Magic pie 3 Axle securing with a "Pitlock" or a "pinhead" Nut Set?

[MagicJacob]

I am looking to secure my Magic Pie wheel to the bicycle frame(regardless of a lock) and I have stumbled upon a few solutions. The thing is I don't know what kind of an Axle I got(Ii have to got a name or a standard)

Any ideas?
Thanks

[Bikemad]

Unfortunately it is not possible to use one of those devices with any of the available hubmotors.
It's only suitable for quick release wheels which have a hollow axle which the locking skewer can pass through completely.

Motorised hubs generally use a larger axle and larger nuts to help withstand the torque which they generate.
A quick release wheel does not transmit any torque through the axle whatsoever and all the skewer does is securely hold the axle in its correct place.

An alternative way of securing the axle would be to use locking wheel nuts:



Something like this would be much more secure:



But they're also a lot more expensive to buy. 

Thread size should be M14 x 1.5 but I would suggest you measure yours just to make sure.
Check this post for more details on checking the thread pitch.

I hope this helps.

Alan
 

[MagicJacob]

Thanks for the reply,
I have measured my axle with a Caliper and got a 14mm, don't know the thread type becuse don't have the tools for that right now(could guess it is 1.5mm).

By the way, I had measured another motor axle diameter and got 14mm.

Basically like you wrote: "Motorized hubs generally use a larger axle and larger nuts to help withstand the torque which they generate."

This sucks, No one makes a secure solution for that kind of an axle
all "pitlock" and "pinhead" got for solid axle is 10mm nuts.

Where do I get(online) that kind of nuts(as in the picture)?
 

[MagicJacob]

I think I have found the locking nuts in the picture(they are originally intended for a car wheel)
The name is "McGard  Wheel Locks"

Here are a few links for M14X1.5

http://www.jegs.com/i/McGard/671/24210/10002/-1?parentProductId=
http://www.amazon.com/McGard-24210-Chrome-Wheel-Thread/dp/B000COTX34

Its not "pitlock" but is should be Ok.

Also got a response from "pinhead", they will be making  14mm nuts(solid axle) next year.

[Sam.Vanratt]

Hi
I'd be very careful with applying such Locks as they are meant for car wheels and therefor are self centering in a countersunk. As you can see the surface for the Nut to the fork is very limited compared to the original.
No normal fork does have such a countersunk. Even with a washer all the force is resting on a very small surface. With a high torque motor like the MagicPie you would just multiply the stress on the dropout (which is already in a "will surely brake soon" deathloop when you use Aluminium).
Cheers
Sam

[MagicJacob]

You are right about the limited surface but you are wrong about the torque. It is applied directly to the axle(that is why it got 14mm diameter instead of the regular 10mm) and via the axle to the bicycle dropout(which should be reinforced with a torque arm(like in the picture).

the force that is applied to the surface of the nut is a Angular Momentum, it is the resistance the nut feels every time you try to affect the rotation of the wheel(when you lean to change the direction of the bicycle).

Angular Momentum is the reason you don't fall down form your bicycle.
the bigger the wheel and the faster you are going the harder it would be for you to change the direction of your bicycle by leaning.

Your argument would be valid only for very intense speeds(you wont be able to come close to that using a Magic Pie III 1000W hub motor).

In any case I will check it out more thoroughly.

[Sam.Vanratt]

HI MagicJacob
I'll agree partly. The konus is pressing the dropout further apart (in all directions). The torque of the Hub is pressing the dropouts apart, so nearly the same effect.
I used such theftlock systems on my older mountainbike and it was done with the cheaper cart parts as well. The Aluminium fork was after about one year on both sides deepend (countersunk) because the dropouts widened in time for about  a few mm afair.
You just have to see how normal hubs are mounted and countersunk mountings of wheels from scooters and cars.
Cheers
Sam

[MagicJacob]

The torque  of the Hub is pressing the dropouts by trying to turn the axle inside the dropouts. The torque applies no force to the sides of the axle.

I will add a drawing sometimes later.

[Sam.Vanratt]

Hi MagicJacob
you don't have to; I'llk add one. Even with a typ Torque arm enough load is put on the dropout (I already shredded three forks from RST CT-COM, Suntour Raidon RL and one noname 28" (all alu)), as the precision of the arms are not so high and even a 1/2mm is enough to dig into the dropout over time (but the arm helps to put an stop to that scenario), but the typ. 3mm steel is not enough over the time.
Because of that I let one build (Torque Arms are not allowed in Germany to use as it changes the basis of the fork so warranty and insurance is dropped).
As I ride about 150km+/d I have different needs and material as most people; that's why I choose the MP3
Cheers
Sam

[Sam.Vanratt]

Just to finish: Bikemad did already post it about the tapering (I called it countersunk) and as it has to be flatened. If you do I don't see a problem (apart from how to flaten it equally)