and should not be used in actual fabrication.

The specs I have looked at say 16mm x 12mm.
If you don't have the motor, wait ...

The specs I looked at said 10mm said across the flats.
I think waiting to get the motor and checking the axle dimensions is an excellent idea. :thumb:

The attached Zip file has a 2D DWG Cad file and and a 1:1 vector PDF file.

 

[Audisport09]

Sorry just to clarify, non of the pictures in this thread are mine. I just copied the torque arm design. Thanks for the help guys. Trying to hunt down an appropriate size file. They never state the width, just length.

If this is the motor you're discussing, the axle is 14mm thread with 10mm flats.

Hello, I don’t think the specs on that site can be trusted. It is saying that Magnet Height is 50mm which is QS205. 10mm/14mm is also QS205 which is what I have right now.

 

[Audisport09]

Ideally I want the same shape torque arm but bigger. Any one know anything about cad?

Yes. That is a bloody awful drawing. Color choices alone should get someone horsewhipped.
Here is what I think it is supposed to be. I had to guess at the inside radius's of the cutouts.
Dropout 10mm.jpg
From what I can guess, you have two control points shown in yellow.
The dimensions for those are in red.
The orange dimensions are reference and should not be used in actual fabrication.

The specs I have looked at say 16mm x 12mm.
If you don't have the motor, wait ...

The specs I looked at said 10mm said across the flats.
I think waiting to get the motor and checking the axle dimensions is an excellent idea. :thumb:

The attached Zip file has a 2D DWG Cad file and and a 1:1 vector PDF file.

Oh wow that is amazing. Doesn’t CAD need a checkered background of some sort? Can you edit it for QS273 40h and I will pay you for your troubles. I have a copy made already and have been using them for 2 years. Not the best fit but functional.



I also had 2 (M8s) holes added. Are you able to add to your drawing? I’m I’ve read on here that axle flat is 12mm and length 14mm. Yes I guess I can wait until the motor arrives. But they are taking their sweet time.

 

[LewTwo]

Doesn’t CAD need a checkered background of some sort?

NO ... just accurate measurements.

Can you edit it for QS273 40h and I will pay you for your troubles.

Yes I can and no you can not.
I do CAD drawings because I enjoy it.

I also had 2 (M8s) holes added. Are you able to add to your drawing?

Yes, but I have to guess at the locations. Does this look about right?

I guess I can wait until the motor arrives.

That would be wise. Making a hole smaller is a lot more difficult than making it larger.
Getting it right the first time is better yet.

 

[E-HP]

What's the purpose of all of that additional material above the 90 degree section in the photo above. Does it align with something on the frame to provide additional support? It didn't look like it in the example photo. If id doesn't, and you're making changes anyway, maybe some of it can be trimmed down.

This version of the motor states 12mm axle flats, but also requires motorcycle disc brakes, but I've seen the 16mm axle in a few listings for the 8kW version of the motor.
http://www.cnqsmotor.com/en/article_read/QS%20273%208kW%20E-Motorcycle%20Spoke%20Hub%20Motor%20Conversion%20kits%20with%2072V110KPH%20top%20speed/842.html

 

[Audisport09]

Doesn’t CAD need a checkered background of some sort?

NO ... just accurate measurements.

Can you edit it for QS273 40h and I will pay you for your troubles.

Yes I can and no you can not.
I do CAD drawings because I enjoy it.

I also had 2 (M8s) holes added. Are you able to add to your drawing?

Yes, but I have to guess at the locations. Does this look about right?
Capture.jpg

I guess I can wait until the motor arrives.

That would be wise. Making a hole smaller is a lot more difficult than making it larger.
Getting it right the first time is better yet.

Thank you so much for the help, much appreciated. That looks good, as long as they in that general area, I could always make some adjustments. Ok, I will wait but I’m 99% percent sure based on research I’ve done on here. Do these pictures help?

 

[Comrade]

...

A flatbed scanner would be much better for what you are trying to relay. Photo lenses have significant distortion.

 

[Audisport09]

...

A flatbed scanner would be much better for what you are trying to relay. Photo lenses have significant distortion.

Really? Like so?

 

[LewTwo]

What's the purpose of all of that additional material above the 90 degree section in the photo above. Does it align with something on the frame to provide additional support? It didn't look like it in the example photo. If id doesn't, and you're making changes anyway, maybe some of it can be trimmed down.

Rounding that inside corner would also alleviate the stress riser.

 

[Audisport09]

What's the purpose of all of that additional material above the 90 degree section in the photo above. Does it align with something on the frame to provide additional support? It didn't look like it in the example photo. If id doesn't, and you're making changes anyway, maybe some of it can be trimmed down.

This version of the motor states 12mm axle flats, but also requires motorcycle disc brakes, but I've seen the 16mm axle in a few listings for the 8kW version of the motor.
http://www.cnqsmotor.com/en/article_read/QS%20273%208kW%20E-Motorcycle%20Spoke%20Hub%20Motor%20Conversion%20kits%20with%2072V110KPH%20top%20speed/842.html

That motor is defiantly for a motorbike. I’m looking to get a QS273 40h with disc and freewheel attachments.

 

[Audisport09]

What's the purpose of all of that additional material above the 90 degree section in the photo above. Does it align with something on the frame to provide additional support? It didn't look like it in the example photo. If id doesn't, and you're making changes anyway, maybe some of it can be trimmed down.

Rounding that inside corner would also alleviate the stress riser.

Not sure what a stress riser is, but I technically don’t need this part I guess, but I’m not fused.

 

[E-HP]

...

A flatbed scanner would be much better for what you are trying to relay. Photo lenses have significant distortion.

Really? Like so?
EPSON002.JPG
EPSON003.JPG

I believe the important measurements for fabricating the modified TA would be what is analogous to the 90 mm measurement in the diagram, but for the center of each of the other two mounting/anchoring holes. None of the photos or sketches captures those measurements very well.