Madone SLR seatpost / ISOspeed HELP

Hey TR community,

I put my Madone on the the trainer for the first time yesterday and I noticed it has quite a bit of sway side to side In the seatpost (not vertically like the isospeed is supposed to move). There is also a clicking. I can replicate this movement with my hands with the bike off the trainer.

I’m wondering if anyone had experience with this?? Is this normal?

Clicking is not normal. There may be a small amount of movement sideways, but it should not be very noticeable.

I’d suggest taking it in to your Trek dealer to be reviewed by a tech.

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My mate had the exact same issue had two replacement frames from Trek (LBS) before it was solved.

Damn, really? I’ve ridden mine around 6000km so far. Did it take a bit to develop? They replaced it no problem? @robcumine

The first bike, the LBS tried shims which didn’t work, replacing the frame, exact same problem, not even into 1 ride, next frame had zero issues. Go back to your LBS Trek Dealer, and present the problem. Based on Scotts issue and the help he received I hope your local Trek dealer has the same confidence.

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Did you check your seat post torques?

Just recently experienced the same thing and it could just be a loose bolt at the bottom of the seat mast. My LBS slipped off the cap that covers the top tube/seat mast junction, revealing the bolt (large Allen size) and tightened. Problem solved.


Just came across this forum I am on my second frame set from trek due to this problem and now it’s happening again. Every couple of ride we got to keep retightening to get rid of the excess side movement from the seat post. Still waiting to hear back from trek on this issue!!

Have you put loctite on the bolt when you retightend it?

No I didn’t, because I remember on the first frame we put blue locking compound on the bolt and it didn’t help but I may give a go again.

Hey all, i know this is late, but removing the cap and tightening the bolt where the top tube and the seat tube converge completely fixed this. You can see the bolt in this video (6/8mm keys)

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Hi all, I just ran into this thread. I have a 2020 Madone SLR that has been having the same problems. I was out on a ride one day the Iso-speed bolt worked loose and my seat mast was swaying side to side really badly. I stopped and thought I had a flat tire but soon realized it was the seat mast. I’ve taken it back to the shop twice now and the problem keeps coming back. This is extremely frustrating as it is now in my head, and racing season is about to begin for me.

I’m curious what will trigger my shop to contact Trek and possibly replace my frame. I can tighten the bolt at home but it should not be that way for such an expensive bike. I feel like the bolt is just ratcheting loose inside with every micro bump on the road.

Hi, I also bought a 2019 Madone slr6, i have had the problem of the slider moving back towards the seatpost after about 30km. I have had it at the bike shop, they tightened the seat post bolt but it still doing it. Firmed up the bolt and now that has put a pimple in the frame and i did not even cranked on it. It would be interesting to here from Trek on their so called team riders bikes if they have any problems

I have had the same issue. What began as movement in the ISOspeed seatpost eventually became a frame crack on 2 different SLRs. I am on my 3rd replacement frame in as many years.

In every case where the frame cracked, it was an audible, very loud crack while I was riding. The most recent crack is on the underside of the top tube in a spot that is not visible without removing the ISOspeed entirely.

The previous crack was in the ISOspeed bolt hole. The bolt had backed out and caused a big piece of carbon to “chip” off. Prior to the first crack, I was plagued with creaking and the bolt would not stay tight under any circumstances.

I will add that Trek has been very responsive to every warranty claim. Everytime Trek replaces the frame, I request compensation in product.

I have a 2019 Trek Madone SLR and having the same problem. The seatmast moves side to side. I’ve tightened the isospeed bolt which only temporarily solved the problem. It got to the point where I was pulling to the side of the road every 10 miles to retighten. I’ve used loctite and it helps a lot but still need to retighten about every 150 miles. You’d think a $7K bike wouldn’t have problems like this.

Also with the same problem.
The seatpost started to move sideways.
Have taken the bike to the LBS, but afterwards with riding the seatpost makes a lot of noise.
After a ride I found out that there was something was loose rolling in my frame.
The repair shop probably didn’t see the above movie, because he drop the rubber damper in to my frame (very sloppy).
Now I repair it myself, by replacing bolt and nut in the iso-system by a new one and sealt it with a little bit of Loctite 243. I could not find how tight the bolt must be, so I tightened it with 10NM
Now after a 2K Kilometer’s the seatpost starts to wiggle again! After inspection found a crack in my frame. Tomorrow to the LBS

Guess i’m in the same boat, is yours making this noise aswell?

yes, I also made a ticking noise and i was told by my fellow cyclists that my saddle was swinging very much.
it is very easy to unclip the protective cover and lift the rubber rim so that you check your frame.
The problem is that i’m tall, heavy and strong (! :slight_smile: ) . (195cm, 98kg), but within the specs of the Madone. It just has to stay intact !!
Wait for the reaction of Trek, understand that they are very customer friendly. keep in touch.

That might be the problem then, i’m about the same size. guess we are too heavy for this isospeed toy

Same boat as those above. I have a 9 month-old 2019 Trek Madone SLR6. I ride only on tarmac 100-150 miles a week (but took a few months off during the lockdown) and twice in the past few weeks I’ve noticed that the seatmast is moving side to side. I stop on the side of the road and tighten the isospeed bolt which seems to solve the problem. Then I take it to the LBS for an inspection, just to be safe, ASAP. It’s frustrating, but so far nothing serious. Like some of the posters above I’m on the big end, 212 LBS, but well within Trek’s stated weight limits. Like them I’m wondering if the Madone isospeed isn’t clydesdale-friendly. My wife wants me under 200 LBS; now that the bike agrees with her it might be time for a diet. Anyway advice and info on how Trek responds to the issue welcome!