DaveSSS 

I've got three bikes with AXS - two with Force and one with the newer Rival cage. These are all yaw derailleurs that are not supposed to have the cage parallel to the big ring like non-yaw FDs. I checked mine and the tail end of the cage is furthest away from the big ring due to the yaw. I don't have to do anything special to make mine work. The height and cage clearance are just within spec. I've never used a wedge either. My cranks all have a 16T difference for more range. No chain drops in 15,000 miles.

Jonob

Levi (SRAM (Tickets))

Jun 22, 2023, 16:39 CDT
Hi Jonathan,

Thanks for getting back to me. It does seem strange that the issue is solved for a while and then pops back up. Based on that, I would apply a fresh thin coat of Blue Loctite 242 to the mounting bolt as well as the limit screws, as it could be that we have adjusted enough times that the factory Loctite is worn away.

As far as troubleshooting a chain drop to the inside, here are some instructions for that:

If the chain drops inboard when shifting to the small chainring: With the front derailleur in the inboard position, rotate the low limit screw clockwise 1/8 turn. Repeat until the chain no longer drops from the chainring.


As far as downshifting at a high cadence, it is possible, depending on timing and pressure here, that this could cause a shift failure. I recommend that when you are shifting any front derailleur system, it is best to keep an average cadence, keep even pressure, then actuate the shift and allow the chain to move fully to the other chainring for a full crank rotation, then proceed from there to whatever power and cadence you would like to be at. If you have any other questions or concerns, don't hesitate to reach out!

Warm regards,
LeviSRAM Rider Support

eduskator

You can't screw it indefinitely though. At some point, you'll be out of specs. My low limit screw sets the FD cage under 0.5mm for sure - my chain rubs on it just a little when on the small ring / big cog, but it's not dropping anymore since I did this. I did 1/8 turn adjustments each time and rode it until I no longer had chain drop when going from the big to the small ring. It took 3-4 times.

I recommend that when you are shifting any front derailleur system, it is best to keep an average cadence, keep even pressure, then actuate the shift and allow the chain to move fully to the other chainring for a full crank rotation, then proceed from there to whatever power and cadence you would like to be at. If you have any other questions or concerns, don't hesitate to reach out!

This is bullcrap at this price tag. If you ask my opinion, it's the kind of answer a company gives to its clients when it has an engineering issue with a product that they're not able to fix. I've had 2 bikes equipped with Ultegra DI2 and 2 other bikes with 105 before my current one equipped with Force AXS and never did I have a chain drop under load. I beat them up pretty good during their life (used it like it's meant to be used) and I've never had a chain drop, under hard load or not. It clearly doesn't like to be shifted under hard load and it lets you know, but the chain does not drop.

PeteHski

You could be right, but front shifting under heavy load is simply not a good practice. I ride with some fast groups and I notice some guys are complete rock apes when it comes to shifting. No mechanical sympathy at all. The crunching noises their drivetrains make is horrific, but I guess it works for them. I just prefer a smoother style of shifting, which is near silent.

But it probably does explain why some riders suffer more chain drops than others. Whether that’s a SRAM thing or not. I’ve had about the same number of rare drops on both SRAM and Shimano. My Shimano 105 R7000 will occasionally drop on a front downshift if the cadence is very high and the road is bumpy. My SRAM Force has dropped occasionally when upshifting. Nothing different to what I’ve experienced with older setups through the ages. Chains drop occasionally as we see in the pro peloton.

DaveSSS 

What was not explained was that turning the low limit screw CW moves the cage outward and closer to the chain. You could keep turning the screw until you get chain rub, when in the largest sprocket and little ring, the turn it CCW 1/4 turn at most.

The high limit screw is left hand threaded and works such that turning the screw CW moves the cage inward. In the big ring and smallest sprocket, turn it CW until you get some chain rub, then go CCW 1/4 turn. Never turn the high limit screw unless the FD is in the big ring position. I never shift under a heavy load, but you have to keep the crank moving, or you could create a chain drop.

Camilo

I call BS on that one. Of course, what do I know, I've only had two AXS bikes in the household for almost three seasons and neary a limit screw movement that wasn't caused by a screw driver. They're no different than any other FD in that respect. Why would they be. BS.

Camilo

The jig and the marks are just startig points IMHO. Like every other FD in the world, a decent mechanic (home or pro) knows that you just tweak the FD if it's not working perfectly. I don't even use the SRAM AXS FD jig to set them up.

Jonob

fair enough

Jonob

Are your bikes force or red ?

Camilo

Yes. Mechanical Force, Mechanical Red, two AXS Force. And for comparison, several Shimano bikes from Claris to Dura Ace over the years. I've never seen a FD limit screw work loose. But just one person's experience.

eduskator

+1. Never seen, had or heard of such issue.