Billriv1

Hi guys. I have attached a pdf file with a diagram of the MXUS XF15 rear hub motor. This is my first wheel build and I don't know what the measurements in the diagram show. I think the measurements may show the information I need to input into bikes.ca online spoke calculator, but they are not labeled so I don't know what they are measuring. Some of the measurements seem obvious, but I want to be sure to avoid any costly mistakes. I have not received the motor yet and will, of course, double check any measurement information I get by measuring the motor itself.

Can anyone find the following measurements in the attached pdf file:

Flange Diam. mm

Flange Spacing mm

Dishing Offset mm

Axle Length mm

Hole Diam. mm

Doc_Wui

EDIT: These are from your link, but I don't believe this is for the XF15.
My Take
A. Flange Width 44
B. Flange Diameter 128
C. Dishing 3
Use 135mm and 3Mm for the last two. Also single cross. When you put numbers into the Grin calculator, you will find that (B) and the ERD of the rim matter the most.

Other calculators give different results. I use Grin too, and round it down to the nearest mm.

Doc_Wui

By the way, you call it an XF15, but I suspect you have the wrong diagram here. I looked up one of those motors and believe the flange diameter was around 140. Better wait til you get it in your hands and measure with acalipers.

Billriv1

I got the diagram from a Chinese website. I have found that some Chinese vendors are not very careful with the information they provide. Some of the provided information on the item they are selling simply does not match the item. There is also a definite lack of specificity when describing items. Thanks for sharing your concern and yes, I will wait until I get the motor and measure.

Thanks,

Bill

Doc_Wui

I remember thinking that the MXUS XF15 is a pretty strong motor for a 20" wheel and it is bigger than what you linked. Here's a drawing off aliexpress.

It's a little wider than the typical 135mm axle at 139 mm. WIth an alloy frame, you'll have to play around with the washers and the spacers under the freewheel to get it back down to 135mm. Looks doable to me though.

You can't trust the drawings anyway. I bought a rim from a US vendor and their published ERD turned out to be a typo. Get your parts in and measure.

Billriv1

It's a little crazy when you get different specs from diagrams on what is supposed to be the same motor. This is a definite buyer beware issue. Thanks as always for your help.

Bill