Popping saddle

[JHZR2]

I've been mountain biking a few times this year already. The saddle on my Scott scale 29er seems to be popping as I go over dynamic terrain. Either that or the top
Tube on the frame or the headset.

Everything feels/looks good.

Is this common?

I'm pretty sure it's the saddle and not the frame. On these Al hydroformed frames, do they tend to pop when stressed?

 

[mpvue]

aluminum frames radiate noise differently than steel; cannondales were notorious for clicking bottom brackets.
try to isolate the noise and identify when it happens. try rocking on the seat with your hands while off the bike.
seatposts click too. pull it out and grease it. toghten the cranks and BB cups too. rear Q/R's can make noise if they aren't tight either, as well as replaceable derailluer hangers.

 

[cchase]

Try standing. If the noise goes away, you've at least isolated the saddle.

Are you a bigger guy?

 

[JOD]

If your frame is making noises, you have serious issues! They only make sounds when they're broken, or about to break.

I'd make sure it's coming from the saddle, i.e. it doesn't make noise when you're standing. A common source of noise is the bottom bracket cups (or bearings w/BB30) moving in the aluminum BB shell. Another common source of noise is the saddle to rail interface or the seat post head mechanism itself. In either case, the solution is pretty simple: pull it apart, grease it and re-install. I've also seen guys wrap the rails in Teflon tape, but that doesn't seem to last as long.

If you only get the noise seated, it probably is the seat post head/rail interface.

Aluminum frames are really good at amplifying noises, so sometimes these things can be tough to track down. Often, if you have a hub with aluminum end caps, the hub/fork or hub/frame interface can be making noise, but it's hard to figure out where it's coming from on the bike. That's another area you'd want to check.

 

[JHZR2]

It is the saddle, transmitting through the seat post to the aluminum tube in the frame. The sound just travels!

Verified by pulling on things, and the seat made the noise consistently.

Not sure there is much I can do or worry about then... Maybe I'll just check the alignment of everything.

Everything else on the bike is solid. It really is a nice light and fast handling 29er.

I am bigger, 6 ft 5 ish and around 250.