maybe a covered topic but do carbon drop bars reduce vibration

[Gummee]

Not exactly the answer the OP was looking for, but my TET CX had a steel fork where all the other bikes in the stable at the time had carbon forks.

There was noticeably more 'zing' to the bars with the steel fork than the carbon forks. Using the same wheels/tires. AL bars on everything

YMMV

M

[marciero]

In light of the absence "directional compliance" in the design/layup of these bars (which according to one of the manufacturers in the Velo article, has not been done) I find the "yes" responses surprising. The selling points of of the carbon bars are stiffer, lighter, can do more refined shapes, probably in that order.

[Mark McM]

Originally Posted by marciero

In light of the absence "directional compliance" in the design/layup of these bars (which according to one of the manufacturers in the Velo article, has not been done) I find the "yes" responses surprising. The selling points of of the carbon bars are stiffer, lighter, can do more refined shapes, probably in that order.

Zipp claims that their carbon handlebars have improved comfort - but they don't say they have improved compliance. They base their comfort claim on ergonomic shape improvements, including curves that fit the hand better, and bar tops that spread the load across the palms better.

If the bars fit your hands better, then I agree they may be more comfortable to you. But I also agree with marciero - they are not likely to be more compliant. Remember, carbon fiber has a higher stiffness/weight ratio, and carbon handlebars aren't much lighter (if at all) than aluminum handlebars. If you read Velonews article previously linked, you'll see that the carbon handlebar makers also state this. In fact, one carbon handlebar maker recommended that if a rider was looking for compliance, they should get 25.8 mm aluminum handlebars.

[Kontact]

Originally Posted by Gummee

Not exactly the answer the OP was looking for, but my TET CX had a steel fork where all the other bikes in the stable at the time had carbon forks.

There was noticeably more 'zing' to the bars with the steel fork than the carbon forks. Using the same wheels/tires. AL bars on everything

YMMV

M

Carbon (and aluminum) road forks have been tested to have more compliance than steel forks.

The problem with handlebars is that they hang out in space and we yank on them quite hard while having metal stuff clamped to them. For safety and to resist clamping forces, CF bars are likely over built.

I've seen more broken CF bars than aluminum working in a shop, and many of the bars where broken under the tape where you can't see or hear the damage.

CF bars are a little lighter, but this may (currently) be an less useful place to use carbon, like cranks.

[11.4]

Compliance and comfort aren't always the same thing. What really affects comfort isn't whether the bar bends but whether it transmits vibration. Carbon bars have become better at that, partly just because they can be shaped so effectively (such as flat tops, so you're resting a wider part of your hand on the bar, and differentiated wall thicknesses over the length of a bar).

And it's all about the details. Aluminum bars got lighter and lighter for years with the use of heat-treated alloys. But those bars were fiercely uncomfortable to ride. Older soft-alloy bars were more comfortable because they didn't transmit the vibration as much. I suspect that some of the equipment manufacturers' comments come from trying to cater to the mass market -- they'll say that a carbon bar is stiffer because that's what people want to buy for $250, while they know that those buyers will push down and measure bar flex as a proxy for comfort.

If you want more suspension in your bars, either lower your front tire pressure (as someone mentioned above), or get wider bars which naturally will flex a lot more, position be damned.

[19wisconsin64]

Yes, carbon bars without a doubt soften road buzz. However, some carbon bars soften the buzz / vibration more than others. I recall my carbon track racing bars to be far stiffer and less forgiving than any other bar I ever road....and I also recall my Zipp Countour carbon bars as seeming sort of soft and flexy to me.

The original poster brings up a good point.....it does not seem like there is a rating system for handlebars in terms of stiffness / flex amount.

[veggieburger]

IMO, the greatest advantage of a carbon bar (as mentioned) is the ability to shape the material. Flat tops, finger grooves, dips, bumps, surface area.....find a carbon bar your hands really like and hoard a couple for the years ahead.

[Mark McM]

Originally Posted by 11.4

And it's all about the details. Aluminum bars got lighter and lighter for years with the use of heat-treated alloys. But those bars were fiercely uncomfortable to ride. Older soft-alloy bars were more comfortable because they didn't transmit the vibration as much.

This makes no sense. Stronger alloys allow handlebars to be made with thinner walls, so they can be lighter. But the stiffness of an alloy does not change when you harden it - these lighter, thinner wall bars will be more compliant than heavier bars. So lighter, harder alloy bars should be more comfortable. And in my experience, they are. (Also note that aluminum doesn't have any meaningful damping, so vibration absorption will not change with alloy.)

[Kontact]

Originally Posted by 19wisconsin64

Yes, carbon bars without a doubt soften road buzz. However, some carbon bars soften the buzz / vibration more than others. I recall my carbon track racing bars to be far stiffer and less forgiving than any other bar I ever road....and I also recall my Zipp Countour carbon bars as seeming sort of soft and flexy to me.

The original poster brings up a good point.....it does not seem like there is a rating system for handlebars in terms of stiffness / flex amount.

Has anyone actually measured this?

Originally Posted by veggieburger

IMO, the greatest advantage of a carbon bar (as mentioned) is the ability to shape the material. Flat tops, finger grooves, dips, bumps, surface area.....find a carbon bar your hands really like and hoard a couple for the years ahead.

In theory, but most shaped carbon bars sold right now have a lower cost alloy bar of the same shape. Hydroforming is pretty effective.

[cadence90]

Fair Wheel Bikes - Road Handlebar Review - Updated: April 25th, 2016.

FWIW.
.
.

[Black Dog]

Originally Posted by 19wisconsin64

Yes, carbon bars without a doubt soften road buzz. However, some carbon bars soften the buzz / vibration more than others. I recall my carbon track racing bars to be far stiffer and less forgiving than any other bar I ever road....and I also recall my Zipp Countour carbon bars as seeming sort of soft and flexy to me.

The original poster brings up a good point.....it does not seem like there is a rating system for handlebars in terms of stiffness / flex amount.

This statement does not have any evidence to back it up. And for the record, anictdotal evidence is not actual evidence. Frequency absorption of bars is not just a property of a material that occurs regardless of design. Yes CF does absorb higher frequency vibrations better than some other materials, when all else is equal and with bars that is not necessarily the case. Lots of claims and no data on the so called comfy carbon bar. Hell, even the manufacturers are saying that they are not and I would bet that they have their own in house testing data to back that up . They do not want to make a claim that can easily be tested and called out.

[eddief]

They do measure deflection and FSA carbon bars appear to have the most. When I ride in the drops and pull up I would swear the bars seem to have a "bending" feel to them = not stiff in the vertical plane. Not sure how that translates to absorbing vibrations, but it might follow that the flex I feel is also absorbing bumps?

"Reduced weight is a wonderful thing, but carbon bars offer another advantage: they tend to damp high-frequency vibration better than aluminum bars. Composite structures generally damp vibration better than metallic ones, and many riders have found real-world damping benefits when they fit a carbon handlebar. It would be interesting to quantify carbon bar damping; one way to do so would be to wire an accelerometer to the drops and then gently strike or pluck the bar, letting it “ring” at its natural frequency. One could then read the accelerometer data to see how quickly the vibrations dissipated. This ring-down test may be on the Fairwheel menu for a future article, but is outside the scope of this test.

Most bars are obviously similar in concept, but still very different in execution. Finding a bar that is comfortable to a rider involves personal preference as to the shape and depth of the drop as well as reach, flare, sweep and flex. Because of this we’re going to keep our opinions on fit and shape to a minimum, leaving those up to each individual to find what is right for them."

[Black Dog]

Originally Posted by eddief

They do measure deflection and FSA carbon bars appear to have the most. When I ride in the drops and pull up I would swear the bars seem to have a "bending" feel to them = not stiff in the vertical plane. Not sure how that translates to absorbing vibrations, but it might follow that the flex I feel is also absorbing bumps?

"Reduced weight is a wonderful thing, but carbon bars offer another advantage: they tend to damp high-frequency vibration better than aluminum bars. Composite structures generally damp vibration better than metallic ones, and many riders have found real-world damping benefits when they fit a carbon handlebar. It would be interesting to quantify carbon bar damping; one way to do so would be to wire an accelerometer to the drops and then gently strike or pluck the bar, letting it “ring” at its natural frequency. One could then read the accelerometer data to see how quickly the vibrations dissipated. This ring-down test may be on the Fairwheel menu for a future article, but is outside the scope of this test.

Most bars are obviously similar in concept, but still very different in execution. Finding a bar that is comfortable to a rider involves personal preference as to the shape and depth of the drop as well as reach, flare, sweep and flex. Because of this we’re going to keep our opinions on fit and shape to a minimum, leaving those up to each individual to find what is right for them."

They say that the bars dampen vibrations then they say it would be great if there was some emperical evidence about dampening. They are just assuming that it is happening somehow because in general CF dampens. And here I was thinking that the horse came before the cart.

[pdmtong]

Originally Posted by veggieburger

IMO, the greatest advantage of a carbon bar (as mentioned) is the ability to shape the material. Flat tops, finger grooves, dips, bumps, surface area.....find a carbon bar your hands really like and hoard a couple for the years ahead.

^ this. some weight. perhaps some vibration benefit...maybe, maybe not.

it's the shape that makes carbon bars attractive.

Example: Ritchey Evo Curve
- ovalized tops with no hard trailing edge in the flats.
- flat transition to hoods
- nice curved drops

[eddief]

I am thinking there might be more whip in those graphite shafts than their steel counterparts. Does whip equal flex? Does flex equal vibration absorption? Or is this apples and oranges of different colors?

PhD please speak up.