Can you find the gear reduction ratio of a geared hub motor without opening it up?

[Ridersofthenorm]

Aside from the question in the title, if you just want to hear me vent then then continue reading:

I found the actual motor online from the company (AKM) and looked at their spec sheet and they just don't list poles or magnets or gear reduction ratio.

I have:

• Searched extensively online
• Sent emails in Chinese, French and English to Aikema. Asking them the information I need.
• Reverse image searched to find sellers that rebranded it, hoping they'd list controller configuration information (they didn't)
• Searched in Chinese, Russian, and other languages of countries where Ebikes are popular
• Did however find a Ukrainian seller (Evel.ua) that made a Youtube video where they opened it up. (It's the one on the left) But they do not list the gear reduction ratio either. I also can't say for certain if it's the same motor but it looks identical and has almost the exact same measurements.
• Got a Chinese friend to give me invite access to a Chinese tech forum that you need an invite from some other chinese app to get into it
• Found that it's rebranded by "TopBikeKit", "Yose Power", and "Evel", not sure how many others but they do not list the info needed either
• After reverse image searching further I found a listing on Alibaba and messaged the seller there. No reply.

This has been such a pain in the ass. I'll say that as someone that has built E bikes for many years and loves the hobby, the biggest plague of this hobby is:

1. Proprietary parts where companies have this weird need to put anti tamper stuff all over bikes even though they don't have the infrastructure for having an RMA service or shops. like seriously what the f*ck is the point in that? i'm not talking about batteries either, that I get. But, I've seen hub motors that have anti tamper screws on them, or the myriad of displays (Which isn't always a good thing) requiring their own manual. Or the amount of times that I've had to take a perfectly good brand new controller and cut off every single connector because they use different connectors. etc
2. The quantity of components that are rebranded or made in house without any sort of spec sheet or anything listed on them.

Thanks for coming to my TED Talk

 

[Chargeride]

take it apart, far easier.

 

[Slaphappygamer]

Most geared hub motors have a 5:1 gear ratio.

You can count the magnet poles by rotating the wheel SLOWLY backwards. You can do this with the bike off. You will feel “cogging”. Each time you feel cogging, that is one magnet. Then just half that number and you have your “magnet pole pairs” value. Use the air valve to use as a “marker. Line it up with the floor or seat/chain stay.

 

[indianajo]

All the 5 brands I have had have been about 5:1. Different connectors, different widths to the disk mount, different shaft sizes, different impedances (especially 300 w versus 1000 w). But all have been about 5:1. The 350 w (even Bafang) and 750 w (no name brand) have been incapable of climbing 77 hills in 24-30 miles at gross 330 lb without melting the winding. The 1000 w Cutler Mac 12t and the 2018 48v 1300 w ebikeling were capable. Those have now been outlawed in most of USA. Even if not outlawed, nobody will sell you one but alibaba. In quantity 8.
Anti-tamper screws came on the bafang takeoffs of the uber jump rental fleet. Presumably to prevent customers from tampering. I ground a slot in them for a flat blade screwdriver and replaced with allen socket screws. Reason, case screws come unscrewed in about 1000-2000 miles in all brands: Unless doped with Key-tite. No, blue Lok-tite does not work. Red Lok-tite requires a torch to take off, so I don't use it near heat sensitive windings.