Bottom Brackets - Thoughts on Ceramic & Should it spin freely?
116
Member
801 days
fpugsley posted 7 weeks ago.
My thoughts on ceramic bearings is this: They cost more than the component did new, and they might save you 1 watt?
The pulley nearest to the cassette it designed to 'float' to align itself with the cassette cog. Is that the slop you are talking about?
164
Member
151 days
GGehrke posted 7 weeks ago.
FSA and some of the others claim that normal BB's consume 4% of your total wattage, but ceramic only eats 0.5%. So at 200W, that's a gain of 7W, which is really not insignificant. Some of my aggressive rides are less than 10W difference from my easier ones. I was hoping someone might have some more anecdotal evidence than that, though.
And I currently have my derailleur apart to clean everything, so once I put it back together I'm going to verify that the pulleys are operating correctly. I think having given them a thorough cleaning I'm not worried about that any more.
164
Member
151 days
GGehrke posted 7 weeks ago.
Oh, but ceramic pulley bearings are pretty frivolous, I agree wholeheartedly there - I'm pretty sure their CLAIMED savings is on the order of 1W or less. But they're also not unreasonably expensive. And the 1W is over Dura Ace, so I would maybe save 1.2W over my lowly ultegra ;)
This morning I had my chain off and spun my cranks. They made maybe 1 rotation. Nice and smooth - no grinding or anything, but I was pretty surprised at how quickly they slowed. On my fixie they go and go and go.
Does anyone know if this is a sign that the BB needs replacement? I have about 2000 miles on the bike. Ultegra BB.
Which got me thinking about ceramic. Does anyone here use a ceramic BB? Thoughts?
What about ceramic pulley bearings? I noticed a lot of slop in my pulleys this morning as well and was thinking that might be a good place for high quality parts.