I had about a mile left of my 14 mile ride this morning when the bolt that holds the saddle to the bike suddenly sheared in half. It's an 09 Trek Valencia. As I felt the seat suddenly loosen, I was able to stand and bring the bike to a stop with no damage to my nether region, but it was still a little shocking.

Thankfully there was motorist behind me kind enough to honk and point out that I had lost my saddle.

Here's an admittedly crappy picture of the bolt:



I'm assuming this would be covered under warranty. Regardless, I'm letting Trek know about it.

i've broken quite a few of these. They're always a suprise when they go. It's gotten to the point where I now usually carry a spare. Not much the manu****urer can really do. It's a bolt. they don't make the bolts. It's a 50 cent part, for which the bike shop would probably charge you 2 to 3 dollars.

Perhaps make sure when you remount your saddle, that the seat isn't waaaaaaay back on teh rails. More towards the middle of the rails. that will help in the future. If you are sitting waaaay back on the rails, your top tube may be too short. Either a larger bike, or a set-back seat post will help.

Good luck, glad you weren't hurt. I've crashed a few times from this happening to me.

Are you guys big? Also, it might be worth find a better grade of bolt that has more shear and tensile strenght.
Also, you should make sure it is torqued properly.
https://en.wikipedia.org/wiki/Screw

I'm not a "guy" and no. Jackass.

Avoiding some of the ostensibly more controversial portions of the post above, I agree with this sentiment. If you have a "nut/bolt/fastener" shop in your town, they'll be able to fix you up; I'm not sure if Home Depot or the local hardware stores would be well versed in various bolt grades. A proper grade 8 bolt will not break.

.

You also might want to place a bit of grease on the threads of your new bolt. It seems to be missing on the one pictured.

LUBE is GOOD

+1

It's an honest question and relevant to the problem at hand. You can choose to answer or not at your own discretion, but automatically assuming it was an attack on you is pretty weak.

I would go to the Trek dealer you presumably bought the bike from and see if they will warranty the seatpost, or at least provide a new bolt free of charge (more likely).

Thanks!

Sorry, but it was a fair question. Even used "big" where it could have been much more derogatory. I certainly didn't read it as such. Your response was certainly more inflammatory.

That happened to me twice. After the second time I examined the clamp. The two halves of the clamp have these grooves that fit together so the seat doesn't tilt when the bolt is tightened. Mine were worn. I theorized that the seat slipped, backward, I suppose, and thus pushed the top half of the bracket forward, and that force would have been perpendicular to the bolt, and snapped it off. Just a theory. I bought a new clamp (I think I had to buy the whole seat post). Centering the seat in the bracket, in the front-to-back direction, would reduce the force that wants to tilt the seat back.

Sorry if you took offense to my post. None was intended. Also, I had no way to tell your gender from your post.

At least some people got a laugh out of it.

Jeff

Well that was uncalled for. maybe you need to lighten up?

No pun intended.

This is admittedly old information (2011), but in case it hasn't made it your way, and might apply: https://www.mybikeadvocate.com/2011/1...eat-clamp.html