2019 Sram Force ETAP

Discuss light weight issues concerning road bikes & parts.
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Alexbn921
Posts: 552
Joined: Wed Apr 10, 2019 6:39 pm

by Alexbn921

Loud rear brake is most likely a resonance issue. First take out the pads and clean them with alcohol. Then clean the rotors with alcohol too. Next bed them in evenly.
If that doesn’t fix your issue, then securing the hose with a zip tie can mitigate the vibration. Beyond that you will need to add dyno mat to spider or stick on weights to the stays to change the vibration characteristics of the frame. Also, a stiffer mount or better fitting interface can help.

SandwichNP
Posts: 49
Joined: Sat Nov 16, 2019 3:22 pm

by SandwichNP

Thanks, I was thinking alcohol clean first. It seems to get worse when I get back from the ride compared to when I leave, so my thought was some kind of grime build-up, but that seems unreasonable as I pretty much only ride in the sunshine.

by Weenie


revkev
Posts: 5
Joined: Mon Jun 01, 2020 1:51 am

by revkev

RE: Noisy Drivetrain

I recently bought a Canyon Ultimate with SRAM Force eTap AXS (not that it matters but I always have to google the capitalization and word order for this groupset haha... I should just be okay with getting it slightly off). Like many others, I did notice that it seemed to be a bit noisy - kind of reminded me of what you hear when your chain / drivetrain needs to be degreased and re-lubricated. So I did that after a few rides - and it still sounded basically the same.

I would not say I have a solution or a fix exactly - but I did spend some time trying to work it out and reduce the noise and I think I may have made some progress toward a quieter drivetrain - and without swapping in any Red components (which does seem to have legitimately helped others but is, in my opinion, not exactly a solution or a fix - it's just a replacement part - although, admittedly, its nice that it doesn't require a completely new groupset).

My setup:
Bike: Canyon Ultimate CF SLX Disc 8.0 SL (also have to look this up to get it right!)
Size: XS
Chainrings: 48/35
Crank Arms: 170mm
Cassette: 10-28 - It appears that there are 3 dampening rings or whatever between the 4 smallest cogs which I believe was an update by SRAM to the Froce Cassettes.
Distance on bike: 330 miles / 530 kilometers
I basically haven't changed anything from how Canyon sends them out besides adding pedals and bottle cages and swapping in latex tubes.

What I did:
1. Detailed the chain and cassette -- completely removed them, degreased them, scrubbed them down, rinsed them, dried them.
2. Degreased large chain ring -- didn't remove it or anything - just used a cloth to clean it up. Didn't even try to clean the small ring.
3. Shortened the chain -- SRAM says in a YouTube video (linked below) that the correct chain length should be determined by wrapping it around the big chain ring and the largest cog at the back, pulling the ends together, and then adding one outer link and one inner link. When I did that it seemed to me that my chain had 2 extra links - so I removed them. And eventually reconnected them with a new Power Lock.
4. Front Derailleur Setup -- I just followed the instructions in SRAM's YouTube video. With the chain off I used the markings to adjust the height and angle. I tweaked the high limit to help with setting the angle relative to the big chain ring (I ended up changing it again once the chain was on, though). And finally tweaked the position of the wedge piece.
5. Re-installing Chain / Jockey Wheel Feeding -- I don't want to make too big of a deal out of this... but on the rear derailleur the lower jockey wheel has alternating thick and thin teeth. I paid no attention to how my chain hit those before removing it - but when I reinstalled the chain I made sure the thicker teeth went through the outer links and the thinner teeth went through the inner links. Again, for all I know, it was like that before too.
6. Re-lubricated chain -- shifted through all the cogs and both chain rings.
7. Adjusted all limit screws -- high and low limit screws for both front and rear derailleur as well as the b-limit screw for the rear derailleur -- all according to how SRAM says to do so in their YouTube video.
8. Micro adjustments to rear derraileur -- The video briefly touches on this but not much more than saying to micro adjust the direction it's having trouble shifting. I connected my AXS app to the components while I did this because it will tell your what micro adjust position you're in (up to 29 I believe). I experimented a little bit to see how it sounded or felt at different adjustments - then finally set it where it seemed to be the smoothest shifting both directions, which for me was 8/29 but I'm not sure that's valuable information to anyone else.

SRAM's eTap AXS Setup YouTube video: https://youtu.be/Bx-kB7rNFJQ

Observations after:
1. The bike is quieter and smoother than before - but I wouldn't say it's quiet and smooth yet.
2. It is so much louder and vibrates more "in the stand" than on the road. Sometimes I would get into my own head and be pretty convinced I made no progress (maybe even made it louder!) when I was testing it in the stand. But once I went around the block on it I realized that it was quieter than before. There's obviously no buzz of the tires on the road or wind in your face when the bike is "in the stand"
3. The cassette is just beginning to show signs of wear - some silver coloring peaks through the black coating now. It's still pretty new, only 330 miles / 530 kms - but I'm hoping that it may just need more riding for it to "wear in" a bit more and truly be quiet and smooth.
4. The chain still seems to do some sort of "pulsing" when turning the cranks - not exactly sure the cause, but it does seem related to noise and vibrations. It almost seems like it sort of lightly pops off of the chain ring, cog, jockey wheel instead of smoothly moving on - which seems like a problem lubricating it would solve but apparently not. Maybe a little more wearing in.

Anyway - hopefully that contributes to the body of knowledge approaching this issue. Would love to hear if anyone else has seen more progress toward a fix or solution. Or even if simply putting more distance on it has helped.

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