I found more of the Portuguese bearings....

I bought my 74' Commando from the original owner and my guess is the rear wheel bearings have never been changed out. It's the same bearing as the layshaft, which I wasn't aware of until now.
32,000 miles on the clock and they seem to be holding up. I will be changing out the two in the wheel and the double row in the brake hub. New bearings are cheap insurance!

There's also a 6203 bearing in the front wheel (side opposite the disc).

Jonez69 said:

I bought my 74' Commando from the original owner and my guess is the rear wheel bearings have never been changed out. It's the same bearing as the layshaft, which I wasn't aware of until now.
32,000 miles on the clock and they seem to be holding up. I will be changing out the two in the wheel and the double row in the brake hub. New bearings are cheap insurance!
View attachment 123438

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That's one way to look at it. The quality of the Chinese new bearings doesn't hold a candle to what used to be in there, so if there's no pitting or roughness, I put pthe bearings back in there.

I have a question concerning bearing replacement, front and rear. Since bearings are replaced with sealed versions, does the assembly still require the felt retaining washers
for proper spacing within the assembly? Can the double row bearings 06-7688 be found in sealed versions as well?

concours said:

That's one way to look at it. The quality of the Chinese new bearings doesn't hold a candle to what used to be in there, so if there's no pitting or roughness, I put pthe bearings back in there.

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Good insight, thank you! That was my first inclination/temptation, but thought they may be a risk. I know this particular bearing is under different stress loads in the gear box.

Jonez69 said:

Since bearings are replaced with sealed versions, does the assembly still require the felt retaining washers

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No.

Jonez69 said:

Can the double row bearings 06-7688 be found in sealed versions as well?

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Yes. 4203 2RS.

6203 is also used on the idler pulley ona Whipple super charger.
My friend owns a NAPA and says that may be the most common used bearing there is..

To be clear, it's not that there is anything wrong with 6203 or 6203-2RS bearings. That one bearing in the gearbox made a Portugal originally often made a bad mess. A quality roller bearing to replace it solves that problem plus makes the gearbox much easier to take apart.

The 6203-2RS bearings I normally use come from a US company and I buy them on Amazon in boxes of 10. I am under no delusion that there iis a bearing factory in Florida! I was buying my bearings from the US Office oof 123bearings (A French Company). Theirs cost much more and now with tariffs are way too expensive. I have no idea where those are made.

FAG bearings, a German Company, *might* be made in Germany but most are not. FAG is having a big problem with knockoffs. Ashley (AN) and I just recently with them to verify some bearings I bought that took so long to deliver that I figured they came from China. They were marked identically to one AN sells. They turned out to be genuine - both the ones I bought and the ones AN sells. I would normally just buy from AN but a US seller had them for significantly less - I had no idea is a US office of an foreign (probably China) company. I also have no idea how they got genuine FAG bearings shipped to then and then to the US with tariff and still cost much less. I'm guessing the "fell off a truck" at the China FAG factory and were certifiable real, but essentially free. Of course they could have come from a US FAG factory, but then why two weeks shipping?

The famous US brand Timken:

Most Timken bearings for the U.S. market are assembled domestically in the United States, but the company also manufactures components and complete bearings in China, India, Romania, and Taiwan.

Timken operates in more than 40 countries, with a long‑established headquarters and major operations in Ohio.

A key detail: a package labeled "Made in USA" may mean the bearing was assembled and packaged in the U.S. even if some components were produced abroad.

Finally:

If a bearing is marked C3 or C3 or even CN it means that it's manufacture have been certified and you know the clearance. If not maked, it doesn't mean bad per se, just not certified.

Most of the big names are made in many places. For instance, those 6203-2RS (06.5542) that AN is selling are marked FAG Portugal.

"
The famous US brand Timken:

Most Timken bearings for the U.S. market are assembled domestically in the United States, but the company also manufactures components and complete bearings in China, India, Romania, and Taiwan.

Timken operates in more than 40 countries, with a long‑established headquarters and major operations in Ohio.

A key detail: a package labeled "Made in USA" may mean the bearing was assembled and packaged in the U.S. even if some components were produced abroad."

The above statement harvested from some AI is wildly inaccurate as it applies to the bearings we use in our motorbikes. Timken does continue to manufacture high precision high end bearings for aerospace and defense here in the US.
All the cheapo bearings used for wheels and so forth, if you can find one that says Timkin it sure as heck isn't made in the US or assembled in the US. I work in these factories to repair their machinery, and believe me when I tell you, the Timken goodness we enjoyed for so many years is long gone unless you're building Airplanes and the like.

concours said:

That's one way to look at it. The quality of the Chinese new bearings doesn't hold a candle to what used to be in there, so if there's no pitting or roughness, I put pthe bearings back in there.

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I examined my bearings, including the brake drum. They all felt smooth so I repacked them and put them back into service.

MichaelB said:

6203 is also used on the idler pulley ona Whipple super charger.
My friend owns a NAPA and says that may be the most common used bearing there is..

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Indeed! Our submersible well pump failed this past springtime after a little more than 40 years 200 feet down in the well.

The cause of the failure?? A failed inner race on a Canadian made NTN 6203.

The really strange thing was that the performance of the pump increased in the 2 weeks prior to the failure. A pulsation heard in the water line alerted me to the issue.

TJBaker57 said:

Indeed! Our submersible well pump failed this past springtime after a little more than 40 years 200 feet down in the well.

The cause of the failure?? A failed inner race on a Canadian made NTN 6203.

The really strange thing was that the performance of the pump increased in the 2 weeks prior to the failure. A pulsation heard in the water line alerted me to the issue.

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NTN sold some super duper sealed bearings for snowmobile idlers a few years back. Really heavy duty double lip seals. I liked 'em.
Gone now.



Royal Distributing sold a knock-off.

The latest Superblend mains I fitted came from India. Should I be worried?
The 'Portuguese' issue has nothing to do with the quality of the bearing, but has a lot to do with the standard 6203 being under-specified for the layshaft location, where shaft flex causes the cage to break up.
The 6203TB used and championed by the Late, great Mick Hemmings allows the flex without issue.
Edit: the C as in C2, C3 refers to the specified clearance alone.

B+Bogus said:

The latest Superblend mains I fitted came from India. Should I be worried?

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No as they are the ones currently sold by AN are marked "India".

B+Bogus said:

The latest Superblend mains I fitted came from India. Should I be worried?
The 'Portuguese' issue has nothing to do with the quality of the bearing, but has a lot to do with the standard 6203 being under-specified for the layshaft location, where shaft flex causes the cage to break up.
The 6203TB used and championed by the Late, great Mick Hemmings allows the flex without issue.
Edit: the C as in C2, C3 refers to the specified clearance alone.

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Not strictly true, the photo shows a portuguese bearing with the cage still intact but a ball breaking up. I caught this early as i was replacing the kickstart spring for a clients 850 Mk2a. Found the sleeve gear bushes had started to migrate out of the sleeve gear and were getting munched by the gears ( a lot of bronze in the oil) Cured that by grinding a circlip groove into the sleeve gear bore ala Mk3

dobba99 said:

Not strictly true

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The failure mechanism which causes the back wheel to lock up is the cage breaking up - or isn't it?

B+Bogus said:

The failure mechanism which causes the back wheel to lock up is the cage breaking up - or isn't it?

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Chicken or egg discussion. I got my feet wet on this forum early on with this topic.

In steel two elements are important - sulphur and phosphorus. 'Dirty steel' often fails tensile tests due to sulphide inclusions. When corporations chase money, is quality a major issue ? - The aircraft and defence industries are usually much more closely controlled. Falling off a motorcycle is different from falling out of the sky. 'Fit for purpose' ?

I purchased a sleeve gear bearing that was not fit for purpose.
Sent it back to the retailer (now retired) and got refunded. Their supplier was curiously silent.

acotrel said:

In steel two elements are important - sulphur and phosphorus. 'Dirty steel' often fails tensile tests due to sulphide inclusions. When corporations chase money, is quality a major issue ? - The aircraft and defence industries are usually much more closely controlled. Falling off a motorcycle is different from falling out of the sky. 'Fit for purpose' ?

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Please Al, tell us more....