GM Frog Battery 36v10Ah doesn't fit on the seatpost

[maciel]

Hi guys,

I'm a newcomer here. I've building an e-Bike but since I finished the gross part I have had to stop at this.

Simply, the Golden Motor Frog Battery won't fit on my saddle tube. My tube is 26,9mm width. The battery needs something like 34,8 ~ 35,2mm to fit.

What makes me sad and angry is that the GM Website has never said the width of the saddle tube needs to fit it correctly. They don't show any size of the batteries of the hole inside the holder.

Anyone can see any solution for me in this issue?

This picture illustrates what I said.

 

[liveforphysics]

Yes. Find a piece of pipe that can act as a bushing.

 

[Hillhater]

Is that really the biggest problem you have had to deal with ?

 

[nicobie]

I sure hope that that little bit of plastic around the seat post isn't the only thing holding the battery up.

 

[Rassy]

Welcome to the forum Maciel,

Like LFP said, make a bushing. Use a short piece of plastic water pipe or electrical conduit. Cut a slot in it lengthwise so it can be compressed.

Also, you want to separate those 3 keys now. If you take a little ride like that and the key falls out you will have lost all of them.

Good luck with your e-bike.

 

[spinningmagnets]

If you have a precision measuring caliper, this will be a very easy fix the first try. You measure the Outside Diameter (OD) of the the post, the Inside Diameter (ID) of the pack clamp, then divide the result in half to determine the wall-thickness of the adapter bushing.

I have made many split-bushings out of brass-pipe and soft-steel electrical conduit (both cheap). The OD of the bushing isn't very important, it only needs to be reasonably close, since you can compress or spread the bushing to fit. Spreading is easier since you can pound it down over the post. If the difference in iD/OD is small, you can buy an adapter bushing from problemsolvers.com

http://problemsolversbike.com/products/category/shimsandspacers

 

[maciel]

If you have a precision measuring caliper, this will be a very easy fix the first try. You measure the Outside Diameter (OD) of the the post, the Inside Diameter (ID) of the pack clamp, then divide the result in half to determine the wall-thickness of the adapter bushing.

I have made many split-bushings out of brass-pipe and soft-steel electrical conduit (both cheap). The OD of the bushing isn't very important, it only needs to be reasonably close, since you can compress or spread the bushing to fit. Spreading is easier since you can pound it down over the post. If the difference in iD/OD is small, you can buy an adapter bushing from problemsolvers.com

http://problemsolversbike.com/products/category/shimsandspacers

I appreciate your reply.

I think this bushing won't be enough, since I have a 27,2 mm diameter of the seatpost and 35mm to fit the holder, I need about 8mm of diameter or 4mm of wall-thickness for the bushing, so none of the shims and spacers of this website and other major sites that I've seen will fit the size that I need (The shim that you have posted has only 1,585 mm of thickness [1" ID, 1"1/8 OD])

Could you reply here with some pictures of the bushings that you have made? It's being very difficult to find an aluminum tube or any other metal to match the sizes. I've been thinking to do it with a PVC tube, but i don't know what kind of glue or something else I'd need to stick together on the seatpost.

 

[vanilla ice]

What kind of clamp does that kit use? Can you take some more photos?

 

[maciel]

I've found these two spacers

http://www.chainreactioncycles.com/Models.aspx?ModelID=6258
Brand-X CNC Alloy
27.2 - 31.6

and

http://www.chainreactioncycles.com/Models.aspx?ModelID=43709
USE Aluminium Shim
31.6 - 34.9

What do you guys think?
They will get firm and stable or I'll have to solder both pieces on the seatpost?

 

[Hillhater]

What do you guys think?

this spring to mind ???..

 

[spinningmagnets]

Could you reply here with some pictures of the bushings that you have made?

Here's a pic of the shims I made to fit a 1.0" (25.4mm) diameter BMX handlebar onto a 31.8mm MTB stem (6.4mm difference, 3.2mm wall thickness). I don't know what that is in inches, but I measured it with a caliper in thousandths of an inch, and went to the hardware store with the calipers. I found a combination of a copper pipe and a brass pipe that equalled the wall thickness I needed.

Since I couldn't slide them on, I had to make each bushing in two pieces. Since your bushing seems to have a need to be quite thick, you might consider wood?