Need a new seatpost for my next frame and these seem to be great value, about a third of the price of a Thomson (which I normally use), but are they up for a pounding from a 92kg seat prone rider 😕

I’m about the same weight as you. 5’11” on an 18″ 456.

Twelfty seatpost bent after 12 months. Replaced under warranty though.

They seem pretty tough. I bought a 2nd hand one for fixing a tag-a-long bike trailer onto my bike, and no problems with it, and it gets alot of load put through it.

I did have another one where one of the bolts snapped while riding, which was a bit inconvenient! However probably my fault as with this style of clamping if the bolts are slightly loose they can fail. I managed to buy a replacement bolt from a local bolt shop as On-One weren’t interested in sending me a replacement bolt.

Overall for the money I don’t think you can go wrong.

I bent one too, they are pretty naff if you ask me.

For their weight, which is relatively light for an alu seatpost, they are very good. I have three which spend theor lives pretty much at max extension and they are still straight. 85 kg peak based rider, so they take a battering!

Mine broke but I am a 105kgs lump.
Having said that this is mainly my commuter bike.
I ride a full susser for proper mtb duties.

mmmmmmmmm….2 good, 2 bent, 1 broke and a broken bolt !. Me thinks I will stick with Thomson. Cheers guys 8)

Another bent one here. Fat biffer though.

Two bolt posts need bolts nice and tight or bolts fail through fatigue loading.

Yep it’s your fault customers, you didn’t fit it properly 🙄

i bent one too. i’m 12.5 stone.

I’ve had 2 for for about 5 years and they’ve been fine. 12 and half stone riding trail centres and FoD mainly.

I also snapped a bolt on my Twelfty and although I was able to source a replacement bolt I couldn’t find one of those conical brass ‘washers’.

What do you suggest Brant? Do they have a proper name or summink?

Bent one, but TBH it was my fault. 4X course – rider not used to flat pedals. Bike dropped away full weight on landing taken by the saddle 😮

10th second later my shins crunched into the pedals, which took some of the pain away from my balls, I don’t mind admitting I had a little cry to myself once I had rolled down to the bottom of the course.

Oh the post is still in use mind, I gave it to one of the girls we ride with as she’s only light.

Another broken bolt here… but used without issue for many months before it failed, but lost confidence with the bolts so replaced with Thompson…

Buy cheap, buy twice 🙁

I’ve got one in my c456, only had it since December but it’s been fine so far. I’m now around 14.5-15 stone, and ride about 100-150 miles a week. Was actually about to order a new one for a commuter bike I’m building.

One of the bolts broke on mine.
I had only used it on the my Pompino road bike, and I weigh about 60kg. So not very impressive. Plus I couldn’t find anywhere to buy replacement bolts, or the top part of the clamp.

You pays your money, you takes your choice. Anything with an On One sticker on it is prone to failure IME, plenty of alternatives for similar money

I couldn’t find anywhere to buy replacement bolts, or the top part of the clamp.

I found replacement bolts at a local hardware store. Did you not find the top clamp?
Mine broke when I was going pretty slowly so I was able to recover it without crashing, but I do think about it when I’m going quickly or if I take it on the odd trail.
Pretty odd when it goes cause one minute everything is great then a second later your butt is being cheese grated by the rear tyre.

Anything with an On One sticker on it is prone to failure IME

I’d disagree, I’ve had a lot of on one kit, the only naff bit being a chain tensioner that the jockey wheel split in half in the snow.

Seatposts however, I’ve bent everyone I’ve ever had, except for those with Thomson on the side.

I got a secondhand one, broke one of the bolts and managed to buy a new pair off someone on here who had bought a handful.

Just resurrected it as my lovely Alien post broke, the head/clamp starting twisting inside the post (yeh, the one with the crap clamp with tiny bolts that was near impossible to adjust)

My Twelfty has that weird mottled wear that Mr Overshoots picture shows.

Mine felt as if it had a disconcerting amount of flex and i was not confident with the length of post sticking beneath the top tube of my Soul, so swapped back to Thomson. Well priced and light, mind.

101kgs with a 27.2mm on HT scandal for a year or so, no problem.