Bottom bracket bearings - removing seals and lube

Discuss light weight issues concerning road bikes & parts.
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kavitator
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Joined: Sun Sep 21, 2008 9:07 pm
Location: Slovenia---that forest land

by kavitator

In my TT bike i have BB30 bearings - last year i put in EZO 68062RS - clean all lube and remove inner seal on both.
They run really smooth (i spray in bearings olny WD40 before race)

But when i watch FrictionFacts results there can be around 1-2W between the best and worst bearings

Now i will replace with same bearings (EZO steel rubber sealed) - looks like water came in bearings and on soma places there is damaged place where balls run

do you think there is more than 2watts difference or just in head (when rotate crankset backwards it really spins better than with original bearings)

by Weenie


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LouisN
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Joined: Mon Feb 19, 2007 3:44 am
Location: Canada

by LouisN

I was thinking of doing the same, but with all the bearings ( RD pulleys, rear wheel, BB) to experiment on TT's.
I guess between worst and best conditions there can be a few watts saved...

Louis :)

mattr
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Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Pretty sure you can find something better than WD40. That'll be displaced from the bearing track within a few hundred meters. Even a light, dry chain lubricant would be far better.

sungod
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Location: it's raining, it must be uk

by sungod

depends what 'best' and 'worst' are, and where 'typical' fits

unless there's a different specific definition from ff, 'worst' could be poor tolerance really crap bearings, that are 1.9w worse than 'typical' bearings from 99% of sources, with 'best' being just <= 0.1w less than 'typical'

unless the environment is really clean, bearings without seals are going to collect dust, pollen, and other airborne contaminants, if not cleaned every time maybe it could soon give more drag than seals

if the frame isn't sealed, especially at the seat post, water/dirt can get down into the bb shell, with no inner seals the bearings can easily suffer

then there's individual variation in bearing shell tolerance and the effect that has on drag once pressed into the bb shell (the bearing will very slightly distort), and of course resistance under no/low load may not match behaviour under load

with such marginal effects, unless you know and control all parameters i don't think you can predict effect on drag

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kavitator
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Joined: Sun Sep 21, 2008 9:07 pm
Location: Slovenia---that forest land

by kavitator

TT bikes mostly are less ridden than road bikes. Also in nicer weather

I remove seals also from bearings in rear wheels (disc wheel) - it is taiwan and freehub looks like novatec.
Bearings are NBK (trash for road bikes) but here they works well (15mm axle and big bearing with big balls)

I will try again remove inner seals and put oil for chain (dry lube)

For one year it must be good :)

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LouisN
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Location: Canada

by LouisN

IMO oil chain will leave a residue.
I have a teflon spray lube used for industrial purposes that litterally "dries" by itself and forms a very light film over the bearings.

I would also clean and respray the bearings once every few rides if you want this method to be efficient.
Adda decent graphite waxed chain and it should make a smooth drivetrain .

Louis :)

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WinterRider
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by WinterRider

LouisN wrote:I have a teflon spray lube used for industrial purposes that literally "dries" by itself and forms a very light film over the bearings.


I wonder if that spray might be decent for chain lube.. outside surfaces? I use a penetrant for pins.

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LouisN
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Location: Canada

by LouisN

Maybe for short TT's but not for road use.
It doesn't withstand the use for long and starts squeaking after a while...

Louis :)

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kavitator
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Joined: Sun Sep 21, 2008 9:07 pm
Location: Slovenia---that forest land

by kavitator

BB bearings - when they are cleaned from grease spins like crazy - i leave outer seal, lubrucate them with chain oil ceramic and 2 drops of dry lube. They spin really smooth now. Crankset alone turns like crazy

rear disc wheel after one year of removed seals and grease - it is like new. Laso freehub gets only light oil

Chain is cleaned - ridden around 200km - and lubricated with finishLine ceramic wax lube - when it dry out little dry lube will be added.

I leave rear derailiur wheels like they are (shimano Ultegra 6800 and Duraace chain)

Compared to my new road bike with shimano 105 praxis works crankset - it runs much smoother

It will be 24 hours team race this weekend - and nice weather.

I will relube chain couple times (and before that clean it)

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Patto
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Joined: Wed Sep 14, 2016 8:33 pm

by Patto

Having free spinning bearings with no load is different to spinning bearings with a centrifugal force imposed.

Chain lubes and lubes with solid additives, will need to be replaced weekly if you are seeking marginal gains. A number of issues can arise. The additives will fall out of suspension. The carrier oils will pool leaving naked bearing which can corrode, develope scum interacting with airborne particles.

Old fashioned is best, plain light oil for marginal gains or grease.

by Weenie


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