Bosch Cx motor noise

Bearing Man

Trade Member
Oct 3, 2018
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www.ebikemotorcentre.com
It is purely the seals letting water in. You could use the best grease in the world, but it won't help much if water is present!
 

Charliefox

Esteemed Pedelecer
Feb 11, 2015
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Culloden Moor Inverness
It is funny how seals on my motorcycle were able to stop the gearbox oil coming out or the water coming in at the exposed area of the chain cog. As I remember it was a seal only at the exit hole and not combined with a bearing. And all my cars spent years swishing through drenching rain without the wheel bearings getting rusted up. Why is it so hard to seal Bosch, Yamaha etc motors when hub motors seem to take mud and rain without such problems? Granted they are set higher up.
 

Fat Rat

Esteemed Pedelecer
Jun 7, 2018
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UK
It is funny how seals on my motorcycle were able to stop the gearbox oil coming out or the water coming in at the exposed area of the chain cog. As I remember it was a seal only at the exit hole and not combined with a bearing. And all my cars spent years swishing through drenching rain without the wheel bearings getting rusted up. Why is it so hard to seal Bosch, Yamaha etc motors when hub motors seem to take mud and rain without such problems? Granted they are set higher up.
The seals on the engine / gearbox are stopping oil coming out you hit them with a spray of water they will let it in they are more resistant to water as there better designed and a different make up to bearing seals
Now if Bosch had designed a motor housing to take a proper seal there wouldn’t be half the problems but problem being then the motor would be wider and heavier and the shaft more complicated and inevitably would cost more,
Now Wheel bearings suck in water like crazy when hot and driven through floods in the winter and most wheel bearings are changed due to water damage the thing is there surprisingly well hidden in relation to the bearings on a Bosch motor
I’m not here defending Bosch / Yamaha etc here but it’s not the fault of the bearing seals as such .
 
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Bearing Man

Trade Member
Oct 3, 2018
115
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www.ebikemotorcentre.com
Also, seals add friction, friction sucks battery juice :)
 
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soundwave

Esteemed Pedelecer
May 23, 2015
15,971
6,292
if you want the best performance from bearings the less friction the better.

top end race bike will run no or very little lube in them at most a splash of baby oil.

tho they wont last long but if u are racing and have a van full of wheels then not a problem lol.
 

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