idiots guide to changing rear 8 fun wheel bearings please?

footpump

Esteemed Pedelecer
Mar 19, 2014
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hello all have bafang fun 8 rear hub moter wheel on my vita uno (kudos) 26" mtb.

a while back 2 spokes were replaced and (side to side play noticed in wheel bearings) at rear

I would like to replace these bearings but cannot find anything specific to ebikes youtube etc

not sure how I get to the bearings ,does cassette and moter have to be removed I have not as yet removed rear wheel until I know what I am doing.

so idiots guide step by step if possible?

I did ask this a while back but cannot locate my post.

thank you all
 
D

Deleted member 4366

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The side to side play is not normally a bearing issue. There should be a nut on the outside, which pulls a shoulder on the axle against the bearing to stop the axle moving sideways. The nut is normally on the left side. I guess that your nut has come loose.
 
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footpump

Esteemed Pedelecer
Mar 19, 2014
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well I have taken the rear wheel off and can see nothing disk roter side that might be tightened.
does the cassette have to be removed to get too a (nut) there is nothing obvious that is visible?

front wheel has a nut either side of spindle which is plain to see so now a bit stumped

thank you
 

flecc

Member
Oct 25, 2006
53,197
30,602
No, don't touch the cassette. It's the inner spindle nut against the l/h side of the alloy motor housing. First loosen the wheel nuts quite a lot. Then tighten the inner spindle nut that's up against the alloy housing on the left side to make sure the spindle is fully pulled to that side as far as it can go. When tight, tighten the outer wheel nuts again and that should have removed the side play.
.
 

footpump

Esteemed Pedelecer
Mar 19, 2014
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thanks flecc there simply is no inner nut , roterside has a domed black bearing , cassette side has sleeve with flanged ends that slides over the spindle ,then locknut.

unless something has been lost when spokes were replaced.

I have never noticed a inner nut when I ve removed the wheel.

if I could get the of posting pics I would.

ill take pics of wheel and go to local lbs to see if they can shed ligjht on this

thank you
 

flecc

Member
Oct 25, 2006
53,197
30,602
In that case fully tighten the left hand outer wheel nut first, then tighten the right hand wheel nut. That should register the spindle fully into the motor shell and take out any side to side play.

Let me know if that gets rid of the side play.
.
 

footpump

Esteemed Pedelecer
Mar 19, 2014
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hi as I have damaged the moter lead I have not replaced wheel but took pictures and went to local bike shop it seems i have push fit bearings not adjustable cones like the front wheel
 

flecc

Member
Oct 25, 2006
53,197
30,602
Yes, those precision bearings are the usual on Bafang motors. As d8veh said, it's highly unlikely they will allow any side play, hence our advice on making sure the spindle is fully over into the hub shell.

When like that the inner spindle shoulder registers the hub shell and motor with no side play.
.
 

footpump

Esteemed Pedelecer
Mar 19, 2014
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thank you flecc I think the penny has dropped if in the past the cassette side of spindle was tightened first, it might not be seated correcltly creating undo movement.
bit new to the mechanics of ebikes.
 
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footpump

Esteemed Pedelecer
Mar 19, 2014
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hi all I am not 100% sure which way up this coller fits onto the spindle on the moter side there is wear as shown in pick , I think its flange side upwards but this collar fell out of the moter wheel so not completely sure
 

footpump

Esteemed Pedelecer
Mar 19, 2014
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I repaired moter lead and replaced wheel, tightened left side to 35nm then tightened right side.
unfortunately there is still (play) side to side when gripping the wheel horizontally.
I did notice movement when holding the freewheel cassette itself , but I do not have the correct tools to undo or tighten the cassette lockring.

thank all
 

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