Difference between decent hubs and very good hubs in watts?
Moderator: robbosmans
I've read somewhere (can't find the link), that the difference between different brand of hubs is very small, if we are talking about performance. Does anyone know the hard data in watts?
Also, how many watts are saved by upgrading to ceramic bearings?
Also, how many watts are saved by upgrading to ceramic bearings?
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I don't know if anyone has tested hubs with representative riding loads. Friction Facts was thinking about it a couple years ago, but I haven't seen anything.
At any rate if the hubs have decent tolerances and bearings aren't preloaded, are properly adjusted, and are broken in, you won't see much difference. Some bearings save a fraction of a watt by using light seals and grease, which quickly disappears as soon as you get dirt in them. Bearings with a small ID will have a little less drag as well. Ceramic bearings can save you a small fraction of a watt, all else being equal.
At any rate if the hubs have decent tolerances and bearings aren't preloaded, are properly adjusted, and are broken in, you won't see much difference. Some bearings save a fraction of a watt by using light seals and grease, which quickly disappears as soon as you get dirt in them. Bearings with a small ID will have a little less drag as well. Ceramic bearings can save you a small fraction of a watt, all else being equal.
formerly rruff...
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Not likely measurable on the road; maybe in a lab.
However, I'd expect that sealing would make a measurable difference - minimalist hubs with just the native cartridge bearing seals vs all weather hubs.
However, I'd expect that sealing would make a measurable difference - minimalist hubs with just the native cartridge bearing seals vs all weather hubs.
petromyzon wrote:Not likely measurable on the road; maybe in a lab.
However, I'd expect that sealing would make a measurable difference - minimalist hubs with just the native cartridge bearing seals vs all weather hubs.
does the sealing make them faster or slower?
Slower. Drag is proportional to seal linear length, given the same seal design. No seal = no seal drag.
The data I've seen comparing bearings and sealing basically shows that once you pass a certain level of roundness/tolerances performance is pretty much indistinguishable. The only benefit to ceramic or ceramic hybrids (of various types) is that you can easily run without seals, that's pretty much the total benefit to ceramic. All the other things like lubrication changes and such are equally applicable (and just as beneficial) in high quality steel bearings. Running seal free on steel is far higher risk though. Doesn't do ceramic much good either, but they'll at least run a few thousand miles in poor conditions before replacement, steel might do a few hundred.
As far as hub designs go, the difference between a good and an excellent hub is unlikely to be in the bearings or drag, unless you are comparing cup and cone with cartridge. Most of it will be weight, shiny toys, brand value (and marketing budget!).
On the other hand, you may have some pretty major differences in freewheel drag depending on design. If you coast a lot this might be an issue.......
The data I've seen comparing bearings and sealing basically shows that once you pass a certain level of roundness/tolerances performance is pretty much indistinguishable. The only benefit to ceramic or ceramic hybrids (of various types) is that you can easily run without seals, that's pretty much the total benefit to ceramic. All the other things like lubrication changes and such are equally applicable (and just as beneficial) in high quality steel bearings. Running seal free on steel is far higher risk though. Doesn't do ceramic much good either, but they'll at least run a few thousand miles in poor conditions before replacement, steel might do a few hundred.
As far as hub designs go, the difference between a good and an excellent hub is unlikely to be in the bearings or drag, unless you are comparing cup and cone with cartridge. Most of it will be weight, shiny toys, brand value (and marketing budget!).
On the other hand, you may have some pretty major differences in freewheel drag depending on design. If you coast a lot this might be an issue.......
mattr wrote:
As far as hub designs go, the difference between a good and an excellent hub is unlikely to be in the bearings or drag, unless you are comparing cup and cone with cartridge. Most of it will be weight, shiny toys, brand value (and marketing budget!).
On the other hand, you may have some pretty major differences in freewheel drag depending on design. If you coast a lot this might be an issue.......
These are important issues if true - would be interesting to see how cup and cone hubs compare vs cartridge and also some data on freewheel drag.
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Friction facts has measured the difference in bearings in Bottom brackets and pulleys. The results are most likely going to be quite similar. you can buy their report if you want. If I remember correctly the difference between the best and worst was at most around 1 watt.
As an engineer I would say theres very little point in investing in ceramic bearings. lots is made of ABEC grades of bearings, etc, but honestly the lodas placed upon bearings are so insignificant it doesnt matter. pay more attnetion to making sure your bearings are well mantained and yu wont be losing anything.
As an engineer I would say theres very little point in investing in ceramic bearings. lots is made of ABEC grades of bearings, etc, but honestly the lodas placed upon bearings are so insignificant it doesnt matter. pay more attnetion to making sure your bearings are well mantained and yu wont be losing anything.
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Bearing and freehub drag tends to be really very small between most properly-adjusted hubs. I recall the Friction Facts test, even if the conditions were not ride-load representative (I cannot recall off the top of my head), was around a watt or less. Much moreso than wattage lost to bearing drag, the biggest difference on is likely to observe between hubs is the lateral stiffness of the final wheel.
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Customers often ask me what the benefit of an expensive hub is and it is sometimes in bearing life but that is more to do with the design of the hub rather than the quality of the bearings although that can play a part. Expensive hubs though do jot have the monopoly on long bearing life though.
So expensive hubs are nice if they are reliable but it is mostly a weight or bling thing. I roll around on miche hubs and will continue to do so as they are cheap and reliable. I do have some other hubs like campagnolo record and chorus and some dura ace but I can't say they are better at doing the job of a hub than miche. There are some difference in geometry that can be useful but no hub is perfect, there is always a compromise somewhere.
Ceramic bearings are a joke. Never sold one and am not likely to either with my opinion of them. They offer a reliability advantage if they are good and that's about it but given the price it's not really worth it.
So expensive hubs are nice if they are reliable but it is mostly a weight or bling thing. I roll around on miche hubs and will continue to do so as they are cheap and reliable. I do have some other hubs like campagnolo record and chorus and some dura ace but I can't say they are better at doing the job of a hub than miche. There are some difference in geometry that can be useful but no hub is perfect, there is always a compromise somewhere.
Ceramic bearings are a joke. Never sold one and am not likely to either with my opinion of them. They offer a reliability advantage if they are good and that's about it but given the price it's not really worth it.
So whats the opinion of Extralite hubs? Specifically the CyberFront/Rear SP? I was interested in building up a set of alloy wheels with these hubs but I've been advised that they aren't very durable and mainly for limited "special" use only. Cant find a lot of reviews for these hubs so figured I'd ask in here.
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It is the rear hub that is likely to give shorter bearing life not the front. Extralite has changed the rear hub so there two bearing in the free hub rather than one and bushing which will help. I think fair wheel did a review and they find they are reliable enough they just need regular attention (preloaded adjustment).
https://fairwheelbikes.com/c/reviews-an ... ub-review/
https://fairwheelbikes.com/c/reviews-an ... ub-review/
Thanks, a lot of good posts here.
So I guess, the generel opinion is, that if we are talking bearings, and the hubs and bearings are
1) properly adjusted, and
2) well serviced,
then the difference between decent and excellent hubs is minimal and no more than 1-2 watts?
So I guess, the generel opinion is, that if we are talking bearings, and the hubs and bearings are
1) properly adjusted, and
2) well serviced,
then the difference between decent and excellent hubs is minimal and no more than 1-2 watts?
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