torque arm picture thread

[Arlo1]

I belive in a pinch bolt for hi power apps with regen!

Love your pinch bolt idea of welding the nut onto the frame, I take it the weld holds up just fine?

Also those holes in your motor, I might do the same to my HS3540 not for cooling but for the UK rainy weather in the winter...and the summer grrrr

I live on vancouver island in a rain forest! I ride in the rain all the time the heat in you motor keeps it dry inside! Yeh I get some pretty good torque on the pinch bolts and if you can't weld a nut then just get a peice of steal with a hole in it to weld to the frame.

[dogman]

I would think water in the motor would be pretty harmless compared to the dry sugar sand I have rooster tailing from my rear tire.

I see your point John, about the two bolt setup I use. That's why I have the second nut on there, locknuting both bolts. Coming up on a year's use now, and never had it work loose. I torque it pretty good, using grade 8 bolts that can take it, then romp down the locknut. My idea is only going to work well with a bike like the mongoose, that has a huge flat steel plate for a dropout.

[Arlo1]

My idea is only going to work well with a bike like the mongoose, that has a huge flat steel plate for a dropout.

Thats why I welded 1/4 inch steal to the drop outs!

[John in CR]

My idea is only going to work well with a bike like the mongoose, that has a huge flat steel plate for a dropout.

Thats why I welded 1/4 inch steal to the drop outs!

+1 on the 1/4 plate for dropouts. That's all I use and then since I like at least double that at the axle, I use much smaller pieces to thicken at the dropouts.

[TonyReynolds]

Thanks!

[auraslip]

Ok I've re-thought this torque arm situation. I want it to be simple. Meaning I can do it with hardware store parts. It also needs to be relatively easy to remove for tire changes (not that it's really an issue with the right precautions)

The main problem for me was derailleur clearance. It dawned on my that if I could spin the axle 90" then it wouldn't be an issue, so I filed my drop outs so that the flats of the axle would be horizontal. And now I have lots of room!



This is about as good as I can come up with. I haven't worked out the actual hardware, but I'm thinking 1/8" width by 1" wide L bracket for the top, and 1/4" steel plating on the bottom. Since they'll be pressed right against the original drop outs and the chain stay protrudes out a bit, the L bracket will have to have the bottom leg removed and both torque arms will have to be trimmed to clear the chain stays.

It will be secured to the drop out with bolts and to the chainstay with a U-bolts. I'll apply the pinch bolts first, and then the U-bolt, and then FINALLY drill into the dropouts. This way the chainstay will see most of the torque, rather than the weaker aluminum drop outs.

John says the big problem with this design is the complete reliance on bolts to produce the pinching force, and I agree. However, it would be easy to modify this quick drawing by using a larger L bracket to incorporate 4 bolts rather than just 2. This would spread the clamping force out along the axle. The devil is in the details, so if any of you have any suggestions I'd love to hear them. I believe this design is solid because it's based on KISS principles. It should work for most bikes, is simple to remove, and is easy to do correctly; All you need to make it is the hardware, a hack saw, and a drill. A tap would be superior than just using nuts, but is not totally necessary.

[John in CR]

I wouldn't call bolts a big problem at all. I just know how I am about preventive maintenance and pre-flight safety checklists, so reliance on bolts is a bad idea for my own bikes.

[Kingfish]

Still working for me after 3-1/2 months
~KF

New and improved!

I thought that I would update this information. The ghetto front torque arm was replaced after 7 flawless months in July with my custom designed and professionally machined assembly. Mounted as a pair, they survived 2500 miles On the Road to California and back without any issues. The 2WD eBike had regen on the front hub only. I was grateful that this was one of the least problematic items on my trip and remained tight the whole time

Chief features are:

• new EBike-Kit hub motor with disc brake option
• enabled the disc brake, and
• designed a 2-link and clamp assembly.

The keyed torque arm is crafted from 1/4" thick stainless steel, whereas the link and clamp are from aluminum. Stainless steel fasteners were used to attach the pieces, and Blue Loctite was used all threads - including the M14 nut.

Cheers, KF

[auraslip]

Nice KF - I'd like to know more about that. Where you got it made, etc etc.

I have that same fork BTW. Right down to the gold speckled "fishing lure" paint job.

Do you have anymore pics of your bike ? I wanna see a cross country riding 2 wheel driving bike!

[Kingfish]

Nice KF - I'd like to know more about that. Where you got it made, etc etc.

I have that same fork BTW. Right down to the gold speckled "fishing lure" paint job.

Do you have anymore pics of your bike ? I wanna see a cross country riding 2 wheel driving bike!

"fishing lure" paint job: hehe - yeah it reminds me of that too

The trip is in my sig The last 3 pages of the thread provide a good concise brief of each day and there are plenty of pics in the backfilled stories. Page 27 has several pics as well.

The design is mine; I used AutoCAD to draw it up, and I had it made locally. There are essentially four parts: linkage (arm and link) and clamp (2 halves). It's a pretty straight up design that works around the disc brake mounting. My machinist prefers anonymity. It has crossed my mind to do a production run. The big question is matching the diameter of the fork.

If there is enough interest and commitment I can make these available to ES folks.
Best, KF

[Diamondback]

id be interested in a pair of these if you do decide to make a production run.

Jason.

[Kingfish]

id be interested in a pair of these if you do decide to make a production run.

Jason.

Cool! I need to collect a bit of data to ensure a proper fit. Here’s what I would like to see:

• Take a close-up pic of the fork where the axle passes through – with the M14 nut removed, and/or provide the year make and model of the fork.
• Also it would be helpful to measure the fork diameter where the clamp will go: Take the measurement from the axle equal to the radius of the hub motor – just above where the disc brake mounts as displayed in the image of mine. Suspension Forks are often egg-shaped or oval instead of perfectly round, therefore we need to take this diameter measurement in two directions: Front to back, and from the inside to outside. I use digital micrometers and the preferred units are in millimeters, although I can convert inches to mm easy enough. Make sense?

If we get enough people to commit and if the fork diameters are close enough then a production run is feasible at a reasonable cost.
Best, KF

[Diamondback]

sounds good.

ill have to get some measurements made.

gives me the excuse to go buy a set of digital verniers.
been wanting a set for a few years, now i have a good reason to go buy a set

Jason.

[jhinshel]

Hi,
I am after a cad (or similar file) for a torque arm. I appreciate that I would have to adapt this, but this would serve as a good starting point for me.
I would be grateful if someone could make one of these available.
justin

[John in CR]

Hi,
I am after a cad (or similar file) for a torque arm. I appreciate that I would have to adapt this, but this would serve as a good starting point for me.
I would be grateful if someone could make one of these available.
justin

Justin,
They're so easy, how about you try to come up with an even better design? An ideal torque arm that will fit any bike has been elusive. Ideal includes simple, as little steel as practical (for those who erroneously think ounces matter on even such a critical part of an ebike), but with a broad surface that clamps firmly to the axle.

[Quajochem]

I have 2 good thicker torque arms now! and they are VERY well secured!! Because this happened to my first arm in my first 200m with my mac:


I grinded the axle to an exact fit on one side now:


I also tried to dissipate the forces evenly on the fork as to stress it as less as possible.
On one side I made use of the eh 'thing/brackets' that normally hold the diskbrake caliper.
I also looked at the direction they want to turn in when you hit the throttle.







O in fact there are 3 torque arms on it.

[Timma2500]

I got some ideas from this thread for my torque arms so i thought i'd contribute what i learnt.

10mm thick mild steel made using a grinder, drill, file and M6 tap:

001.JPG (187.58 KiB) Viewed 1144 times

005.JPG (186.43 KiB) Viewed 1144 times

017.JPG (195.04 KiB) Viewed 1144 times

020.JPG (229.01 KiB) Viewed 1144 times

Paul

[neptronix]

These plates tolerated 6kW-8kW of very torquey power for a good amount of time, and pretty strong regen as well ( 700-1250w ).

In the end when i dismantled the magic pie bike and sold it's componentry, after almost 2 years of abuse, i still had to bang on the axle to get the motor out of it's dropouts. I looked at the torque plates and they were still perfect. I couldn't believe it.

I've been preaching this method of making torque plates for mid-high power setups for a long time now. They might not have stood up to a Crystalyte 54xx or cromotor hubzilla, but they were pretty effing strong.

Always overbuild your torque mounting bits. You'll pat yourself on the back later rather than kicking yourself in the ass as you gradually pump more & more power into your motor

[Farfle]

here is the axle/dropout setup from the dual pie. Better than clamping dropouts. good for 3.5kw of regen, and 22kw of output power.

[spinningmagnets]

Cross-posting these two threads so a search will turn up both:

"Found an awesome torque arm" (3 pages)
http://endless-sphere.com/forums/viewtopic.php?f=1&t=11570

Some pics of what happens when you don't use a torque-arm, and the wires in the hub are ripped out at the root..

[RC Extreme Power]

My solution after mistake of not using them.

Sorry I do not know how to post pictures direct into post.

Milton

[John in CR]

Paul,
I'm sorry I missed this one back when you posted it. That's pure artistry with a grinder and a file resulting in a perfect torque arm in both looks and function.
John

I got some ideas from this thread for my torque arms so i thought i'd contribute what i learnt.

10mm thick mild steel made using a grinder, drill, file and M6 tap:

017.JPG

Paul

[GMUseless]

Paul,
I'm sorry I missed this one back when you posted it. That's pure artistry with a grinder and a file resulting in a perfect torque arm in both looks and function.
John

I got some ideas from this thread for my torque arms so i thought i'd contribute what i learnt.

10mm thick mild steel made using a grinder, drill, file and M6 tap:

017.JPG

Paul

Indeed! I hand filed and grinded the arms for my Kona Supreme, mine look terrible, and it was an assload of work. Yours look CNC'd...to have been done by hand is mind blowing.

[spinningmagnets]

http://endless-sphere.com/forums/viewtopic.php?f=6&t=43721

[auraslip]

Sorry for the crappy picture.

Torque arms were from DOC. Decided they had too much play to be useful.
Chopped them up and tapped them out to make them clamping.
Then Glued to the frame.
Then decided they should be drilled in.
Hard metal. Got really hot drilling it. My bad. This made the glue pop one off.

Oh well. They work fine for 6kw.
Will they work for 10kw?
Loving how easy it is to remove the motor though!