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.