1x drivetrain wear

[Red Tornado]

When I rode exclusively 1x9 I got by with replacing chainring, cassette & chain once a year. That's riding it twice a week 35-40 weeks a year.

[NHAero]

I've been really pleased with what seems to be longevity of the SRAM 1x11 XX1 gear on my MTB, but I do the best job of all my bikes with chain lubing and staying on top of chain wear on that bike. I've replaced the chain once in 3-1/2 years, and the largest cog (which is aluminum). It gets ridden on a weekly morning group ride of 12-20 miles, I use it a bunch as my commuter and errand bike, and ride it solo too. I'm guessing I've put >3,000 miles on it and it was used when I got it. The drivetrain is expensive so I want it to last!

I ran 1x11 as a trial on my CAAD10 and I could tell in extreme gears vs 2x set-ups. Not sure why it doesn't seem perceivable on the MTB but think it's because the riding conditions change so fast - sitting, standing, etc., and the fact that I'm in the center half of the cassette most of the time here on MV because it's not very hilly. That's not true on the road, in a 1x I use all the gears regularly.

I believe we've known for a long time that larger chainrings and cogs are more efficient. This is one reason (which may first be counter-intuitive) for wanting sub-compact cranksets. My Anderson is 44-33; the Firefly is going to 46-34; and the Litespeed MX conversion is 40-28. This means that I'm in the big(ger) ring most of the time. Sure, the 46 is less efficient than the 50 or 53, but, I spend much more time in that ring vs. if I had a larger big ring.

[chiasticon]

Originally Posted by Mark McM

In a sport of marginal gains, the extra losses in the 1x drivetrain are significant - An extra loss of 2% is like adding an extra 4 lb. on a climb.

you lose a lot more than 2% if you drop your chain mis-shifting over bumpy terrain.

[dddd]

Originally Posted by chiasticon

you lose a lot more than 2% if you drop your chain mis-shifting over bumpy terrain.

This is why it is better to add more rings, same as on my 'cross bike, so when I "drop" my chain, it is only onto a smaller chainring.

I can't recall how many times that I have overtaken a formidable cx competitor because they dropped their chain (using 2x), but I've maybe lost the chain off of the"redundant" smallest (of three) rings once in twenty years.

It's the bigger 16t drop that causes so many chain drops in the era of compact chainsets, but 'cross bikes usually limit the size difference to 8 or 10 teeth on a double.
The narrower chains wouldn't seem to help either, since they present a smaller target for the small ring's teeth to fall into (admittedly the inside width changes have been small).

Having a large difference in size of two adjacent chainrings causes chain drop because there is a greater distance over which the chain bows during a downshift, and the inward distance is affected by the highly variable amount of tension on the chain.

[gdw]

Originally Posted by Blue Jays

You are seriously replacing entire drivetrains every other month?
That is some remarkably powerful riding. That is awesome!

A 1x on a mountain bike is good for 8-1500 miles where I ride before you often need to replace the chain and cassette, the front chainring lasts much longer. When you're training for events like the Leadville 100 or some of the long multiday adventure races or backpacking routes it's pretty easy to rack up 6-800 miles a month.

[benb]

Regardless of efficiency losses and whether it's 1X/2X/3X the cassettes & chains & rings seem to wear out faster as the # of sprockets in the back goes up. The sprockets have less material surface to handle the stress and the chain is narrower as well.

I still ride 3x9 speed on my MTB and 2x10 speed on the road. 2x10 definitely wears out faster than 2x9 did for me. My 3x9 setup is positively ancient.

I'd probably be just as happy to be on 2x9 on the road. And I don't really see 2x11 or 2x12 or 1x12 having any benefit that would outweigh faster wear. Sure I appreciate it the extra gears but it's not a huge deal. I'm not sure where the cutoff is. I'm fairly certain I wouldn't be psyched about 2x5 or 2x6.

A lot of these "drop the chain" and "mis-shift" issues IMO have nothing to do with the group set configuration. You either get your bike sorted out correctly or you don't, whether you learn how to do it yourself or you take the time to find a good mechanic to work with.

[benb]

Originally Posted by dddd

It's the bigger 16t drop that causes so many chain drops in the era of compact chainsets, but 'cross bikes usually limit the size difference to 8 or 10 teeth on a double.
The narrower chains wouldn't seem to help either, since they present a smaller target for the small ring's teeth to fall into (admittedly the inside width changes have been small).

Having a large difference in size of two adjacent chainrings causes chain drop because there is a greater distance over which the chain bows during a downshift, and the inward distance is affected by the highly variable amount of tension on the chain.

This... 3X MTBs had small tooth transitions on the rings as well. I think mine is 22/32/42, or maybe 22/32/46. For sure the granny ring is mostly vestigial if you're fit/racing but those 3X MTB front derailleurs are not difficult to dial in, dialing 2X road Compact Fronts with the 16-tooth jump is the most finicky setup I've dealt with. 2X Fronts with 12-14 tooth jumps have been easy for me to dial in to be bullet proof over the years too.

I have 105 with a 34/50 setup on one of my bikes right now though and it was not difficult at all to get dialed in and never drops the chain. Some compact setups are fine if you get all the variables right. I have had other compact setups on that same bike that were terrible though.

The only good reason I can come up with for the disappearance of road triple and rise of the compact road setup is it allowed the manufacturers to drop the triple front brifter SKU. With the integrated shifter/brake being the most complex part on the bike that seems to make sense. It never made any sense to me from a riding perspective. The compact rings almost never shift(ed) as well as a setup with smaller jumps and the larger jumps always made for more awkward transitions and more frequent front shifts for me.

[avalonracing]

Originally Posted by Mark McM

Based on the test report in the latest issue of Velonews, you'll also have to accept a loss of drivetrain efficiency, also. In the report, they tested an SRAM 1x drivetrain against a Shimano 2x drivetrain (the chainrings/cassettes were selected so that they had the same range of gear ratios). The 1x had a lower efficiency in all gears - the 1x had average loss of 4.9%, while the 2x had an average loss of 3.8%. At the extreme ends of the range, the losses of the 1x were far worse than the 2x - in the highest gear, the 1x had a loss of 7.6%, while the 2x had a loss of only 5.2%. In a sport of marginal gains, the extra losses in the 1x drivetrain are significant - An extra loss of 2% is like adding an extra 4 lb. on a climb.

But .0003% of that loss in efficiency can be offset by $800 ceramic bearings.

[benb]

Originally Posted by avalonracing

But .0003% of that loss in efficiency can be offset by $800 ceramic bearings.

Yah and another $3000 on parts to trim an additional 4lbs off the bike.

(Ignore the gut)

[palincss]

Originally Posted by Red Tornado

When I rode exclusively 1x9 I got by with replacing chainring, cassette & chain once a year. That's riding it twice a week 35-40 weeks a year.

It's my understanding that on double and triple chainring road bikes, chain rings are usually good for around 30,000 miles. Either 1x dramatically increases wear over a double or triple setup, or you are doing some amazingly huge miles. If you did a century every riding day, 80 times a year, that's still only 8,000 miles a year. That's a lot for a chain and a cassette run with a worn chain, but still only 1/4 of what you'd normally expect from a chain ring.

[palincss]

Originally Posted by gdw

A 1x on a mountain bike is good for 8-1500 miles where I ride before you often need to replace the chain and cassette, the front chainring lasts much longer.

Am I reading that right? A chain only lasts 8 miles?

[Mark McM]

Originally Posted by palincss

It's my understanding that on double and triple chainring road bikes, chain rings are usually good for around 30,000 miles. Either 1x dramatically increases wear over a double or triple setup, or you are doing some amazingly huge miles. If you did a century every riding day, 80 times a year, that's still only 8,000 miles a year. That's a lot for a chain and a cassette run with a worn chain, but still only 1/4 of what you'd normally expect from a chain ring.

Obviously, chainring wear depends on many factors, including riding terrain, environment (water, dirt, mud, etc.), rider size/power, etc. But another very large factor is chainring size - smaller chainrings wear much faster than larger chainrings.* Not only do you spend all your riding on a single chainring instead of spreading it out over two chainrings, but that single chainring is smaller than the large double chainring that you spend most of your time on with a double drivetrain. Plus, on a single chainring, you spend more time in extreme cross-chaining combinations, which also accelerated chainring wear.

I'm not at all surprised that chainrings in single chainring drivetrains wear much faster.


*Consider: Cassettes are usually made from steel, while chainrings are usually made from aluminum. Even though aluminum is softer than steel, chainrings usually outlast the cassette. And that's even though you spend more time on any given chainring than on any given cassette sprocket. The longer life of chainrings is because they are much larger than cassette sprockets. The exception here is for inner chainrings on triples, which are often quite small. Not surprisingly, these chainrings are often made from steel, lest they wear too fast.

[benb]

I've worn out chainrings in way less than 30k miles on a double.

The one I wore out was a 10 speed 34 ring on a compact on my All City Space Horse, that bike basically gets rode & treated almost like a mountain bike in terms of dirt/salt/moisture exposure, and I don't do a super good job cleaning it as it's my bad weather bike.

Hard to say how many miles were on that ring.. maybe 10k, maybe less. It was about 4 years of use. That was a Tiagra crankset too so maybe lower quality. The crank & BB were fine though.

There is no denying when a ring is worn... not fun, I replaced it ASAP.

The XT rings on my MTB are 3x and I think I bought them in 2001 and they're still not toast. Probably close though. They're thicker rings though since they're 9 speed, and they're higher end than the ones I wore out on my Space Horse.

I've never worn out a 39 or a 53 ring on a road bike that primarily sees pavement. I've usually gotten rid of the crankset as every other part is trashed and the cranks/rings are still fine. I'm vain enough/not cheap enough that I usually want the crank to mostly match the rest of the bike.