Been running an I beam seatpost and SL saddle on my pride and joy. Last night the post split vertically and the head section which holds the saddle came out of the post.

Anyone else had this happen?

I really liked the set up. Pretty light and comfortable. Was just contemplating a replacement saddle. Only ever used for XC and trail riding. The post is a couple of years old but was not used massively last year. New I beam saddle or thomson and traditional saddle?

Do a search, there be a long thread on this, not uncommon!!

I initiated a thread here last year, can't find it for some reason…. started it after 2 post failed within one month.
1st one purchased from on one a year previously so had a fair amount of use.
the 2nd was a month old purchased from CRC (the newer micro adjust type) used 4 times and failed whilst riding allong a canal path

Both failed with a vertical split, in both cases during v cold weather, the thread identified that this type of failure had occured repeatedly, and those individuals which contacted the importer seemed to get a generic 'only ever had 2 posts fail' type of answer………

I won't be risking my safety with this post system again, shame as I really like the concept and like the saddles, I continue to use the railed versions

+1 T1000, sold the remaining saddle and have been on good old rails for nearly a year, will never go back to the i beam system now, simply don't trust it.

Aye, failures are well documented! It never took off for a reason!

I don't think that the rail design is fundamentally flawed when riding in very cold weather, just that the number of failures (at least documented on here, last winter there were lots) would indicate that that particular implentation of the design isn't quite right?

Is yours still in warranty? Its not fit for purpose, you should be able to get your money back, though I'm not sure if you have let them fix/replace it a number of times first? (if not within a certain short period whereby you essentially refuse the contract of sale, rather than simply ask to be refunded)
I'm no expert on this though so don't go quoting anything

James, the failure appear to have happened on the 'classic' and 'micro' headed aluminium posts; where the heads bond into the posts the posts split vertically, I've not seen any head failures.

I guess the failures in cold weather are due to either the bonding agent not performing well in the cold and or some expansion/contraction issues between the bonded parts (not convinced about this as both parts are aluminium) all I know is lots fail in the cold……..

I didn't bother with the warrantee on the 1st one (just accepted in good faith that occassionly products fail) bought a 2nd one from CRC who refunded without a problem.

Get a Kore I beam seat post from CRC. Excellent weight but never any problems for me – I've got 5 in total!

Cheap too!

I love mine, and to be fair, know plenty of people who have snapped standard posts also, so ain't too fussed.

I found the original thread: http://www.singletrackworld.com/forum/topic/sdg-post-failures-design-flaw/page/3

Mine failed in the same way. In cold weather – and on a canal towpath!

Cannot take it back. I originally bought a saddle post combo from On One a good few years ago. I bought a new post off ebay (new and boxed) when I built up a new bike as I really liked the system and my post was a little worn. I put the original post back on my bike when the new one broke. Needless to say it will not be there for long.

Had'nt really dawned on me, but mine went in cold weather too….

Had a 27.2mm x 400mm post and ST saddle for quite a few years now, with no probs whatsoever. I ride in all weathers and it's v cold over here in the US at the mo. It's on my On-One 853 and has seen action in Scotland, Wales, England and now the US. I weigh approx 11.5 – 12 st, maybe it has a weight limit,(not saying anyone is a lard arse that broke one :-), still, sods law says mine will self destruct now that I've sung it's praises.

I've got a Kore carbon and a Kore alloy I beam post. Both were a fraction of the price of the SDG posts and have been trouble free since I've had them.

smurf

Can't believe the thread has got this far and no one's called anyone a fat biffer yet… 😉

I have a carbon i-beam post and an alloy one and never had any issues. Also had one on my DH bike (until I sold the bike) with no problems.

That is my ten pence thrown in.

I only weigh a little over nine stone, but have a history of destroying posts and saddles, my 16 stone friend does'nt get it….

oooo I didn't know about this, been using one for over a year without any issues. Nervous now.