domane seat post crack... warranty-able?

Discuss light weight issues concerning road bikes & parts.
Posts: 51
Joined: Fri Oct 24, 2008 3:10 pm

by Thirstyman

I had the same problem with my Madone seat mast and they told me to pound sand (always torque wrenched) . Glad it worked out better for you.

User avatar
Posts: 1538
Joined: Sat Sep 05, 2009 11:20 am

by euan

It doesn't matter what the max torque of the seat mast is, it might be higher than the max torque the seatpost can take.

The amount of of torque that should be applied is the minimum required to hold the mast in place without slippage.

by Weenie

Posts: 888
Joined: Tue Dec 23, 2008 2:57 pm
Location: NYC

by em3

Fisherfreerider wrote:The max torque on our seat masts is 7nM and the Bontrager preset torque wrench is 5nM so he is not over-torquing anything.

The correct torque is the minimum needed to fix the seat mast securely without going over the MAX torque spec for the BOLT. So if 4Nm is sufficient to hold the seat mast, then why crank it to 5Nm. The OP stated that he always used the 5 Nm preset key, yet the seatmast still damaged the seat tube. Assuming he did everything correctly are you saying he should confidently crank it to 5 Nm again?

Posts: 6
Joined: Wed Aug 06, 2014 2:41 pm

by rwlinda

Here another person with a cracked Trek Set Post (2013 Madone 5.2). The crack looks exactly the same as in a picture shown in an earlier post. Right now Trek is evaluating the claim my bike shop sent (10 days ago already!).
I'm fearing Trek won't replace the frame as all signs look like the seat post was over torqued. Having a torque wrench I always feared torquing it to the max 7Nm (that Trek /Bontrager say is safe to apply) because it is really, really tight, so I never torqued all the way to 7Nm, but still the seat post cracked, apparently during one of my rides.

Anyway, I checked out some companies that can fix carbon and if Trek doesn't come forward, I'll most likely get it fixed for about $300.

As someone mentioned "we" should just ask our dealer and leave it up to Trek .. I'm glad others shared their story and turns out more people have the exact same problem. To me that looks like a manufacturing issue Trek might want to look into, because it's not right a frame can be damaged that bad by a seat post!

Post Reply
  • Similar Topics
    Last post