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Can't remove hub generator
#1
Hello, I need help to unscrew generator from front wheel hub because I'm out off options, even master knowed little about this type generator. It was impossible to unscrew it with regular wrench and only resulted in nut denting. According to diagram hb-nx70 generator should be removable but place where it unscrews looks as if all solid. Maybe I missed something? Here's some images:

[Image: Image.ShimanoHBNX70RP.gif]

[Image: t0Jtu26SOP0dEbnu1Wmywoac4-zddTkaMnbLxP5jwxc=w720-h540]
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#2
how about a picture of the other side, and some at oblique angles?

Are you sure the exploded view is for your hub?
Nigel
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#3
(04-22-2014, 03:14 PM)nfmisso Wrote:  how about a picture of the other side, and some at oblique angles?

Are you sure the exploded view is for your hub?

Exploded view is for this hub, just google up hb-nx70 model and see images.
I will attach photo of the another side. I also wonder in what direction it should be unscrewed, anticlockwise? I tried both.
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#4
With the dyno section on the left side; the threading should be standard right hand, meaning counter clockwise to loosen. The drag caused by the dynamo should tighten the thread.

Is there enough meat on the hex feature to clamp it in a vice?
Nigel
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#5
(04-22-2014, 06:46 PM)nfmisso Wrote:  With the dyno section on the left side; the threading should be standard right hand, meaning counter clockwise to loosen. The drag caused by the dynamo should tighten the thread.

Is there enough meat on the hex feature to clamp it in a vice?

Yes, there is still. But I guess I could need tool that would grab more firmly nut, probably octagonal wrench? Could screws not allow to unscrew generator because on other side there are some kind holes?
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#6
The holes on the other side are for mounting a brake disc.

Do it the same way as is preferred to remove freewheels - put the hex into a heavy duty bench voice, grab the rim and tire with your hands and turn. Note: bench should be bolted to the floor.

http://thebiketube.com/tutorial/how-remove-bicycle-freewheel-even-stuck-one see 4th paragraph down. Note that the direction to turn is the same as for removing the freewheel.

and from: http://sheldonbrown.com/freewheels.html
"The usual technique for removing a freewheel from its hub is to clamp the freewheel puller into a solidly-mounted vise and unscrew the wheel from the freewheel. If your vise allows this, it works better if you clamp it so that the wheel is in a vertical position. permitting you to twist harder without having your feet slip on the floor. This gives you better purchase to turn the wheel. I used to work in a shop where we had a vise mounted sideways on a door frame for this purpose. My present vise has an extra pivot that permits the jaws to be rotated 360 degrees. Unfortunately, most vises lack this useful feature, so you may have to make do with a horizontal wheel orientation."
Nigel
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#7
(04-22-2014, 10:03 PM)nfmisso Wrote:  The holes on the other side are for mounting a brake disc.

Do it the same way as is preferred to remove freewheels - put the hex into a heavy duty bench voice, grab the rim and tire with your hands and turn. Note: bench should be bolted to the floor.

http://thebiketube.com/tutorial/how-remove-bicycle-freewheel-even-stuck-one see 4th paragraph down. Note that the direction to turn is the same as for removing the freewheel.

and from: http://sheldonbrown.com/freewheels.html
"The usual technique for removing a freewheel from its hub is to clamp the freewheel puller into a solidly-mounted vise and unscrew the wheel from the freewheel. If your vise allows this, it works better if you clamp it so that the wheel is in a vertical position. permitting you to twist harder without having your feet slip on the floor. This gives you better purchase to turn the wheel. I used to work in a shop where we had a vise mounted sideways on a door frame for this purpose. My present vise has an extra pivot that permits the jaws to be rotated 360 degrees. Unfortunately, most vises lack this useful feature, so you may have to make do with a horizontal wheel orientation."

Already tried using mini bench but only get nut denting. It's made not from steel but probably softer aluminum alloy. Bench can touch only two surfaces but octagonal wrench could use all nut surface and do less damage. So probably I'll need to find such or make own. Thanks for trying to help.
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#8
Ok, managed to open hub by homemade wrench. I found there a lot of greasy rust and even water, wire was shorted somewhere so after fixing that wheel spinned more freely.
I wanted to remove also magnet as now it is useless at this moment for me. But magnet ring is strongly holding to hub lid. Any way to remove magnet without doing significant damage?
Moreover is it possible to replace cups because they have pits?

[Image: SAM_8730.JPG]
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#9
Please share a picture of your homemade wrench.

It is not possible to separate the magnet from its backing without destroying it.

The bearing cups - possibly, but may be impossible to find replacements.

Recommend clean things up the best you can, and when you reassemble use a water resistant grease - lots of it, to keep the water out. I use boat trailer wheel bearing grease - inexpensive and designed for loads and speed far higher than any recreational bicycle application; and far worse environments.
Nigel
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#10
If magnet with steel ring is not glued or welded but just pushed in it could be possible to remove with special tools. I at least have idea to drill holes on another side and either screw in screws or use rods to push it out. But I'll do it later maybe I can find ways not to damage lid.
Today I bought and installed bearings with cups, they were different but fitted.
Wanted to learn more about grease. Probably most of them are resistant to water. Which of them is slickest and best for part durability, containing teflon or graphene particles? I use what I have - universal grease Amsoil 1500 NLGI EP2 or russian "Solidol"

You asked for homemade wrench photo here it is. I used just aluminum alloy part from window blind that was thrown after building remont and it happened to have a 32mm notch that made work easier.
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