Latest News 56 – Chain efficiency vs Longevity

Alrighty here we go, something I have wanted to be able to publish for a long time – I finally have clearance!

Some chains have outstanding wear longevity, but are not very fast.

Some chains are very fast, but have very poor wear life.

Some chains do a mighty fine job of being both very fast and great wear lifespan.

Depending on what speed of bike and groupset – you can now check a simple graph and decide what is the right chain for you (or chains if you race and are clever enough to have a dedicated race chain and training chain vs racing on the same chain you hammer in training which makes little sense – you will always need another chain sooner or later, pre buying next chain to be your dedicated race chain costs you no more – when training chain reaches 0.5% wear, race chain moves over to become next training chain, one new chain as normal to be next dedicated race chain).

Some quick info highlights re chains at the moment

Sram eagle Xo1 and XX1 chains have frankly amazing wear durability due to Srams HARDCHROME treatment. This is very different to the level of chrome treatment used on their 11spd road chains (PG1190 or PG1170). Srams 11spd road chains with whatever that chrome treatment is have just ok longevity. Hardchrome, from a wear longevity perspective, is all that and a bag of chips.

Srams GX and NX level chains do NOT have hardchrome, and have really very average (aka, poor) wear lifespan. Do not buy GX chain, make the step up to X01, the difference in price will be pay for itself about 50 times over.

However- since most people sadly buy GX level, and GX level chains are mostly OEM equipped, Sram is prioritizing production of GX / NX chains. As such x01 / xx1 level chains are now almost impossible to find. I have back ordered some ages ago, and am looking at late 2023 to receive them. Balls.

If you run eagle and you cannot get x01 / xx1 – think about the YBN SLA 12spd. Whilst nothing matches the wear longevity of x01 / xx1, it is still well up on GX, and it is a VERY FAST, VERY Smooth chain, it rocks on eagle drivetrains. Use a top lubricant and wear life is still very good. It is a much better option overall vs going GX.

And for those who race it is a much faster race chain vs any eagle chain.

SRAM AXS ROAD 12spd

Similar to above – AXS Force and Red level have Srams HARDCHROME treatment and have outstanding wear longevity. Rival does not. Do not buy rival, step up to Force level. If you already have Rival chain, keep a VERY CLOSE eye on wear life – remember if you get caught out running chain past 0.5%, you risk destroying very expensive cassette / chain rings.

KMC / YBN 12spd compatibility with AXS Road 12spd

Sram AXS road chains are thinner – both external width and internal width between inner plate links –  than KMC / YBN 12spd chains which are still an 11/128 standard chain (same internal width as 9, 10 & 11spd chains – 12spd 11/128 are just thinner as yet again thinner plates vs 11spd).

When Sram went very thin for axs road 12spd, they increased the height of the link plates to retain sufficient metal and tensile strength. The taller link plates required larger rollers to match.

The larger rollers require a tooth profile on cassette and rings to match.

For a while now KMC claimed their 11/128 standard 12spd chains are compatible with all 12spd systems, including AXS road.  YBN have now also joined in with this compatibility claim for their 12spd chain.

Considering AXS road is a completely different standard, being compatible across both standards I have always felt is a stretch.

To an 11/128 standard chain, running on AXS road cassette / rings etc – the larger troughs between teeth to allow for the oversize rollers of AXS road flat top chains would, for an 11/128 standard chain – seem like they are running on a quite worn cassette and chain rings.

Also as an 11/128 chain is wider, gear tune must be EXACT to avoid rubbing on the more closely spaced cogs of AXS Road vs other 12 spd systems based on an 11/128 standard chain.

Over time a number of people have tried running KMC and YBN SLA 12 on AXS road, and the reports I have had back is that all is sweet.

However – please note that ZFC STRONG recommendation is to NOT run an 11/128 standard chain on AXS Road.

If one puts a new chain on worn cassette, it can jump under high load as the mesh is poor. This can in worst cases lead to broken teeth off cassette, or a snapped chain. Snapped chains at speed can be exciting (ie if snaps under stand up sprint). Aside from the excitement of having the chain suddenly snap, the chain can then fall into your spinning rear wheel. What happens then is an epic lock up skid, and often ripping chain through your chain stay, ruining wheel, frame, and rear mech. Good times all round.

If a new chain is put on worn chain rings, chain can jump off rings under high power. Again if this happens whilst standing up pedaling and high power, people do go over the handlebars for a hot date with asphalt. Let me tell you, asphalt is a crap date.

So whilst these chains seem (according to anecdotal evidence from around the world) – work on AXS road, for me it is a very dangerous choice to make. There will just be very little safety buffer. As the rings and wear over time, what little buffer there is to start with may disappear on you.

Note that SRAM themselves state you must not mix any other standards with AXS road, they are not compatible, they are a different standard. This is a very very different situation to running say a kmc or ybn 11spd chain on Sram 11spd, as they are both the same standard, same dimension chain and rollers. AXS road 12spd is not.

It is tempting to run kmc / ybn 12spd as it is notably faster than srams axs road chains – and especially for steady state riding such as triathlon events – it seems to be going all groovy – but take all the above cautions into account. For road racing I think it would be an extremely risky path to take. Broken bones / broken bikes are not faster than intact bones and bikes. So if you average 200w steady state in an ironman and your AXS road bits are new, and your gear tuning exact – maybe and KMC or ybn 12spd is going to be all groovy and faster. But smash many hundreds of watts or more up a power climb, attack, sprint….. personally, if I was me, I would not be doing that on a chain that is a completely different standard to the tooth profile of my cassette and chain rings. Risk / reward ratio is just WAY out in my opinion.

Okey dokey, those bits covered – I am VERY pleased to present the first chain efficiency and wear life consolidated data.

Huge thanks to CeramicSpeed Denmark R&D lab for allowing public use of their chain speed data. CeramicSpeed use their extremely accurate testing to decide which models of chain to offer with their UFO prep.  ZFC had been hoping to be able to openly publish their test data for a long time, however it obviously needed to get some clearance as there is a potential for brands with slower chain models to be less happy. Why upset any apple carts when the data was obtained purely for internal decision making re ensuring CeramicSpeed provide the fastest racing chains.  However, it has been agreed that such data would be of high value for cyclists when matched with wear lifespan, allowing a simple graph to assist all cyclists make the chain selection for training and racing.

The chart will be updated as more tests are completed. Further data on chain wear lifespan across many chain models can be found on excel spreadsheets in chain test data page on Zero Friction Cycling website. I spent a big block of resources on that testing project in collaboration with Cycling Tips re finding best chain article.  ZFC hopes as always this helps you make informed decisions based on extremely robust and independent test data so you can stay low friction and low wear in your cycling.

**Head to www.zerofrictioncycling.com.au and chain efficiency test for full data and information***