(Too??) light seatpost

Discuss light weight issues concerning mountain bikes & parts.

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Asterixx
Posts: 7
Joined: Mon Jan 20, 2014 8:36 pm

by Asterixx

Hi there!!

I am not looking for a incredibly light component to hold my saddle but first options (k-force and Bontrager XXX Lite) seem difficult to find in 27.2x400mm..

I have seen the Engage Revit seatpost, at 150/160 gr for 380 or 400mm (I am not sure).
It is designed by ax-lightness but it hasn't got weight limit and is approved for mtb.

I am going to use it to train and race in a hardtail XC MTB

What do you think? Will I endanger my parts??? I have not seen any broken in google...

Thanks!!

PS I weight 75/80kg!

by Weenie


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DanW
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by DanW

I wouldn't judge a part's durability purely on its weight... or even price or place of origin to be honest. Most stuff is made pretty damn well made nowadays.

My £50, 135g (27.2, 400mm) Chinese carbon post has been faultless for my 80kg XC riding :D The post has a daft name (Climax on ebay) and the 27.2 isn't available without decals but I just removed the logos.

Asterixx
Posts: 7
Joined: Mon Jan 20, 2014 8:36 pm

by Asterixx

It can be very well made indeed!! But I would like some feedback to be absolutely sure...
I supose it is more dangerous for CX to have a seatpost collapse by the way they mount the bike jumping on it.
I broke a handlebar in a descent but I supose it can not be compared.

Climax is a strange name for a seatpost... :D

mattr
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by mattr

There was a guy on here who broke an ax lightness post racing cross. AFAIK it was out of warranty anyway.

Asterixx
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Joined: Mon Jan 20, 2014 8:36 pm

by Asterixx

Yes, I found that story looking for information about engage. Engage is said to be a "cheap" and daily usable range of products, and they don't have rider weight limit, but they are still VERY light!
Are other ax lightness seatposts prone to break?

krzysiekmz
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by krzysiekmz

Every time Ax-Lightness comes up as a topic the story of this broken seat post comes up as well :)

It happened, that's it. Can and does happen to all other brands too. The individual who has had used that particular seat post had issues with contacting Ax Lightness(if my memory serves me) and made a big fuss out of it.

150-160g seat post is just light nowadays. That's for both aluminum and carbon. 90-100-110g is superlight and pushing weight limits etc. Get one if you like it and enjoy. You can get a Thomson Masterpiece and tune it with titanium hardware/carbon cradle for under 200g unit.
Engage line-up seems a bit overpriced to me. Have a look at MCFK as well.

I just got a carbon seat post off flea bay that has good reputation and is 160g in 27.2x400mm. Looking forward to try it out.
Also have a seat post/seat combo on my WW bike that's 135g total. That's pushing the limits but is has been fine and I love it.
Orbea Oiz - xxxx
MSC Koncept Carbon Di2 - 6955g
Leichtkraft Team Carbon - 6868g.

mattr
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by mattr

krzysiekmz wrote:Every time Ax-Lightness comes up as a topic the story of this broken seat post comes up as well :)
Hell yeah, it'll still be "current" news when i'm too old, grey and fat to get on a bike.

And FWIW i only raised it to show that they DO fail. But very very rarely. That thread is several years old, and the part was even older.

Biggest issue with these pushing the envelope parts (which that seatpin was at the time) is they have NO robustness, i.e. they will work right up to their design limits and no further. If your seat pin slips at 5Nm, cranking it up to 6 or 7Nm (as many many people will) might stop it slipping, but there is also a very real risk that you'll crush the post.
A 200 gram carbon post, you could probably take to 10Nm before you get into the same sort of risk level.

Much like that ax post that failed, IIRC the user was a 4th cat on his first (?) season of cross, so likely to be on and off the bike more often than an experienced rider, poor remounting technique, using an old part. Hardly that surprising it failed, i believe i pointed that out on the thread in question.

TBH, all the ax lightness parts i've heard of (very few) that have failed or been claimed to be "not fit for purpose" have usually been built badly, or woefully bad part selection. Things like 1 kilo pairs of wheels being used as a daily rider by a 100 kilo commuter (they rub the brake pads), handlebars being torqued until they stop slipping (i cracked my bars) and so on.

If you've bought the right part, and followed the instructions for assembly and used a load of common sense, there is no real reason why they would fail.

Asterixx
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Joined: Mon Jan 20, 2014 8:36 pm

by Asterixx

An image to ilustrate the part in question

Image

DanW
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by DanW

If you want it then go for it! I wouldn't have any concerns on durability. I have to echo the other comments here that it isn't especially great value when you consider the other cheaper, lighter options. I ordered one and it looked nicely made although I returned it as the setback proved a little too much for the fit I wanted.

Asterixx
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Joined: Mon Jan 20, 2014 8:36 pm

by Asterixx

I think I will go for it...

Thanks for all the comments!!

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cerro
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by cerro

Seems great, got one for my roadbike. Had an AX Daedalus earlier on a roadbike and my favourite for mtb is AX-Lightness Europa. Superlight but great quality

by Weenie


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