# Is the BBInfinite that much better than the Shimano BB72-41B Bottom Bracket?



## KiloKilo7 (Sep 13, 2015)

Hello,

I see the demo of the BBInfinite BB spinning super freely, but in practical terms is it really that much better in actual riding than the standard ultegra Shimano BB72-41B Press Fit Road Bottom Bracket? 

I saw some info, that said the BBInfinite demo is a bit misleading, because under load the bearings perform differently and not that much better than the Shimano BB72-41B (?)

I am doing a new build, and received the Shimano BB in the kit, wondering if I should drop $150 to $200 for the BBInfinite.

Thanks,
Ken


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## cxwrench (Nov 9, 2004)

Long term it (BBI) will probably have less noise issues than a Shimano PF. I've installed a couple and I was reasonably impressed. Neither has had any problems at all. Get steel bearings not ceramic.


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## KiloKilo7 (Sep 13, 2015)

I am not so much concerned with long term reliability, but rather performance. Is the performance of the BBI that much better than the Shimano PF? In other words, will I spin that much more efficiently? less watts? The BBI cranks spins a lot more revolutions than the Shimano BB when on a stand and you give it a "twirl", but how much advantage is the BBI in real cycling under load?


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## cxwrench (Nov 9, 2004)

KiloKilo7 said:


> I am not so much concerned with long term reliability, but rather performance.* Is the performance of the BBI that much better than the Shimano PF?* In other words, will I spin that much more efficiently? less watts? The BBI cranks spins a lot more revolutions than the Shimano BB when on a stand and you give it a "twirl", but how much advantage is the BBI in real cycling under load?


Uhhhmmm...no. Does your living depend on this? 

The reason the crank 'spins' more on the stand is that the grease fill in expensive (espeically ceramic bearings) is less and thinner so they will do exactly what you're talking about. It gives the impression of a 'faster/more efficient' bearing.


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## xxl (Mar 19, 2002)

cxwrench said:


> Uhhhmmm...no. Does your living depend on this?
> 
> The reason the crank 'spins' more on the stand is that the grease fill in expensive (espeically ceramic bearings) is less and thinner so they will do exactly what you're talking about. It gives the impression of a 'faster/more efficient' bearing.



I must take issue with this; ceramic bearings' efficacy is _well _documented, and can _definitely_ benefit riders who spin at high cadences, say 50,000 RPMs or so.

But that's not the only benefit ceramic bearings have; they are roughly three times as effective as SS bearings at getting money out of riders' wallets.


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## cxwrench (Nov 9, 2004)

xxl said:


> I must take issue with this; ceramic bearings' efficacy is _well _documented, and can _definitely_ benefit riders who spin at high cadences, say 50,000 RPMs or so.
> 
> But that's not the only benefit ceramic bearings have; they are roughly three times as effective as SS bearings at getting money out of riders' wallets.


I can't believe I left these details out of my post, thankfully you were paying attention as usual and added the corrections. Whew.


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## Finx (Oct 19, 2017)

KiloKilo7 said:


> I am not so much concerned with long term reliability, but rather performance. Is the performance of the BBI that much better than the Shimano PF? In other words, will I spin that much more efficiently? less watts? The BBI cranks spins a lot more revolutions than the Shimano BB when on a stand and you give it a "twirl", but how much advantage is the BBI in real cycling under load?


I don't think any casual cyclist or mechanic is going to be able to quantify this for you. You might find someone on youtube (or somewhere) who has done some kind of test, but without some kind of complex scientific equipment there is no way anyone can tell you if, or how much better the performance is in one bottom bracket over another.


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## Lombard (May 8, 2014)

But just think of the bragging rights you will have with your riding buddies. You can make grunting noises while telling everybody you have superior ceramic bearings. :idea:


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## tlg (May 11, 2011)

Ceramic bicycle bearings are a myth created to separate you from your money. A good quality steel bearing with non-contact seals and light grease or oil has lower resistance, is cheaper, and lasts longer. 

The only reason ceramic bearings 'feel' faster is because they use non contact seals and little to no grease. Moreover, ceramic bicycle bearings are NOT fully ceramic bearings. They are ceramic hybrids. The balls are ceramic and the races are steel. Which means the very hard balls will wear out the races faster... making them LESS efficient. Derp.

www.hambini.com/ceramic-bearings-vs-steel-bearings-an-engineering-analysis/


Ceramic bearings are red. 










Enduro is the Cermic beaing. OUCH! Your expensive ceramic bearing is less efficient after 1,000km










Total Power saving
The graph below shows how much power could be saved over 1000km between different bearing brands and their seal types. NTN, NSK and SKF dominate this chart and that is largely due to efficient seals and metal cages. The ceramic bearings which are coloured in red are not quite as efficient over a prolonged distance. If the evaluation window was extended to 10,000km, the ceramic bearings would perform much worse as a more significant track would have worn into the bearing races thereby increasing friction.










But hey... if you're racing for money, have the budget, and a race team to continually maintain your bearings every 1,000km, by all means go ceramic. But of course, you could do it cheaper (with less resistance) by just taking the grease out of your steel bearings.


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## Kerry Irons (Feb 25, 2002)

xxl said:


> I must take issue with this; ceramic bearings' efficacy is _well _documented, and can _definitely_ benefit riders who spin at high cadences, say 50,000 RPMs or so.
> 
> But that's not the only benefit ceramic bearings have; they are roughly three times as effective as SS bearings at getting money out of riders' wallets.


You're underestimating the value of ceramic bearings. Their benefits tend to kick in at more like 5,000 RPM. Plus they are a lot better in highly acidic environments. So jet engines, steam turbines, chlorine compressors. Stuff like that. Stop trying to minimize their benefits!


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## Kerry Irons (Feb 25, 2002)

tlg said:


> But hey... if you're racing for money, have the budget, and a race team to continually maintain your bearings every 1,000km, by all means go ceramic. But of course, you could do it cheaper (with less resistance) by just taking the grease out of your steel bearings.


More to the point, if you are racing for money AND your sponsor makes ceramic bearing products or you can get a sponsor who makes ceramic bearing products, by all means . . . .


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## xxl (Mar 19, 2002)

Kerry Irons said:


> You're underestimating the value of ceramic bearings. Their benefits tend to kick in at more like 5,000 RPM. Plus they are a lot better in highly acidic environments. So jet engines, steam turbines, chlorine compressors. Stuff like that. Stop trying to minimize their benefits!


Obviously you don't know how to really spin, and 50,000 RPMs is above 5,000 RPMs, so there. 

As to highly acidic environments, I haven't ridden like that since the Seventies.


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## Lombard (May 8, 2014)

xxl said:


> As to highly acidic environments, I haven't ridden like that since the Seventies.


If you can remember the 1960's, you weren't there.


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## Jay Strongbow (May 8, 2010)

Finx said:


> I don't think any casual cyclist or mechanic is going to be able to quantify this for you. You might find someone on youtube (or somewhere) who has done some kind of test, but *without some kind of complex scientific equipment there is no way anyone can tell you if*, or how much better the performance is in one bottom bracket over another.


So in saying no one can answer you've actually answered, correctly, the question too.

The question was: "is it really that much better in actual riding" Not: Is there some minute difference that MIT might be able to detect.

If no one this side of Nobel prize winners can figure it out then it's not going to make a difference in my riding.


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