ceramic BB?

[young Ed]

so what is so great about ceramic BB's that warrant them to have a price tag of minimum just over 40 quid? what have they over the shimano un55 for example at about 10-15 quid?
Cheers Ed

 

[T.M.H.N.E.T]

They're a different component. UN55 is a cartridge BB with an axle of your choosing through it. A part designed to last a few thousand miles and be trashed.

Ceramic BB's tend to be totally serviceable offer greatly reduced friction, and would be used with higher end chainsets.

 

[Mr Haematocrit]

Ceramic bearings are mostly made using ceramic silicon nitride (Si3N4) which is both lighter and harder than traditional steel bearings, although zirconia is also sometimes used. Steel bearings have a hardness of around 30 million lbs per square inch. Ceramic bearings by comparision measure 47million lbs per square inch.

Thanks to silicon nitride being less dense than steel the bearings are up to a third lighter than comparable components made from steel. In addition due to the extra fine finish they are less prone to friction and therefore create less heat. They also require less lubrication.

One of the main obsessions of the serious cyclist is of course weight so any component that reduces the weight of the bicycle is naturally welcome. However, the performance benefits of ceramic bearings are not chiefly down to the weight savings they offer, but rather from their hardness and surface quality. These combine to create reduced levels of friction. "Ceramic balls are smoother, so they roll with less friction. Most companies offering hybrid-ceramic bearings are using a harder steel alloy for the races (compared to all-steel bearings), which will polish into a smoother surface and compliment the hardness of the ceramic balls."

This reduced friction means that the bearings offer less resistance and so require less energy to roll.

Riders using ceramic bearings can also expect a smoother riding experience. Fitting ceramic bearings will make the bike feel like it is rolling smoother. If a cyclist has ridden a bike fitted with ceramic bearings and then returns to steel bearings, it is likely that slightly more vibration will become noticeable. Jonathan Day of Strada Wheels, says that whilst diffcult to quantify, a possible benefit to this reduced vibration could be less fatigue felt in the legs over the course of a long ride or race.

The relative hardness of ceramic bearings results in increased durability over comparable steel bearings. Ceramic material does not rust, unlike steel, meaning exposure to moisture is less of a concern, particularly for full ceramic bearings. They require less lubrication and do not suffer from pitting.

However, there is a risk of chipping, particularly where they are located in areas that are susceptible to water or grit ingress. So whilst ceramic bearings can last between 5 and 20 times longer than steel bearings it is important that they are fitted and maintained correctly. If so, Jonathan Day says that the increased wear resistance means that an initial investment in ceramic bearings should be paid back over time.

 

[T.M.H.N.E.T]

I'll get my coat

 

[young Ed]

Ceramic bearings are mostly made using ceramic silicon nitride (Si3N4) which is both lighter and harder than traditional steel bearings, although zirconia is also sometimes used. Steel bearings have a hardness of around 30 million lbs per square inch. Ceramic bearings by comparision measure 47million lbs per square inch.

Thanks to silicon nitride being less dense than steel the bearings are up to a third lighter than comparable components made from steel. In addition due to the extra fine finish they are less prone to friction and therefore create less heat. They also require less lubrication.

One of the main obsessions of the serious cyclist is of course weight so any component that reduces the weight of the bicycle is naturally welcome. However, the performance benefits of ceramic bearings are not chiefly down to the weight savings they offer, but rather from their hardness and surface quality. These combine to create reduced levels of friction. "Ceramic balls are smoother, so they roll with less friction. Most companies offering hybrid-ceramic bearings are using a harder steel alloy for the races (compared to all-steel bearings), which will polish into a smoother surface and compliment the hardness of the ceramic balls."

This reduced friction means that the bearings offer less resistance and so require less energy to roll.

Riders using ceramic bearings can also expect a smoother riding experience. Fitting ceramic bearings will make the bike feel like it is rolling smoother. If a cyclist has ridden a bike fitted with ceramic bearings and then returns to steel bearings, it is likely that slightly more vibration will become noticeable. Jonathan Day of Strada Wheels, says that whilst diffcult to quantify, a possible benefit to this reduced vibration could be less fatigue felt in the legs over the course of a long ride or race.

The relative hardness of ceramic bearings results in increased durability over comparable steel bearings. Ceramic material does not rust, unlike steel, meaning exposure to moisture is less of a concern, particularly for full ceramic bearings. They require less lubrication and do not suffer from pitting.

However, there is a risk of chipping, particularly where they are located in areas that are susceptible to water or grit ingress. So whilst ceramic bearings can last between 5 and 20 times longer than steel bearings it is important that they are fitted and maintained correctly. If so, Jonathan Day says that the increased wear resistance means that an initial investment in ceramic bearings should be paid back over time.

you just typed all that just for me?

i feel honored!

so for say cycling to LE and then up to JOG and then back down to kent or the other way round, a ceramic bearing would be better considering it is roughly a 1.7k mile trip? during which i don't really feel like rebuilding the BB on the hard shoulder of a busy A road!
Cheers Ed

 

[Mr Haematocrit]

IMHO a ceramic bearing is always better, but not always needed.

 

[young Ed]

IMHO a ceramic bearing is always better, but not always needed.

TBH you can happily ride round the world on a few un55 so ceramic is not really needed for me at least
might get one when i eventually ride through france and belgium and germany and Netherlands and then up through scandinavia and down through russia and then through estonia etc and then france back to kent
i might get a ceramic for that but i won't be doing that little ride for a while yet!
Cheers Ed

 

[Tim Hall]

One of the main obsessions of the serious cyclist is of course weight .

You sure about that?

 

[Mr Haematocrit]

You sure about that?

It would of course be defined as what you consider to be a serious cyclist.
A serious cyclist to me is someone who is continuously seeking and focused towards improvements in their own performances and that of their bikes, they take a very calculated approach to performance. They cycle to obtain specific goals rather than for the simple enjoyment of cycling.
These are the kinds of people I consider to be serious cyclists when using the term in this instance as the only people I feel purchase ceramic bearings are those looking for marginal gains, or those with more money than sense.

An enthusiastic regular recreational cyclist probably would not be looking at ceramic bearings with wheels and better group sets being more likely performance upgrades

So to answer your question, yes I'm sure (going by my thought process)

 

[Dusty Bin]

Trackies still ride good old square taper - even at elite/world cup level. If it's good enough for them...

so for say cycling to LE and then up to JOG and then back down to kent or the other way round, a ceramic bearing would be better considering it is roughly a 1.7k mile trip? during which i don't really feel like rebuilding the BB on the hard shoulder of a busy A road!

Cyclists (even serious ones) somehow managed to ride thousands of miles before ceramic bearings were invented. Many of them still do...