Torque Arms using Wrenches

[silentguy]

Used some 3/4" and 19mm wrenches with hose clamps for torque arms.

The wrenches were cheap, $8 for 9 wrenches at Home Depot

The hose clamsp were a couple of dollars.

Advantage is I always have a wrench if needed.

I've tested it going over some bumps and at speed of about 25mph, and the wheel is solid,
I dont think it will be falling off again ....

I spray painted the wrench and hose clamp black to match the forks, as silver was just too shiny.

 

[BikeFanatic]

That looks good, stealthy ghetto torque arms, I may ty thaat with my front EBIKE kit, Do you use special washers or washers inside the axle somewhere?

 

[silentguy]

You should buy some hardened steel washers, and hardened steel nlylon locking nuts.

They are slightly yellowish in color.

The nuts are few dollars at a good hardware store, washers about 60 cents,
but much better than having to rebuild the wheel as I just did ....

There is a big difference to the soft washers and nuts that came with my WE kit.

 

[dnmun]

that is not a torque arm. it is just a 19mm wrench secured to the axle nut. it will do nothing to stop you from twisting off the axle. you need to use a proper torque arm. or even try to use the torque washer that came with your hubmotor if it doesn't have a torque arm. you can have muffler shop weld a short bit of an arm onto the tab to make a torque arm out of a torque washer, but a real torque arm is cheaper, fits tighter and is stronger steel, and easier to use in the long run and you can use your wrenches as wrenches. that doesn't do a thing to help.

 

[amberwolf]

It's a neat idea, but it has two problems.

One was just pointed out: The torque arm doesn't hold the *nut* in place, it holds the *axle* in place. All the wrench does is hold the nut, which could actually make it easier to unscrew from the motor, if the motor should start to turn in the dropouts, depending on the direction the axle is threaded for the nut on that side.

The second problem is that you've just supplied the tool to allow a thief to take your wheel off. Then all they need is a coin or similar to undo your hose clamp. Of course, if you run your locks thru the wheel, too, it's not as big a problem.

Unfortunately almost every bike I ever see "locked up" does not run a lock into the wheels, just around the main frame. Or else, they run it around *just* the wheel, leaving the rest of the bike easy to steal if the wheel is removed.

EDIT: If your axle was long enough, and had flatted sides all the way along it's length from the motor casing outward, you *could* put smaller wrenches on the *inside* of the fork, ones sized to hold the axle flats, and that *would* work. But it doesn't look like it's long enough; there's probably less than 1/2 the width of the wrench of axle left sticking out, and you'd need the whole width. I suppose you could grind down the wrench so it was thin enough, or get thinner wrenches...

Actually, I guess they could still go on the outside of the fork, under the nut, if you had to.

FWIW, the way you have it now would be great for helping to prevent axle creep on regular wheels, or disc brake wheels. Just not the hub motor axle, because of the way force is transferred to the bike frame from the wheel.

 

[silentguy]

Ok, Thanks for the clarifications.

I'll have to rethink this then.

Without getting into welding, I'll try to figure things out...

No torque washers came with my kit,
just a soft nut with a flange, and 2 even softer steel washers.

I assume as torque washer has a tab on it that fits somewhere on the fork ?
My fork doesnt have anywhere to fit the tab either.

 

[silentguy]

Ok, I may turn the wrench around, and try to put the open end on the axle instead of the nut.

That should prevent twisting of the axle.

I probably do need to get some thinner wrenches though.

 

[dnmun]

russell used one of the short torque arms from his 9 continents kit on his bike. he was able to attach it to the fender eyelet on his front fork, perfect angle on his bike for that.

try not to overtighten the nut to compensate because you can strip the threads on the axle because half the threads are missing where there are flats on the axle.

 

[silentguy]

How about a hose clamp tigheted to a the axle, and then through a wrench, and the other end of the wrench secured to the inside of the fork with another hose clamp.

Hose clamps are probably not strong enough though.

I guess I will have to fork out the $20 for the laser cut torque arms ....

I'd like to make them myself, to save time, but I dont have the tools ....

 

[317537]

Yer. Plastic ties work just as good as a hose clamp but you need to cut them if you wants to remove them. Can be easier on the paint. Use a few ties if ya worried. The black ties are much strronger than the soft white ties.
Looks good.

try not to overtighten the nut to compensate because you can strip the threads on the axle because half the threads are missing where there are flats on the axle.

Yea that happened to me but the thread was stripped on the nut, Lucky hey. The alloy frame I was using for the rear wheel was too thick and didnt allow enough axle to be threaded upon.

 

[silentguy]

I guess I should have installed it like the first pic in this thread.

With the open part of the wrench down and on the axle, not the nut.
Except I would put the hose clamp through the wrench hole, but maybe the clamp doesnt get as tight that way.

Also the top part of the wrench needs to be secured to the backside of the fork.


http://endless-sphere.com/forums/viewtopic.php?f=4&t=1664&start=60

 

[amberwolf]

I'd do the hose clamps exactly as you already have them; as long as they prevent the wrenches from moving then they'll work. You could add a second one at the axle end, perhaps.

 

[silentguy]

This is my interim solution.

Using a thin 10mm wrench on the axel and a tie wrap.

I probably should have the wrench arm secured to the other side of the fork,
but the axle position was not good for that.

 

[AussieJester]

Still looks to be on the nut not the axle? the axle is still able to spin is it not? Why cant you put the wrench on the inside of the fork on the axle and fasten it in the same manner you have in that pic? Whats actually stopping it? If its the angle of the flats on the axle perhaps use a smaller wrench and cut the opening to match the angle of the axle better ?

KiM

 

[silentguy]

The wrench is on the axle, not the nut. The axle can't spin.

THere's not much axle left, I probably could put the thin wrench on first, and then the nut, which would be more secure.

Yes, it's the angle of the flats, which has the wrench on the front side of the fork, not the rear side.

I am trying to do this without welding or having to cut metal.

 

[amberwolf]

Since you'll also have the nut on the outside of that wrench holding it down, you could still use a hose clamp at the base of it, down near where the fork flares for the dropout and the wrench starts to flare.

It would help secure the wrench.

Then you can also use a little "L" bracket (like those on cabinetry, but of the strongest steel you can find at the hardware store) that would bolt to the end of the wrench up top, and hose clamp the other part of it vertically to the fork, with two clamps to keep it from moving at an angle. If you can't find one with the exact length already, just get a longer one than is needed, and mount it on the fork, then drill thru the wrench handle hole into the bracket so that the holes line up, and bolt them together.

 

[AussieJester]

The wrench is on the axle, not the nut. The axle can't spin.

.

My apologies it's hard to tell by the picture

KiM

 

[silentguy]

Amberwolf,

Thanks for the pic, I'll try to find some angle iron, I should be able to rig that up.

 

[vanilla ice]

How thin is that wrench?

 

[silentguy]

Wrench is about 5mm thick or 1/8 "

Thinnest I could find. It barely fits on the axle, as the Nut takes up most of the space, and the axle is not that long.

 

[chet]

This is my interim solution.

Using a thin 10mm wrench on the axel and a tie wrap.

I probably should have the wrench arm secured to the other side of the fork,
but the axle position was not good for that.

It looks like the 10mm wrench is outside the axle nut. If this is the case, you need to figure a way to hold the wrench from twisting away from the axle. It will be ok as torque arm if there is an axle nut holding it in place.

 

[silentguy]

Yes, I dont think I can get the wrench on between the axle nut, as there is not enough clearance,
and the wrench hits the fork.

I will probably use a hose clamp near the dropout, so the wrench cant come off.

There's not enough axel left to put another nut on either.

 

[vanilla ice]

Are there spacers on the axle between the motor and fork?

 

[Doctorbass]

If you dont have state of the art and strongest torque arm and just hae normal torque arm ( arond 1/8 to 3/16 thick) I RECOMMAND TO ADD A WRENCH + HOSE 2 CLAMP PER WRENCH PER SIDE.

Never forget that dealing with multi kW power and dropout that are not designed to hold the torque applied by a flatened axel, REQUIRE STRONG RENFORCEMENT on the bike.

This have been discussed ALOT of times over many threads.

I repeat The lock nut IS NOT ENOUGH !!!

---ALMOST IF YOU HAVE THE REGEN ENABLED--

REGEN MAKE THE MOTOR AXEL TO FORCE I BOTH DIRECTION SO IT WILL LOOSEN THE NUT EVEN THOUGH YOU HAVE A LOCK NUT.

Never forget... YOU WILL BROKE YOUR DROP OUT AND SPIN THE AXEL JUST ONE TIME... BELIEVE ME THIS TIME WILL BE JUST ENOUGH FOR YOU. YOU WIL BE SO SCARY IF IT HAPPEN.. THAN YOUR NEXT IDEA WILL BE TO ASS TORQUE ARM.. SO WHY NOT ADING THEM NOW AND MAKING THST STRONG ENOUGH :wink:

I personally never had any problems with spun axel or broken dropout.

Even though I have 3 X5 motor used with between 5kW to 15kW peak each so I've never had any trouble
…REAL STRONG Torque arm IS A MUST.

YOU MUST UNDERSTAND THE FORCE applied on the edge of the flat of the axel when having like 150Nm torque on the hub and, the result is a force as high as 3 tons!!!

For each Nm of torque your motor have it’s 20kg of force applied on the edge of the axel flat

So to realize the importance, you can go on the ebikes.ca simulator and simulate the force of your setup.

http://www.ebikes.ca/simulator/

Ex: a typical 5304 on a 26" wheel, at 48V and 50A controller is 97Nm of torque from stall to acceleration.

97Nm x 20kg = close to 2tons already!

Now this is your job to evaluate correctly the kind of torque arm you need.

I recommand to have more rencorcement than less.


Formula idea
http://endless-sphere.com/forums/viewtopic.php?f=2&t=7503&p=114852&hilit=torque+arm+formula#p114852

Torque Arm For X5 Rear Motor
http://endless-sphere.com/forums/viewtopic.php?f=2&t=4087&start=120&hilit=torque+arm+wrench


My actual setup:

Doc

 

[silentguy]

NIce pics.

I am going to leave the wrenches on the nut too, as well as use the smaller wrenches on the axle for torque arms.

There are no spacers on my axle.
The nut is just very wide.