Magic Pie wobble

[JS]

What do you make of this?

http://www.youtube.com/watch?v=UYW26c68vcI

Brand new install, never driven yet (battery hasn't arrived yet). It looks like the right side bearing is crooked. Maybe bent axle? Or maybe the whole casing is machined wrong. Would be quite a disappointment to have wasted nearly $1000 for this build and have it wobble like hell.

On top of everything, when I went and got the wheel trued, they said the spoke arrangement is totally ridiculous and it would be more suitable for a horse cart wheel.

Oh the joys of buying cheap and getting cheap 

[DirtyGinge]

yup, just checked mine and no such problem.....maybe an offside bearing ??....wherebouts are you in the world ?

As for the spoke arrangement, I know that there is a big debate in the wheel world about radial spokes....the alignment as such apparently on a normal wheel doesnt allow enough give in the wheel, and that the radial design places too much strain on the hub, however when the pies were laced different there were problems with broken spokes etc....

Look at google images for similar products which put massive power through the wheel and you will see a simliar pattern as the pie, if not the same

Cystalite 5304
nine continent

etc ........

even a lot of the tour de fance bikes are laced radially ( straight)


Where did you purchase yorur kit from ?

[JS]

There's one positive side though: when I got the wheel trued, it also got rid of the wobble of the rim. So now it's an interesting combination of a wheel that spins quite straight, with a bouncy MP in the middle.
The other side seems fine. Problem is just at the gear side.

It came directly from Goldenmotors. Waiting for their reply to my email about this. Let's hope they'll be able to communicate this time.

[Bikemad]

It looks like the right side bearing is crooked. Maybe bent axle? Or maybe the whole casing is machined wrong. Would be quite a disappointment to have wasted nearly $1000 for this build and have it wobble like hell.

The wobbling freewheel unit would not be caused by a bent axle or a misaligned bearing, it can only be caused by a poorly aligned/machined side cover, but this should not have a noticeable effect upon the correct operation of the wheel, as long as the rim and tyre is running true.
It might be possible to improve the run-out by unscrewing the cover fixing bolts and refitting the cover in another position, but doing this could result in the rim being slightly out of true again.

On top of everything, when I went and got the wheel trued, they said the spoke arrangement is totally ridiculous and it would be more suitable for a horse cart wheel.

It's all too easy to ridicule something you don't fully understand, and from that comment, I'm guessing the guy who trued your wheel is not a qualified mechanical engineer, and also has no concept of the very real benefits that this so called "totally ridiculous" spoke arrangement brings to the Magic Pie.

The current Magic Pie's spoke pattern may appear to be a little unorthodox and unconventional, but it is certainly not "ridiculous".
I spent a great deal of time studying the original spoke pattern and devising the current spoke pattern, before posting my proposal, along with some detailed drawings for GM to consider.
Following testing and proving the suitability of my original design concept, GM have subsequently implemented the suggested spoke layout into all of their current spoked Magic Pies. Just because something may seem a bit different to what you'd normally expect to see, it does not mean that it should be labled as ridiculous!

Alan
 

[GM Canada]

What do you make of this?

http://www.youtube.com/watch?v=UYW26c68vcI

Brand new install, never driven yet (battery hasn't arrived yet). It looks like the right side bearing is crooked. Maybe bent axle? Or maybe the whole casing is machined wrong. Would be quite a disappointment to have wasted nearly $1000 for this build and have it wobble like hell.

On top of everything, when I went and got the wheel trued, they said the spoke arrangement is totally ridiculous and it would be more suitable for a horse cart wheel.

Oh the joys of buying cheap and getting cheap 

Wow! That doesn't look good. What country are you in and who did you buy it from?

Gary

[GM Canada]

It looks like the right side bearing is crooked. Maybe bent axle? Or maybe the whole casing is machined wrong. Would be quite a disappointment to have wasted nearly $1000 for this build and have it wobble like hell.

The wobbling freewheel unit would not be caused by a bent axle or a misaligned bearing, it can only be caused by a poorly aligned/machined side cover, but this should not have a noticeable effect upon the correct operation of the wheel, as long as the rim and tyre is running true.
It might be possible to improve the run-out by unscrewing the cover fixing bolts and refitting the cover in another position, but doing this could result in the rim being slightly out of true again.

On top of everything, when I went and got the wheel trued, they said the spoke arrangement is totally ridiculous and it would be more suitable for a horse cart wheel.

It's all too easy to ridicule something you don't fully understand, and from that comment, I'm guessing the guy who trued your wheel is not a qualified mechanical engineer, and also has no concept of the very real benefits that this so called "totally ridiculous" spoke arrangement brings to the Magic Pie.

The current Magic Pie's spoke pattern may appear to be a little unorthodox and unconventional, but it is certainly not "ridiculous".
I spent a great deal of time studying the original spoke pattern and devising the current spoke pattern, before posting my proposal, along with some detailed drawings for GM to consider.
Following testing and proving the suitability of my original design concept, GM have subsequently implemented the suggested spoke layout into all of their current spoked Magic Pies. Just because something may seem a bit different to what you'd normally expect to see, it does not mean that it should be labled as ridiculous!

Alan
 

I'm with you 100 percent on that Alan. I have sold alot of pies and since the new spoke pattern very few people contact me for spokes. I take that to mean there are alot fewer issues with spokes coming loose and being retightened improperly and then breaking.

Gary

[JS]

The wobbling freewheel unit would not be caused by a bent axle or a misaligned bearing, it can only be caused by a poorly aligned/machined side cover, but this should not have a noticeable effect upon the correct operation of the wheel, as long as the rim and tyre is running true.
It might be possible to improve the run-out by unscrewing the cover fixing bolts and refitting the cover in another position, but doing this could result in the rim being slightly out of true again.

Since I'm getting the silent treatment from GM China (why aren't I surprised?), I took off the freewheel cover and refitted it. Now most of the wobble moved to the (already trued) rim.
So, problem is with the crappy machining of the cover. Lots of sharp edges there from unfinished machining, extra metal shrapnel and paint, all causing the plate to misalign.
I guess it's time for some metalwork to make it fit better, since warranty issues with Chinese seem pretty much impossible.

[Magzy]

All GM will be concerned about is if they have to replace it or not coupled with the inane ability to (appear) to not give a flying whatsh!t with regards to your emotional wellbeing. (i.e. the opposite of great customer service)

That said, from your post below it would appear that the underlying issue is now fixed?

Can we see a picture of the shoddy machining metal spikes and paint?
Having seen the innards of a couple of MP's we'd be able to tell you the consensus...

..and yes, you get what you pay for.

Where abouts on the planet are you?

[JS]

Sorry, no pictures from the paint and metal since I already cleaned them away. But cleaning them didn't help, the problem still remains.
Looks like the threads of the freewheel unit have not been machined straight. Can't fix that with better fitting of the plate itself.

I really can't understand the customer service, since it only needs a few angry customers to scare lots of new ones away. For example if I had read this thread before buying, I probably wouldn't have bought from GM at all.

Well, they still have couple of weeks to answer. Then I can force a reaction from them by opening a Paypal dispute.

Unfortunately I'm NOT in Canada, so I can't deal with the great customer service there. Quite a contrast to their Chinese counterpart.

[gf3]

could the problem be a badly machined free wheel and not a badly machined pie? may be with trying a different free wheel just in case.

[GM Canada]

could the problem be a badly machined free wheel and not a badly machined pie? may be with trying a different free wheel just in case.

Thats an intersting point. What does it look like with the freewheel off. does it still act the same?

Gary

[JS]

A Shimano freewheel not machined straight? No, I can see the inbalance in the hub itself.

Once again I removed the freewheel side cover, scraped all the paint out of there, cleaned with xylene, bit of sandpapering and filing and now it's slightly better.

When the cover bolts are off, I can spin the cover around a bit, but it gets stuck at one point. So it IS crooked. But that's not something I'm willing to pay to have machined straight. And even that wouldn't help if the freewheel threading itself is not straight.

I'll just have to wait for the battery pack and see how it feels on the road.

[ffranck]

Hello,

I must have got a Magic Pie from the same batch because I have exactly the same problem.
I received it last week directly from GM. I just tested it on a small 24V batt and it works ok but from 15km/h the wobbling is quite obvious when riding the bicycle. Any solution to make it better would be welcome!

cheers

[Bikemad]

it works ok but from 15km/h the wobbling is quite obvious when riding the bicycle. Any solution to make it better would be welcome!

As long as the wheel and tyre are trued correctly, any slight offset/wobble in the hub will not be noticed.

When my original Pie arrived is was out of true and not even concentric with the axle.  I trued the rim perfectly and then fitted my tyre, which was unfortunately very slightly out of true, but I am not able to notice it while riding.

Alan
 

[ffranck]

As long as the wheel and tyre are trued correctly, any slight offset/wobble in the hub will not be noticed.

That makes sense, I probably have some other problems with the centering of the motor. I searched quickly but I did not find too much info on how to adjust the motor and wheel, is there a topic or a tutorial somewhere?

Franck