Carbon v Alu seatpost?

JesseD

My seatpost snapped today halfway through a race, no obvious damage, no crashes etc, just snapped?

It was a carbon one that came standard with my Felt Z75 so imagine it was only a cheap one anyway.

So I need to buy a new one and am wondering is there that much difference between a decent alu one and a carbon one around the same price?

I can imagine Alu will be stronger but have more road buzz transmitted, and maybe a weight penalty whereas the carbon will have a bit more flex, be more delicate but be marginally more comfortable?

Shuggy76

I genuinely couldn't tell the difference between my carbon one compared to my alu one, from a road buzz and weight difference perspective. I say just get the one you like the look of, comfort will be affected by tyres and tyre pressure, saddle choice and bib shorts. Other than that, it's all snake oil... How come it snapped then? Was the seat clamp over torqued or something?

JesseD

No seatpost was torqued properly, I hit a bump at 30 mph whilst sat in the saddle and almost came off, the rear felt soft after that so much so I thought id punctured. When I stopped and checked it had snapped about 1 inch above the clamp.

Will have a look at Alu ones as well and carbon!

antonyfromoz

JesseD wrote:

No seatpost was torqued properly, I hit a bump at 30 mph whilst sat in the saddle and almost came off, the rear felt soft after that so much so I thought id punctured. When I stopped and checked it had snapped about 1 inch above the clamp.

Will have a look at Alu ones as well and carbon!

I have never tried one but I have read good things about titanium seat posts - although they also seem to be pretty expensive.

JesseD

It's going on an a Alu Felt Z75 frame, which is my only bike at present but will be used as a second bike soon as I am going to purchase a new race bike for next year, so I don't want to spend a fortune.

The reason I'm thinking Alu is because it will be more durable than carbon at the same price point and may even be better. So if there is no discernible difference in ride quality from the two then Alu wins for me, a slight weight penalty is fine given the racing I will be doing for the rest of the season will be crits.

jgsi

I had a carbon Cyrano .. that also cracked but got my money back off Wiggle, bless 'em... the alloy Cyranos ,cant tell the difference... I like the saddle clamping system Fizik uses.

kajjal

Carbon doesn't make much difference to most people. Only if you are keen on weight saving really.

JesseD

Borrowed an Alu Ritchey seatpost off a club mate so I could ride till I get one, if I am honest I could tell the difference between that and a carbon one, it wasn't bad just different, more road buzz but not a massive amount. Going to ride it for a week and then make a decision I think.

JesseD

Ok so 2 rides on the alu seat post totalling around 100 miles and I can definitely tell the difference between alu and carbon, I can feel more road buzz through the saddle which does leave you a little more beaten up which has resulted in me getting fatigue in my lower back much quicker than usual.

Everything else on the bike is the same (tyres/pressure/saddle position/height etc).

Luckily enough I looked at the warranty info on the Felt Website and all Felt branded products supplied on bikes are guaranteed for 2 years, I contacted my LBS where I bought the bike and emailed them some pics and they are getting me a replacement under warranty. Great service from these chaps, no quibbling or anything, just “yep we will get you a new one and if you need a loan post in the meantime we will lend you one!”

Bobbinogs

That's pretty good service. I am surprised you felt so much difference in the post material as I struggled to determine any real difference when I last swapped (from alu to carbon) but that was on a steel frame so maybe the type of posts and frame material all have some effect, with some variables having varying degrees of affect and in different ways.

keef66

The Felt Z series have quite a slope to the top tube, so I imagine potentially quite a lot of seatpost showing? In those circumstances I imagine you could easily feel the difference between an alu and a carbon post.

I'm a bit of a shortarse, so my bikes don't have much post out of the frame. I can't honestly tell the difference between my carbon and alu posts. In fact I've just ordered a new inline one to experiment with fit on one bike, and went for alu.

JesseD

Bobbings – Great service from them to be fair, I used to buy all my stuff online but am now finding that I am buying stuff instore more and more unless there is a huge price difference. Its worth paying a little more to build that relationship up and also I do like to give to local businesses where I can, plus I do get a discount from them as I use them so much and race against them a lot.

Kee66 – I think you have hit the nail on the head, I have 8-9 inches of seat post showing from the seat tube so the carbon must flex more than the alu posts. I also read somewhere that if you can achieve the same saddle position that having a small layback on your post will be more comfortable than an inline one. I was going to go for an inline post but as my LBS are getting me a replacement under warranty then I will go with the layback one again.

fenix

I've broken 2 alu seatposts - one I think was a lovely Hope one too. The seat clamp pulled out of the post. :-(

If you run a long post I think the carbon damping is worth having.

imposter2.0

JesseD wrote:

Ok so 2 rides on the alu seat post totalling around 100 miles and I can definitely tell the difference between alu and carbon, I can feel more road buzz through the saddle which does leave you a little more beaten up which has resulted in me getting fatigue in my lower back much quicker than usual.

Without wishing to denigrate your experiences, I really do wonder how much of this is placebo and/or post-rationalisation. You are clearly more adept at identifying such differences than me, because I literally cannot tell what type of seatpost I am riding on without checking first...

bbrap

I ride both types and can honestly say I can't really feel any difference. Unlike one of our riding group who was wittering on about how the carbon post he got second hand off eBay was much more comfortable than the ally one he had before. Did not have the heart to tell him that what he had was a carbon wrap FSA and not a full carbon post (and given his frame is a couple of sizes too big and he has at least an inch of exposed post I doubt a solid iron bar would feel any different).

JesseD

Imposter wrote:

Without wishing to denigrate your experiences, I really do wonder how much of this is placebo and/or post-rationalisation. You are clearly more adept at identifying such differences than me, because I literally cannot tell what type of seatpost I am riding on without checking first...

I honestly don’t think it’s a placebo effect as I was kind of hoping I couldn’t tell the difference as an alu post is cheaper than the equivalent carbon one, I had already picked out an alu Zipp Service Course SL post to match my bars and stem and it was way cheaper than the carbon version.

£55 as opposed to £150 for the carbon one!

However my lower back is telling me otherwise and given everything lese is the same the only difference would be the seatpost.

mamil314

Is this stepping on the rake Again?

Bobbinogs

mamil314 wrote:

Is this stepping on the rake Again?

Is that the same as hiding the sausage?

keef66

Bobbinogs wrote:

mamil314 wrote:

Is this stepping on the rake Again?

Is that the same as hiding the sausage?

They both sound potentially painful. I'm not sure I want to know... :shock: