I am on an SL7 with a GXP BB as I have a SRAM crankset. A buddy of mine said I should consider going ceramic and insists I look into ceramicspeed or Kogel. Is there any value in spending hundreds of dollars on a ceramic BB or is just snake oil and marketing to get people to buy another component with very little wattage saved? Thanks for any info!

INHO a waste of money. Putting ceramic ball bearings in your bottom bracket will not make you faster or a better rider nor will your races last longer, especially if you never service the BB. I don't know the GXP BB off the top of my head, but guessing it takes standard 1/4" bearings or maybe sealed cartridge bearings. I'd simply service it if it was needed.

You might save a few watts, but typical usage, they wear out faster. It is because the balls are much harder than the races, so races wear out. I believe it made the GCN list for least cost effective upgrades.

The single biggest waste of money in the entire industry. Ceramic bearings are great in pure radial loads, clean environments, high heat, and very high (thousands and thousands) rpm applications. None of which happen with a bicycle.

If you go ceramic you have to go all in, BB, Hubs and Jockey wheels. I spent 8 weeks test ceramics based on Power, Speed, Heart Rate and timed efforts and over the 8wks I saved 14w over standard bearings so for the likes of MVDP, Alliphilipe and Wout it makes a difference but for the standard weekend warrior, don't have that pizza on Friday with 6 beers will be a better saving.

The advantages of ceramic bearings are so tiny in cycling applications that they're basically irrelevant. When you subject a bearing to the loads typically seen on a bicycle, the effects of ball and race material are so small compared with the effects of seals and lubrication that - even in a very high precision lab setting - very careful testing is required to determine the effects of ceramics versus other factors.

For example, in the 2013 Friction Facts bottom bracket study, while the top-performing bottom bracket did use ceramic bearings, it was tested at only .03 watts faster than the top-performing steel bottom bracket in the test. If you're riding along the flats at 20mph, .03 watts is literally only going to improve your speed by one or two thousandths of a mph.

Another thing you might notice in that study is that even the slowest bottom bracket, an extremely beefy setup that uses rollers instead of balls for the bearings, performed within 2W of the fastest bottom bracket. So this is an area where there usually just isn't much room for improvement in the first place.

Are there any particular behavioral issues with your bottom bracket that led to the question being asked?

when it comes to bottom bracket drag, the biggest drag is due to the (micro) misalighment of the two holes of the bb shell. This misalighment is due to the loose tolerance of the bicycle industry.

You will cut a lot of grams off your rolling weight, but that will mostly be because your wallet is lighter!

better off going with needle bearings in a BB.

And if memory is correct, the second biggest source of drag is grease shear.

The grease will cause more drag than you save. Not even talking about real-world dirt.

yep, grease and seals

For track bikes where they're used indoor, they don't even use seals and only a very light oil for lubricant.

For road bikes, and i use bearings with non-contact seals and a very light llubicant. But this means I can't get to use my bikes in wet and dirty condition, which I don't.

Nope.

Multiple studies showing difference from modest steel normal bearing to best ceramic BB is under a watt. Maybe under a half watt. Google it.

Once you exceed about 15 MPH aero drag exceeds everything else all other drag sources combined. As your speed increases beyond 15 MPH the difference becomes progressively greater. If your objective is to ride significantly faster you need to work on your aero position on the bicycle and, of course, the motor.

save the cash...unless you are a monster sprint master gunning for a world record attempt at some land speed record.
​​if not. buy the regular replacement buy new shoes. more bling.

It will reduce your overall weight because your wallet will be significantly lighter. Otherwise, no.

Buying ceramic bearings for a bicycle is one of the most efficient means of getting rid of excess cash. Exceeded, perhaps, but contributing to a political campaign.

You'll never notice a change while riding, but you can become the blowhard at post-ride gatherings bragging about fractions of a watt savings because of your bearings!

+1

OP: send me $100 and I will say I installed ceramic bearings in your bike. You never notice the difference. And if you notice, it is placebo. So we both will be happy.

The alignment, size and roundness of the BB holes in the frame will determine how long the BB lasts, and how easy the bearings roll. So the frame manufacturer already determined 99.99999999% of what your BB can do. Pressing fancy bearings into an ovalized, and non-aligned hole will not make a difference.

Yup. The bike industry will sell you an insanely overpriced bearing with (claimed) unnecessarily high tolerances for you to run in a sloppy housing that was manufactured the absolute cheapest way possible. The ultra-precise bearing is promptly destroyed in a small fraction of its designed life by a misalignment. Rinse and repeat.

I have Ceramic Speed in my BB and like it a lot and it works great.

Do you 'feel' faster because of it?

I recently picked up a CK ceramic bottom bracket for my new MTB. It spins nice, but as many have said I'm not sure I can tell the difference. And for the record I didn't buy it expecting anything special. More of a wait and see approach to its overall value.

What I can tell you is on another bike I have a Wheels Mfg angular contact steel bearing BB. There aren't enough O's in smooth to describe how nice it spins, and it was $100 cheaper too. I can only hope the over-priced and over-hyped ceramic BB can match the performance and longevity of the Wheels BB.

Just how aero do you have to be to make up for not having a bottom bracket on your bike?

I drank the kool-aid and bought a CS bb. It’s good, but can’t tell any difference from my previous push cup.