we are 5 years (is it?) forward from mollema’s infamous fucking SRAM!! and i don’t think it was wholly appreciated during SRAM’s of it’s new RED groupset in may that SRAM has equaled - at least equaled - shimano in FD shifting.
i just wrote about the FD shifting today. only this function. because SRAM had pretty much solved everything else in the 2x drivetrain, unless you’re just a confirmed hater of the 10t cog. if so then i guess you still in the blanking SRAM camp. but as to FD shifting, this was the revelation of this groupset for me. and that’s something, since there were a lot of really great upgrades that - soon enough - will filter down to force and rival (and thereby become affordable for us mortals).
i wrote why i believe the FD is so much better than prior FDs from SRAM, and i wrote as far as i got as to why SRAM could - IP-wise - engage in functionality previously (i assume) covered by IP. but i didn’t come to a conclusion on that. i’m going to continue to drill down on how the IP landscape has changed, allowing SRAM to make the FD it does, and i will post what i find in this thread for whomever is interested. if any of you have any ideas on this i’m glad to hear it. some of our folks in the lavender room helped me a bit this morning.
unless you’re just a confirmed hater of the 10t cog. if so then i guess you still in the blanking SRAM camp.I am a confirmed hater of the 10t cog. Still, I have SRAM AXS Red on my latest bike, albeit the no-longer-current version. I could not be happier with the shifting overall, and it is hard to believe it is even better in the latest version. Looking forward to reading what you discover. And, as irresponsible as it would be, an upgrade is tempting…
As a sram fan, I think the prices are way overboard. 5000 euros for a complete groupset is just crazy.
The top tier is undeniably dentist territory. But SRAM’s trickle down drop-off is, IMO, very good. And pretty fast in release after the halo product. SRAM Apex used to be considered something like Walmart bike territory. But AXS Apex is, outside of weight, pretty much identical in performance to Red.
Just today SRAM released the S-1000 Transmission RD. No cost shown as it’s OEM-only for now, but I bet bike manufacturers are going to get the thing for a couple hundred bucks And it’ll likely be near identical in performance to XX1 Eagle.
These are both 1x-specific, obviously, but I’d bet the better FD shifting gets down to Force and Rival within a year.
I have SRAM AXS on two bikes, a fat bike and a full suspension mountain bike. Both of these are 1 X 12, XO1 on there fat and GX on the MTB. Work great! I also have Red eTap hydro 11 speed on a Litespeed T3 disc. Both front and rear work great. On the back sometimes I have to look on the computer and then look back to be sure it shifted, it did and very seamless. I only check the front most of the time since I’m always on the 53 with an 11-26 cassette on the back. It very flat where I live but can get windy. Running 165mm cranks my cadence is usually 83 rpm to 120 rpm.
One thing I was told by some people at SRAM is that this is the first FD designed only around 142x12. So it’s designed around one chain line. Which is part of why the cage is so much narrower and has much shorter more precise movements. SRAM states that it is not compatible with rim brake frames or QR disc brake frames.
SRAM has a patent filed in 2016 describing a sensor that picks up changes in the orientation of the rear derailleur pulleys. Those changes cause “the component to perform the action in response to the determination that there is a newly engaged gear.†Could that action be FD trim? Is the input that SRAM uses to trigger a change in FD position different than Shimano’s input and if so could that be the way SRAM avoids infringing? That seems unlikely because if it did then the trim in the FD requires the sensor in the RED RD. But SRAM says, “that trim will happen if is paired with a Force or Rival AXS system. So, I don’t know. I’m out of my depth here. I believe I know why the shifting is so good; I just can’t navigate the IP that led us here.
I suspect this is fundamentally correct.
But it’s not a sensor. The AXS system fundamentally knows your current gearing selection. The RD broadcasts it. This is why, for example, your Garmin or Wahoo can show your current gearing.
So I suspect the FD is just listening for what gear the RD says it is in, and adjusts trim accordingly.
That’s the “sensor” in the FD. It’s just listening to the standard broadcast from the RD.
So I suspect the FD is just listening for what gear the RD says it is in, and adjusts trim accordingly.
So basically what Di2 has done since the beginning?’
Yes. If you read the front page article you’ll get the speculations about how the new SRAM system might sidestep a presumed Shimano patent on electronic trim.
SRAM has a patent filed in 2016 describing a sensor that picks up changes in the orientation of the rear derailleur pulleys. Those changes cause “the component to perform the action in response to the determination that there is a newly engaged gear.†Could that action be FD trim? Is the input that SRAM uses to trigger a change in FD position different than Shimano’s input and if so could that be the way SRAM avoids infringing? That seems unlikely because if it did then the trim in the FD requires the sensor in the RED RD. But SRAM says, “that trim will happen if is paired with a Force or Rival AXS system. So, I don’t know. I’m out of my depth here. I believe I know why the shifting is so good; I just can’t navigate the IP that led us here.
I suspect this is fundamentally correct.
But it’s not a sensor. The AXS system fundamentally knows your current gearing selection. The RD broadcasts it. This is why, for example, your Garmin or Wahoo can show your current gearing.
So I suspect the FD is just listening for what gear the RD says it is in, and adjusts trim accordingly.
That’s the “sensor” in the FD. It’s just listening to the standard broadcast from the RD.
it could be that the orientation of the pulleys is how SRAM avoids existing patents. but i’m just guessing of course. while the RD knows the gear you’re in, maybe it can’t use that to inform the FD. but SRAM says the new RED FD is backward compatible with other AXS RDs which means that the new RED RD contains no information or functionality that helps control the FD.
SRAM has a patent filed in 2016 describing a sensor that picks up changes in the orientation of the rear derailleur pulleys. Those changes cause “the component to perform the action in response to the determination that there is a newly engaged gear.†Could that action be FD trim? Is the input that SRAM uses to trigger a change in FD position different than Shimano’s input and if so could that be the way SRAM avoids infringing? That seems unlikely because if it did then the trim in the FD requires the sensor in the RED RD. But SRAM says, “that trim will happen if is paired with a Force or Rival AXS system. So, I don’t know. I’m out of my depth here. I believe I know why the shifting is so good; I just can’t navigate the IP that led us here.
I suspect this is fundamentally correct.
But it’s not a sensor. The AXS system fundamentally knows your current gearing selection. The RD broadcasts it. This is why, for example, your Garmin or Wahoo can show your current gearing.
So I suspect the FD is just listening for what gear the RD says it is in, and adjusts trim accordingly.
That’s the “sensor” in the FD. It’s just listening to the standard broadcast from the RD.
it could be that the orientation of the pulleys is how SRAM avoids existing patents. but i’m just guessing of course. while the RD knows the gear you’re in, maybe it can’t use that to inform the FD. but SRAM says the new RED FD is backward compatible with other AXS RDs which means that the new RED RD contains no information or functionality that helps control the FD.
(pure speculation)
Per Rappstar, maybe the sidestep is that there’s nothing that SRAM considers a “sensor” in the RD. Only the commanded position is used. Usually a servo motor that can move to an absolute position has something integrated inside that would be considered a “sensor” to achieve that. But maybe SRAM is hoping that a servo motor with no other sensor is enough.
again speculating. The FD can know what gear the RD is in. Any AXS RD would tell it that. If it needs to sidestep that, what it might do is that the FD uses:
the specific model of RD - again, any AXS RD will broadcast this
the current gear
Based on knowing the model of the RD and the current gearing, the FD could then calculate the angle of the pulleys - within some margin of error based on chain length, which is not knowable nor inferable (that I can see). And then use that information to assign trim.
I suspect we could prove this out if you swapped a standard Red RD for either an Eagle AXS or AXS XPLR RD, which have different cage lengths. If the trim adjustment differs, that might answer the question. Then again, the variance in pulley angle itself might be just a workaround. I.e., you don’t actually need to know pulley angle. Except for IP reasons.
In other words, the same basic calculus could be done using just gear selection. BUT if you can create a credible approach that does use pulley angle in some small - but meaningful - way, then you have a unique approach. Even if the end result of the actual trim is the same, if you come to that conclusion using a unique methodology, I suspect that approach would be sound. But it’s also perhaps a very delicate balance, which may be why SRAM is keeping mum. Reveal too much - or say the wrong thing - and the uniqueness becomes revealed to be more sleight of hand than substance.
But certainly I can see an implementation where the calculus is unique enough to credibly evade patent infringement and which falls within the scope of what SRAM itself has filed.
One thing I was told by some people at SRAM is that this is the first FD designed only around 142x12. So it’s designed around one chain line. Which is part of why the cage is so much narrower and has much shorter more precise movements. SRAM states that it is not compatible with rim brake frames or QR disc brake frames.
I’ve got a rim brake Gen 2 Trek SC and upgraded to the new SRAM FD, RD, chain and cassette. IMO the FD shifts significantly quicker than my other rim brake Gen 2 Trek SC with the eTap AXS. I’ve got just over 300 miles on the new group set so I’d disagree with SRAM in their statement that’s it’s rim brake non-compatible. Both FD and RD shifting is like butter.
I’ve got just over 300 miles on the new group set so I’d disagree with SRAM in their statement that’s it’s rim brake non-compatible.
Fair point…as long as SRAM continues to manufacture the prior generation Red/Force AXS rim-brake “brifters” most of the new stuff, including FD shifting, should be available. Or, in your case, where braking is a fully independent thing from the rest of the drivetrain.
I bought a new bike a year and a half ago - I wanted a true All Rounder, so went with the Argon 18 Krypton Pro - came with SRAM Force AXS - of course a new upgraded version of SRAM Force came out right after, I pulled the trigger on this!
I had been riding Shimano Dura Ace Mechanical . . well . . for a very long time. Other then loaner bikes with eShifting this was my first time full-time with electronic. I head/read all the “SRAM’s crap” comments. Once set up, by the top-level mechanic who built up my bike, the shifting and performance has been flawless and fantastic. So I have no idea what the “SRAM’s Crap” comments were all about!
I bought a new bike a year and a half ago - I wanted a true All Rounder, so went with the Argon 18 Krypton Pro - came with SRAM Force AXS - of course a new upgraded version of SRAM Force came out right after, I pulled the trigger on this!
I had been riding Shimano Dura Ace Mechanical . . well . . for a very long time. Other then loaner bikes with eShifting this was my first time full-time with electronic. I head/read all the “SRAM’s crap” comments. Once set up, by the top-level mechanic who built up my bike, the shifting and performance has been flawless and fantastic. So I have no idea what the “SRAM’s Crap” comments were all about!
i think SRAM’s FD shifting has been unforgiving compared to shimano. if you have the FD set up correctly then the shifting is good. if there’s anything dodgy about the set up, or if it goes dodgy, you can be the victim of a derailment. shimano on the other hand, bombproof FD shifting.
this changed in my opinion with new RED. perfect FD shifting and shimanolike bombproofness.
