How do I adjust the brake shoes on my Sakura/Erato Wheel?

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Last seen: 9 years 7 months ago
Joined: Wednesday, April 8, 2009 - 06:12
Points: 90
How do I adjust the brake shoes on my Sakura/Erato Wheel?

I've got a Sakura S50, which is made by Erato, based on a Baotian BT49-QT9 body.

Some pics of mine here:

My rear brake does not work at all anymore - it appears to have seized completely inside the hub. For a while it was possible to pull it on but then it just bound and had to be kicked/hammered to get it off again. Clearly the hub needs sorting out, but having taken it off the bike I can't work out how to get it to bits. Or at least I don't want to get too gung-ho without having some idea of which bits should move.

Here is a pic. Clues very welcome:
[not sure how to incorporate images in the post - the 'Embedded image' facility only seems to allow a particular set of websites, not mine, which is where my pics are. I've tried a bbcode image link and a plain link above].

[editor note: there is an embed image button above the editing area which helps you include images]

I assume all these chinese moped hub motors are very similar, so hopefully some of you will already know how to do this. Unfortunately the importer 'Sakura Battery Co''s website has gone so I assume they have disappeared too (I've been told the guy wanted to retire), so I'm kind of on my own here, unless Erato or other importers have info. The thing currently works fine except that I have no rear brake which as at best annoying and at worse rather dangerous.

I note that there is a Haynes manual for Chinese motorcycles, which might be informative but I assume this only covers ICE versions so won't help in this case of how to get the wheel/motor apart.

You can see that it looks rather sad in those photos - it was stolen by local youths and recovered with a lot of superficial damage about 6 months ago. I have just finished arguing with the insurance company and got parts to fix it myself. It has been still working apart from rear brake light (and rear brake) but looking rather beat-up. Whilst I've got it in bits to replace various plastic panels and parts, I'm taking the opportunity to paint the frame properly (it was rusting rapidly despite being only 9 months old), add a watts-up to measure current in use, and hopefully fix this brake problem. I'll take some more photos to inform other Sakura owners left in the lurch.

Last seen: 9 years 7 months ago
Joined: Wednesday, April 8, 2009 - 06:12
Points: 90
Re: How do I adjust the brake shoes on my Sakura/Erato Wheel?

I'll answer my own question in case anyone else has the same problem.

Unfortiunately I don't have any photos as my camera was on the blink.

The ring above the aluminium casting just slides off the shaft(with a bit of plusgas and wiggling to release from rust).

In principle so does the aluminium casting, however this was not at all easy due to corrosion where the steel shaft passes through the casting. Lots of plusgas to start with, then clamp flats on shaft in large vice or use adjustable spanner. The use rubber mallet on the sticky-out bit of the casting to try to get it to rotate on the shaft; back and forth until there is some movement. Be careful because it would be quite easy to crack the casting (hence the rubber mallet). I had to give it a fair amount of GBH. Eventually it will free up until you can rotate it all the way round and get more plusgas in. Then it should be possible to draw it off the shaft with upward pressure whilst rotating.

Now you can dissamble brakes (very simple - 2 springs and 2 shoes). Then start to work on freeing-up the brake actuator spigot. Again this was entirely siezed. Soak for a day with plusgas. Clamp casting in a vice (ideally with protectors), and use large adjustable spanner on the brake actuator spigot until it turns. Again rubber hammer very helpful in getting some movement. Once it has rotated some you should be able to hammer it out downwards through the casting (again take care to support it close to the spigot whilst belting things).

After cleaning up corrosion and rust and putting in some grease it also goes together nicely and everything rotates as it should. There is a spacer inside the hub - don't forget to include it.

Hope that helps. I did try taking the motor side to bits too (lots of small allen bolts) but couldn't see how to release the cover plate. Anyone know?

And finally what does the little 2-speed lever on the end of the shaft actually do? Does it just adjust hall/windings offset?

Sakura s50 (Efun A)

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