Help!! Is my Sestpost long enough?? 🤕

[Monkeeee01]

Just got this seatpost in the post and I didn’t measure how long I needed (stupid I know ).

I’ve read that it needs to be inserted at least down to the bottom of the top tube, which as you can see from the photos it does ‘just’ - when held next to the existing one.

Is this going to be ok? I am a relatively short guy (5-7) and weigh 11stone

Thanks in advance

 

[MattiThundrrr]

Does your other post have a "minimum insertion" mark on it? That could be used as a starting point. Just judging by eye, it looks like it's close to the right length, I wouldn't feel comfortable it it was much shorter.

 

[Monkeeee01]

Does your other post have a "minimum insertion" mark on it? That could be used as a starting point. Just judging by eye, it looks like it's close to the right length, I wouldn't feel comfortable it it was much shorter.

Yeah good shout, I’ll check. Thanks

 

[Imlach]

Generally speaking as long as it goes below the TT weld I'm totally OK with the insertion. Just make sure, as Matti says, that the minimum insertion of the post is not exceeded. By picture it looks fine to me.

 

[Imlach]

To put your mind at ease I have been riding a cheapo steel post with about the same amount of insertion at 145kg and it still seems OK! Bike and post.

 

[Monkeeee01]

Yeah thanks guys, I compared the old one for the min insertion line and the new one goes in as far, and is to the weld on the top tube so I think it’s fine.

I’m not sure I like the look of it now tbh but I’m sure I’ll get used to it…..

 

[bikeworkshop]

That's not ok from my perspective.
I've seen so many aluminium framed bikes broken at the top of the seat tube, often with more insertion than this.
(I've repaired dozens of steel frames, but aluminium ones go in the scrap. )

You'll get away with it if it's a showpiece, but in regular hard riding, the post is flexing the top section and it will fatigue and snap, without a doubt.

In an older alloy frame, id look for a beautiful snug fit and at least a couple of inches below the bottom weld.

 

[Monkeeee01]

That's not ok from my perspective.
I've seen so many aluminium framed bikes broken at the top of the seat tube, often with more insertion than this.
(I've repaired dozens of steel frames, but aluminium ones go in the scrap. )

You'll get away with it if it's a showpiece, but in regular hard riding, the post is flexing the top section and it will fatigue and snap, without a doubt.

In an older alloy frame, id look for a beautiful snug fit and at least a couple of inches below the bottom weld.

Hmmm ok, I mean I do want to ride it occasionally but not hard. I’ve got other bikes for riding hard. This is somewhere between a show piece and an occasional rider over the South Downs in Sussex.

I still have other seatposts so I can always swap it out if need be before a ride.

Thanks man

 

[TreaderSteve]

Flog the Syncros - you'll probably get your money back - get another, longer one = peace of mind.

 

[Nabeaquam]

I’ve had two old 1930s steel frames that I got cheap because the top of the seat tube was snapped off because the post wasn’t in far enough. One was garbage, the other I fixed and ride. Better to be safe than sorry. You can see the weld just at the top of the brazing. You can get in there good with wire welding. Aluminum is garbage if this breaks.