Drivetrain lubrication for indoor training

Question

Indoor training seasons starts and I'm again about to set up my direct-drive trainer this weekend. Before doing so and after experimenting with different methods of lubrication over the years, I'm wondering:

What kind of lube should I use for my indoor trainer?

I tend to use light-running oils or dry lubes because the drivetrain stays cleaner. At least in my experience, even on a chain/cassette that have been cleaned thoroughly, some grit/excess oil occurs over time using "just" oil, something like a dry lube (or even wax) isn't prone to this effect so much.

On the other hand, riding indoors pretty much eliminates dirt sticking to the drivetrain for obvious reasons, and that's the main reason why many people refrain from using thick/cheap oil for outdoor riding. It does the job but pulls too much dirt and grit to the chain and all the moving parts. On the other hand, tradtional oils stick to the drivetrain better and typically last longer.

I'm aware of drivetrain efficiency differences between those products, yet marginal, but I would argue that a few watts don't matter for most of us on an indoor trainer during winter.

Second aspect: Does riding indoors extend periods between required (re)lubrication, can I just go for way longer than I would outdoors because there is practically no dirt buildup?

My feeling is that at least for dry lubes, the drivetrain gets noisier after riding around ~150 km (or even less), so I would re-apply lube even if the chain is reasonably clean. Dry lubes/wax sometimes seems to peel/chip off, is this the same for plain mineral oils? I haven't seen any dripping oil on my floor/bike, so do lubricants go anywhere at all if there are no external factors like water and dirt?

In case of doubt, I would still go by ear and shifting feel, but I'd be interested in other's experiences.

Answer 1

The purpose of greasy and sticky lubes is to resist being washed out by water. (Hopefully this will never be a concern in your home.) The disadvantages to comfort and convenience are obvious.

If your aim is to reduce chain wear thoroughly removing grit is more important than the choice of lubricant. As long as it is a bike chain lube. Light machine oil or such will not do as it will be displaced by high pressure at contact surfaces.

With dry lube products be extra careful to ensure they do not contain PTFE (or other PFAS). They are already very problematic in regular outside use, you really don't want to contaminate your indoor spaces with that.

Answer 2

The bike I put on my trainer is the trekking one, that I happen to use sometimes for utility purposes (and remove from the trainer then). So I continue with the lubricant that is on the bike. In this case it's dry lube (drip wax on the other bikes - I'll pass this one to drip wax when changing the chain).

I thought about wet lube, but discarded the idea: the bike is in the basement, that is of course less dusty than a dry gravel track, but the cleaning process that follows the conversion from wet to dry is more tedious than wiping the chain with a cloth and adding a bit of dry lube when it's necessary (note: a factor on my aversion to wet lube is that dolomite is used on bike paths and in parks here, so wet lube collects this dust quite fast).

Answer 3

Here is the case for wax as an optimal lube if you are OK with the added difficulty of using it. It's not just about drivetrain losses. Wax has also been shown to produce lower wear than wet lubes. Consider the data from Zero Friction Cycling. Focus on test block 1. This test block has the chain prepped (strip factory grease completely, then add the test lube), then run for a simulated 1k kilometers with no added contamination. Kerin does re-lubricate the chain during each block, but I forget the interval. Each cell describes the percent of the total wear allowance (0.5 percent elongation) that the chain goes through in the block.

Most of the melt waxes he tested produced zero wear in this block. The best wet lube matches this, with a few other wet lubes close behind. Drip waxes tend to be in between standard wet lubes and molten waxes. However, most of the wet lubes in the test have significant wear. Nix Frix Shun's lube, which was very well-regarded when launched, got 12.6% wear.

That said, a clear downside of wax is the difficulty of the logistics, particularly the chain prep. You could buy a pre-waxed chain, e.g. from Molten Speed Wax or Silca. You could use drip wax on that. Alternatively, you could just leave the factory grease on, and re-lube the chain with a high-quality wet lube. I believe Kerin did test this combination, and it produced quite good wear results, but it's been removed from the current chart.

Answer 4

Whatever is cheapest. when you're training, it doesn't matter how much Resistance you have. it will just mean you get a little bit of extra speed when you go outside. as such, there really isn't a good reason to do anything fancy at all as long as the chain isn't falling off.