Trek Domane SLR headset / front IsoSpeed decoupler creaking

[steelaxis]

Hello,
So I just got a new Trek Domane SL5 2019 and I discovered the same issue as sennder, a 2mm gap between the headtube cover and the isospeed top cap.
I contacted trek by email, will see what they say about that.
since I have not had the time to ride the bike yet I don't know if it cause any issue but this is definitely not normal.

[sennder]

Hello,
So I just got a new Trek Domane SL5 2019 and I discovered the same issue as sennder, a 2mm gap between the headtube cover and the isospeed top cap.
I contacted trek by email, will see what they say about that.
since I have not had the time to ride the bike yet I don't know if it cause any issue but this is definitely not normal.

I took my bike back to the LBS after I noticed the gap. The mechanic said that it wasn't normal and removed 2 of the 4 thin washers he had installed. Turns out that the washers are supposed to be included with the bike (my frameset supplier had failed to include them), and an adjustable number are installed to ensure no creaking and no gap.

Take it back to your LBS and they should be able to remove a couple of washers for you. While you're there, have them stuff the front isospeed with grease (standard practice at most shops).

--Sennder

[AdrianGodley]

Hi

Did you ever get this issue resolved? I had the same issue and the fix for me was as follows.

I changed the grease to white lithium. The grease I was using before wasn't stiff enough and was getting displaced. I also noticed the top cap was completely flush with the spacers. So when I torqued it down it wasn't putting the correct amount of tension into the isospeed. I fixed it by adding a 0.5mm spacer above the handlebar stem. I find I have to strip and re grease after 5000km or so.

[bfeist]

When I torqued my top cap to 4nm after adding some spacers the headset creaked but only when riding it, where it previously had been silent. I backed off that torque a little and it’s back to silent again. I think 4 nm is too much pressure on the headset for this system. I have a 2018 Domane SLR.


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Just wanted to say thanks for this tip. Rode my brand new 2022 Domane SLR etap red today and it had constant handlebar creaking. After reading your tip, I loosened the handlebars and backed off the cap to around 3nm (I had mine at 5nm). This completely resolved the issue in the shop. We'll see on the next ride, but now at least I know what to play with.

Edit: Completely solved now. I narrowed down the creaking noise to the spacers above the handlebars, under the cap. I believe the creaking is the spacers moving against each other and against the step and cap. Others troubleshooting this might want to try some lithium grease between their spacers.

Love this bike!

[xukaiwen]

Hi, I had a similar problem of creaking when I put any weight on the bars of my 2022 Trek Domane SL. If I rode with no hands, then no noise. Put my hands on the bars, incessant creaking.

I tried greasing everything I could. I changed the stem. No improvement.

But when I moved the stem almost to the top of the available stack height, the sound disappeared. I inspected the stem and noticed that the top cap wasn't quite touching the upper-most spacer. Hmm. It couldn't be the top cap causing all this noise, could it?

I went and got a spare, carbon top cap I had laying around and threw it on the bike. I made sure it fit snugly on the spacers.

The new top cap instantly fixed the creaking. Now the bike is as silent as I could hope for.

Stupid problem to have, a creaking top cap, but I hope this helps someone. I'm no engineer, but my guess is the flex of the front isospeed causes the stock top cap to rub the spacers the wrong way.