Mid drive chain efficiency and longevity tips

[neptronix]

Wanted to share some things i know about mid drive efficiency from a mechanic standpoint.

Chain type and configuration:

Video featuring Zero Friction Cycling talking about watt losses per chain type, chainring size, etc:

Original Data:
Chain Testing - Zero Friction Cycling

These results should be ~2x worse on ebikes, because mid drives put substantially more force on the chain continuously, creating more friction.

Quick takeaways:
- The single, totally average 8 speed chain tested here had the lowest friction.
- The less well the gears line up, the more friction. A high amount of mismatch is called 'cross chaining'.
- oversized derailleur pulleys save ~1 watt, but also reduce the cross chaining penalty, which saves more watts.
- The larger the tooth count on the rear and front, the better for low friction, and also gear durability. An ideal lowest gear is 13t-15T, so if you can run an oversized chainring, great!

Lubrication:

Lubrication matters a ton. Mid drives beat on chains, so you should use the best lubrication possible.

This video measures the friction losses in terms of watts per various types of lubricants:

Quick takeaway from the video:

You can imagine that these losses add up to 10's of watts when you have a 750w or higher mid drive plus human power going through a chain!

SILCA makes a chain lube with tungsten disulfide that forms a protective film on the chain and noticeably reduces wear. The video includes a demonstration of the friction difference:

SILCA also makes an ebike lube: Synerg-E E-bike Lube

SILCA's lubes score up there with waxes, except for in dirty environments. ( screenshot of zero friction's data below )
A few other brands are starting to catch on to tungsten disulfide.

Drip wax performs much better in dirty/dusty environments, but needs needs more frequent applications and is higher maintenance.

Wax is excellent in all regards but has high maintenance needs and might do bad in rain/cold environments.

Consider at least using a very high end lube on this list or drip wax ( to resist dirt ), depending on your environment.




Let me know if i'm missing some other aspect that can minimize chain wear and reduce friction here

 

[scianiac]

I mean I think the real takeaway from zero friction's testing is wax dip lubes obliterate drip lubes no matter how fancy. Honestly I have no need for real chain longevity (total ride miles is low) or efficiency (never have range concerns) or any of that but I will never go back to drip lubes, wax is just so much better from a convenience perspective. So rarely do I ever have to do anything, honestly so far I just wax them when new and forget about them. And they are so clean, even on a bike that rides through only dirt and mud they are are spotless. I guess the other side is the wax performs better under high loads and I'm certainly putting these poor chains through high loads.

I use a wax I made myself that is optimized for longevity in ways commercial waxes are not, also I made it before commercial waxes were widely available so I don't think it's really worth it as much and mine is still based on the older MoS2 tech, if I made it again I would use WS2 but this will probably last forever so. I would guess mine is a little better than the Molten speed original in wear and friction but I don't really know. Future versions I would also experiment with the base wax materials more not just the additives.

 

[raylo32]

Interseting... but the problem I see with wax is that while it protects the body of the chain well from picking up dirt and contaminants it has very low shear strength so it seems that it would quickly wear away in the bearing and articulating parts... and since it is solid there is nothing to flow in to restore lubrication to those points. There are probably plenty of research reports showing advantages and disadvantages depending on whether they were published by wax mfgs or drip lube mfgs.

 

[Chalo]

I mean I think the real takeaway from zero friction's testing is wax dip lubes obliterate drip lubes no matter how fancy. Honestly I have no need for real chain longevity (total ride miles is low) or efficiency (never have range concerns) or any of that but I will never go back to drip lubes, wax is just so much better from a convenience perspective.

Yeah, wax is so convenient that not one mechanic at any bike shop I've worked at since 1992 uses it.

Waxing chains is a hobby. Every cyclist already has a hobby. Also, even the cruddiest chain's friction losses disappear in the noise of other far more significant drags on the bike, up to the point it's too rusty to pass through a rear derailleur.

When you can hear your chain, lube it. When it's elongated, replace it. Turning it into some kind of drawn-out kitchen project is for very bored retirees.

 

[Yanis]

Interseting... but the problem I see with wax is that while it protects the body of the chain well from picking up dirt and contaminants it has very low shear strength so it seems that it would quickly wear away in the bearing and articulating parts... and since it is solid there is nothing to flow in to restore lubrication to those points. There are probably plenty of research reports showing advantages and disadvantages depending on whether they were published by wax mfgs or drip lube mfgs.

I personally use drip wax (Bike7 pro wax) and I'm very happy with it. I first degrease the chain and the rest of the transmission, and then use it as a classical drip lube. When I need to lube again, I just rub a cloth on the chain to clean it a little and drip the wax on it (I don't remove the chain).
With an oil-based lubricant I was getting a little over 1000km until reaching 0.5% elongation on a HG93. Now with the Bike7 wax it's more like 1500km and the chain is clean all the time, which is big upside to me.
The only downside is that it needs to be applied every 300 km (no matter the weather). But I never have to degrease the chain again before re-applying wax so it's totally worth it to me.

 

[neptronix]

I watched many videos about chain waxing.
It does seem high maintenance and the benefit over a very good lubricant is small.
I imagine that if you're competing in an offroad pedal bike race, i see why you'd be into it ( the wax doesn't absorb dirt and will consistently perform in a race )

Lubricants containing tungsten disulfide seem like the top low maintenance option for the average rider.

 

[scianiac]

Interseting... but the problem I see with wax is that while it protects the body of the chain well from picking up dirt and contaminants it has very low shear strength so it seems that it would quickly wear away in the bearing and articulating parts... and since it is solid there is nothing to flow in to restore lubrication to those points. There are probably plenty of research reports showing advantages and disadvantages depending on whether they were published by wax mfgs or drip lube mfgs.

I mean Zero Friction's testing is the most rigorous and unbiased I've seen, the shear strength seems to be just fine and really the wax in part acts as a carrier for the additives that do much of the work by actually getting trapped between the metal surfaces but the wax does a better job of keeping the additives from being displaced. The actual surface pressure of a chain is quite high because the area is so small and we are putting quite a lot of load. Using just straight oil would perform quite poorly in the same way using base oil in your engine would be terrible. It's the high pressure additives that do the work when high pressures are involved and wax stays in place better by not being squished out of the way by pressure.

Yeah, wax is so convenient that not one mechanic at any bike shop I've worked at since 1992 uses it.

Waxing chains is a hobby. Every cyclist already has a hobby. Also, even the cruddiest chain's friction losses disappear in the noise of other far more significant drags on the bike, up to the point it's too rusty to pass through a rear derailleur.

When you can hear your chain, lube it. When it's elongated, replace it. Turning it into some kind of drawn-out kitchen project is for very bored retirees.

I don't totally disagree, I'm sure there are high end bike shops that will wax chains or you can buy chains pre-waxed. It is a time consuming process the first time, requires equipment and if I ran a bike shop I certainly wouldn't bother. The friction I don't care about but I do like a clean chain that I don't have to worry about and yes waxing is a hobby but if you haven't noticed most of us here are in this hobby for stuff like this. If we didn't care about little stuff like this, over analyzing things and tweaking things most of wouldn't be on this forum.

I watched many videos about chain waxing.
It does seem high maintenance and the benefit over a very good lubricant is small.
I imagine that if you're competing in an offroad pedal bike race, i see why you'd be into it ( the wax doesn't absorb dirt and will consistently perform in a race )

Lubricants containing tungsten disulfide seem like the top low maintenance option for the average rider.

Honestly the waxing part is trivial, takes very little time and cost. I just leave the wax in a baby crockpot from goodwill, plug it in, wait for it to melt, dump chain it, leave it for a while, swish it around, pull it out and hang it on a a hook above the wax and put it back on the bike, the excess comes off by itself. The cleaning the super sticky packing grease that comes on the chains though is a pain the ass as it takes several rounds of strong solvent to get it all out.

 

[raylo32]

I guess this is where we agree and disagree. That was my point, you have very high loads in the articulating parts which will easily scrape away any dry wax that then flakes off and is gone leaving what, exactly? Whereas with oil based lubes the "messiness" means that the stuff gets picked up and redistributed and that will keep those areas from drying out totally. At least for a while.

The actual surface pressure of a chain is quite high because the area is so small and we are putting quite a lot of load. Using just straight oil would perform quite poorly in the same way using base oil in your engine would be terrible. It's the high pressure additives that do the work when high pressures are involved and wax stays in place better by not being squished out of the way by pressure.

 

[Chalo]

I personally use drip wax (Bike7 pro wax) and I'm very happy with it. I first degrease the chain and the rest of the transmission, and then use it as a classical drip lube.

Repeated reapplication of the wax drip lube (as needed) eventually drives off the oily part without having to spend time and chemicals degreasing the chain.

 

[scianiac]

I guess this is where we agree and disagree. That was my point, you have very high loads in the articulating parts which will easily scrape away any dry wax that then flakes off and is gone leaving what, exactly? Whereas with oil based lubes the "messiness" means that the stuff gets picked up and redistributed and that will keep those areas from drying out totally. At least for a while.

Eh whatever, you are free to ignore the evidence all you want, I'm more interested in the tribology science of why it does work. This is not some new idea that is only based on theory, there have been many well executed empirical tests done over many years. But hey just becauce you've just heard of it, took a few seconds to think about it and made a decision I think you should go with that, honestly ignore me, this whole thread and the 1000s of hours of testing, just shoot from the hip my man.

The wax is trapped too deep inside the chain to just fall off. You have to take into account the shape of the chain, the wear occurs between the pins and the plates, the rollers act to make it hard for it to escape that way as do the distance and gap between the plates. It's likely the wax does get smeared around but it just gets smeared to the other side of the pin and stays there. The space between the pin and plate flanges is fixed, there can only be a certain amount of wax in there and it's too thick to just drip out or be exchanged by outside material or air so while it probably gets moved around until the two metal parts are very close and riding on the additives and wax, the rest just sits on the other side until it's smeared back in, just like oil but less likely to be exchanged with outside material. It's true that the part of the wax performance is due to preventing contamination but if you look at the testing any decent wax outperforms lubes in clean conditions by a wide margin as well.

 

[neptronix]

Looking at the tests again..
.. wax, and even drip wax seems to do great in dirty conditions.
..and a mid drive rider is more likely to be riding in this condition, so maybe a high end lube wasn't the best recommendation.

Drip wax seems to be a nice middle ground.
I didn't research drip wax much. Is it really the convenience of lube, but with wax? What's the tradeoff?

 

[Yanis]

Drip wax seems to be a nice middle ground.
I didn't research drip wax much. Is it really the convenience of lube, but with wax? What's the tradeoff?

It seems to me too.
As I said, the only downside I see after a couple years of use is that you need to re-apply it more often (every 300km, or when you start to hear the chain). One annoyance I mentioned was the cleaning of the factory grease, but Chalo said you can even skip that. I probably will keep doing it anyway since even if there is no mechanichal benefit, that initial degreasing helps keeping the chain clean. Wax doesn't stick so dust doesn't mix with it like it does with an oil lube. That mixture of oil and dust is not only dirty, but also highly abrasive.
I use my bike as my principal mean of transportation in Paris and suburbs (this city and its surroundings is becoming a heaven for cycles btw). I don't care about watts savings, I want my transmission to be clean, silent, durable and easy to maintain. Drip wax does that for me.

 

[99t4]

At this point, what I want to know is how much these differences in chain lube frictions have on the overall effect on a roadgoing ebike. The charts show a measureable difference between products (isolated) but how large is the chain's friction contribution in the overall efficiency picture. Seems like it is just signal noise compared to aerodynamic losses for example.

I did the old school chain wax method in the '80s. Melted bricks of paraffin (candle) wax in a large coffee can over the stove, dropped the chain in, swished it around, hung it to cool. I really liked how clean the chain stayed, and it appeared to shed dirt well but two or even one rides in the rain required rewaxing. Wore out several chain breaker tools (removing pins). Also, cold weather (near freezing) caused unpleasant chain skipping. Not a workable solution in a rainy environment.

After that, Boeshield. Not real long lasting, dirty messy chain.

After that, Tri-Flow, as that is what my local friendly bike co-op uses, and they would refill my old Boeshield drip spout bottle with Tri-Flow for cheap. Lasted quite a bit longer than Boeshield but dirtier and messier.

Currently I am trying Dumonde original and so far (first application) am really liking it, although it does not stay as clean as they promise.

 

[neptronix]

I've updated the first post with information gleaned.
Drip wax or regular wax sounds like a good idea for a dusty/dirty environment like the one i live in.

Sounds like it's not very fun in a rainy environment!

 

[Yanis]

Sounds like it's not very fun in a rainy environment!

Oh I forgot about this. In my experience, rain is fine and doesn't seem to wash the wax away. I can't speak much about riding in mud since I rarely do that, but the few time it happened, I just cleaned the chain with a sponge and water afterwards, let dry, and re-applied the drip wax. Was all fine.

 

[amberwolf]

Interseting... but the problem I see with wax is that while it protects the body of the chain well from picking up dirt and contaminants it has very low shear strength so it seems that it would quickly wear away in the bearing and articulating parts... and since it is solid there is nothing to flow in to restore lubrication to those points.

Unless you live in Phoenix, AZ, in which case it could liquefy for half the year, while the sun is up... :lol:

(I used to try filling my connectors with petroleum jelly (vaseline, etc) as a dielectric grease to minimize water intrusion and oxidation, but starting in late may it would get hot enough in the direct sun to melt it and it would flow out...so while i still use it, I don't bother trying fill them anymore, just coating the contacts.).

 

[neptronix]

What's the ideal lubricant for a super hot environment like that?

 

[raylo32]

Sweat.

What's the ideal lubricant for a super hot environment like that?

 

[lnanek]

As someone living in Cali where it rains once a year, waxed chains are not just less noisy, but also way less trouble. No grease on my wife's clothes or kid's blanket for one.

Two. cleaning is just a super quick wipe down with an alcohol wipe 99% of the time. Maybe if I ride in the rain I'll drop it in my ultrasonic cleaner and then a pot of boiling wax, but again, that's like once a year and only takes like 5 minutes labor in-between waiting 20 minutes for the cleaner, 20 minutes to boil, and overnight to dry. I always do multiple chains at once too.

I also have drip wax for in-between cycles, so removing the chain isn't often required.

Wet lube chains were way more trouble. Huge dirt magnets. Felt like I was cranking the chain through my chain scrubber with solvent and applying lube again once a month - and it was still noisier and messier for my wife and kid even when clean. Just seems silly in retrospect. I was an idiot for decades putting crap on my chains that just made dirt stick to them immediately and grinded my drive chains.

 

[amberwolf]

What's the ideal lubricant for a super hot environment like that?

I stopped using any on the chains, because the ones that work are flinty-dust-magnets and make the chain wear worse, and make them grimy and dirty so that it gets on my work clothes, or on me if I have to do any roadside work. I don't have easy access to chains on most of my creations for removal/cleaning/etc., so I just replace them when they wear out.

EDIT: So if you live and ride in dry conditions where rust isn't an issue, you could live without any lube other than whatever came on the chain (or you can clean that off to keep the dust from sticking to it and grinding the chain up over time), if the above also applies to you.


These days I'm not putting much load on them with my legs, so they last much longer than they used to before I began adding motors to the bikes (which I had to do because I'm wearing out). The new trike will run the motor thru some of the chains, so those will probably wear out faster than the ones the pedals go thru.

 

[neptronix]

Think you guys just converted me into a drip wax enjoyer. These are good points.

 

[Chalo]

At this point, what I want to know is how much these differences in chain lube frictions have on the overall effect on a roadgoing ebike.

Nothing you can feel, at all. Even no lube whatsoever won't slow you down-- but it will make noise that might annoy you, and will accelerate the wear process.

 

[ZeroEm]

Thought everyone waxed. Never knew about wax before my trike. used to pour oil on my bike chains. In the oil field we used on 90wt on chains, they ran in it (Chain cases design with low spot full of oil). Seen a chain laying on the ground don't remember now 6 months or a year and still had oil on it no rust.

When I joined EndlessSphere read about chain waxing. Wanted to keep my trike clean no lube slinging all over and on me.
When my trike was new started waxing my chain. Maybe three or four times in 5-6000 miles. Bought a new chain have not put it on yet.
A just waxed chain is quite, don't remember when it was time to wax again, think when I could hear the chain. A fresh waxed chain will flake and wax gets on gears tubes idlers. It is clean, never worried about water or dust. I stand by wax, never bought a spray. Always took the chain off and put it in a Iron skillet full of hot wax and work the chain around. when the wax started cooling would hang it up until cool enough to handle. Had a out side gas burner but it's gone will need to figure out hot to heat the wax now.

 

[Chalo]

In the oil field we used on 90wt on chains,

Now that is effing gross, at least on the road. Thin wicking lube, applied to the whole chain and then wiped off the outside as much as possible, is how bike chains get oiled.

 

[scianiac]

Had a out side gas burner but it's gone will need to figure out hot to heat the wax now.

Go to goodwill or a thrift store and find a baby crockpot, see them all the time, no idea what they are for, maybe sauce of some sort? You can just leave the wax in it.