Bearing swap experiment

Thorbjørn Bjørgren /

Hello all

Just finished a rebuild of my e 50, and I have left the gearbox side main bearing inner bearing seals in the bearing, (Codex 6203 NR),- just to see if the bearing holds up..

I know that they usually get lubrication from the oilmist in the gearbox, but if they deliver a sealed bearing to me , they must think that thats the way it should be..

any experience u may have is welcome.

engine setup:

standard cyl.head

50 cc (38mm) cylinder slightly ported (12 mm intake) 179 deg (flush)

Stay safe,- wear a mask, and keep riding folks!!

Thor

Re: Bearing swap experiment

It's a universal bearing. I've always removed the seal with a small dental pick. Pulls right out.

It's gonna seize if you leave it.

Re: Bearing swap experiment

Metal shield or rubber seal?

Re: Bearing swap experiment

My Simplex calls for open crank bearings .

When I rebuilt the motor I installed sealed bearings ( both sides sealed ) .

That was about 9 years ago . Not sure just how many hours they have ran , but , they don't seem to be doing any worse for wear . ;)

Re: Bearing swap experiment

Thorbjørn Bjørgren /

It is the metal ones.. think they only keep " bigger items" from entering the bearing or do they seal airtight??

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Ive already given it a little test.. ran 3 heat cycles in idle, one cycle at 1/4 throttle and Coast for like 3 km.. then i admit i thought..f..k it and let it boog det and "let it rip" !!! No weird noises, lots of power, and less vibration than before the overhaul..

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Metal ones... dont think they can keep the oilmist out.. ive already ripped it all the way with nothing but power and joy to follow.. i hope my theory is correct

Re: Bearing swap experiment

> Thorbjørn Bjørgren Wrote:

> -------------------------------------------------------

> Metal ones... dont think they can keep the oilmist out.. ive already

> ripped it all the way with nothing but power and joy to follow.. i hope

> my theory is correct

Sealed bearings are lubed , inside the seals . ;)

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Do I understand correctly , that you´ve been running your sealed bearings for 9 years with no problems?? then i must be "in the clear", of course minding my correct lubrication and so on ..

Re: Bearing swap experiment

Dirty30 Dillon /

Sealed bearings do not permit the oil from 2t mix into them. Obviously, that would go against the "sealed" title.

Also, it's just a bad idea. There is no benefit to not letting the motor lubricate itself with charge.

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Thanks.. but the thing is.. the bearing in that side is lubricated from the gearbox oilmist i.e. sealed towards the crankcase with the usual seals.. the metal guards in the bearing are not as tight as the rubber ones are they?.. i can take the clutch off and gain access to the bearing that way.. is it possible to remove the metal guard thingy that way? (edited)

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Bonus info: it os not a "performance bike" yet..though it does perform rather well..( approx 50km/h) on a standard 45:13 ratio) i am not in the 10k+ rpm range yet.. so dont you think it will keep running?

Re: Bearing swap experiment

Dirty30 Dillon /

> Thorbjørn Bjørgren Wrote:

> -------------------------------------------------------

> Thanks.. but the thing is.. the bearing in that side is lubricated from

> the gearbox oilmist i.e. sealed towards the crankcase with the usual

> seals.. the metal guards in the bearing are not as tight as the rubber

> ones are they?.. i can take the clutch off and gain access to the

> bearing that way.. is it possible to remove the metal guard thingy that

> way?

The metal guards are meant to hold in hot grease, so they will keep out oil just like they keep the oil/grease inside them and dust out.

Again though, you have a bearing that can either be bathed in a large reservoir of constantly moving oil, or one that is sealed and is constantly swarthing around the same ~.1 ounce of grease.

There is no question as to which style will last longer under any circumstance.

Re: Bearing swap experiment

> Thorbjørn Bjørgren Wrote:

> -------------------------------------------------------

> Do I understand correctly , that you´ve been running your sealed

> bearings for 9 years with no problems??

That is correct .

And , yes there is a question as to which will last longer .

The sealed bearing is bathed in it's own grease that is sealed from any outside contaminates .

An open bearing is subject to which ever contaminates happen along . Any from running no or little air filter and those particles that make their way through the carb fuel ways . It's a well known fact that plenty of crap gets through carbs .

There's also any metal that gets worn off neighboring pieces that can lodge in an open bearing , which will not happen in a sealed bearing .

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Cheers m8.. ill see what is possible .. would like NOT to be taking the whole thing apart again...

Re: Bearing swap experiment

Metal ones arent same like rubber seal, thats why they are called shield not seal. You are correct that they are not 'air tight' and oil can get inside them (such shielded bearings are in some spoked 12mm rims, for same reason is good idea to change to sealed bearings + i feel better with brand name instead asia quality) .

Re: Bearing swap experiment

Dirty30 Dillon /

So running shielded bearings means a) no protection from engine contaminates as they are open to the crankcase, and b) LESS fuel/oil mix intrusion because the majority of the bearing is blocked.

Seems like a lose-lose.

Re: Bearing swap experiment

Thorbjørn Bjørgren /

Bearing is this one.. see attachment

Screenshot_2020-11-15 Krumtap Lejer Simmeringe.png
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