When new bike day turns bad! Trek Domane SL5 seatpost has slipped out of range :(

So I just bought a new Trek Domane SL5 on Friday hoping to get back into road cycling after a long time away from it. On my first ride out after about ten minutes I noticed the seat height was a bit low. I went to lift it, but found that the adjuster bolt had slipped below the cut out allowing access to said bolt. After another 15 minutes of futile pulling and cursing it, I called my wife for a lift home since I didn’t want to make it worse by sitting on it more.

It’s now back in at the store, where three of us tried unsuccessfully to pull the seat post up (it may have also spent some time hanging from my squat rack with my body weight pulling on the seat) and waiting for the mechanics to come into work next week. Has anyone had a similar issue with a trek seatpost? I’m quite heavy (over 100kgs) at the moment so thats probably part of it

That really sucks! I have the same bike as you and Im 92 KG. No issues with it but to be honest I am in a 54 frame and the seat post is almost all the way down. It might be raised one mm. Turns out I should have been in a 52. Bike just fits although trek is nicely sending me a 1 cm shorter stem.

I had a seat post slip way down on me. I was able to get it back in place. It happened again and I took it to the lbs. They seat it need anti slip compound. It is a common problem with carbon fiber seat posts.

I had the exact same issue with my 2020 Domane SL. I hit a bump on a gravel descent and landed on my saddle with some force, which pushed the seatpost bolt out of the adjustment window. My LBS was able to get it out with no damage to the frame or seatpost (not sure how exactly), so chances are good you should be able to get it fixed easily.

And I’m sorted! LBS fixed it, their theory was they hadn’t put enough carbon paste in, so it slipped until it found some…

Apparently two guys pulling on it was all it needed

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I’m having the same issue with my BRAND NEW Trek Domane SL6 eTap. The seat post will slip down until it will finally bottom out. Pulling the seat post out, it seems to me that there is too much slop between seat post and seat post tube. Not a snug fit. The bike shop that I purchased it from (1.5 hr drive) is going through a remodel and will be closed until Nov. 20th, just my luck. I have carbon fiber grip gel on order and will give that a try. Please comment if you are having the same problem and if a solution for this problem has been found. I’ve never had a Trek bike but I guess I’ll find out if they stand behind their product.

Totally gutted 10 miles in and Mike just done the same. Totally slipped. Stopped and just can’t pull it out. Had three Trek bikes and never had this problem before. Waiting for wife and totally not happy as was enjoying my pedal out.

I guess I am very lucky with my domane. I went from a 54 specialized roubaix to a 54 trek domane. Seems I needed a 52 domane. I have a thin riser between my cleats and shoes and have the seat down all the way on the domane. The seat cant go down any further at all.