I know what RD and FD mean, but what does FA mean?
I know what RD and FD mean, but what does FA mean?
Frontal area.
Frontal area I believe
.
… because of the mass and inertia of large cassettes and the considerably less frictiony drive trains …
I am puzzled by this. Could you clarify how/why/where drivetrains are getting considerably less ‘frictiony’ ? And also how the mass and/or inertia of large cassettes offer any advantages?
ceramic bearings. lighter/better oil. optimized chains and chain/tooth interaction. oversized bearings. you didn’t get these memos?
Not sure if there is a lot of evidence to support this big improvement in drivetrain friction.
In the big picture, relatively few people use ceramic bearings (do ceramic bearings come stock on any shimano stuff?), and their friction savings (if any, depends on the application) is very very very small.
Most of the best chain lubricants avail today are wax based, and riders have been waxing chains for at least 100 years.
I have not heard much about “optimized chain and tooth interactions” (any evidence or whitepapers that you can direct me to?), but l would bet good money that many 1x chainrings (with taller teeth and/or narrow wide teeth) create more drivetrain friction than similar 2x chainrings.
Finally, oversized bearings, while usually stiffer, actually create more friction than than the smaller bearing set ups they replace.
Not directly back to you Josh but I’ve been tracking my gear ratio while riding (display field on garmin coming from electronic shifting). I’m starting to get a feel but lots of times I’m not focused on it like a cling or group riding.
Is this being stored in the FIT file somewhere? And if it is, anyone doing anything with it? Like Garmin Connect or TrainingPeaks?
I’ve got a 55/42, 11-28 on my TT bike and gone back and forth on my road bike between a 50, 11-32 and 53/39.
I’d like to look at my rides over time and see which ratio I’m really using and how often. Then make a smarter decision for what I want going forward.
We discussed that article in the other thread and I can’t help but think that there is more going on than just the chain angle on the small cogs or chain tension etc.
Basically the sram system uses a clutched rd which you absolutely don’t need, also narrow wide has to add to losses.
Additionally there has to be a “sram†factor when compared to Dura Ace in the additional watts.
I wish they just compared sram 1x and 2x but this is impossible as sram hasn’t invented a functional FD yet.
Maurice
Jordan’s point that a 2x drivetrain doesn’t have 2x as many usable ratios as a 1x is also spot on.. many of them overlap or nearly overlap, though this assumes similarly large ranges of cassette.
I would say that statement is a bit of a strawman though. To me, the point of a 2X isn’t to have unique gear ratios, but to have overlapping sets of gear ratios with reasonable gaps that ALSO allow for chainlines that aren’t extreme at one end or the other. I’m OK with the fact that there may be duplicated ratios across the chainrings since the point of the 2X is to get the wide range WITH the reasonable gaps. The overlap just means there’s “hysteresis” in the decision to move from one chainring to the other 
I love the graphic presented by davews09… it certainly highlighted for me that modern, electronic FD’s probably have at least 2x the FA of the mechanical derailleurs we were looking at back in 2008-2009, so the advantage of losing the FD is probably greater than the 2-4 watts we measured at that time.
Yeah…I was going to say something about how that illustration shows how much of a “carbuncle” the Di2 motor or eTap battery of a FD is…yowza…
… because of the mass and inertia of large cassettes and the considerably less frictiony drive trains …
I am puzzled by this. Could you clarify how/why/where drivetrains are getting considerably less ‘frictiony’ ? And also how the mass and/or inertia of large cassettes offer any advantages?
ceramic bearings. lighter/better oil. optimized chains and chain/tooth interaction. oversized bearings. you didn’t get these memos?
Not sure if there is a lot of evidence to support this big improvement in drivetrain friction.
In the big picture, relatively few people use ceramic bearings (do ceramic bearings come stock on any shimano stuff?), and their friction savings (if any, depends on the application) is very very very small.
Most of the best chain lubricants avail today are wax based, and riders have been waxing chains for at least 100 years.
I have not heard much about “optimized chain and tooth interactions” (any evidence or whitepapers that you can direct me to?), but l would bet good money that many 1x chainrings (with taller teeth and/or narrow wide teeth) create more drivetrain friction than similar 2x chainrings.
Finally, oversized bearings, while usually stiffer, actually create more friction than than the smaller bearing set ups they replace.
i haven’t had time to answer this, but i’ve been thinking about it off and on over the past couple of days since you posted it. basically, what you’re saying, if you think this through, repudiates the narrative of entire business and technologies. forgetting what shimano, SRAM and campy are selling, what you’re saying basically is that everything jason has written, all his testing, everything friction facts and ceramic speed are doing and have done, is a lie. a fraud. and i know you’re not saying it in those words. but that’s the net result of what you’re saying, no?
for example, i think jason would say that larger pulley wheels reduce friction thru (for example) reducing the bend in the chain. you’re saying no, the pulley wheels increase friction. and (according to you) nothing has come along - including jason’s magic chain elixirs - that’s any better than what we had 30 years ago, that the net effect of buying a thousand dollars from jason is that you just increased friction in your drive train.
ergo, jason’s test results are lies, ergo, jason’s a fraud. tell me why what you wrote is not saying that?
First, absolutely nothing I wrote said, or implied, or meant to imply, that anyone is a fraud.
I think you might be reading too much into this. First, it is possible to question something without calling anyone a fraud. Second, the only thing that I was saying was that I have not seen anything much showing significant decreases in drivetrain friction.
But, if I am wrong, heck, please educate me.
Clearly, ceramic bearings make a difference. The question is, how much of a difference do they make in the friction dept.? A watt? A fraction of a watt? And how many drivetrains have them? I don’t know of any stock shimano drivetrains (I mention shimano because they seem to have the lowest friction drivetrains) that have ceramic bearings, but I could be wrong. If I am, please let me know.
Sure, there are lots of great convenient low-friction lubricants (heck, I use some myself), but the apex of low friction chains (based on the evidence that I have seen to date) still seem to be waxed chains, which have been around forever.
As well, 1x and 2x each have their own advantages, but I personally have not heard much about “optimized chain and tooth interactions” (any evidence or whitepapers that you can direct me to?), except as applicable to better shifting (but not lower friction). I also said that I thought that many 1x chainrings (with taller teeth and/or narrow wide teeth) might create more drivetrain friction than comparable 2x chainrings (the added friction might be very small, but it seems very unlikely to me that 1x rings would be lower friction than 2x rings).
About oversized bearings (at least those that are used in modern BBs) do of course have advantages. For example, they are usually stiffer. But the actual oversize bearings (there are more balls rolling in the bearing, and each of those balls has to roll a longer distance with every single revolution), those bearings actually have a bit more friction in totallity than than the smaller bearing set ups they replace (for example, traditional high-quality loose bearing, circa 1980s, BBs).
Many new component developments have lots and lots of very significant operational advantages, I totally agree with you there. I am just not aware of any of those developments significantly reducing drivetrain friction.
All that said, if I am wrong about any of these things, I would always like to learn more.
Oooooh… this is getting so good!!
I need to point out that people are conflating my anti-10t cog stance as being anti 1x… it’s not. I love 1x and as mentioned previously was involved in the birth of it… my contention is that we are doing it wrong, or at least doing it sub optimally.
Jordan’s point that a 2x drivetrain doesn’t have 2x as many usable ratios as a 1x is also spot on… many of them overlap or nearly overlap, though this assumes similarly large ranges of cassette.
I love the graphic presented by davews09… it certainly highlighted for me that modern, electronic FD’s probably have at least 2x the FA of the mechanical derailleurs we were looking at back in 2008-2009, so the advantage of losing the FD is probably greater than the 2-4 watts we measured at that time.
For the benefit of davews09, the 6 watts comes from a recent Velonews article showing a 6 watt advantage in testing to a 53-11 compared to a 48-10. In the original reading and ST thread related to the article, the headline was ‘1x sucks’ which I defended 1x in and pointed out that it isn’t the fault of 1x but rather the use of these small cogs… each tooth lost in the rear cog has a disproportionately larger effect on friction than the previous one…
So the original statement made on the Marginal Gains podcast was that the 10t cog was a bad idea and that if you need a gear like that you should be going up on chainring so you can use larger cogs in the rear… and I may have called the 10t stupid, and I’ve been known to refer to it as a ‘vanity gear’ in the past… which is somewhat provocative on a number of angles, but my big point was that people will spend $1000 for ceramic bearings to save 1 watt or $750 for oversized pulley wheels to save 1-2 watts and then use a 48-10 when a 50-11 would be at least a watt or two faster and a 53-12 would be a watt faster still and that’s assuming you use it… which most don’t. I tell my ProTour teams that the ONLY point to the 11t cog in a TT is to give you better chainline to the 12t cog… so much better to go 56t front and spend 90% of your time in the 13-14-15 with the occasional 12 or if something crazy happens, you have the 11, but honestly it rarely gets used.
In my opinion the problem with how we’ve tried to do 1x is that we’ve tried to match the range of something like a 53/39 with 11-34 to prove the point that the 1x can match the range of this super wide 2x… which I would argue is way wider than most anybody actually needs also…
At the end of the day, riders should spend the money saved on the FD and buy a couple of cassettes that provide more specificity for the situation at hand. Or at least think of moving to a 50x11 setup as being at least the equivalent of a ceramic bearing upgrade over a 48-10 setup.
Exactly.
It’s “what we can do” versus “what we should be using it for”.
Where I gravel grind I do not need to be going faster than 40/12 combo. I run a 12-32 with a 40T for gravel. I’ve been able to use that bike, with gravel tires, in the local A group ride just fine. The rarity of needing to use a 10 or 11t is silly to justify having it on some 1x setups. On my gravel bike at 110rpm the 12 cog gets you nearly 30mph. 30mph, on gravel. You really spending that much time in that speed zone home slices?
It takes a couple minutes to swap a cassette or a front ring.
Also, 110 rpm on a 50-12 is 35mph. I don’t think a lot of people on here are actually spending a lot of time dolling out power flat or downhill at 35mph in TT bars. There’s some for sure. But that goes to highlight how silly for an average joe a 10, and maybe 11 cog is.
IMHO the perfect setup for most average joe TT folks and tri folks is probably 52 to 54 in the front and a 12-25 in the back. 1x. A 54 and 25 combo at 80 rpm gets you down to 15mph. A 52/12 combo gets you over 35mph at 110rpm. Most folks would probably do great with a 52 and 12-25.
First, absolutely nothing I wrote said, or implied, or meant to imply, that anyone is a fraud.
I think you might be reading too much into this. First, it is possible to question something without calling anyone a fraud. Second, the only I was really sying was that I have not seen anything much showing significant decreases in drivetrain friction.
But, if I am wrong, heck, please educate me.
Clearly, ceramic bearings make a difference. The question is, how much of a difference in the friction dept.? And how many drivetrains have them? I don’t know of any stock shimano drivetrains (I mention shimano because they seem to have the lowest friction drivetrains) that have ceramic bearings, but I could be wrong. If I am, please let me know.
Sure, there are lots of great convenient low-friction lubricants (heck, I use some myself), but the apex of low friction chains (based on the evidence that I have seen to date) still seem to be waxed chains, which have been around forever.
As well, 1x and 2x each have their own advantages, but I personally have not heard much about “optimized chain and tooth interactions” (any evidence or whitepapers that you can direct me to?), except as applicable to better shifting (but not lower friction). I also said that I thought that many 1x chainrings (with taller teeth and/or narrow wide teeth) might create more drivetrain friction than comparable 2x chainrings (the added friction might be very small, but it seems very unlikely to me that 1x rings would be lower friction than 2x rings).
About oversized bearings (at least those that are used in modern BBs) do of course have advantages. For example, they are usually stiffer. But the actual oversize bearings (there are more balls rolling in the bearing, and each of those balls has to roll a longer distance with every single revolution), those bearings actually have a bit more friction in totallity than than the smaller bearing set ups they replace (for example, traditional high-quality loose bearing, circa 1980s, BBs).
Many new component developments have lots and lots of very significant operational advantages, I totally agree with you there. I am just not aware of any of those developments significantly reducing drivetrain friction.
All that said, if I am wrong about any of these things, I would always like to learn more.
well, just to be clear. i think what you’re saying is that UFO Drip is no better than what we we were using (or could’ve used) 30 years ago. maybe you’re right! i’m not saying you’re wrong. i’m just trying to understand what you’re saying.
OSPW have more friction by design than standard sized pulley wheels. here is the ceramic speed narrative on this. i am totally cool with you claiming this is untrue. i’m not taking a position. just, this is your position? that ceramic speed’s claims are in fact the opposite of what they claim, they add not reduce friction? because of it’s not your position, then okay, but i misunderstand your position and i’d like you to educate me on what it is.
FYI, the new SRAM AXS RED group uses oversized ceramic bearings as standard. i suspect, as with electronic shifting, ceramic bearings will flow down into cheaper and cheaper price points. so, this question of whether these technologies actually work are germane, not arcane.
well, just to be clear. i think what you’re saying is that UFO Drip is no better than what we we were using (or could’ve used) 30 years ago. maybe you’re right! i’m not saying you’re wrong. i’m just trying to understand what you’re saying.
OSPW have more friction by design than standard sized pulley wheels. here is the ceramic speed narrative on this. i am totally cool with you claiming this is untrue. i’m not taking a position. just, this is your position? that ceramic speed’s claims are in fact the opposite of what they claim, they add not reduce friction? because of it’s not your position, then okay, but i misunderstand your position and i’d like you to educate me on what it is.
FYI, the new SRAM AXS RED group uses oversized ceramic bearings as standard. i suspect, as with electronic shifting, ceramic bearings will flow down into cheaper and cheaper price points. so, this question of whether these technologies actually work are germane, not arcane.
I do not personally know about ufo drip, but the last bit that I read on this topic in general seemed to say that the best new lubes were indeed very very good (again, I use some of these–rock and roll lube), but not really better than classic waxed chains with regard to friction (but better in regard to convenience).
And I do not know specifics about ceramic speed oversized pulleys. What I do know, based on the most recent reading that I have done, is that the friction improvement from pulleys like these, if it exists, is very very small. It is so small that it is hard to measure. And folks different from the manufacturer that try to measure frictional improvement seem to show less improvement than the manufacturer’s measurements (are we surprised?). Further, most of the frictional improvement in such pulleys is not the ceramic bearings, instead it is more that large pulleys reduce the friction of chain bending. But even here there are diminishing returns, if the pulley is too big, the savings from reduced chain bending is swallowed by the additional friction of the chain having to rub/wrap around the bigger pulleys. And we haven’t even touched on the potential aero penalties of huge pulleys and cages.
With SRAM axs and other groups, I don’t have personal experience. The ceramic upgrades can be good (but the friction savings from ceramic bearings alone is very very very small), but the oversized bearings still follow the laws of physics. All other things being equal, oversized bearings have slightly more friction than smaller traditional bearings.
Many new technologies work, no disagreement there. It is just that most of these new technologies improve stiffness, shifting, operation, convenience, etc. Not many of them specifically address and/or improve drivetrain friction.
Further, most of the frictional improvement in such pulleys is not the ceramic bearings, instead it is more that large pulleys reduce the friction of chain bending. But even here there are diminishing returns, if the pulley is too big, the savings from reduced chain bending is swallowed by the additional friction of the chain having to rub/wrap around the bigger pulleys. And we haven’t even touched on the potential aero penalties of huge pulleys and cages.
I’d say even this is hypothetical and hasn’t been proven, and only really come into play at the extreme low cogs(11-12t) where the chain actually interfaces with more of the pulleys, with a vertical cage the amount of chain bend is pretty minimal, comparisons between the group’s small and large pulley sets are never shown with the same bearings. The majority of the gains come from reduced cage tension, lighter grease, and less weatherproof low friction seals. I have yet to see a company simply swap ceramic balls for steel balls and shown a measurable difference.
well, just to be clear. i think what you’re saying is that UFO Drip is no better than what we we were using (or could’ve used) 30 years ago. maybe you’re right! i’m not saying you’re wrong. i’m just trying to understand what you’re saying.
OSPW have more friction by design than standard sized pulley wheels. here is the ceramic speed narrative on this. i am totally cool with you claiming this is untrue. i’m not taking a position. just, this is your position? that ceramic speed’s claims are in fact the opposite of what they claim, they add not reduce friction? because of it’s not your position, then okay, but i misunderstand your position and i’d like you to educate me on what it is.
FYI, the new SRAM AXS RED group uses oversized ceramic bearings as standard. i suspect, as with electronic shifting, ceramic bearings will flow down into cheaper and cheaper price points. so, this question of whether these technologies actually work are germane, not arcane.
I do not personally know about ufo drip, but the last bit that I read on this topic in general seemed to say that the best new lubes were indeed very very good (again, I use some of these–rock and roll lube), but not really better than classic waxed chains with regard to friction (but better in regard to convenience).
And I do not know specifics about ceramic speed oversized pulleys. What I do know, based on the most recent reading that I have done, is that the friction improvement from pulleys like these, if it exists, is very very small. It is so small that it is hard to measure. And folks different from the manufacturer that try to measure frictional improvement seem to show less improvement than the manufacturer’s measurements (are we surprised?). Further, most of the frictional improvement in such pulleys is not the ceramic bearings, instead it is more that large pulleys reduce the friction of chain bending. But even here there are diminishing returns, if the pulley is too big, the savings from reduced chain bending is swallowed by the additional friction of the chain having to rub/wrap around the bigger pulleys. And we haven’t even touched on the potential aero penalties of huge pulleys and cages.
With SRAM axs and other groups, I don’t have personal experience. The ceramic upgrades can be good (but the friction savings from ceramic bearings alone is very very very small), but the oversized bearings still follow the laws of physics. All other things being equal, oversized bearings have slightly more friction than smaller traditional bearings.
Many new technologies work, no disagreement there. It is just that most of these new technologies improve stiffness, shifting, operation, convenience, etc. Not many of them specifically address and/or improve drivetrain friction.
i don’t mean to flog you over this. it’s just that my feedback from the field is that some of the traditional cassette inners haven’t kept pace with the increases in drivetrain friction reduction. it’s the friction in the system that causes a cassette to break free of the inhibition to freewheel. taking me as an example, i don’t often just coast. i keep my legs rotating very slowly about the crank (if i’m not tucking). using some of these newer, slipperier drivetrains, this can be an issue. here’s another way to look at it. pedal your bike backward while it’s on the workstand. a really slippery drivetrain, combined with a hub that has tight seals and heavy grease, the freehub may not break loose, and the chain may just sag and gather between the crank and the cassette. the friction in the drivetrain overcomes the friction between the hub and the cassette assembly, traditionally. that’s no longer a given.
I totally know what you’re talking about. For me, it seemed to happen a lot with some of the much earlier models of zipp hubs, or more specifically zipp freehubs.
However, that issue is not caused by having a super low friction drivetrain. It’s caused by having a high friction freehub. Get the freehub friction lower and, at least with the normal sized cassettes that I have used (11-25), it stops happening immediately.
Anyone know what happened to the friction facts website? I was hoping to get a comparison on these lubes and drivetrain components from a 3rd party but oddly enough ceramic speed is the first thing to pop up in my search. Did this site go away?
I totally know what you’re talking about. For me, it seemed to happen a lot with some of the much earlier models of zipp hubs, or more specifically zipp freehubs.
However, that issue is not caused by having a super low friction drivetrain. It’s caused by having a high friction freehub. Get the freehub friction lower and, at least with the normal sized cassettes that I have used (11-25), it stops happening immediately.
i’m not noticing it in zipp hubs. i’m noticing it in a lot of hubs. a lot of hubs. and it’s not hubs that are built with greater friction than in prior generations. i don’t think it passes the test of reasonableness that this issue is because hubs suddenly got stickier whereas drivetrains have not achieved their goals of lower friction.
Me neither I don’t notice it in zipp freehubs of today. I noticed it in zipp freehubs from 20 years ago. Especially when they were filled with overly thick grease.
To clarify, this is not a hub issue, it is a freehub issue.
Do you realize that when you’re going downhill, and you’re either holding your pedals still, or just pedaling slowly at a nice easy rate, the drivetrain friction could be massively high or massively low, it doesn’t matter because your legs are either holding or moving the drivetrain.
So this observation that you’ve made, it is all about the freehub. Drivetrain friction, whether it be hugely low or hugely high, has nothing at all to do with it, you have completely taken it out of the equation, because you’re holding the drivetrain with your legs.
If you are interested, there’s an easy test to show you that this “auto feeding” problem with the chain comes 100% from a freehub issue.
here’s another way to look at it. pedal your bike backward while it’s on the workstand. a really slippery drivetrain, combined with a hub that has tight seals and heavy grease, the freehub may not break loose, and the chain may just sag and gather between the crank and the cassette. the friction in the drivetrain overcomes the friction between the hub and the cassette assembly, traditionally.
Friction in the drivetrain isn’t what overcomes the freehub stiction. The freehub gets pulled backwards by the chain being pulled - after traveling through the pulleys - into the bottom of the chainring. Increasing the drivetrain friction while keeping everything else equal would actually make the freehub stiction worse, since it would decrease how forcefully the chain pulls on the back of the cassette. (Another way to visualize it is: it’s harder for the upper run of the chain to feed into the cassette if it’s harder for the lower run of the chain to feed out.)
If the upper run of the chain sags due to chainring rotation, the lower run of the chain must un-sag by a similar amount. In practice, this means that the tension cage on the rear derailleur releases that amount of chain by rotating forwards slightly, and the tension on the lower run of the chain increases. When the tension on the lower run of the chain becomes great enough to overcome freehub stiction, the freehub starts rotating backwards.
So, when the upper run of the chain sags, the issue is that the freehub stiction is high relative to the chain tension.
Now, there is a correlation here: lower chain tension does reduce drivetrain friction, so a lot of low-friction drivetrains will have this issue, because they achieve their low friction by using a really lightly-sprung tensioner.
Probably, anyway, maybe. I’m not actually an expert on drivetrain physics.
Anyone know what happened to the friction facts website? I was hoping to get a comparison on these lubes and drivetrain components from a 3rd party but oddly enough ceramic speed is the first thing to pop up in my search. Did this site go away?
Ceramic Speed bought it, I think…