I’m trying to identify this seatpost and figure out why the saddle clamp keeps shifting while I’m riding.
The clamp uses a center rod/bar that passes through the top of the seatpost. Under riding load, that rod slowly slides forward, which changes the saddle angle/position. Eventually the saddle can come loose, which is dangerous. I’m tightening both sides incrementally with a torque wrench, so I don’t think this is just uneven tightening or me guessing at torque.
So I’m wondering:
Does anyone recognize this seatpost or clamp design?
Is the center rod supposed to be captured against the rear stop, or should it be able to sit somewhere in the adjustment range?
Could I be missing a spacer, washer, keyed part, or orientation detail?
Is there a known torque spec for this style of clamp?
Has anyone dealt with this clamp slipping forward under load?
Any help identifying the post or explaining the correct setup would be appreciated.
by johnthephotog
4 Comments
That is not a Bontrager seatpost. It’s some knockoff or aliexpress special.
As noted it’s not Trek/Bontrager.
The design is like that I’ve seen on Darimo stuff.
The more novel concept uses dyneema loops rather than metal hardware but I’ve seen this before, just never on Bontrager.
The design looks like a 3T mountain bike post I used to have. It broke a long time ago 🤔
Doesn’t look safe to me.