Cockpit improvement

I do 40 k every day in London with my fixed bike. I was thinking to upgrade to either carbon stem or carbon handlebar or both carbon to decrease weight and improve comfort. Any safety issues with using carbon fibber stem or handlebars? Shall I change one of them or both and what is the best combination?

What are you running at the moment? And what sort of bars? Drops? Risers?

You might feel some comfort improvement with crabon bars but it's generally accepted that carbon stems are barely lighter than a good forged alu one, and much more expensive.

Consider tyre choices first - far cheaper and probably more noticeable results.

For the last 7 years, I am having basic alu stem and drops. Together weight about 550 grams. A bit flexi when pushing hard uphill but still transfers a good amount of vibration. I was thinking that a better cockpit set will be stiffer and also more comfortable. It is true, carbon is much more expensive than good alu stem with same weight, though I would expect it to be more comfy.
I am not sure what is the best,
carbon stem – alu bars
alu stem – carbon bars
both carbon

Consider tyre choices first - far cheaper and probably more noticeable results.

I can only go for 23 tyres on the front, the rear can take 25 and it is a good improvement

You could try wider rims too, like the current flavour of the month, the Velocity A23.

Also, a carbon post will be a lot comfier than an alu one, especially a stiff one (oo-er) like a Thomson.

Apart from that, I really don't think a carbon stem will be worth it - many of the ones you can buy are super-stiff sprinter's stems that won't do much for comfort. Carbon bars definitely ought to make a difference though. 3T Team ARX stem (forged alu with titanium bolts) and 3T Team bars (carbon) would be comfortable, strong and ~320g for the combo in average sizes, so a pretty big weight saving over what you're using. Maybe not the stiffest bars in the world, but more stiffness might equal more harshness in this case.

Also, if you're talking about comfort, performance and weight upgrades, have you considered upgrading the fork? You haven't told us the spec of what you're currently riding so it's all a bit speculative.

I have an old Easton CT2 flat bar on my single speed which I had spare from a upgrade on my mountain bike, they were slightly damaged at the ends from bar ends so I cut them down by 20mm at each end, they have proved to be comfortable & strong. All 3 of my bikes use Easton carbon bars, I think the construction of the carbon weave should make them unlikely to fail in the same way as a lightweight alloy bar can.

Also, if you're talking about comfort, performance and weight upgrades, have you considered upgrading the fork? You haven't told us the spec of what you're currently riding so it's all a bit speculative.

I just got a new langster 2012 alu frameset. I set it up with handmade wheels with CXP23 on Formula hubs, scwhalve durano+ tyres, carbon specialized pave seatpost, specialized toupe saddle, standard alu drop bars and stem, 105 front brake with dirty harry lever, sugino cranks, carbon cell BB, spd xt pedals. The cranks and the bar and stem are left from my old 2006 langster so It worth to upgrade.

Are they track style drops or road?

Compact drops are going to be more comfortable than track drops.

^not entirely true, if you fit the bike correctly on conventional drops the change to compact may reduce your comfort

often carbon bars flex more than aluminium, but that flex gives greater comfort, such as less road buzz

road anatomic drops not track, just weighted them around 400 grams (stem is 180 grams), pretty solid but transfer plenty of road vibration

You also asked about safety issues.
I looked into this when considering purchasing some carbon drops. Basically it boils down to how you treat your bike. I like throwing mine around so the answer was 'no' for me.
The grams the bars would shed outweighed the peace of mind I would lose.

This blurp is from Competitive Cyclist:

''An engineer at FSA summarized the carbon bar situation very succinctly. He said that if the consumer demands F1-quality componentry, they need to have an F1- type mentality about it. How expensive are the composite components on an F1 car? Outrageous. How many races do most of those components make it through? Oftentimes one only. The notion that such components are built to last as long as a well-made carbon or alloy frame is simply wrong and misses the point entirely. Carbon bars, like carbon rims, are made with pure performance in mind, i.e. durability isn't paramount.

So, to answer the question, are carbon handlebars safe? Yes they are. But if you crash them, or otherwise submit them to odd side loaded forces (such as having your bike tip over when leaning against your car or garage wall), do everyone a favor and replace them.''

Think about it.

I just got a new langster 2012 alu frameset.

I can only go for 23 tyres on the front, the rear can take 25 and it is a good improvement

I don't think this is true - are you 100%? Pretty much every modern carbon fork will take a 25c and a lot would take a very tightly squeezed 28c (which I wouldn't suggest tho). From the ones I've seen on my commute they'd also take a 28c rear.

My vote would be for 25c tyres, checking your bike is set up correctly (including installing two proper drop brake hood leavers) then possibly carbon bars, and if you want to drop weight a lighter alu stem with ti bolts. When i was looking Deda and Ritchy were the best option for weight and price.

I am not sure what is the best,
carbon stem – alu bars
alu stem – carbon bars
both carbon

Carbon stems are a bit of a waste of time. They need to be stiff to function as a stem, so dont add comfort. They end up the same weight as an alu stem. They are more sensitive to bolt torque.

Carbon bars are great. The good ones are fine tuned for ride, and stiffness. Dont over clamp them and they will be fine.

Get a 25mm front tyre first.

What about tyre pressures? What do you use (front/rear), and how much do you weigh? You probably don't have to waste time/energy/money on a consumer mission.

I'm liking this thread. Proper good feedback here. It's often a fine line on this forum between asking a question which gets flamed and asking a question which receives useful, simple info.

I don't think this is true - are you 100%? Pretty much every modern carbon fork will take a 25c and a lot would take a very tightly squeezed 28c (which I wouldn't suggest tho). From the ones I've seen on my commute they'd also take a 28c rear.

My vote would be for 25c tyres, checking your bike is set up correctly (including installing two proper drop brake hood leavers) then possibly carbon bars, and if you want to drop weight a lighter alu stem with ti bolts. When i was looking Deda and Ritchy were the best option for weight and price.

The brake bridge on the back of a Langster frame is very tight indeed- I couldn't get a 28 in there, 25 was the biggest I could go.

What about tyre pressures? What do you use (front/rear), and how much do you weigh. You probably don't have to waste time/energy/money on a consumer mission.

What sort of bike forum member are you???

Buy £250 carbon bars first. Drop front tyre pressure from ??? to < 100 PSI after. Keeps the industry ticking over innit.

£250? Compromising on your handlebars is not a good idea Mr Furry.

I suspect that the only correct bike forum answer is a proper bike fit, followed by a custom stem / bars combination from whoever is the current 'builder du jour'.

Perhaps a bar tape (pads?) / tyre change might be the quickest easiest change.

Maybe just learning to use your elbows as effective suspension, you cunt.

Is that better? A reversion to form? I aim to please, even if that means displeasing.

Your elbows arent going to move fast enough to absorb road buzz.

.....you twat.

;)

I don't think this is true - are you 100%? Pretty much every modern carbon fork will take a 25c and a lot would take a very tightly squeezed 28c (which I wouldn't suggest tho). From the ones I've seen on my commute they'd also take a 28c rear.

My vote would be for 25c tyres, checking your bike is set up correctly (including installing two proper drop brake hood leavers) then possibly carbon bars, and if you want to drop weight a lighter alu stem with ti bolts. When i was looking Deda and Ritchy were the best option for weight and price.

I am going for Crud Road Racer mudguards so I can go up to 23 front and 25 rear tyres. Yes, before I was running marathon + 25 tyres and was really comfy but during the very cold days of winter I was getting plenty of rust on some parts of the bike from the salt so I had to use mudguards.