Stainless Steel Torque Arms - $12.50ea

[JeffD]

After riding 725 miles without any torque arms (against the advice of many on the forum ) I figured it was time to get a torque arm or 2 for my rear hub.

Between my lack of metal fabrication skills/tools and limited budget, my options were limited. I read that mn_aerorider1 I bought a stainless steel torque arm for $12.50 from Doug at http://www.texaselectricbikes.com. (Note: The torque arm is not listed on their website - you'll need to call and order it.)

I order a pair and they arrived last night. Here is what they look like:





They come in 2 sizes 14mm with 10mm flats (for the larger 5300 series hubs) or 12mm with 10mm flats (for the 400 series).

Next step - the installation...

 

[michaelplogue]

Can the angle of the cutouts be custom ordered, or is it a 'one size fits all' deal?

 

[Drunkskunk]

Nice find! I think I'll be ordering me a set of these.

 

[JeffD]

Can the angle of the cutouts be custom ordered, or is it a 'one size fits all' deal?

Hi michaelplogue - I don't have the answer to this. My guess it is 'one-size fits all' as you said. I don't know if they make these 'in-house' or order them in bulk from China or somewhere. The 2 arms I got are exactly the same (same cutout angle etc).

I have read that the Crystalyte axels manufacturing is not exactly high-precision and the axel sizes have some variance. I noticed that (for my 408) they arms do not simply slip over the axel like a washer. I will need to do some careful filing to make them fit but hey I'd rather have a tight fit than have some slack.

 

[JeffD]

The fit was really close - took me all of 2 mins work with my rotary tool to make it fit perfect. Not a big deal at all.




As it turns out the cut out angle is pretty good for my bike.

So I'm thinking I will hose clamp the end onto the chain stay...unless anyone has any other better solutions to offer.

Side Note: the lock nuts I got from Tacoma Screw a few weeks back were still as tight as they were when I put them on.

 

[lawsonuw]

Can the angle of the cutouts be custom ordered, or is it a 'one size fits all' deal?

Since the torque arms look like they were cut with a CNC Laser or Plasma cutter I'd expect them to be available in any angle. Someone should ask though.

Marty

 

[recumbent]

Can the angle of the cutouts be custom ordered, or is it a 'one size fits all' deal?

Since the torque arms look like they were cut with a CNC Laser or Plasma cutter I'd expect them to be available in any angle. Someone should ask though.
Marty

Woo, Hoo, I will definately phone them tomorrow and find out, and order a pair.

Thanks "Jeffd", I've been trying to make a set using flatbar, and had trouble with those oblong holes.

 

[Drunkskunk]

So I'm thinking I will hose clamp the end onto the chain stay...unless anyone has any other better solutions to offer.

Well, I got a couple ideas. First being hitting up a bike shop for the thing they use to bolt the arm from a drum brake to. those go around the chainstay and have a single bolt that should fit that hole. Or use a piece of the strapping used to mount a car stereo. wrap it around the chainstay and stick a bolt through it.

The problem with hose clamps is they are designed to burst. they look like a piece of half inch wide stainless steel strapping, right? But they aren't. look where the groves are cut. the strap is only as strong as the metal on the sides of the grove. About 2 milimeters. Less than the striength of a single spoke.

 

[JeffD]

the thing they use to bolt the arm from a drum brake to...or...a piece of the strapping used to mount a car stereo

Hey Drunkskunk - those sound like much better ideas but I have no idea what either of them are. Anyone have pics, sketches, or further details so I can find me such things?

 

[fechter]

The torque arms are going to try to move toward the chainstay, not away from it (unless you are using regen braking). I'd suggest a "P" shaped metal strap like the ones used on a coaster brake. Alternately, if you could find something to fill the gap between the chainstay and the end of the arm, then use a hose clamp to hold it together.

 

[diver]

cant you use plumbers strap for the P clamp

 

[Drunkskunk]

here's what the drum brake arm and the "thing" they use to hold it with look like. I should have said coaster brake and P clamp.

 

[michaelplogue]

These guys have various sizes (just do a search on "P clamp")

http://www.fastenal.com/web/products/detail.ex?sku=0708779

 

[knoxie]

Hi

I thought everybody knew Doug was selling these? I have had em for a couple of years on my BMC? ermm? pretty sure I mentioned it many times? ok well yes they are good arms, the pictures of the ones posted dont look quite as tidy as my ones, look like they have been plasma cut badly? maybe Doug has changed suppliers.

You wont need 2 arms on a 408? 1 will be plenty plenty, I would use more than a P clip to hold it in place, as Fechter says the arm will want to move towards the chainstay, you need something solid inbetween the stay and the arm then a clamp to hold that in place.

Knoxie

 

[JeffD]

Hi I thought everybody knew Doug was selling these? I have had em for a couple of years on my BMC?

Everybody knows now. Maybe with the increase demand they may earn themselves a place on his website.

I dream of upgrading my power to something that would need 2 arms. Besides for $12.50 you can afford 2.

Knoxie - are you able to post a pic on how you secured your arm on your BMC?

 

[knoxie]

Hi Jeff

I used my old Currie frame mount, but you could just about knock up anything really, its the same mount that I used here on my home made X5 arm.

 

[pwbset]

Just ordered two of these torque arms... here's the background conversation:

Phone Lady - "Doug.. just got another order for these torque arms!"
Doug - "Jesus.. another one?!?"
Me - *chuckling* "Sounds like a hot item."
Phone Lady - "Yeah, we had an order for 50 of them come in today also."

Internet Powerâ„¢

:lol:

 

[JeffD]

There is a huge market for affordable rear hub torque arms. I'm glad they are there helping to fill the gap.

I ordered 2 just for good measure but 50!!!?? That seems like overkill to me. :wink:

 

[Iron Yeti]

Stupid question. What exactly do torque arms do. Ok, maybe that was a really stupid question, I am still curious.

 

[curious]

I've got one also but it does not fit properly on my bike. (actually everything I do last few months resists me big time ).
I found a solution for now using U-bolt from a hardware store but it bends the arm slightly and sure looks ugly ...

 

[docnjoj]

Looks OK to me! Maybe cut off the bolts a bit and cover ends with acorn nuts! Its much better than destroying your motor and maybe hurtting yourself too! Rear motors can spin in their forks as I have found too many times!
otherDoc

 

[rkosiorek]

if you want it to look better just take a hacksaw to the Ubolt and trim it so you don't have so many threads sticking out, dress the cut ends with a file so they look neat.

but it looks like a good sturdy mount.

do you have a lock washer under the nut?

with the wiring the way you have it with the slot in the axle pointing up - avoid riding in the wet. water will run down the cable and straight into the slot/motor. the wires should exit below the axle with a slight loop there so the water would tend to run down the cable and drip off of the lowest point of the loop harmlessly onto the ground. not as neat i agree but it could save some water and rust inside the motor can.

rick

 

[docnjoj]

Yeah1 What Rick said too! Its quite destructive to have Ur motor spin! Wet isnt so good ether! Runaway bike!
otherDoc

 

[curious]

I'll definitely trim the u-bolt threads once I get everything in place.
Waterproofing the setup is yet another matter, the hub wires are just part of the trouble. I may turn it around as suggested but my initial plan was to use silicone filler to seal the wire exit point completely.

 

[Kraeuterbutter]

Hello..

i see all this torque-arms, and they are realy long arms..

how neccessary is this ?

i have an Hub-motor which is rated
180Watt at 24V
250Watt at 36V (500Watt peak)
with an controller which is rated: 7A continouse and 14A peak

the motor is a geared front-hub-motor, used in a 26" wheel (Schalbe Big-Apple tires, so maybe 27" )
the bike is an old mountainbike with an steel fork


the ebay-seller gave me two torque-washers..
unfortunatly - also after grinding my fork (otherwise the motor-axel would have not slipped in completely) -
the torque-washer does not fit..

look:

i would have to grind another 4mm that it fits.. but than the fork would be weakend very much

so: i thought about something like this:

with the torque-washer i would have only about 11mm of an arm
with the torque-plate it would be ~22mm long arm

so only halfe the torque-amount...
will i be ok with that, or should i use - like you - a much bigger (not that nice looking) torque-arm ?!?
thx !