Grease

[jois]

It's a bit more complicated than that.

viewtopic.php?t=121287

Not much more, it does exactly the same job on any bearing and just as well, I'm aware people get obsessive about things that make no material difference, I do myself sometimes, just not over things as mundane as greasing wheel bearings.

Some things are just a matter of opinion whilst others are based on experience, with a third category based on "harder" or more objective data. Personally I feel a mix of the second & third is better than a mix of the first and second (which is what you seem to be offering in your grease-opinion). The problem with the latter is that the experience involved may be very limited - as when a fellow has used only one grease without trying any of the hundreds of others.

So .... just so you don't have to, I summarise here a Hambini web page, with a link to what seems to be a better choice as an all purpose bicycle grease.

The grease recommended is described here, with a handy pdf data sheet to download should one want it. Of course, the data sheet is from the manufacturer but seems to be something far less inclined to the hyperbole that an out-and-out advert would suffer from:

https://www.mobil.com/en/lubricants/for ... th-shc-007

It's available in several grades of viscosity. (See below re NLGI numbers).

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The Hambini take-aways are:

A bearing grease is different from an anti-seize grease, with the former meant to lubricate moving parts that interface under pressure and the latter serving only to prevent thread lock-ups from galling and the like. Anti-seize greases shouldn't be used in bearings or other moving parts as they tend to contain stuff (like copper) that'll cause abrasion.

Stuff used to lubricate moving parts needs to be chosen based on a standard of viscosity but also on having a degree of resistance to water ingress & damage. In effect, the lowest degree of viscosity (becoming an oil liquid when heated/pressured by use) gives ideal lubrication but would need constant renewal, especially if water got involved. A more practical viscosity results in a grease with some solidity in use but only a minimum; and with ingredients providing a degree of resistance to being diluted or otherwise quickly degraded by water. Ingredients to provide extra-slipperiness (such as teflon) can help in reducing the stiffness of the grease needed as they remain on the bearing surfaces for a while when most of the grease has liquified and departed.

The viscosity measurement of a grease is expressed as its the NLGI number, with 000 being near liquid, 1 being soft and 3 being firm. Choose a grease with an NLGI number for the purpose in a bike bearing - and recognising a trade-off between time it'll last in the bearing against how much drag on the bearing it'll cause in use. Firm - more drag but less maintenance; soft - minimum drag but much more maintenance (renewal).

An NLGI of between 1 and 2 is recommended as an all-purpose grease for bicycles.

Any grease should be used sparingly in bearings, to take up around one third of the air space within the bearing race parts. Packing in grease is said to increase the internal friction (and heat) generated "exponentially" (meaning only "at an ever-increasing rate"). Fully-packed bearing will result in a very sluggish bearing performance, as in stopping the wheel freely rotating on a bike after just a small number of revolutions, perhaps less than one.

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Do the greases mentioned by the OP have their NLGI numbers published? That might be a starting point in considering their suitability for various bike bearings.

Cugel

I'm not disagreeing with any of that and non of that is disagreeing with me

[Stevek76]

Gone down the rabbit hole of bike maintenance today. Took my crankset out and the shaft was liberally smeared with white grease. Isn’t this completely pointless? Surely it’s just the bearings/cup threads that need greasing?

Follow up question. If I wanted to re-grease the bb bearings do I need to remove the bb cups?

This is presumably a two piece crankset? Grease will help provide a barrier to corrosion just incase any moisture sneaks in, a well greased axle will also help keep everything sealed as much as possible against any ingress of water.

Regarding the bearings, no you can regrease them in the in the bike. Though note that quite a few external bbs (or internal press fit ones) aren't designed to be serviced in that manner. They can be but you do need to be careful getting the plastic top cap/hat off as it can be quite brittle. Seals on the bearing units can be a little fragile also.

Do the greases mentioned by the OP have their NLGI numbers published? That might be a starting point in considering their suitability for various bike bearings

Didn't see any on the sheets i saw but I'd suspect they're rated at '2', which is a fairly standard goopyness for cycle greases. Lighter greases tend to be limited to more specific uses such as free hub ratchets (more like a 1 or lower) and some suspension greases. E.g slickoleum (which also gets sold with the usual cycle uplift as slick honey and sram butter) rates itself as 1.5

Regarding what hambini says, worth bearing (heh, unintended) in mind that he is very much of the marginal gains, every watt counts mindset so will lean towards low friction over low wear so naturally has a somewhat different idea about what a good bearing grease should be compared to brucey. Though from personal experience wheels definitely do far more than a single revolution even when fully packed. It would be quite something for grease to stop the relatively high rotating mass of a wheel that quickly. Perhaps a specialist damping grease might do it but you wouldn't normally be putting that in bike bearings!

[Cugel]

Regarding what hambini says, worth bearing (heh, unintended) in mind that he is very much of the marginal gains, every watt counts mindset so will lean towards low friction over low wear so naturally has a somewhat different idea about what a good bearing grease should be compared to brucey. Though from personal experience wheels definitely do far more than a single revolution even when fully packed. It would be quite something for grease to stop the relatively high rotating mass of a wheel that quickly. Perhaps a specialist damping grease might do it but you wouldn't normally be putting that in bike bearings!

Yes, the Hambini fellow seems focussed on the high performance stuff, even if his focussing might have the intent of rubbishing it when its not (high performance - or spec, at least).

I have seen folk pack their bearing with excessive grease in the past, on the principle that "more must be better" - in the days of nearly universal cup & cone wheel bearings, loose ball bearing BBs and similar headsets.

Some wheel hubs had a grease port hole in the middle of the axle through which one pumped grease until the old stuff came out of the bearings, past the lock nuts! This certainly packed not just the bearings but the whole axle running through the hubs. It certainly did slow the wheels down from a free-spinning until enough grease eventually squidged out to allow them to run more freely. The same effect could be seen on cranks that were not at all keen to spin after their owner stuffed as much grease as they could into the BB.

Part of the problem was undoubtedly the use of rather thick grease, often something got from a garage meant for somewhat heavier duty. In truth, we were all rather ignorant concerning what engineers undoubtedly knew. We tended to follow the made-up-stuff perpetrated by fusty old bike shop owners who had long ago formed some queer notions about how to maintain stuff and then refined it all into outright prejudice, dogma and adamantine practices that they insisted were "the only way".

Cugel

[honesty]

Gone down the rabbit hole of bike maintenance today. Took my crankset out and the shaft was liberally smeared with white grease. Isn’t this completely pointless? Surely it’s just the bearings/cup threads that need greasing?

Follow up question. If I wanted to re-grease the bb bearings do I need to remove the bb cups?

This is presumably a two piece crankset? Grease will help provide a barrier to corrosion just incase any moisture sneaks in, a well greased axle will also help keep everything sealed as much as possible against any ingress of water.

Regarding the bearings, no you can regrease them in the in the bike. Though note that quite a few external bbs (or internal press fit ones) aren't designed to be serviced in that manner. They can be but you do need to be careful getting the plastic top cap/hat off as it can be quite brittle. Seals on the bearing units can be a little fragile also.

Yeh, XT triple, with a Hope ceramic bottom bracket. I think looking at the Hope website the bearings are meant to be serviceable, so I’ll try and be careful with the cover. Thanks.

[NickJP]

I use Penrite QCA Grease MX9, which Penrite recommend for use in slow speed bearings. In 500g tubs it's pretty cheap from auto supply houses, and a tub lasts a long time when used on bicycles. However, I think Penrite is an Australian company, so I don't know in what other countries it is available.

https://penriteoil.com.au/assets/pis_pd ... %20MX9.pdf

Penrite also have a useful PDf on their website explaining greases: https://penriteoil.com.au/assets/tech_p ... reases.pdf.

[tim-b]

CJ used to recommend https://www.mobil.com/en/lubricants/for ... shc-pm-460
Mobil XHP 222 grease is also good. Slightly heavier at NLGI 2, adheres well and resists water-contamination and rust
You can get proper data sheets as well, which is always a good sign for me

[tooley92]

CJ used to recommend https://www.mobil.com/en/lubricants/for ... shc-pm-460
Mobil XHP 222 grease is also good. Slightly heavier at NLGI 2, adheres well and resists water-contamination and rust
You can get proper data sheets as well, which is always a good sign for me

Challenging to find in small quantities, I buy mine here

https://www.ebay.co.uk/itm/392312562904 ... media=COPY

[jb]

Once a new tub of grease has been obtained it should be treated with reverence. Undo the seal in clean atmosphere and decant a small quantity into a small jar or tub with a lid on, this for general use. then replace the new 'pure unsullied' tub into a locked cupboard surrounded by high voltage electrified razor wire with a few anti-personnel mines sprinkled about, depending on the amount of wanabe mechanics lurking around that may want dip their grubby paws into your untainted supply.
Otherwise you may as well slap grinding past into your new bearings.

[Airsporter1st]

Once a new tub of grease has been obtained it should be treated with reverence. Undo the seal in clean atmosphere and decant a small quantity into a small jar or tub with a lid on, this for general use. then replace the new 'pure unsullied' tub into a locked cupboard surrounded by high voltage electrified razor wire with a few anti-personnel mines sprinkled about, depending on the amount of wanabe mechanics lurking around that may want dip their grubby paws into your untainted supply.
Otherwise you may as well slap grinding past into your new bearings.

There’s a lot to be said for buying whichever sort of grease you finally decide to use in tubes, rather than tubs. Inevitably more expensive but I would rather sacrifice economy of scale for cleanliness.

[Jules59]

"There’s a lot to be said for buying whichever sort of grease you finally decide to use in tubes, rather than tubs. Inevitably more expensive but I would rather sacrifice economy of scale for cleanliness."

I load my nice new, clean, bike grease into 20ml syringes.

[Airsporter1st]

"There’s a lot to be said for buying whichever sort of grease you finally decide to use in tubes, rather than tubs. Inevitably more expensive but I would rather sacrifice economy of scale for cleanliness."

I load my nice new, clean, bike grease into 20ml syringes.

That’s a good idea. I use Krytox GPL 205, which comes in syringes (not sure whether it retails that way or is decanted after purchase) and it lasts ‘forever’.