Magic Pie 5 Front Hub Motor ...Off Center Wheel

[donaldallen3797]

Has any one else had or heard of this problem ? Magic Pie 5 vector "black pie" Front hub motor ...mounted correctly ...I have been over this a bunch of times ..but ..the wheel/tire is offset ... the side of the motor/hub with the controller is and has to be wider than the other side due to the controller cage .. The rim/tire is directly above the hub/motor so it is offset ...to the right .. No way to "space" the motor ..it's made for this size dropout ...It's in the dropout all the way ... I just checked ...again ..today

I ride this bike almost every day . I'm partly handicapped and this is 1 way to get some exercise ..I cannot walk or stand for long but I can ride this thing for hours .. It has never let me down ...

I have tried a couple of forums and put a few "ticket's" in with Golden Motors ... No one has come up with a fix for this or a reason for why it is this way ... The only possible "fix" is to adjust the spokes to "dish" the wheel ... I'm not comfortable with this as I have ruined 1 Magic Pie messing with the spokes ..tried to have the motor/hub put on another size wheel ...ruined it ..spokes popping ..just wrecked it ..I'm not very sure this could be "Dished" this much ...

Thank You for reading this long book of a problem ..Any Ideas will be really appreciated ... Don

 

[mrgardiner]

Any chance it is set up for a disc break? I don't have a magic pie, but I have been looking at the front wheel kit for a long time. Likely a mechanical issue with the spokes/axel. I know this is not much help, and I hope you are able to post a solution soon.

Good luck!

 

[Mickatroid]

If the wheel has spokes then the issue may just be what a wheel builder calls 'dish.'

If you take the bike to a bicycle mechanic they can check this. It is normal for a wheel to move a bit.

I once bought a pair of wheels for a non-electric bicycle. The front wheel was so far out I could not get the rim brakes to work and that was from factory. You may have the same quality control problem. I got the bill from the bicycle mechanic and sent it to the supplier, along with photos. The supplier covered the cost

 

[donaldallen3797]

Just got another "Answer" from Golden Motors Canada ... They won't speak with you ..only thru e-mail ..and just keep giving me non sense answers .. They say the spokes need to be "adjusted" ...it's 3/8 inch ..can the wheel move that far from "dishing" ... I really don't understand why this was designed like this ...

 

[LewTwo]

Not unusual for GM wheels to 'need' adjustment.
I have also seen the GM wheels spoke holes drilled in an irregular pattern.

 

[SlowCo]

On the photo you posted it seems the left side of the axle is seated higher and better centered in the drop out then the right side. Even 1 mm of difference can cause the wheel to be tilted so much that it looks like that.

 

[donaldallen3797]

... First Video I ever made .. Hoping someone can explain this to me .. I really like the bike ..have been riding it most every day since late 2019 .. At first it was explained to me that this is just how it is Now Im getting "Something wrong with the Bike" ..It's an Electra Townie , very common ... Also told it's mounted "crooked" ... not in the forks all the way .. I have checked several times ..It's in correctly ..special Lawyer Lip Washers and all ... Thank You in advance for any Help/Advice you can give me ... https://www.youtube.com/watch?v=KrUQdr_yjUo

 

[donaldallen3797]

On the photo you posted it seems the left side of the axle is seated higher and better centered in the drop out then the right side. Even 1 mm of difference can cause the wheel to be tilted so much that it looks like that.

Thanks for the reply ... I have checked a few times ..the axle is in the dropout all the way ..The tire is vertical when pointing straight ahead ... The Motor/hub is designed with the controller in the left side ..."seems" because of that the motor/hub must be mounted off center ....The rim/tire is directly above the motor/hub so it's off center too ... There is no spacers the axle is slotted to fit a 130 mm dropout ... Here's a video that might help ... https://www.youtube.com/watch?v=KrUQdr_yjUo

 

[LewTwo]

Here's a video that might help ... https://www.youtube.com/watch?v=KrUQdr_yjUo

Not any help at all. Get the wheel off the floor. Spin the wheel.

 

[Chalo]

Go to a bike shop if you can't figure it out. This isn't a hard problem, but you're not getting it.

It's either wheel dish, which a bike shop can measure and correct if necessary; or it's unequal axle insertion to the dropouts. They probably can help you with that too.

My best guess is unequal insertion. That's why the tire looks more or less centered between the fork tips but not at all centered in the fork crown.

 

[amberwolf]

If I zoom way way in on your picture, and draw a line between what appears to be the top of the axles on each side, and another between what appears to be the top of the dropout plates on each side, there is a difference of about 10 pixels in height between the two sets of lines. (I actually think the top of the right plate is even higher than I drew the line to, making the offset even greater, but can't tell for sure).

This could just be an artifact of the angle of the picture, or the design of the plates being different on each side perhaps, or the lighting, etc.

But if it is not, it means the axle is not perfectly perpendicular to the fork, which will put the wheel at an angle as it appears to be in the picture (assuming that's not an optical illusion).

So my bet is, like others above, that the primary issue is that hte axle isn't perpendicular.

If it is really fully in each dropout, perhaps check the *shape* of each dropout relative to the axle shape--I expect that they don't match the axle shape fully, and also that one dropout plate lets the axle sit just a hair deeper in it than the other.

 

[donaldallen3797]

Hello ... Thanks so much for the replies ... I have went thru the "tilted" wheel theory a few times ... Golden Motors told me that too ... I asked if the axle is seated all the way ...do I grind one side to make it deeper or pull up on the other side ..to "center" the wheel .... They told me if it's in all the way then leave it ... I checked again ...4th? time .. Its in all the way ...and ...the way the axle is made it just fits the dropout ...It's a large threaded axle and machined to fit perfect in a 130 mm drop out ...no spacers ... I put a level on the motor and it's straight up and down when the wheel is pointed straight ... I have put 1000's of miles on this bike ..steers straight ..no crazy tire wear ... I don't think it's "tilted" but still I have no way to absolutely prove it

I was/am a happy clam riding this most every day ... I looked into the off center wheel when I first build the bike ... I got the Idea that it was just the way it's designed ...for the controller in the hub and maybe for disc brake use ... So now 3? years later I was just checking to see if they "fixed" it on the new ones ... But .. I'm now getting some people telling me there should be nothing wrong .. That either I installed it wrong ..or theirs something wrong with the bike .. I'm just trying to get to the bottom this ..If It can be fixed that would be great ...

Then there is the "dishing" theory .. This "might" fix it.. Needs to be dished 3/8 inch .. I have read where the spokes will hit the motor/hub before it moves that much .. still if it could be moved some that would be great ... My first Magic Pie ..was a MP3 20? years ago .. I wanted to move it to a different bike with a different size rim ...Bought the rim and spokes from Golden Motors had it laced ...and it was never right again ..loose broken spokes constantly .... So that's why I'm hesitant to dish the wheel ...It should have come between the dropouts to start with ..This is a very common bike ..

Thanks ..Sorry this is so long ..Hope it describes what I've tried already .. Don

 

[amberwolf]

.the way the axle is made it just fits the dropout .

If so, that would be an unusual dropout, or unusual axle.

Just an aside, for information you might not have: Most of these forks (all I've seen of this type) are made for a 10mm round axle, so the curve at the top is usually of just the right shape to fit that size circle. Most of these axles are 12mm, 14mm, or larger circles, with two opposing sides cut flat for a "double D" shape. This means that a motor axle does not go all the way into the dropouts, which is normal. Some people file the dropouts to accomodate this difference in circular shape, but this isn't always done perfectly evenly, and so a tiny difference in axle seating can occur, causing a tilted wheel.


Not being there, I can't tell exactly what you've got or see the fit, angles, etc., so can only go by the info you've provided. If you've already tested and measured all the suggested things, and none of them are the problem, then I have no idea what the cause is, or how it could possibly be fixed; I just don't know anything else that could cause it (unless the fork itself is bent up or manufactured incorrectly).


Just for curiosity, have you ever tried *not* seating the axle fully, but instead setting the wheel up so it is evenly placed between the fork legs and brake pads, and *then* tightening down the axle hardware, so that even though the axle is no longer seated fully, the wheel is straight?


Regarding dishing, while incorrect dishing is a very common problem with hubmotors (some are literally designed in a way that makes it impossible to lace into a rim and center that rim in the dropouts, without spacers on one axle shoulder)--that only causes a wheel to be offset evenly to the left or right.

But based on the pictures I have seen so far, your wheel appears to be tilted (so the outermost circumference (tire) is farther to one side than the center is), not offset. Dishing doesn't fix that, it just shifts the entire rim left or right.

 

[amberwolf]

. ..Bought the rim and spokes from Golden Motors had it laced ...and it was never right again ..loose broken spokes constantly ..

That happens primarily because the rims almost all of these companies use are not strong enough for the too-thick spokes they also use; they often simply can't be tensioned correctly to work as a spoked wheel without placing so much stress on the rim that it causes tiny, often "invisible" failures of the rim.

If they used the correct spoke gauge for the rims, then it would be possible for the spokes to be correctly tensioned wihtout breaking the rim (deformation and/or cracking at the nipple holes) which then loosens the spoke, which then shifts around and fatigues until it breaks, usually right at the J-bend in the spoke flange of the hub.

It may be counterintuitive, but thinner spokes make a stronger wheel; 14g or 14-15 double butted would be the best choice for most of the ebike hubmotor wheels out there.

Very few of those wheels have rims strong enough to handle the tension of thicker spokes...and they don't need rims that strong. Even my heavy duty cargo bikes and trikes (carrying hundreds of pounds, and themselves weighing hundreds, too), don't use rims and spokes that strong, they don't need them. Regular bicycle rims, and the right gauge spokes for those rims, are strong enough. (SB Cruiser uses a stronger rim and thicker (13/14 single butted) spokes on the rear wheels only because those are what I could get cheaply and easily for the small wheel diameter I required then. The next implementation will have much larger diameter wheels, and regular 14/15 double butted spokes...whenever I get the trike built).

I've had only one motor wheel with 12g spokes that survived medium-term use without rebuilding it, and I still had to adjust tension multiple times (and retrue the wheel); it used an ex-BionX wheel rim, don't recall who made it but it was apparently stronger than the usual stuff, strong enough to not just plain fail like most of them have.

 

[donaldallen3797]

Hello ..thanks for the replies ..and an Apology for not listening/believing you about the wheel being tilted ..after riding this for over 2 years and all along thinking it was "normal" and "off center" I took it apart and really looked ...and YES you were right it must have been tilted .. put it back together looking straight and within 100 yards it went tilted again the rim brakes rubbing clued me in .... I took it apart again and changed a few things ..ground out a little of the lawyer lips so I could get bigger washers in there than the suggested "horseshoe" ones ... I roughed up all contact areas with sandpaper to give a better grip ...been 2? months now ...wheel is centered and seems to be not moving ....Thanks Again for your Patience ..

 

[amberwolf]

FWIW, I recently had and fixed an issue with a front regular bike wheel, QR axle, not fully seating and clamping correctly, and tilting and even the QR coming loose and unlatching, because of a lawyer lip issue:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&p=1736168&hilit=lawyer+lip%2A#p1736168
So unfortunately it does happen....