[rscecil007]

I've got a question for those of you running Transmission with a 52mm chainline. I have SRAM Transmission on two bikes, and both setups are nearly identical (only difference is one has XX, the other XO):

Transmission cassette/rear derailleur
Transmission chain (both have XX chains)
Boost 148 rear end frames (Epic Evo, Santa Cruz Hightower 4)
SRAM. Eagle X01 3 bolt cranks (normal boost spacing)
Wolftooth 32t B-stop chainring, 3mm offset for 52mm chainline

Everything was fine for a quite a long while on both frames (and I had one set up mounted on a Hightower 3 for awhile as well with zero issues,) but recently when putting the power down, the drivetrain makes what I can only describe as a slight grinding sound. Almost like back in the days of 11 speed when you'd put a new chain on a used cassette that you let go a bit too long, there'd be that period of time where you could hear the chain wearing and mating to the cassette. If that makes sense.

Sorry to be that guy, but it's hard to describe. It's not a horrific grinding sound, just more of a "something is not right." Doesn't' do it in the stand either. You really have to be putting power down somewhere in the mid to lower gears out on the trail to hear/notice it. Still shifts fine as well, so it's not affecting anything there.

My reason for sticking to a 52mm chainline with Transmission, and not 55mm, is to give me a better chainline in the gears I use the most. Alot of what I ride in the PNW is crank and drop, so low end sees alot of use. Stock Transmission 55mm chainline with the 52t cog is cross chained like crazy. It's way way better with 52mm chainline.

Both setups have about the same miles on it, but no way it's enough for anything to be worn out or I wouldn't think so at least. And I swear somewhere SRAM said you could use Transmission with a 52mm chainline, but I can't find it now.

Anyone have any thoughts/suggestions? Maybe the WT chainring is wearing prematurely? I know SRAM sells a steel 3 bolt ring now that's T-type compatible...

And to get ahead of it, yes it's all installed correctly, torqued, etc etc.

Thanks for any help, much appreciated.

 

[NoahColorado]

Probably the chainring, not the chainline.

 

[rscecil007]

Probably the chainring, not the chainline.

That's what I'm thinking too, I don't see how the chainline would affect this.

Prob going to order a few of the steel SRAM chainrings today.

 

[ClydeRider24]

I'm running a 55mm line, but I'm dealing with this exact noise (and other related issues) on my Tallboy 5. Nasty "grinding" noise in lower gears under heavy power. You can find my responses/updates in the "SRAM Transmission Problems" thread. Long story short, I've found no solution, even after my cassette and chain being replaced under warranty.

Like you, I noticed early on that in 1st gear (52t) the drivetrain was "cross chained" pretty badly. More so than my other 12spd bikes, and enough so that I almost EXPECT it to be noisy. I'm actually not sure why it looks that way, as the chain line is "straight" in 7th gear, which should be OK.

I spend a lot of time in lower end of the cassette, so I inquired to SRAM last week about changing my cranks to a 52mm setup, thinking maybe that would help with some of the cross chaining and noise. My question/comments to them regarding that topic, and their response is below:

Myself: ".......Second, I’m still really questioning the chain line on my setup. Crank spacers are 100% correct (have been checked numerous times at this point), but the chain is noticeably more cross-chained in the lowest gears than my other 1x12 setups. I can’t help but wonder if this is partly to blame for the noise/vibration and accelerated wear? I know all the transmission drivetrains are based on 55mm chain line, but if I didn’t know any better, I’d think this thing needed a 52mm crank/chainring setup.......

.......Another point, just for reference.
I mentioned the chain line previously. Currently, it “aligns” in 7th gear. I realize this should be satisfactory, but given that the majority of my riding is spent in the lower half of the cassette, and that is where the noise/vibration is occurring, I can’t help but wonder if biasing the chain line slightly in the that direction might be of benefit? Is altering the suggested spacer configuration something you’d advise against? Or is it worth experimenting with?"

SRAM: "We don't recommend changing the spacer configuration, the specified order maintains the correct chainline and q-factor, so we wouldn't advise that."

 

[Hurricane Jeff]

There is a guy on Youtube @lovemtb or something like that, that has run just about every Sram or Shimano groupsets, even mixed Sram/ Shimano and used older Sram with new Transmission and even used the 52mm chain line with Transmission using older XO cranks.

 

[rscecil007]

FWIW

I contacted WT about this, and they responded that I needed a 55mm chainline. I shot a note back asking how that would solve anything, since it was really doing it in the lowest 1-3 gears or so, and a wider 55mm chainline would just make things worse for those gears. They responded "55mm is what SRAM recommends."

Called SRAM, guy I spoke to was super helpful, and said initially when Transmission came out they were pretty strict on the 55mm chainline, but as time went on and they saw more setups, 52mm should work in most circumstances.

 

[minimusprime]

I'm running axs transmission on two of my pedal bikes. One has a 55mm chainline with a full gx transmission groupset, including cranks. The other is using a transmission derailleur/cassette/chain and x01 eagle crankset with a standard eagle chainline. Both of them operate and shift perfectly.

 

[rscecil007]

I'm running axs transmission on two of my pedal bikes. One has a 55mm chainline with a full gx transmission groupset, including cranks. The other is using a transmission derailleur/cassette/chain and x01 eagle crankset with a standard eagle chainline. Both of them operate and shift perfectly.

What type of ring do you have on your setup with the X01 cranks/52mm setup?

 

[Octopuss]

I vaguely remember I briefly tried 52mm chainline, but the chain was crossed pretty badly regardless, and on top of that it was rubbing on the smallest cogs, so I ditched the idea.

 

[ClydeRider24]

I vaguely remember I briefly tried 52mm chainline, but the chain was crossed pretty badly regardless, and on top of that it was rubbing on the smallest cogs, so I ditched the idea.

When you say rubbing on the smallest cogs, what do you mean?
I ask because although I get most of my noise in the larger cogs, the wear I'm seeing after only a few months on the "sides" of the smaller cogs is pretty alarming.

 

[Octopuss]

I mean just that - the chain was rubbing against them. I think it was either the two or the three smallest ones.
If there wasn't the rubbing I guess 52mm chainline would be a tiny bit better, but I don't remember seeing dramatic difference (but that was my previous frame so what do I know...) in the horrible crossing on the largest cog. But then again I don't use the two largest cogs all that often (or not for a long time when I do despite doing a lot more climbing this year), so this is not a problem for me.

I guess this can vary very slightly frame to frame, but from my own experience SRAM seems to know what are they saying when they tell us to use 55mm chainline, and there isn't much of a compromise to be found anywhere.

The initial setup and the hell-fail the GX groupset (Transmission specifically, no experience with GX mechanical over here) didn't motivate me enough to experiment with various combinations of components to figure out what would work better (if that was possible).

I have XX cassette (with X0 chain) and can honestly see almost zero wear after about 1500km (I have 3 chains that I swap around about every 500km but that's likely not making any difference, or not at this point in time yet).

 

[ClydeRider24]

I have XX cassette (with X0 chain) and can honestly see almost zero wear after about 1500km (I have 3 chains that I swap around about every 500km but that's likely not making any difference, or not at this point in time yet).

That's crazy. My chain and cassette show a lot of wear after only about 500 miles (since the original chain and cassette were warrantied). I clean the cassette and chain about every other ride, and only use R&R Gold and Squirt.

 

[Octopuss]

I don't see a lot of wear there, or the photo is too low resolution. What I actually see is the paint or whatever it is slowly coming off, but that's normal I think. My X0 cassette did the same thing, but the teeth edges were unchanged.

 

[minimusprime]

What type of ring do you have on your setup with the X01 cranks/52mm setup?

I'm using a works components chainring with mine. I don't actually recall why I ended up buying this chainring specifically. I was ordering two reach adjust headsets and just added this one to the order... that being said it works flawlessly with t-type.

GEO SRAM Narrow Wide Chainring - Direct Mount - Boost 3mm Offset

SRAM Direct Mount 3 Bolt Round Chainring with 3mm Boost Offset - Narrow Wide - 11 Colours - GEO Deisgn - UK Made

workscomponents.com

 

[rscecil007]

UPDATE: Ended up being the chainring. I put one of those new cheap steel SRAM T-type rings on, and did about 3500ft of climbing this weekend. Quiet as a mouse, didn't once make any of the odd noises it made with the WT ring. And the ring was the only thing I changed, same offset/chainline as the WT as well.

I've hit up Wolftooth to see what they have to say, both rings have ~250 miles on them, MAYBE 300 at most. No way they should have worn out that fast, disappointing if so for the money. Always had good look with Wolftooth stuff for years and years now, so hopefully this is just a blip.

In the meantime I need to order at least another cheap SRAM ring for bike #2, or order a few lighter weight aluminum ones. David Golay over at Blister said he's running Hope's new T-type combatible ring in a 52mm chainline config with Transmission, and it's working perfectly.

 

[Octopuss]

I would like to try SRAM chainring to see whether there is any difference, but I am stuck with T because I have RF Era cranks I love the cranks, don't get me wrong, but it kind of limits your possibilities to experiment.