Silicone oil

[Andre Jute]

Silicone oil is good clean oil. I have it in my gym for the treadmill rolling floor, and have just been using it to clean out the manufacturing grunge, and free up the slip joint action of a new pocket knife. In the treadmill 10ml covers about 12sqft for two or three months of daily use amounting to a 100+ hours of hefty pounding.

Yet you never hear about silicone oil for bicycle use. I wonder why not. Expense? I buy it in 250ml bottles off eBay for about fifteen quid delivered, so it is fractionally cheaper than Rohloff chain oil (Oil of Rohloff). Or is there some technical reason bicyclists don't use silicone oil?

[John Saxby]

is there some technical reason bicyclists don't use silicone oil?

Interesting, Andre -- thanks for this. Is silicone added to the oil?

This cyclist doesn't use it, 'cos I've never 'eard of it. Wisht I could claim a technical reason, but ignorance will have to suffice.

I use silicone in various household applications, especially as weatherproof interior & exterior sealant.

[PH]

The usual argument for not using silicone on a chain are that it has poor adherence and washes off easily.  But I've never tried it and if it works for you it works for you...

[Andre Jute]

Thanks, gentlemen. John, I think that it is rather that silicone oil is used as the binder in sealants and grouts and suchlike, and the whole is named "Silicone" for the most expensive ingredient rather than the downmarket "Cheap Chalk Seamfiller" which would be more true. Paul, I haven't tried silicone oil for anything on my bike, and won't unless someone knowledgable declares it beneficial. I used to use copper grease in assembly, or cleaner teflon if there were no moving parts, and recently Phil has served me and my bike loyally. I still have mostly full tubes of all, so I'm not actually forced to experiment.

[PH]

Paul, I haven't tried silicone oil for anything on my bike, and won't unless someone knowledgeable declares it beneficial.

I must admit, I'm a sucker for the Greatest Oil ever, I never seem to learn, I keep falling for the promises of perfect lubrication, with minimum maintenance and perfectly clean.  I've promised myself to not buy any more till all the half bottles are used up, but I may have said that before...

[geocycle]

As a student I used silicone oil for making microscope slides. We used to embed the materials in it and then sandwich it beneath a coverslip. We then used paraffin wax to seal it. Completely irrelevant but it triggered a memory!

[Jornw]

Hi Andre,
I think I can add a word of warning regarding silicone oil/silicone grease. Silicone oil has lots of useful applications:  it is more or less non-toxic, has excellent electric properties, long life-time, chemical, thermal and mechanical stable etc. Applications range from make-up additive to transformer oil to paint additive to hi-tec heat transfer fluid in aero-space. As a lubricating compound, it is used to enhance sealing property of "rubber" O-rings, and reduce friction between plastic materials, rubber, wood  etc.

BUT, silicone oil/grease is not at all suited for lubricating high pressure metal-metal interfaces. By high pressure I mean the combination of high loads across low contact areas.  On a bicycle, such high pressure parts would be bearings in hubs, pedals, bottom bracket and steering. Likewise, I envisage that a chain or Rohloff hub lubricated with silicone oil will be short-lived. 

One other bad property with silicone oil is its ability to "creep" along surfaces, and eventually find its way in between electrical switches and connectors and cause loss of contact. This was a common problem in many old fashion telephone exchanges.

Conclusion is: Keep silicone oil at safe distance from your bike.

[lewis noble]

Beware the oil warriors . . . . . .

Silicone sprays and greases can be v useful for many household / garage applications, e.g. door rollers, plastic to metal contact and so on.  But for bike chains and fittings, I'll be sticking to the 'correct' lubes.  Yes, it would be good to know if they are actually that different, but I've had good service from, for example, Finish Line chain lubricants and will be sticking to them.

Pretty well all other bolts / fixings on my bikes are treated with copper slick; prevents corrosion, and although I don't think it is intended as anti-lock, I've never had anything work loose - I guess because threads 'seat' better.

Lewis

[Andre Jute]

Thanks for the warning, Jornw. It turns out that besides the treadmill belt lubricant, I have a little pot of a thinner silicone oil bought at enormous expense to dip the sealing rings of flying watches with enormous unnecessary pressure ratings just in case you ever ditch in the drink and your corpse sinks through 200m/660ft -- "Our customer died but our product is in pristine working condition." But I wasn't actually planning to put silicone oil on my bike until some knowledgeable party oozed enthusiasm and preferably experience.

FYI, the chain of my Rohloff is a KMC which runs on its factory lube for its entire life inside a Chainglider -- reasons and plenty of experience by other forum cyclists passim on the forum. I add no lube, and do no cleaning. My entire bike is designed to reduce maintenance to an oil change and a single shot of grease once a year, both on the Rohloff.

Lewis, copper grease was certainly put to me, probably on this forum, as a requirement for an anti-seize assembly of spinning bits on a bike, especially on the axles.