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hub bearing marginal gains
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so its time to replace the bearings in my mavic wheels and i want to go with a quality/low friction non ceramic bearing....my question is would i benefit from a angular contact bearing or are the quality radial bearings just as good for wheels.....if it matters im about 170 lbs and lucky to break 1400 watts in a sprint....thanks for any help and advice.
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Re: hub bearing marginal gains [bikeman12-1] [ In reply to ]
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Radial.

Seals and grease will probably be the majority of the losses.
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Re: hub bearing marginal gains [rruff] [ In reply to ]
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Is anyone using open and clean (zero grease) bearings in their wheels?

Don't stop when you're tired. Stop when you're done.

- D. Goggins

Last edited by: PinaMan: Aug 1, 19 12:44
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Re: hub bearing marginal gains [PinaMan] [ In reply to ]
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PinaMan wrote:
Is anyone using open and clean (zero grease) bearings in their wheels?

Ive done this for a race. I decided to go “all in” and removed the seals and grease from hubs, bottom bracket, and pulleys. Used a very small amount of lube in there.
Everything spun super freely. I then re-serviced everything after the race. But I’m also the type of person that loves this kind of work on my bike.

Alex Arman

Strava
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Re: hub bearing marginal gains [doublea334] [ In reply to ]
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doublea334 wrote:
Ive done this for a race. I decided to go “all in” and removed the seals and grease from hubs, bottom bracket, and pulleys. Used a very small amount of lube in there.
Everything spun super freely. I then re-serviced everything after the race. But I’m also the type of person that loves this kind of work on my bike.

I've asked, because i own few pro yoyos (yes, spinning toys). And every time i bought a new yoyo, i would open bearing and completely clean it (zero grease). Main reason for removing all grease is huge spin time gain. Side effect is noise. But here is the thing. Yoyo can spin up to 8000 RPM, and based on some quick search, wheels spin only ~300 RPM. And even tho yoyo spins at ~8000 RPM, bearings are not destroyed (because of heat / resistance) after few spins.

So noise should be a lot lower compared to yoyo, since RPMs are at ~3.7% compared to yoyo. And since bearings are open you can clean them (dust or anything) at any time.

Don't stop when you're tired. Stop when you're done.

- D. Goggins

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Re: hub bearing marginal gains [PinaMan] [ In reply to ]
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Yoyo bearings do not support a heavy load and thus don't wear down quite as fast. I would think if you run your wheel bearings without any lube, then the bearing races and balls would wear down pretty quickly with your mass pressing down on the balls.
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Re: hub bearing marginal gains [bikeman12-1] [ In reply to ]
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Phil Wood "carbonyte" steel bearings.
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Re: hub bearing marginal gains [RichardL] [ In reply to ]
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I understand what you're saying and i was thinking about heavy load as well. But greased bearings support exactly the same heavy load. Grease that's in bearing is (constantly) pushed out of / away from contact between ball and rail, because they fit together very well, and with very small contact point.

So if you do it for a race, like doublea334 said, i think it should be ok. And if bearing is open you can grease it for any training ride at any time. Also,... if you're using steel bearings,.. they are very cheap compared to ceramic.


jimatbeyond: you working for Phil Wood? lol
You posted exactly the same thing in "Non ceramic bearings" thread created by bikeman12-1.
It is possible to get bearings for half of the price of Phil Woods bearings.

Don't stop when you're tired. Stop when you're done.

- D. Goggins

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Re: hub bearing marginal gains [PinaMan] [ In reply to ]
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Why bother to grease at all if the grease that's in the bearings is constantly pushed out of the way?
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Re: hub bearing marginal gains [jaretj] [ In reply to ]
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Why use engine oil if it just drains back to the pan?

There is grease between the bearing and the race, not much, but there is some.

Formerly MTBSully
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Re: hub bearing marginal gains [PinaMan] [ In reply to ]
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I use carbonyte bearings in the bottom brackets that I sell and they are fast.
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Re: hub bearing marginal gains [jaretj] [ In reply to ]
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Folks are missing the knowledge of how rolling element bearings 'work' and how the lube plays it's part.

Some points and some over-simplifications:-

For starters, free-spinning on no load is not a meaningful indication of the performance under load - under no load the drag is from seals and the lube (grease) getting moved around. But that loss is V small compared to the losses under load if inadequately lubed (number of free spins of a crank really means feckall !)

Using grease in a bearing rather than oil is just to stop the oil from running out !
Whilst most of the grease is pushed away, there is still a small amount between roller (or ball) and the raceway. And within the gease there is OIL. ( grease is a 'soap' that has a base oil in there).
Its the OIL doing the lube. The grease soap is merely a 'carrier' and acts sort of like a reservoir.

When the roller/ ball is under load 2 things occur (a) the ball and raceway deform elastically, and (b) the rolling motion results is a converging gap that causes the oil to be squeezed into the 'nip' and provide hydro-dynamic lubrication ( think of a surf board getting 'lift' because of the movement of water under it and the slight angle it's at front-to-back).
Oil under pressure (v high localised pressures in the contact area not a few paltry psi) increases significantly (massively) in viscosity, which is why the rolling element is kept off the raceway and in turn why roller element bearings have low friction !

Put all together its called Elasto-hydrodynamic Lubrication ('EHL' or EHDL).
Very very little OIL is needed for it at any one point in time.

Grease is just the convenient 'carrier' for the base oil and brgs have enough in to provide years worth of supply.
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Re: hub bearing marginal gains [bikeman12-1] [ In reply to ]
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No seals and very light oil in my race wheels. I won't win, but it's less time I have to spend on the race course.
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Re: hub bearing marginal gains [BobAjobb] [ In reply to ]
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In Reply To:
BobAjobb wrote:
Folks are missing the knowledge of how rolling element bearings 'work' and how the lube plays it's part.

Some points and some over-simplifications:-

For starters, free-spinning on no load is not a meaningful indication of the performance under load - under no load the drag is from seals and the lube (grease) getting moved around. But that loss is V small compared to the losses under load if inadequately lubed (number of free spins of a crank really means feckall !)

Using grease in a bearing rather than oil is just to stop the oil from running out !
Whilst most of the grease is pushed away, there is still a small amount between roller (or ball) and the raceway. And within the gease there is OIL. ( grease is a 'soap' that has a base oil in there).
Its the OIL doing the lube. The grease soap is merely a 'carrier' and acts sort of like a reservoir.

When the roller/ ball is under load 2 things occur (a) the ball and raceway deform elastically, and (b) the rolling motion results is a converging gap that causes the oil to be squeezed into the 'nip' and provide hydro-dynamic lubrication ( think of a surf board getting 'lift' because of the movement of water under it and the slight angle it's at front-to-back).
Oil under pressure (v high localised pressures in the contact area not a few paltry psi) increases significantly (massively) in viscosity, which is why the rolling element is kept off the raceway and in turn why roller element bearings have low friction !

Put all together its called Elasto-hydrodynamic Lubrication ('EHL' or EHDL).
Very very little OIL is needed for it at any one point in time.

Grease is just the convenient 'carrier' for the base oil and brgs have enough in to provide years worth of supply.

So I may be wrong in my understanding but is it possible to put to much grease in a bearing ? From a performance standpoint
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Re: hub bearing marginal gains [BobAjobb] [ In reply to ]
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I'm not missing the knowledge, I was being sarcastic so the extreme could be thought about, like you explained.

I should have written that in pink.
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Re: hub bearing marginal gains [bikeman12-1] [ In reply to ]
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It is uncommon to find angular contact versions of radial cartridge bearings that are drop in replacements for things like hubs. I'm not positive, but for your Mavic's it is unlikely.. I know that Enduro offers angular contact versions of many of the 6xxx series bearings, but they are often slightly different in width and require hubs that are adjustable for preload without the use of spacers.. so even if they fit, it is possible your version of wheels might not be compatible.. need more information to really say for sure.

As for seals and grease, this is really up to you.. it is very common practice in the cycling industry to grind the races in a way that a 'rubber seal' is non contact and really just serving as a dust shield, so no need to remove the 'seals' in this case. As with so many 'standards' in the bike industry, something like '2RS' in a bearing part number might mean something different from many bicycle industry companies than it might from an industrial supply house.

Years ago at Zipp we started having our Swiss bearing manufacturer grind an additional tiny groove into the bearing race to allow the seal to look like it was contacting, but actually not touch, quite a few companies do this today. We were also the first to use polyamide bearing cages instead of metal and also specified a lube from Kluber that had very high pressure/load rating, but was also rated NLGI 0 which meant that it could flow when the bearing was running to continually replenish the bearing surfaces but also felt like there was hardly any resistance on the bearing in your fingers, unfortunately this stuff was also about $200 per kg, but it was a perfect blend of feeling fast in your fingers and also being fast in the field.

I have seen many teams/athletes and companies using things like open shielding, oils, etc in bearings and can honestly say that it just doesn't work that well under running loads, or adds risk when used in the real world. For about 6 months, Bjarne Riis had this 'bearing guru' work with CSC, he would flush the bearings, put in oil, knife out the rubber lips on the seals, etc.. all claiming these big savings, but the mechanics would get the wheels/bb's after a single day of racing and it all felt like crap and had to be reworked.. we finally sent one of these 'snake oil wheels to the lab alongside a brand new Zipp wheel, the lab found that the snake oil wheel had higher running friction under load as the thin oil was just flung out resulting in ceramic to metal contact. This is why you see experts in this like the CeramicSpeed folks using oil in their pulley wheels (low load) and very high end grease in their hub and BB bearings.

Having said all that.. moving from stock bearings to the fastest bearings available in a wheelsest is worth on the order of 0.8-1.2 watts at 30mph which is certainly a marginal gain, but is also on the order of magnitude of the aero penalty of properly vs improperly adjusted helmet straps or being 2-3psi over pressure on pavement of moderate roughness.

http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc
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Re: hub bearing marginal gains [joshatsilca] [ In reply to ]
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joshatsilca wrote:
It is uncommon to find angular contact versions of radial cartridge bearings that are drop in replacements for things like hubs. I'm not positive, but for your Mavic's it is unlikely.. I know that Enduro offers angular contact versions of many of the 6xxx series bearings, but they are often slightly different in width and require hubs that are adjustable for preload without the use of spacers.. so even if they fit, it is possible your version of wheels might not be compatible.. need more information to really say for sure.
As for seals and grease, this is really up to you.. it is very common practice in the cycling industry to grind the races in a way that a 'rubber seal' is non contact and really just serving as a dust shield, so no need to remove the 'seals' in this case. As with so many 'standards' in the bike industry, something like '2RS' in a bearing part number might mean something different from many bicycle industry companies than it might from an industrial supply house.

Years ago at Zipp we started having our Swiss bearing manufacturer grind an additional tiny groove into the bearing race to allow the seal to look like it was contacting, but actually not touch, quite a few companies do this today. We were also the first to use polyamide bearing cages instead of metal and also specified a lube from Kluber that had very high pressure/load rating, but was also rated NLGI 0 which meant that it could flow when the bearing was running to continually replenish the bearing surfaces but also felt like there was hardly any resistance on the bearing in your fingers, unfortunately this stuff was also about $200 per kg, but it was a perfect blend of feeling fast in your fingers and also being fast in the field.

I have seen many teams/athletes and companies using things like open shielding, oils, etc in bearings and can honestly say that it just doesn't work that well under running loads, or adds risk when used in the real world. For about 6 months, Bjarne Riis had this 'bearing guru' work with CSC, he would flush the bearings, put in oil, knife out the rubber lips on the seals, etc.. all claiming these big savings, but the mechanics would get the wheels/bb's after a single day of racing and it all felt like crap and had to be reworked.. we finally sent one of these 'snake oil wheels to the lab alongside a brand new Zipp wheel, the lab found that the snake oil wheel had higher running friction under load as the thin oil was just flung out resulting in ceramic to metal contact. This is why you see experts in this like the CeramicSpeed folks using oil in their pulley wheels (low load) and very high end grease in their hub and BB bearings.

Having said all that.. moving from stock bearings to the fastest bearings available in a wheelsest is worth on the order of 0.8-1.2 watts at 30mph which is certainly a marginal gain, but is also on the order of magnitude of the aero penalty of properly vs improperly adjusted helmet straps or being 2-3psi over pressure on pavement of moderate roughness.

Josh you always explain things in a way that a non-engineering type person such as myself can understand, I’m mechanically inclined but not engineered if that makes sense ...thanks so much for your insight. A side note for you is that I have a set of zipp 202s that have lasted me close to 5 yrs and still spin beautifully...I’m looking to get the same performance for my mavics.
Last edited by: bikeman12-1: Aug 1, 19 20:05
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Re: hub bearing marginal gains [bikeman12-1] [ In reply to ]
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Phil Wood was the first company to use sealed bearings in the cycling industry.
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Re: hub bearing marginal gains [bikeman12-1] [ In reply to ]
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bikeman12-1 wrote:
So I may be wrong in my understanding but is it possible to put to much grease in a bearing ? From a performance standpoint

Absolutely.
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Re: hub bearing marginal gains [rruff] [ In reply to ]
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Yes, this is what starts to separate bearings for our application from normal industrial applications. Typical industrial bearings may only have 20-25% grease fill, as they are expected to spin at much higher RPM.. so you use a lower quantity of a thicker grease so that it will become soft when hot and be able to migrate around the bearing in use. For cycling, our rotational speeds are well below most industrial motors and the like, so you want to use a higher fill of a softer grease. The higher fill might cost you some tiny fraction of a watt, but will ensure the bearings lasts much longer. Also the high fill % helps keep water and other stuff out as it's hard for contaminants to get into a bearing that is already mostly full of grease.

From experience, if you put a Zipp bearing with 80% grease fill into a machine driven by electric motor at 4000rpm.. the grease will blow the seals off the bearing..

http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc
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