mp3 fit problem

[Garm@n]

I have a major problem with the fit of a rear mp3.  It looks like 1/4" to wide to fit into the rear wheel slot.  If I include the washers I would need at least a 1/2" more spacing.  any suggestions or should I ask Gary to swap out for a front MP III pending the fit.  Please let me know if anyone can help.
Edit
Noticed a design flaw.  There is no possible way to fit the valve into the hole.  The plate is partially covering the hole.  I'll send a message to Gary Salo

[MAGICPIE3FOCUSPOWER]

What is your bike dropouts width?

[GM Canada]

I have a major problem with the fit of a rear mp3.  It looks like 1/4" to wide to fit into the rear wheel slot.  If I include the washers I would need at least a 1/2" more spacing.  any suggestions or should I ask Gary to swap out for a front MP III pending the fit.  Please let me know if anyone can help.
Edit
Noticed a design flaw.  There is no possible way to fit the valve into the hole.  The plate is partially covering the hole.  I'll send a message to Gary Salo

Hello, I responded to your ticket on my website already.

Most bicycles have a 135 rear dropout width. what is yours? also I am wondering if you can provide picture of the valve problem here. I don't understand what plate You are talking about.

Gary

[Garm@n]

I am uncertain of the bike drop out width,  But I am tight by 1/2"  I am trying to stretch out the drop out on the frame, but I am finding that it snaps back once I release the bar separating the rear wheel mount.  I have actually have it opened up by 2/3" and will leave it over night, but I don't think I will find much success with this idea.  Now I am really screwed on this if I can't get it to work.  I just spend money on another scooter I found that was not legal, so it sits as a lesson.
The other problem that I fond after the incorrect drop out was the hole where the valve is inserted for the tube.  The hole is drilled on a angle because the mp3 motor covers the entire rim, but the manufacturer when placing the GM motor the the rim has partially covered the hole for the valve stem.  This looks like a design flaw.  I would like to drill it out, but there 2 question in my head that keep coming
1 will this void my warranty?
2 will this break the water tight seal?
If any experienced builders can provide me with the answer I would like to know.
This concept of building my own ebike is a nightmare.

[GM Canada]

We have discussed this in the ticket on my website. I'll paste part of my response in here.

Is the frame aluminum or steel?

Please test with a magnet. If its steel it should be no problem. If its aluminum then we have to look at how the frame is made.

Can you send a picture of the issue with the valve?

Likely you can drill a hole in the "plate" but without actually seeing it I hate to tell someone "sure drill it out". Also if the wheel is not going to work for you its probably better not to start drilling holes. I think we need to decide if its going to fit first.

The reason I say "if its aluminum we need to look at how the frame is made" is if spreading the dropouts is pulling open a weld it should not be done. I spread the frame on my aluminum Townie. The frame around the wheel is like a big horseshoe. It goes from the axle on one side up around the front of the wheel then curves back again to the axle on the other side. Opening this out a bit is not forcing open any welds. Some frames have this part welded together and forcing it open is directly pulling open the welds so it could be disasterous.

If you look at my chopper you can see the frame comes from the back axle and is welded on the the sides of the main frame. This to me is a bad candidate for spreading the dropouts as you would dirctly be pulling open the welds.



This is not the best picture of my townie but you can see the frame comes from the axle and wraps around the wheel going back to the other side. Opening the dropouts does not apply any pressure on the welds.



Also in this picture you can see another part of the frame coming up from the axle, wrapping around the wheel and back to the axle. another example of how opening the dropouts does not open any welds.



So it depends on your type of metal and if aluminum then the style of the frame. Can you provide any pictures?

Also your warranty is with me. Anything we decide to do together will not void your warranty.

Gary

[Garm@n]

So here are four pictures.  Frame is aluminum, based on sound when tapping and the large welds and it's very light bike.  As I said my only problem is the snap back when I release the screws from the axle of the original rear wheel.  It has been left in this position for the past 18 hours.
-------
The MP3 Wheel  if you look closely at the valve stem hole you can clearly see the problem

[Bikemad]

The 16" Magic Pie II also had an angled hole drilled for the valve, but the outer edge of the side cover appears to have been drilled through at the same time to allow the valve to fit past it:



After looking at your pictures of the frame being spread, I think you might have a problem trying to make the Pie's axle and inner washers fit inside that dropout. The dropout plates in your photo are no longer parallel, which could also cause the axle to bend slightly when tightened. If you look closely at the axle in the photo, it already already appears to be bending to try and match the new angle of the dropouts.



Your bike obviously uses a much narrower axle and dropout than most conventional bikes. In order for the frame to stay at the correct width it would have to be stretched well beyond its yield point to prevent it from simply springing back to the original width. Forcing an aluminium frame apart wide enough to accept the 135mm axle and washers would cause a lot of stress, and could result in the frame cracking over time.

If the dropout on the front forks is wide enough for the front Pie, then I would suggest that you consider fitting a front motor instead.

Alan
 

[Garm@n]

There is another option, trimming (hack saw) the sides of the axel by 1/4"  though I would need aproval from GM rep.  this would also include drilling out the valve stem hole

[ThunderhorseMaker]

Regarding the Valve hole on the 16 inch wheel.
I had a similar problem with my own 16 inch wheel in that the valve would not go through the hole. I solved it by simply drilling it through. Sanding the hole is also advised. Sharp edges are not good for valve stems!

[Garm@n]

Do you remember the size of the drill bit used? 

[ThunderhorseMaker]

Actually no.
I just kept grabbing random bits until they just fit through the first part of the hole. I drilled from the inside of the rim first (the part the tube lives in). That part of the hole was big enough already for me. It was the other end of the hole (that the external part of the valve would be) that was too small.

[GM Canada]

Wow, that fit s not good at all. I certainly understand your concerns.

There is another option, trimming (hack saw) the sides of the axel by 1/4"  though I would need aproval from GM rep.  this would also include drilling out the valve stem hole

That is actually a pretty good idea. If you fell confident enough to cut the sides of the axle back go ahead. Do your best to keep it straight, neat and tidy. Don't take off more then you need. This will not void your warranty with me except the axle will become your responsibility.

Gary

[Garm@n]

Well I was able to trim 1/4"  the axel.  The openeing on the washer had to be filed down,  It is still a very very tight fit,  frame still needs further widening as I will use thicker washer on the valve stem side.  The valve hits part of the v brakes, even after pushing the valve further back into the rim.  So my nightmare continues.  I am extremely surprised of the mp3 weight.  The rear end of my bike always drops once mounted and sitting upside down.  Now I need to solder connectors to my test battery and cross my fingers.

[GM Canada]

I think you should try taking more off the axle rather then stretching the frame. As Alan points out the frame stretched out will cause a bend in the axle creating a new set of problems. Plus when stretching the frame you are directly pulling on a weld and that could be a problem as well.

Gary

[Garm@n]

The problem with triming from the axel, I have less and less clearance with the valve and brake mount.  I already removed the cap from the valve and pushed the valve deeper into the rim.  So cutting from the axel would worsen my position.  BTW I was able to mount a test battery 36v/12a SLA,  It feels slow.  I'll test again with gps when the weather improves.  I'll get more accurate speed of what I'm pushing with a 16" mp3 wheel.  Would you or anyone happen to know what I should be achieving with current setup and what would I get with a 48V/10a LiFeP04 battery.  Thanks