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Ceramic bearings are said to offer reduced friction, lower weight and improved longevity. But are they worth the expense?

Despite the latest advances in road bike design and technology, your bicycle still relies on the humble ball bearing to ensure it all runs smoothly. There are bearings in the wheel hubs, the headset, bottom bracket, pedals and jockey wheels, and they're commonly made from steel. There has been a lot of hype about ceramic bearings in recent years and many people claim they offer a performance upgrade. But what are ceramic bearings and what are the pros and cons?

While regular bearings are made from stainless steel, ceramic bearings are made from ceramic silicon nitride (Si2N4). Rolling resistance is the key trump card promoted by ceramic bearing fans. Because ceramic bearings are rounder with a smoother surface and more uniform size, friction is reduced and that can contribute to a less energy required to turn the cranks or spin the wheels. A ceramic bearing is also harder than steel bearings (up to 30%), which improves durability, and they also don’t rust so less maintenance should be required. 

Most sealed ceramic bearings are actually hybrid ceramic bearings, which combine a steel race with ceramic ball bearings. Full ceramic bearings use ceramic races, which can be lighter and provide the lowest friction, but come at a durability cost. Unsealed ceramic bearings can be used to upgrade components that don’t use cartridge type bearings, like cup and cone hubs.

ceramicspeed bearings1.jpg

ceramicspeed bearings1.jpg

It’s in the professional peloton, a sport obsessed with marginal gains, that ceramic bearings have become popular in the past couple of years. And naturally, where pros lead, amateur racers and sportive cyclists follow, keen to take advantage. Should you be following in the footsteps of the pro racers then, and upgrading your bike with ceramic bearings?

CeramicSpeed is a Danish company, founded in 2007, that specialises in supplying high-quality ceramic bearings to the cycling industry, and is a favourite of many professional cycling teams - you don’t have to look far to spot the telltale company sticker on any frame or hub fitted with the bearings. It’s seen a massive shift in the last two years with more customers keen to take up the ceramic advantage. The advantage, according to the company, is a saving of up to 9 watts with CeramicSpeed bearings in the hubs, jockey wheels and bottom brackets compared to a set of standard bearings

“The main advantages with CeramicSpeed bearings over regular bearings are two-fold,” explains CeramicSpeed Managing Director Martin Banke. “Longevity of a well-built high-quality ceramic bearing, in many cases, can be up to 10 times longer than commonly used stock bearings. The 'rule of thumb', as we like to call it when built well, and of high-quality materials, a ceramic bearing should always be able to outlast and outperform a steel bearing.

“The second advantage of ceramic bearings over stock steel bearings is their performance under load in reducing drag. Performance cyclists are performance driven and all data shows that the best performing bearings for reducing drag are ceramic bearings.”

ceramicspeed bearings2.jpg

ceramicspeed bearings2.jpg

That, in theory, should mean less energy is required to turn the wheels or cranks. Add the lower weight and improved durability, and why wouldn’t you run ceramic bearings? But are all ceramic bearings the same? Of course not, CeramicSpeed is keen to point out that not all ceramic bearings are made equal, and it tells us that a ceramic bearing built poorly with low-quality materials will deliver very poor longevity.

“A lot of bearings can spin well in the hand but that by itself is not enough,” says Banke. “It is really about the performance of a bearing under load, both drag reducing performance and lifetime performance. We are now starting to see a 'shift in the seas', a common understanding that ceramic does last and is very advantageous if of a high enough quality.”

When the benefits sound that good, you’d think all component manufacturers would be embracing ceramic bearings, right? Highly regarded British component manufacturer Hope Technology reckons the efficiency savings are simply too negligible to make them worth the increase in cost.

“We have looked at ceramic bearings in the past and talked them over with our bearing suppliers,” explains Hope’s Alan Weatherill. “They do run with less friction, which offers a significant advantage in industrial applications running at 20,000 rpm. A tiny percentage reduction in friction here can equate to a worthwhile power saving, but when you're only turning at 300 rpm, as you do on a bicycle a small percentage increase in efficiency will make a negligible change to your power output. Certainly not worth the significant increase in cost."

Paul Lew 1.jpg

Paul Lew 1.jpg

Director of Technology & Innovation at Reynolds Wheels, Paul Lew, backs this up and reckons it makes ceramic bearings a poor choice for hubs and headsets, also adding that they offer no weight savings and are only beneficial in environments where high rpm (revolutions per minute) are required.

“For bottom bracket applications, the maximum sustained rpm may be 130,” explains Lew.  “For wheel hub applications, the maximum rpm may be 500 – 600 revolutions per kilometer (depends on wheel/tyre diameter). The maximum rpm values in cycling are far below the typical ideal rating for ceramic bearings which is 10,000 rpm+.”

It’s clear that Alan and Paul agree that the factors that make a ceramic bearing well-suited to industrial and medical equipment applications, and high-altitude operating drone motors (Paul does a lot of work designing drones) where the rpm is high, the load is low and the operating conditions are clean, are factors that mean they’re not suited to cycling.

“Ceramic bearings are beneficial in environments not requiring grease lubrication,” says Lew.  But a bicycle is expected to cope with a vast range of conditions, rain and dirt, and where maintenance schedules may be less than optimal, and the last thing you want is to ride bearings without grease. It’s this requirement to cope with the conditions common to cyclists that offset the promised lower rolling resistance of a ceramic bearing, according to Paul Lew.

“The rolling resistance of a ceramic bearing compared to an ABEC 3, 5 or 7 steel ball bearing is offset by the resistance of the grease,” he says.  “In order for a ceramic ball bearing to out-perform a steel ball bearing, grease is not an option. Does this mean I should run my ceramic ball bearings dry or with light oil? Yes, but you won’t like the result in an environment where the bearings can become contaminated.  If you run your bearings dry they will feel gritty and rough.”

bearings headset.jpg

bearings headset.jpg

Hope’s Alan Weatherill concurs with Paul Lew’s conclusion that ceramic bearings are not suited to the demands of cycling and says their suitability to industrial machinery doesn’t necessarily provide the performance benefit for cyclists that many people and companies claim they do.

“Another issue with using them [ceramic bearings] on bicycles is their hardness,” says Weatherill. “While this again is an advantage in many industrial applications, it's a major drawback on bikes. The shocks from hitting potholes and other road blemishes impact the hard ceramic balls into the softer steel races commonly used. This dent in the race is then felt when the bearing is rotated, giving you rough bearings.”

Then there is the fact that Ceramic bearings aren’t cheap. CeramicSpeed’s BSA Road external bottom bracket for threaded frames costs £298. A Shimano Dura-Ace 9000 bottom bracket cost £39.99, much less if you shop around. A CeramicSpeed bearing upgrade kit for Campagnolo and Fulcrum wheels will set you back £120, and Zipp charges £194 for a CeramicSpeed bearing kit for its wheels. That makes upgrading to ceramic bearings a serious investment, fine for a professional cycling team, less so for a privateer racer.

obb_gxp_mixed_800.jpg

obb_gxp_mixed_800.jpg

The premium for ceramic bearings is high then, and their advantages, while looking promising in an ideal world, appear to stack up much less in the demanding environment that a bicycle is expected to perform and survive in.  So should you choose ceramic bearings? We’ll let Paul Lew have the last word.

“Although the re-selling markup/ margin for ceramic bearings is significant for manufacturers such as Reynolds, and they could represent a profit-center for the brand, we choose not to offer them because they don’t improve performance, and they represent a consumer cost that we can’t justify, and that’s contrary to our value system," he concludes.

David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.

53 comments

Avatar
KiwiMike [1303 posts] 1 year ago
29 likes

Hey - I thought Road.CC was all about taking advertiser's cash, pushing marketing hype and obligatory 4-star reviews?

 

Damn. We're gonna need a better conspiracy theory.

 

smiley

Avatar
Toro Toro [173 posts] 1 year ago
5 likes

Road.cc accused of pushing marketing hype by readers.

Road.cc publishes article downplaying marketing hype.

Regular road.cc contributor promptly comments on how this disproves the "conspiracy theory" that road.cc pushes marketing hype.

Hmm.

I dunno, it's not exactly Operation Jade Helm, is it?

 

Avatar
MMinSC [10 posts] 1 year ago
10 likes

C'mon guys, this isn't BikeRadar...

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Bobbinogs [250 posts] 1 year ago
8 likes

I thought that was an excellent article that explained things and tried to keep things balanced without pushing one way or the other.  Cheers.

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ellisblackman [6 posts] 1 year ago
1 like

+1 for ceramic bearings. 

However, I've had noticeable results from cleaning bearings, sticking an airline on them, getting them up to speed and dropping a tad of Shimano Mineral Oil on them.

I then put the outer seals on (leaving the inners off) and press back into place.

With this combo, you get quicker spool up from reduced drag, lower energy needed to push the wheels round and a reasonable amount of sealing for the British roads. 
Obviously, I wouldn't do this on my training wheels but it's certainly worthwhile on your good set & cheaper than a set of ceramics to boot.

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djbambina [5 posts] 1 year ago
2 likes

interesting that Paul Lew says the extra hard ceramics put dents in steel races... ummm, so do normal steel balls ! if they didn't then they'd break. ( ellisblackman) -Flushing out heavy grease in steel bearings is fine if you are doing a short race on the track like a sprint or kilo, but on the road the hubs get really hot because there is no heat dissaption from grease ( ceramics naturally absorb the heat). i've seen hubs completely disintegrate due to this, with slightly catastrophic results . What i do know is that CeramicSpeed quality ceramics accelerate better, as all of the balls are exactly the same size, as all of them make contact with the races, so the BB is up to 30% stiffer. I believe Lew doesn't offer them because he wants to keep his wheels in a price band - not because they don't make a difference. I've seen SRM and Powertap data that says 10-15 watts difference - same day, same bike, CeramicSpeed bearings.

    

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Rixter [53 posts] 1 year ago
4 likes

That was a good blog. I thought very well balanced. Personally I've never had success with ceramic bearings. I couldn't notice a difference when they were running in my hubs, but I certainly noticed they didn't have the longevity I would expect for the price (they were installed as part of the new wheel purchase). Two techs I spoke with at major bike manufacturers said they would recommend staying well away from them in future. 

If I had my own pro mechanic and cost was not a consideration, I would go ceramic. Since I'm not blessed with a mechanic and cost is a factor, its steel for me  3

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BBB [456 posts] 1 year ago
0 likes

So... apart from the typical "up to .... watts savings" (in the extreme scenario) marketing bs, are they any INDEPENDENT studies proving the claimed benefits for a typical non-competing rider? 

 

 

 

 

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hsiaolc [357 posts] 1 year ago
0 likes

What about titanium beerings?  

 

 

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Morat [263 posts] 1 year ago
3 likes

So... steel bearings are probably better. Hmm. Can you get the sticker on its own?  1

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adam900710 [67 posts] 1 year ago
2 likes
Quote:

ceramic bearings are made from ceramic silicon nitride (Si2N4)

 

The correct one is Si3N4.....

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macrophotofly [273 posts] 1 year ago
2 likes

Bought some Ceramic bearings for my BB from one of the main competitors to Ceramic Speed (similar major cost). Initially impressed with them dry (straight out the box in my hand) but by the time the supplied grease was added and the seals were on there was no difference to the old quality steel bearings.

I certainly didn't see my watt output increase. I have two bikes with identical drive trains apart from the ceramic bearings and swapping between them provides no measurable difference on an indoor trainer with power measurement (Kickr).

I would say save your money and spend some of it on quality steel bearings. Get ones with the highest ABEC rating - it doesn't guarantee the material quality only the roundness, but at least it is something

Avatar
KiwiMike [1303 posts] 1 year ago
3 likes
Toro Toro wrote:

Road.cc accused of pushing marketing hype by readers.

Road.cc publishes article downplaying marketing hype.

Regular road.cc contributor promptly comments on how this disproves the "conspiracy theory" that road.cc pushes marketing hype.

Hmm.

I dunno, it's not exactly Operation Jade Helm, is it?

 

 

HaHa! You fell for the oldest trick in the book (apart from not getting involved in a land war in South-East Asia): Now that you've caught me out, we are free to continue our nefarious plans to have Wiggle buy EVERYONE and do EVERYTHING bike-related in a nifty pastel block print / green anodised finish / 30mm width / disc-braked.

 

[drums fingers] Excellent.

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hampstead_bandit [614 posts] 1 year ago
2 likes

we used to fit ceramic speed bearings to all the S-Works custom builds in our workshop because they came supplied with the frame

the poor BB design (OSBB) with the press fitted nylon cups which tended to 'walk' under load actually caused the bearings to fail long before any wattage savings could be experienced

we'd replace them with regular BB30 steel bearings and those nylon cups bonded with DP420 epoxy,  and riders said there was no difference in feel at crank?

I know in mountain biking we would not use ceramic bearings due to constant impacts / shock loads, can't see it being any different in road cycling due to the state of our highways

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Huw Watkins [148 posts] 1 year ago
0 likes

I've replaced all my Campag Ultra-Torque orginal bearings with Boca Bearings' 'Yellow Seal' ceramics.  Not so much for reduced friction but for far greater durability than afforded by the rubbish that come fitted.  Have never seen the alleged pitting issues.

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earth [357 posts] 1 year ago
1 like
djbambina wrote:

interesting that Paul Lew says the extra hard ceramics put dents in steel races... ummm, so do normal steel balls ! if they didn't then they'd break. ( ellisblackman) -Flushing out heavy grease in steel bearings is fine if you are doing a short race on the track like a sprint or kilo, but on the road the hubs get really hot because there is no heat dissaption from grease ( ceramics naturally absorb the heat). i've seen hubs completely disintegrate due to this, with slightly catastrophic results . What i do know is that CeramicSpeed quality ceramics accelerate better, as all of the balls are exactly the same size, as all of them make contact with the races, so the BB is up to 30% stiffer. I believe Lew doesn't offer them because he wants to keep his wheels in a price band - not because they don't make a difference. I've seen SRM and Powertap data that says 10-15 watts difference - same day, same bike, CeramicSpeed bearings.

    

 

I emailed Reynolds Composites about ceramic bearing well before Paul was employeed by them.  Remember he had his own company called Lew I think and he brought the wheel he made to Reynolds and called it the RZR.  When I asked Reynolds about ceramic bearing they said back then that did not think there was any benefit.  The guy I spoke to said sometimes for short races he ran his steel bearings without seals and got the improvement offered by ceramics but without the cost.  I think they just genuinely don't rate them.  If they did they could always offer an option.

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kev-s [271 posts] 1 year ago
8 likes

When it comes to wheel bearings your best bet is to replace the cheap chinese bearings that come in the majority of sub £500 wheels these days

 

Rather than pay out loads for ceramics try a nice set of japanese skf or nsk bearings from your local bearing supplier, these will outlast any chinese bearing, will cost around £10 more per bearing than the chinese equvilant but no way near as much as a ceramic one would be

 

These bearings are used in industrial machinery and in manufacturing process lines, conveyor bets, rollers etc.. so are hard wearing and smooth rolling, designed to last

 

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JonD [473 posts] 1 year ago
1 like

Mebbe worth adding that there's been a big market in counterfeit bearings for the last handful or years or more. Tbh I dunno how you'd descriminate, but google is your friend.
As for ceramic bearings or buggerall lube - the no of watts you'd save is down in the noise..

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hampstead_bandit [614 posts] 1 year ago
1 like

@kev-s

you make a very good point about cheap bearings. Its something I saw in mountain biking full suspension frames some years back, they used to come fitted with quality bearings on the pivots, and then they started turning up with unbranded generic bearings that would cr*p out after 2-3 months of riding, or actually feel graunchy from new! 

Obviously a massive cost saving for the frame manufacturer if saving $40 on a set of bearings and selling 30,000 frames a year! 

We used to refit the frames with quality Japanese or German bearings sourced by an industrial bearing supplier in Park Royal, and these would last several seasons without issue. Well worth the £5-6 each bearing cost. 

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Ham-planet [112 posts] 1 year ago
0 likes
djbambina wrote:

interesting that Paul Lew says the extra hard ceramics put dents in steel races...

I've never seen him espouse such an opinion. Got a link for that?

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vbvb [620 posts] 1 year ago
0 likes

I think I'll go back to an internal bb next time, for my lightweight commuter bike.

My thinking is, smaller spindle, less stiff (in theory), bigger bearings, much longer lasting (in reality).

The external bearing design is great but only for the first 1000 miles or so.

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Fish_n_Chips [513 posts] 1 year ago
1 like

Interesting article.

I would definitely use if I was a professional racer.

For someone who just enjoys riding, keeping the price realistic and reliability: I'll stick to steel bearings and grease.

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Simon E [3076 posts] 1 year ago
0 likes

Plenty of opinions on bearings (backed up by years of research) from Keith Bontrager in this fascinating Velocast interview. Well worth a listen:

http://velocastcc.squarespace.com/tech5/2016/4/23/episode-34-keith-bontr...

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KiwiMike [1303 posts] 1 year ago
0 likes

Latest related review on the Tacx ceramic bearing jockey wheels is here: http://road.cc/content/review/199145-tacx-t4035-jockey-wheels

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zanf [950 posts] 1 year ago
11 likes

I've been using a ceramic hob for years but its not improved my cycling at all.

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kellyllek [2 posts] 8 months ago
1 like

Much like the 'science' of nutrition or tyre sealant people spin things (pun intended) any way they want. Adding to this most user info is purely emperical. 

I did appreciate though that Martin Banke talks about the performance benefits under load:

"The second advantage of ceramic bearings over stock steel bearings is their performance under load in reducing drag. "

That's what I wonder about. Seeing the demos of the little bearing spinning forever appears pointless to me. I want to know what difference is there under load?  Really it's not just about ceramics, but what about as bearing start to wear and you notice a bit of a grit.. or anything less than perfect. Say I hand spin the wheel and it comes to a stop  sooner than when the bearings are new;   what does that really mean when I'm riding? No differnece? Or 10 watts?  more? 

But I can't imagine this isn't easy to figure out. I see so many aerodynamic windtunnel tests; why not tests with bearings under load. All you'd have to do is take virtually anyone's bike that's been on the road for a few month and test it out. Then replace the bearings, either with new ceramic, or steel, and do the same test, and see if there really is an improvement.  Compare the new steal to the new ceramic, and different manufactures, and provide some real evidence. Don't just spin a little bearing in your hand and pretend it's proof! 

My guess is there is some marginal differnce. But marginal, as a racer, can be huge! And I suppose it's impossible for tests to quantify the psychological gains you get too. If my chain runs dry my bike feels slow. If I lube it up in the middle of a ride I feel much faster. I sincerely believe that a lubed chain vs a dry chain is like 10 or 20 watts faster. Is that real? Is it purely psychological? Or both?  

I was checking this article out though because of another issue; brake pad drag. I went up the Combe Lane climb near London on Sunday and I was one full minute slower than my last time up a few months ago. I was carrying a couple extra things on the bike, but my weight is more or less the same. Did I miss my morning coffee? Was it the extra hours spend on the bike during the week? The garmin popped up with the segment an I could see the seconds I was falling back to my PR with every pedal stroke. Yet I didn't feel that weak: I didn't feel like I should be a minute slower! 

C'est la vie! But I was in the garage last night and making some adjustments when I hand spun the rear wheel, and there was some brake pad drag (disk brakes). I estimate the wheel came to a stop within 10 revolutions rather than maybe 30.  Did that make a wattage differece? Under load would it be more? Then I spun the front one and wow, that came to a stop within 3 revolutions! There was a ton of drag there!  But is it really a significan difference under load on a slow climb? Will that account for my full 60 second difference on a 5min climb?? (I hope and wish!) 

This happens all the time with MTB disk brakes. Most often not as bad as my bike is now but the brake pads can easily be hitting the rotor and causing a minor drag. But even that small drag is probaby way more significant than the difference between the average ceramic vs steel bearings. I really wonder how much all this makes a difference though, under load? 

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fabriciomrtnz [11 posts] 5 months ago
2 likes

I build my wheels and tried a set of hybrid ceramic bearings. They lasted me about a month. My best set of wheels has SKF ABEC 5 steel bearings. They are my everyday wheels and are going for 2 years now.

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KINGHORN [21 posts] 5 months ago
0 likes
djbambina wrote:

interesting that Paul Lew says the extra hard ceramics put dents in steel races... ummm, so do normal steel balls ! if they didn't then they'd break. ( ellisblackman) -Flushing out heavy grease in steel bearings is fine if you are doing a short race on the track like a sprint or kilo, but on the road the hubs get really hot because there is no heat dissaption from grease ( ceramics naturally absorb the heat). i've seen hubs completely disintegrate due to this, with slightly catastrophic results . What i do know is that CeramicSpeed quality ceramics accelerate better, as all of the balls are exactly the same size, as all of them make contact with the races, so the BB is up to 30% stiffer. I believe Lew doesn't offer them because he wants to keep his wheels in a price band - not because they don't make a difference. I've seen SRM and Powertap data that says 10-15 watts difference - same day, same bike, CeramicSpeed bearings.

    

I for one love Ceramspeed BB bearings, definitley spin alot easier, then the fact they have a longer life makes it alot more appealing. I can destroy my shimano press fits in a cpl of months, but these feel as new after 6 months (with a little more labour of course, regreasing).

I wint go for their jockey wheels though, I never have a problem with standard ones and the gains just not worth the cost.

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watlina [80 posts] 5 months ago
0 likes

The Rovel CLX 40 Disc wheels from my S-Works Roubiax are in the LBS this week having the Ceramic Speed bearings changed out to decent steel ones. The front ones only lasted about 5,000 miles before they felt like rocks going round.

Ceramic Speed want £400+ for a new 5 bearing set, a set of good quality steel ones is less than £100

At the moment I've left the BB and headset ones in place as they seem ok.

 

 

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thelighterthief [42 posts] 5 months ago
0 likes

If hard bearings dent the races on bumpy terrain does that mean a frameset with an integrated headset is going to be ruined by a rough road or two?

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