Suntour HESC Hub Motor Bearing Change

[MarkSD]

Hi all - I’ve got 2k mikes on my Crossfire with the Suntour HESC hub motor. I’ve got a clicking noise coming from the back wheel which is is linked to wheel speed and continues when not pedalling. It’s not the spokes as I’ve tightened them. There’s no lateral play on the wheel. I’m suspecting bearings

I can’t find much info on changing the bearings so any advice greatly appreciated. Do you have to dismantle the wheel and remove the spokes to split the motor? Is it easy enough to change the bearing both sides or is the drive side easier than the other because of the cabling? Does anyone happen to know what the bearings are so I can order them in advance? Any specialist tools required?

I haven’t heard of anyone getting this done at Halfords so I assume we’re on our own! thanks In advance for your help. Cheers, Mark

 

[MarkSD]

I’ve had the hub motor out - some photos attached for anyone else curious to know. After removing the cassette, dork disc and casing bolts the whole motor should come out to the cassette side with the cable attached. my route was slightly different - I removed the grub screws holding the freehub to the motor casing which left the motor in the wheel. I then removed the freehub body. Inside the freehub there are 2 bearings separated by a spacer to drift out (6001RSC2 are the ref numbers). When you pull the motor out of the wheel there is a 3rd larger bearing in the wheel casing. I left that well alone as it seemed fine.
Assembly is the reverse process
One tip: you have to use a cassette tool without an internal collar/guide pin because there is no hole through the axle

 

[Nealh]

Well done, afaik this is the first time anyone has posted pics of inside one here.

 

[egroover]

Very useful pics, thanks for posting. I've got 4.5k miles on my Crossfire, bearings seem okay, but knowing what to do if they need replacing is worth knowing

 

[Nealh]

The main issue stil is though finding replacement nylon two stage gears as another user is finding out. Bearing are easy being sealed and most are marked with the size.

 

[saneagle]

From HESC Plantetary Gears thread

The planetary gears are toast. 45mm diameter and 32t.

????????????????????????????

 

[Peter Hartley]

From HESC Plantetary Gears thread

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45mm total diameter and 32 teeth.

 

[JollyRoger]

I’ve had the hub motor out - some photos attached for anyone else curious to know. After removing the cassette, dork disc and casing bolts the whole motor should come out to the cassette side with the cable attached. my route was slightly different - I removed the grub screws holding the freehub to the motor casing which left the motor in the wheel. I then removed the freehub body. Inside the freehub there are 2 bearings separated by a spacer to drift out (6001RSC2 are the ref numbers). When you pull the motor out of the wheel there is a 3rd larger bearing in the wheel casing. I left that well alone as it seemed fine.
Assembly is the reverse process
One tip: you have to use a cassette tool without an internal collar/guide pin because there is no hole through the axle

Hi, I'm rebuilding my hub after someone else completely bodged it. . . .my intro post will explain !, the cable end of the casing, is there meant to be a bearing in there ? the guy from Halfords says no but I've got a niggling feeling it does.......it won't budge when you try and roll it backwards and I don't want to snap the dropouts-I cringe every time I try it.

The photos have helped-thanks, there's a remarkable lack of info/diagrams/teardowns for this motor.

 

[MarkSD]

Hi, I'm rebuilding my hub after someone else completely bodged it. . . .my intro post will explain !, the cable end of the casing, is there meant to be a bearing in there ? the guy from Halfords says no but I've got a niggling feeling it does.......it won't budge when you try and roll it backwards and I don't want to snap the dropouts-I cringe every time I try it.

The photos have helped-thanks, there's a remarkable lack of info/diagrams/teardowns for this motor.

Hi - there are 3 bearings in there. 2 are in the freehub and the other one is pressed into the casing and supports the cable side of the motor.
In the first photo above the inside of the collar is a tight fit over the bearing that sits in the casing - which you can see in the 3rd photo.
The bigger black looking circle in the 3rd photo is the sealed bit of the sealed bearing. I hope that makes sense! if I need to explain that better please ask.
cheers, Mark

 

[MarkSD]

I’ve annotated the inside of the casing photo if this helps.

 

[JollyRoger]

I photographed it as I was stripping it, excuse the crappy quality and the light. . . . .most of it was done at silly o'clock in the morning !

I’ve annotated the inside of the casing photo if this helps. View attachment 50732

Thanks, this one's there. . .it's the black inner ring at the other end I appear to be missing-where the axle locks into the casing....will strip it after tea and send you pics, it's second nature now-takes me about 7 minutes !

Will post teardown pics for info anyway-in case anyone else ends up in the soup like me!

 

[JollyRoger]

I’ve annotated the inside of the casing photo if this helps. View attachment 50732

As promised, teardown photos.......might help someone

 

[MarkSD]

As promised, teardown photos.......might help someone

Wow! You’ve gone way past the point I did so respect - I'm afraid that’s all past my pay grade so I can’t offer any advice but best of luck getting it sorted.

 

[JollyRoger]

Right, quick update. . . . .it would appear that when I take the planetary gears out-the thing spins like a dream both ways. . . . .it drives like a brand new bike, to the extent I've put a mid-drive on my shopping list.

I thought it was a bearing in the hub etc. but obviously not-it's got me baffled. . . . . .am into 3d printing and stuff so I know how stuff works-gears, bearings etc. I built one of them kit jobs-that was fun

Talking of which, the mid-drives are mainly 24v unless you want to pay big bucks.........and my battery's 36v-am not sure and I don't want to blow a hole in my leg half way down the road

I hate Carrera.

 

[saneagle]

Hi, I'm rebuilding my hub .............it won't budge when you try and roll it backwards and I don't want to snap the dropouts-I cringe every time I try it.

The photos have helped-thanks, there's a remarkable lack of info/diagrams/teardowns for this motor.

There's no need for photos and no need to strip down. When a geared hub motor bike jams when you push it backwards, it's a 99% chance that you have a short on one or more of the three phases. That can be when the motor cable is damaged or when a MOSFET in the controller is blown. You can test if it's the controller by disconnecting the motor to see if the problem goes away.

Obviously, if you force the bike backwards in that condition, you can damage the plastic gears.

If the problem is a damaged cable and you try to give the motor power, there's a very high chance that you'll blow the MOSFETs in the controller and end up with both problems.

 

[JollyRoger]

electrically the wheel's fine, it works with a throttle and 20 quid amazon controller-goes like the clappers. . . . .it's when I reassemble the thing-it's like am crushing something.

 

[Nealh]

Mid drives are either 36v or 48v in this modern day, older 24v mid drives are practically extinct.

 

[Nealh]

If the motor is working fine with a cheap controller and then doesn't when put back together then one would suspect the internal clutch mechanism is not releasing.
Not sure how such a mechnism works on a suntour but on my old BPM it was a simple 3 point spring and bearing affair .

 

[JollyRoger]

OK, so update time. . . .got motor going, reassembled it out of sheer boredom and got a bit of play on it then it seemed to ease off a bit until it rolls back OK......with the motor being locked initially, the motor stopper and torque spacer have both snapped, which is presumably their job to save snapping the dropout-just my thoughs......

Anyway, Halfords don't have a clue what I'm on about ! I've double-locked a nut on the axle/motor casing so that's solid, no flats for a torque washer on that side-so the motor's constantly trying to kick backwards pulling the cable with it......it's the torque in the motor

Any suggestions how to further secure it ? Swinnerton have the parts but no date when they're getting any-on a mailing list now

 

[Alex808A]

OK, so update time. . . .got motor going, reassembled it out of sheer boredom and got a bit of play on it then it seemed to ease off a bit until it rolls back OK......with the motor being locked initially, the motor stopper and torque spacer have both snapped, which is presumably their job to save snapping the dropout-just my thoughs......

Anyway, Halfords don't have a clue what I'm on about ! I've double-locked a nut on the axle/motor casing so that's solid, no flats for a torque washer on that side-so the motor's constantly trying to kick backwards pulling the cable with it......it's the torque in the motor

Any suggestions how to further secure it ? Swinnerton have the parts but no date when they're getting any-on a mailing list now

The clutch mechanism that allows the bike to freewheel, and pedal without the motor being engaged is called a sprag clutch. It's unusual for them to fail engaged, but rusting together in the engaged position would be possible. Sprag clutches looks like cartridge bearings from the outside. The large main internal gear that provides drive to the wheel appears to be mounted on a sprag clutch, it should be free one way and bind in the other direction. Pop the seal off to see what's going on inside.

See an example here:

Whether a replacement is available or not is questionsable, but at least you have an explanation as to why the wheel won't roll backwards.