6001 Bearing - Actual Size

[PedallingNowhereSlowly]

Hello,

This is the first time I've got the prospect of replacing cartridge bearings. I could do with a bit of insight from someone whos used to dealing with them, if somone would kindly indulge me.

I've removed said bearings from the 20" (406) wheels on a Thule child trailer. Unfortunately, the old bearings are not stamped or etched. They measure up fairly close to a 6001 bearing, which would be 12mm bore, 28mm outer diametre, 8mm width.

These bearings actually measure :

• 12.76 mm bore (actually, that's the axle. I get a slightly smaller measurement from the bore but I think that's down to not being able to quite fully extend the my verniers due to the curvature of the bore)
• 28.6 mm outer diametre
• 8 mm width (the only measurement that's spot on)

Now, they are quite worn - not that I'd think it would make that much difference. Are these normalish actual measurements for a 6001 or are they non-standard bearings?

I have ordered some stainless steel 6001s, but rather than cross my fingers and hope for the best, I figured I should consulte the hive mind before writing off a set of hubs.

Thanks.

 

[wafter]

The dims sound a bit out to be the nominal metric values you suggest; could be an imperial alternative..?

Might be worth searching for data sheets from bearing manufacturers - two that spring to mind being SKF and NTN..

 

[PedallingNowhereSlowly]

That's a good shout.

In imperial:

Bore size: 0.5" (0.50236"; ≈ 1/2")
Outer diameter: 1 1/8"
8mm: 5/16"

On edit, these maybe?
On second edit: After measuring several times again, the axle is about 12.65 mm which is within 2/1000 of half an inch.

@wafter I think you've just saved me from an expensive mistake. Thank you.

 

[Fastpedaller]

It's unlikely to be a non-standard size bearing. Any manufacturer will avoid using non-standard sizes for cost reasons.

 

[raleighnut]

That's a good shout.

In imperial:

Bore size: 0.5" (0.50236"; ≈ 1/2")
Outer diameter: 1 1/8"
8mm: 5/16"

On edit, these maybe?
On second edit: After measuring several times again, the axle is about 12.65 mm which is within 2/1000 of half an inch.

@wafter I think you've just saved me from an expensive mistake. Thank you.

They look a better bet, I was gonna say imperial sized bearing but was beaten to it

 

[raleighnut]

It's unlikely to be a non-standard size bearing. Any manufacturer will avoid using non-standard sizes for cost reasons.

Given the apparent age of the trike Imperial sizes would have been standard in the UK and USA

 

[PedallingNowhereSlowly]

It's unlikely to be a non-standard size bearing. Any manufacturer will avoid using non-standard sizes for cost reasons.

This is essentially why I ordered some 6001s
However, some manufacturers like to use proprietary parts in order to make repair impossible.

 

[raleighnut]

This is essentially why I ordered some 6001s
However, some manufacturers like to use proprietary parts in order to make repair impossible.

That wouldn't be Raleigh by any chance would it,

 

[Profpointy]

Hello,

This is the first time I've got the prospect of replacing cartridge bearings. I could do with a bit of insight from someone whos used to dealing with them, if somone would kindly indulge me.

I've removed said bearings from the 20" (406) wheels on a Thule child trailer. Unfortunately, the old bearings are not stamped or etched. They measure up fairly close to a 6001 bearing, which would be 12mm bore, 28mm outer diametre, 8mm width.

These bearings actually measure :

• 12.76 mm bore (actually, that's the axle. I get a slightly smaller measurement from the bore but I think that's down to not being able to quite fully extend the my verniers due to the curvature of the bore)
• 28.6 mm outer diametre
• 8 mm width (the only measurement that's spot on)

Now, they are quite worn - not that I'd think it would make that much difference. Are these normalish actual measurements for a 6001 or are they non-standard bearings?

I have ordered some stainless steel 6001s, but rather than cross my fingers and hope for the best, I figured I should consulte the hive mind before writing off a set of hubs.

Thanks.

To echo what others have said 12.7mm is exactly 1/2"

 

[PedallingNowhereSlowly]

Cheapest I can find those SKF bearings is £25 each.
Oofta. These [ebay link] are a bit cheaper - not stainless steel though.

 

[Fastpedaller]

With plenty of grease the 'regular' steel bearings should be good - Any bearing (ss included) won't be much good if water gets inside!

 

[Tenkaykev]

Cheapest I can find those SKF bearings is £25 each.
Oofta. These [ebay link] are a bit cheaper - not stainless steel though.

Oof indeed! I used to purchase bearings when I was working. We used a lot, from miniature to Ginormous. It's worth visiting your local bearing factors and asking there. They carry a fair amount of stock, our trade discount on SKF, NSK, FAG was 80%.

 

[PedallingNowhereSlowly]

With plenty of grease the 'regular' steel bearings should be good - Any bearing (ss included) won't be much good if water gets inside!

I've no doubt these will be plenty good enough for a bike trailer that's probably only going to be used a handful of times before the sprog outgrows it and I sell it on.

 

[Tenkaykev]

With plenty of grease the 'regular' steel bearings should be good - Any bearing (ss included) won't be much good if water gets inside!

We almost always specified " 2RS " for our stock bearings ( 2 RS = 2 rubber coated shields ). That way we could flip one or both shields out if necessary, or to clean out and repack with a specialist grease. What always amazed me was how little grease was in the bearings, even the larger ones ( palm of your hand size etc ), to the extent that I thought " this can't be right " I did query this with the SKF rep once, and he sent me some in house research that showed the vast majority of premature bearing failure was over greasing.

 

[Fastpedaller]

We almost always specified " 2RS " for our stock bearings ( 2 RS = 2 rubber coated shields ). That way we could flip one or both shields out if necessary, or to clean out and repack with a specialist grease. What always amazed me was how little grease was in the bearings, even the larger ones ( palm of your hand size etc ), to the extent that I thought " this can't be right " I did query this with the SKF rep once, and he sent me some in house research that showed the vast majority of premature bearing failure was over greasing.

Maybe over-greasing is a problem with fast-rotating bearings, but in the 'hostile' environment and slow rotation bicycle parts are subject to the opposite may be true?