SKF vs. NTN - fully sealed bearings

Discuss light weight issues concerning road bikes & parts.
hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

kode54 wrote:
Tue Feb 13, 2018 7:58 pm
@hambini,

difficult to get NTN in the US, but as others noted, the Makita 6806 LLU bearings are easy to source. will I notice much of a difference?
If you spin it in your fingers you will instantly notice the difference. However that isn't representative of real life so under riding conditions I doubt you would notice or feel the difference. If you talk numbers, the LLU has around double the friction of the LLB - both numbers are small though.

The Makita 6806 LLU and power tool bearings as a whole are often C3. This one might not be but it's something to consider. In a C3 bearing the axial load capability increases at the expense of radial load capability. In essence you will create more friction purely by geometry.

I have written a section on it here. You will need to scroll down the page a bit. It's ultra condensed and simplified but should give you an idea.

https://www.hambini.com/technical-suppo ... re=default

Hope that helps

Hambini

by Weenie


vinuneuro
Posts: 103
Joined: Mon Mar 06, 2017 10:34 pm
Location: Chicago

by vinuneuro

Hambini thanks for pointing that out. I'd imagine the bearing type is dependent on application. Cutting tools probably use CN bearings, but looks like this one is spec'd in a rotary hammer so it's almost certainly C3 or greater. Unfortunately since you don't get a NSK box with OE parts there's no way to know the full part number.

It's a shame bearing supply doesn't seem to be as abundant here in the US. I have almost everything for the rebuild, silly that bottom bracket bearings would hold things up. If I'm not able to find a reasonably priced US source, will order from Hambini.
'16 Spec Diverge Expert

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

vinuneuro wrote:
Wed Feb 14, 2018 3:00 am
Hambini thanks for pointing that out. I'd imagine the bearing type is dependent on application. Cutting tools probably use CN bearings, but looks like this one is spec'd in a rotary hammer so it's almost certainly C3 or greater. Unfortunately since you don't get a NSK box with OE parts there's no way to know the full part number.

It's a shame bearing supply doesn't seem to be as abundant here in the US. I have almost everything for the rebuild, silly that bottom bracket bearings would hold things up. If I'm not able to find a reasonably priced US source, will order from Hambini.
You are welcome.

When I was last in the US and needed some industrial supply (they weren't bike bearings), I used two companies. One called Fastenal and the other called Grainger. Despite having a trade account, the bearings were about the same price as in Europe. I was expecting them to be cheaper.

NTN supply in to the US doesn't seem that good. It's only an observation but NSK seem like the premier Japanese bearing supplier in the US. The hierarchy is SKF, NSK, Timken. In Europe it tends to be SKF, INA/FAG, NTN/NSK

HTH

Hambini

bobones
Posts: 46
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Hambini, do you have an opinion on EZO bearings, which are a Japanese brand made by Sapporo Precision Group?

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

bobones wrote:
Wed Feb 14, 2018 2:09 pm
Hambini, do you have an opinion on EZO bearings, which are a Japanese brand made by Sapporo Precision Group?
Yes. They are of slightly above average quality (better than far eastern non name but not a Tier 1), the load ratings they list are amongst the highest available but in practice the bearing stiffness is not great, this indicates a geometrical or material difference. SKF and NTN bearing stiffness is higher. EZO bearing tolerances are not a patch on NTN, SKF. What I'm trying to say is if you buy an NTN/SKF/FAG/NSK bearing you will find the difference between the biggest and smallest bearing measured is ~0.001mm. On an EZO it's more like 0.009. It's still within the ISO/JIS/DIN standard and probably indistinguishable to the end user but if you are in the game of making bottom brackets/wheel hubs etc, you can feel the difference. This is the reason why I do not warrant my bottom brackets if the end user elects to replace the bearings with non Tier 1 bearing suppliers - the fit is compromised and the friction and life go in opposite directions.

A lot of cyclists have a high opinion of EZO bearings because of a blog post written by FLO cycling which is here

http://flocycling.blogspot.fr/2011/07/f ... 1-ezo.html

In my professional opinion. The above article has some very poor engineering practices: Measuring bearings with a vernier and proclaiming their accuracy levels, an L10 bearing life calculation that is completely wrong and a few more "questionable" lines of thought. I think it's reasonable to expect a wheel supplier to have an understanding of how bearings work and not make a hash of it.

I appreciate some people will be lovers of FLO cycling and EZO bearings but there are better ones out there.

If we park my engineering opinions to one side and look at the end users. I supply a number of triathletes and two racing teams with bottom brackets/wheel bearings. Almost all of them ride on NTN, there are a very small number that ride on SKF - usually unsealed bearings with oil as the lubricant. In cyclocross, it's completely different, The lion share are people riding on FAG/INA and about 30-40% on a combination of NTN/SKF. Out of the people I know who used to use EZO, all of them prefer NTN or SKF RZ.

HTH

Hambini

bobones
Posts: 46
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Thanks, that's great information. My own personal experience is that EZO don't last particularly well in UK winter or wet conditions, so I'll be going for SKF, NTN or FAG in future.

kode54
Posts: 1266
Joined: Tue May 23, 2006 9:39 pm

by kode54

thx for all this valuable info. all...great to know going forward.

i have checked out your website and try some NTN bearings first.
hambini wrote:
Tue Feb 13, 2018 11:07 pm
kode54 wrote:
Tue Feb 13, 2018 7:58 pm
@hambini,

difficult to get NTN in the US, but as others noted, the Makita 6806 LLU bearings are easy to source. will I notice much of a difference?
If you spin it in your fingers you will instantly notice the difference. However that isn't representative of real life so under riding conditions I doubt you would notice or feel the difference. If you talk numbers, the LLU has around double the friction of the LLB - both numbers are small though.

The Makita 6806 LLU and power tool bearings as a whole are often C3. This one might not be but it's something to consider. In a C3 bearing the axial load capability increases at the expense of radial load capability. In essence you will create more friction purely by geometry.

I have written a section on it here. You will need to scroll down the page a bit. It's ultra condensed and simplified but should give you an idea.

https://www.hambini.com/technical-suppo ... re=default

Hope that helps

Hambini
- AX Lightness Vial EVO D + DA9150 + Enve SES 4.5 carbon hubs
- Parlee Altum + DA9150 + Enve SES 4.5 carbon hubs
- Parlee ESX + DA9150 + THM SRM PM + Enve SES 6.7 CK hubs
- Guru Praemio R Titanium + DA9150 + Enve 3.4 CK hubs

mrlobber
Posts: 722
Joined: Sat Oct 23, 2010 9:36 am
Location: Where the permanent autumn is

by mrlobber

How about 4130 bearings (for 30mm cranks in PF86 frames), are they available from NTN, hambini?

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

mrlobber wrote:
Wed Feb 14, 2018 5:00 pm
How about 4130 bearings (for 30mm cranks in PF86 frames), are they available from NTN, hambini?
Afraid not. Shimano deliberately made their shells 41mm to prevent anyone using a 6806 bearing (which has 42mm OD). All of the conversion systems I have seen use either a 6806 bearing and grind the outside down or a 6706 bearing which is seriously thin. Both have a load rating that is 1/4 of a standard bearing. If you are putting out lots of torque, they won't last long at all.

Hambini

vinuneuro
Posts: 103
Joined: Mon Mar 06, 2017 10:34 pm
Location: Chicago

by vinuneuro

NSK usa office says that if it is C3 it would be marked on the inner or outer race. These Makita oe bearings are marked 6806D on the seal (brown color indicating DDU) and nothing on the inner race, so they are saying that it is a normal CN bearing. I will use these and see how they go.

Fwiw, I also got the DDW (light contact seal) and in the hand the friction difference is noticeable. I imagine the no contact seals are even better. But as discussed and tested it must be some fraction of a watt so will go for the longevity.
'16 Spec Diverge Expert

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

vinuneuro wrote:
Wed Feb 14, 2018 6:59 pm
NSK usa office says that if it is C3 it would be marked on the inner or outer race. These Makita oe bearings are marked 6806D on the seal (brown color indicating DDU) and nothing on the inner race, so they are saying that it is a normal CN bearing. I will use these and see how they go.

Fwiw, I also got the DDW (light contact seal) and in the hand the friction difference is noticeable. I imagine the no contact seals are even better. But as discussed and tested it must be some fraction of a watt so will go for the longevity.
From memory I thought they were marked on the outer race but it was such a long time ago that I saw one that I could be wrong.

Hambini

mrlobber
Posts: 722
Joined: Sat Oct 23, 2010 9:36 am
Location: Where the permanent autumn is

by mrlobber

hambini wrote:
Wed Feb 14, 2018 6:37 pm
Afraid not. Shimano deliberately made their shells 41mm to prevent anyone using a 6806 bearing (which has 42mm OD). All of the conversion systems I have seen use either a 6806 bearing and grind the outside down or a 6706 bearing which is seriously thin. Both have a load rating that is 1/4 of a standard bearing. If you are putting out lots of torque, they won't last long at all.
Bastards.

Thanks for the reply. At least with BB30/BBright/BB386 we have options :thumbup:

pdlpsher1
Posts: 1604
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

Hi Hambini,

I have some new NTN bearings in my Fulcrum wheels. The drag seems very high. I have about 100 miles in so far but the drag didn’t seem to decrease. Would I expect the drag to go down with more miles? I’m not sure if the extra drag is from the seals (LLU) or the type of grease fill, or both. I’m comparing the drag to the standard bearings I had that came with the wheels which are marked 2RS (except the 6803s in the freehub which only had one shield per bearing). Thanks.


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hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

pdlpsher1 wrote:
Thu Feb 15, 2018 1:56 am
Hi Hambini,

I have some new NTN bearings in my Fulcrum wheels. The drag seems very high. I have about 100 miles in so far but the drag didn’t seem to decrease. Would I expect the drag to go down with more miles? I’m not sure if the extra drag is from the seals (LLU) or the type of grease fill, or both. I’m comparing the drag to the standard bearings I had that came with the wheels which are marked 2RS (except the 6803s in the freehub which only had one shield per bearing). Thanks.


Sent from my iPhone using Tapatalk

NTN seals are very good and seal well. However at low RPM the seal friction is the dominant force. Hence if you are spinning them at finger speed then they will feel a lot more draggy (even more than SKF, NSK and FAG). At operating speed, the seal friction will remain the same but is a much lower proportion of the entire drag. This is difficult to demonstrate because the consumer typically cannot spin a bearing up to operating speed in their figures.

NTN seals also do not "lift" until you hit around 40-60RPM (depends on the size). Below that speed they are designed to statically seal whereas most others are not.

HTH

Hambini

pdlpsher1
Posts: 1604
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

Thanks for the good info Hambini. If I had known about this earlier I would have removed one seal per bearing before I installed the bearings. This would have saved me half of the total seal drag. I have watched one bearing video by Oz Cycling (link provided in thread) and he found that seal drag is minuscule compared to drag from the grease. I guess I could also do the experiment myself by removing the seals on a new NTN bearing however I’m afraid of damaging the seals. I hope the seals will break-in somewhat after more miles. I also have a set of Campy Boras that don’t use sealed bearings. And those wheels spin forever compared to my other set that uses sealed bearings.


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by Weenie


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