Changing ally bars and seat post for carbon?

downhill paul

Will it really make a difference to the bike, if so then how much?
I currently own a specialized allez sport. I have never had the bike in bits so I have no idea how much the components weigh individually. I have managed to transform the bike by upgrading the awful axis wheel set for a new set of mavic aksium s wheels. they roll a lot more freely and they weigh quite a lot less than the previous wheel set. the bike currently weighs 9.7kg. will there really be much of a weight difference between ally bars and seatpost compared to carbon? are we talking a few grams, half the weight maybe?
I'm far from obsessed with how much everything on my bike weighs, but I am curious as to the benefits and exactly how much weight can be shaved off.

imposter2.0

A lot of money spent for no practical difference. Save your money and spend it on coaching, or training, or club membership...

Undertones

carbon will be more comfortable as it absorbs road buzz.

Saying that I wouldn't use carbon bars. Crash once and you might write them off. A seatpost isn't a bad upgrade but its only benefit will be comfort to be honest.

MountainMonster

Always remember, comfort is the most important thing with a bike. Any weight savings are negligible in a switch like you are looking at doing.

Also, I wouldn't worry so much these days with carbon bars. Most of the time crashes will not write them off as the material is now much more understood, and thus designed with that in mind.

simon_masterson

Some carbon bars are much lighter than some aluminium bars, but as we are dealing with things that aren't very heavy, the weight savings are consequently fairly small - if you change a heavier seatpost, bars and stem for really light ones, you might save up to 500g or so; whilst some of the easier weight savings you can make on a bike, not really worth the price you'll pay - in isolation, anyway.

mfin

If a bike weighs 9.7kg I wouldn't be spending much money on bars or seatpost. Save up all the ways of throwing money at it, perhaps towards a new bike in the future sometime.

iron-clover

On the Allez sport I probably wouldn't bother changing them for weight saving but for comfort as already said.

I would probably go for a cheap ish carbon seatpost to give a little flex- I would say to look for one >£100 but actually there would by no reason why you shouldn't splash out on a decent one as you can always put it on another bike later on. You can also look out for second hand to save some cash.

As for handlebars- I've never ridden with carbon bars and would probably try thicker bar tape first.

downhill paul

I understand the comfort thing. until now I wasn't sure if the weight savings would make any difference.
before posting earlier, I looked at a set of specialized 200g carbon bars and a specialized 200g seatpost on ebay. is that good or bad? I have no idea how much my current bars and seatpost weigh. I can't find the specs or the weight of them online.
it was only a thought anyway. I'm still in the process of losing weight, which will have far more benefits and advantages than lighter parts for my bike.

debeli

1. For almost all leisure cyclists, a few fewer buns at tea time would make more difference than £300 or more spent on lighter components.

2. Carbon beneath your backside or between fingers and forks will change the 'feel' and comfort of the ride very little. Quite a few people go faster on a bicycle they enjoy riding and can ride in comfort. I can't see carbon steering or seat post improving this.

3. For all the confidence shown online by cyclists who swear by the impact resistance of CF, there will always be that doubt. Most of us do our own servicing and fettling. We are not pro-peleton goombahs whose bikes are prepped for them. I whip down steep hills at 45mph+ (all I can manage these days) with confidence in my components. I do so on bikes that have been down the road several times. Would I do so with such confidence on a heavily-dropped bike with CF components? Would you?

4. There is a place for torque wrenches. I do not use one to fix or build bicycles. I never have and have yet had something fail or perform badly for want of a correct torque setting. When my saddle's in the right position, I just pinch the bolt and forget it. Same with my steering (quill or threadless). I once helped out a cyclist on my commute after his carbon seatpost shattered over a pothole. The inside of one of his thighs was a bit 'ouch'. I suspect an alloy component would not have failed there.

I am, by the way, a Luddite.

iPete

I had a 2010 Allez sport with an alu seat-post, the switch to carbon was very tangible. It really did transform the bike in terms of comfort. It was a Deda Drittissimo and I now have these on all my frames.

I wouldn't bother upgrading it for weight reasons though, if the current stuff works then keep on using it (unless you live in some incredibly mountainous region where every little helps).

Bar Shaker

Undertones wrote:

carbon will be more comfortable as it absorbs road buzz.

Saying that I wouldn't use carbon bars. Crash once and you might write them off. A seatpost isn't a bad upgrade but its only benefit will be comfort to be honest.

A downtube has very thin walls and these are good for damping out the high frequency vibration that leads to muscle fatigue (think of the power plate at your gym). A carbon seat post has very thick walls and behaves more like alloy than carbon. Tap the two different components and listen to the 'thunk' sound and the 'ring' sound from them.

The seat post is like this because it must take high clamping forces. It will not absorb any vibration, it won't cushion any jarring from the road and it won't weigh much less than an alloy one. There are posts with little inserts that claim to absorb vibration but these will be largely placebo effects and the same could be achieved by wrapping bar tape around an alloy seat post.

Spend your money on better wheels or fatter tyres.

cougie

I'd try the seatpost - but not the bars.
Posts are cheap and strong.
Bars are expensive and always get hit in a fall. Bars are basically consumables.

mfin

Are bars consumables? I know some people do take this attitude towards carbon bars. But, do people who don't race take crashing/falling as a certainty? I know I don't.

bigjim

I'm always intrigued by Jobst Brandt theories and his one and only bike. He advocates steel handlebars as he was often hurtling down Alpine passes and wanted that confidence in the bike. He never seemed bothered about weight and in his 70s there were few that could stay with him. I suppose you could call him a luddite or a wise man. Your choice. Oh and his chain is a bit loose.

ben@31

cycling and weight is a "law of diminishing returns" you'll be spending hundreds and hundreds to save just a grammes. Becoming fitter and losing excess body fat would make more difference.

Interestingly one of my bikes is an old Allez and a lot of my fastest times are on it. Its been faster than my v.expensive carbon best bike. Only change I made to the Allez is wheels and tyres.

ben@31

Is the photo the Stelvio pass? Looks awesome. Now on my list of things to do.

TheHound

Bar Shaker wrote:

Undertones wrote:

carbon will be more comfortable as it absorbs road buzz.

Saying that I wouldn't use carbon bars. Crash once and you might write them off. A seatpost isn't a bad upgrade but its only benefit will be comfort to be honest.

A downtube has very thin walls and these are good for damping out the high frequency vibration that leads to muscle fatigue (think of the power plate at your gym). A carbon seat post has very thick walls and behaves more like alloy than carbon. Tap the two different components and listen to the 'thunk' sound and the 'ring' sound from them.

The seat post is like this because it must take high clamping forces. It will not absorb any vibration, it won't cushion any jarring from the road and it won't weigh much less than an alloy one. There are posts with little inserts that claim to absorb vibration but these will be largely placebo effects and the same could be achieved by wrapping bar tape around an alloy seat post.

Spend your money on better wheels or fatter tyres.

That all sounds bull really.

But I'd be saving my money for a decent frame worth upgrading.

bigjim

ben@31 wrote:

Is the photo the Stelvio pass? Looks awesome. Now on my list of things to do.

Yup. Stelvio. More pics.
http://www.trentobike.org/Countries/Europe/Tour_Reports/Tour_of_the_Alps/

desweller

Bar Shaker wrote:

Undertones wrote:

carbon will be more comfortable as it absorbs road buzz.

Saying that I wouldn't use carbon bars. Crash once and you might write them off. A seatpost isn't a bad upgrade but its only benefit will be comfort to be honest.

A downtube has very thin walls and these are good for damping out the high frequency vibration that leads to muscle fatigue (think of the power plate at your gym). A carbon seat post has very thick walls and behaves more like alloy than carbon. Tap the two different components and listen to the 'thunk' sound and the 'ring' sound from them.

The seat post is like this because it must take high clamping forces. It will not absorb any vibration, it won't cushion any jarring from the road and it won't weigh much less than an alloy one. There are posts with little inserts that claim to absorb vibration but these will be largely placebo effects and the same could be achieved by wrapping bar tape around an alloy seat post.

Spend your money on better wheels or fatter tyres.

+1

there is very little bending moment on a seat post anyway, so it is not going to yield much.

Matthewfalle

Essentially more comfort and bling, minor weight savings. Your call really. I run carbon seat posts, 'bars and stems on a couple of the bikes, Ali on the others, so not really fascistic either way.

Much depends what I can pick up at a decent price in the sales tbh....ll.ll

simon_masterson

Bar Shaker wrote:

Spend your money on […] fatter tyres.

Forgive the paraphrase, but this is the bottom line. Not because the properties of the materials don't matter, but because if you want to improve comfort significantly, this is what you need. Many seem to have unrealistic impressions of carbon posts and forks.

That said though, carbon seatposts don't commonly shatter. Carbon fibre can sometimes break easily if flexed in a direction it was not designed to, whereas a metal tube will typically be reasonably strong in all directions (or that's my understanding), but that does not mean that it isn't strong stuff. It takes a fair amount of stupidity even to damage a carbon post by overtightening.

I have a Mike Burrows carbon aero seatpost on my low pro. I bought it for the aero bit (and it looks cool), but I will be sure to report back if I ever snap it!