i broke a twelfty and replaced it with a thomson which i did not break.

never mind, I've used google. 😳

the tompson is ovalised internally, and practically unbendable. the twelfty is inherently bendable.

but cheers tfb.

I've had a few Thomsons, and now have a Twelfty.
I wanted a 27.2 silver post with layback, the daft Thomson design means you can't drop your saddle. Twelfty was the only other post I could find.

All the Thomson's I've had, have slipped. The Twelfty doesn't.

quite. more specifically, i bent the twelfty.

Depends how hefty you are. I've run Thomsons on my bikes for over 10 years but on my latest singlespeed build decided I'd try a Twelfty (when they were a lot more than £15!). Like you say, little difference in weight and its held the seat perfectly for a year without any need for adjustment, unlike Thomsons which seem to develop a creak over time.

Twelfty is the only post I've had in my inbred & scandal frames which hasn't bent (I have 3 twelfty posts in 3 seperate frames, only about 15mm from their max insert mark). Other posts which have bent..> titec, ritchey, race face.

They're great, I really rate them. Clamp is very good to get exact seat angle (I'm very picky on such things). The inside of the twelfty is also ovalised as someone mentioned ref. the Thomson.

I've broken the clamp on a Twelfty and been unable to get spares to mend it. I've never managed to damage a Thomson though (have them on three of my bikes).

Whether that makes a Thomson worth three times as much is another question...

I went safe. Call me a mug. Or a tart...