Gearbox oil

I've used Green Oil year-round, applied sparingly with an old toothbrush to the inside run of the chain. Clean it up with a squirt of WD-40 on an old t-shirt then reapply the lube. Regular lubing, and not putting the bike away soaking wet overnight, seems to keep rust away through the winter. But I might try olive oil now, or even petroleum jelly...

I just rebuilt a bike as a 2x8 speed commuter for the winter. New chain fitted (KMC Z8, about £6) so I'm starting from new and I'm having great success with a 500ml tub of petroleum jelly from Poundworld and an oily rag.

This should come as no surprise though. A new chain comes soaked in hot paraffin wax, AKA petroleum jelly. The chain manufacturers will tell you it's the best lube you'll get and why would they pay more? It does attract dust but that's not such a problem in winter. 

But here's the best thing, it's a pure product with no soaps, perfumes or solvents. So it doesn't irritate my skin, which is important to me because I get contact dermatitis. Apparently you should wipe your chain after every ride. I've never fancied that before now but actually the new regime keeps the chain ridiculously slick and easy to run through aforementioned oily rag, which is now free of light solvents. Previously I've used white spirit (hell's own solvent) and WD40 or GT85 (mist of doom).

Who knew?

WD40 every few rides. 

A chain lube is doing quite a specific job... it should provide protection by carrying the dirt away from the chain, which means it should disappear and be re-applied regularly (which I understand is the whole point of Squirt).

A sticky oil which remains attached to your chain will provide anti rust protection, but also will attract dirt into a paste which grinds away at your drivetrain.

So its a bit of compromise.

Gearbox oils presumably are designed to work well at higher temperatures and pressures, and as a sealed unit, corrosion should be less of an issue in a gearbox.

I use chain saw oil, after first clean from new.  I drop my chain into a tub of gunk and use a small ultrasonic bath to agitate all the road grime out of the inner surfaces, clean in fresh water whilst again ultrsonic action.  so far 4 mins of work.  I then dry chain with a rag and drop it into 1 litre container of fresh chain saw oil, hang dry, 10 mins now.  Wipe off excess and fit chain to bike, wipe down again and leave over night.  Next day oil has gone sticky and doesnt fly off.  Ride several hundred miles, repeat.  End of year buy new chain and do it again.

Pah, I've used olive oil on my best bike's chain on long summer rides. My chain didn't disintegrate and I wasn't 2% less efficient or whatever the claim of the lube manufacturers is. It felt as smooth as their snake oil.

All things considered, I'd choose something designed for the job, but you're going to accumulate shit on a chain in winter. As others have said, it's about keeping it clean: then there are loads of lubricants up to the job of keeping a clean chain moving.

A fair few folk swear by chainsaw oil, although I’ve never tried it myself. Oh, but you do need a proper bike with mudguards. And flaps, of course. 

Its an interesting one, this.

I commute year round by bike (ok I do tend to drive if it's truly awful, as I can't dry my clothes). I have to clean and relive my chain once a week- more if it's been raining.

Still not sure I'd choose engine oil though.

I might try making one from an old milk carton .

The bike has full length mudguards but it's the bow wave that sprays up from either side of the front wheel that sprays the cranks and chain with liquid mud.

The best thing you can do for your chain is to fit mudguards.

To be honest, if your chain is constantly being sprayed by liquid mud like mine is I don't see how they can last anyway. My winter bike chain has just been replaced at 930 miles, the 0.75% end of the checker dropped through every link and it was fine after the ride before! 

I have used engine oil in the past and found it to be great for staying on in bad weather but it does get messy.  Depends on your priorities, keeping your bike lubed or easilly cleaned.  Bike specific oil is another example of the power of advertising and the need for the gullible to but the "correct" product.  Protein recovery shakes also spring to mind.

I've heard a few people recommend it on these forums, so I guess it can't be terrible.

I would imagine most 'dedicated' bike lubes are simply commercial grades of lubricant with a few additives specified by whoever buys them anyway.

Just to play devils advocate though, a bike’s drivetrain, open to the elements, is not the same as a car’s gearbox. The drivetrain on a bike won’t heat the oil, so is there not always going to be a trade-off between retention on the chain (more viscous) and better penetration of the links (less viscous) at the expense of longevity?

Interesting question. I tried Morgan Blue syn lube but found it was so thick it attracted enough muck on the jockey wheels to grow potatoes. I've now mixed it two-thirds syn lube and one third EP90 gear oil to thin it down a bit. Only on the first application so far but EP90 is basically an anti-wear oil for high pressure situations so it ought to be good!