Carbon Fiber helmets. Yea or Nay ?

[Cruizin]

Carbon Fiber helmets are coming on strong. Tons of new models coming out and even bargain basement brands are coming out with Carbon Fiber models.
 
Cycle gear/Revzilla has a big selection here CYCLE GEAR CARBON FIBER HELMETS
 
Got a Carbon fiber helmet that you like? LEt us know below.
 
I have a Bell Star that I like quite a bit
 

[adjuster]

The cost v/s benefit ratio has to change more before I'm willing to buy one.
 
The cost is coming down. That's a good deal, but I've read where a helmet that can slightly deform is better than one that just cracks when you try and deform it. So the plastic helmets crash test as good or better than the multilayer carbon/kelar/fiberglass helmets.
 
There is no perfect material yet, but cost is a factor for lots of riders, or we would all ride the most expensive bikes right?
 
The best F1 and other race cars are carbon fiber, aircraft and many other super light yet strong applications all use the latest expensive technology. In a decade, carbon fiber frames and swing arms will be reality. And most helmets will be some sort of pure CF or composite.
 
But right now? I will keep my tried and true cheaper alternative.

[koth442]

Old housemate had a CF HJC helmet. Hit a garbage truck with a speed differential of 20-30mph. Got off with a light concussion and one phucked up motorcycle.

[alejandro]

I got an AGV K5 (carbon). I love it. Nice and light, comfortable around the ears, reasonably quiet (I wear earplugs anyway), flipdown tinted thing is very helpful.
 
Got a really good price from Revzilla a while ago. They still have a few.

[keithu]

I'm trying to understand who the hell buys this:
 
https://www.cyclegear.com/gear/bell-pit-boss-carbon-helmet

[keithu]

In a decade, carbon fiber frames and swing arms will be reality.

Maybe, maybe not. Carbon fiber bicycle frames have been around for 20+ years now. They are popular with some riders, but there is resistance from others due to a perception - sometimes based on reality - that they're prone to cracking.
 
It's a little weird that there aren't already C-F motorcycle frames. It makes me wonder if there are some serious engineering concerns.

[fddriver2]

I'm trying to understand who the hell buys this: 
https://www.cyclegear.com/gear/bell-pit-boss-carbon-helmet

Someone on a cruiser.... Somewhere..... 

[trokarr]

In a decade, carbon fiber frames and swing arms will be reality.

Maybe, maybe not. Carbon fiber bicycle frames have been around for 20+ years now. They are popular with some riders, but there is resistance from others due to a perception - sometimes based on reality - that they're prone to cracking. 
It's a little weird that there aren't already C-F motorcycle frames. It makes me wonder if there are some serious engineering concerns.

 

[trokarr]

In a decade, carbon fiber frames and swing arms will be reality.

Maybe, maybe not. Carbon fiber bicycle frames have been around for 20+ years now. They are popular with some riders, but there is resistance from others due to a perception - sometimes based on reality - that they're prone to cracking. 
It's a little weird that there aren't already C-F motorcycle frames. It makes me wonder if there are some serious engineering concerns.

The new BMW HP4 has a CF monocoque frame:
 
http://canadamotoguide.com/2017/04/19/bmw-hp4-race-debuts-in-china/
 
 

[joeszup]

I bought a Lazer Monaco two Christmas's ago. I was stepping up from your everyday $100 Bell helmet and it was light night and day. It was so much lighter. I commute daily and until then, didn't know just how much the Bell was aggravating my neck.

[koth442]

In a decade, carbon fiber frames and swing arms will be reality.

Maybe, maybe not. Carbon fiber bicycle frames have been around for 20+ years now. They are popular with some riders, but there is resistance from others due to a perception - sometimes based on reality - that they're prone to cracking. 
It's a little weird that there aren't already C-F motorcycle frames. It makes me wonder if there are some serious engineering concerns.

As an engineer and former composites technician I will answer this:
 
Its WAY too expensive to be in a production motorcycle. Its not a question of volume, CF (and composites in general) are a PITA to work with. Plus the material is very expensive. The BMW linked above has a CF chasis and is crazy expenseive. IIRC there is another motorcycle made entirely out of CF but I think its MSRP is above $50k USD. Furthermore, the engineering required to design a properly functioning motorcycle frame compared to designing a bicycle frame is vastly different. CF behaves very non-linearly making finite element analysis models (FEA) very difficult. Motorcycle chassis are tuned to behave as a spring mass damping system for a variety of reasons that do not exist in a bicycle chassis. These added parameters make a properly designed chassis even more difficult. Thus the added cost of extra engineering, extra manufacturing costs out weighs benefits (if there are any other than weight savings). 
 
Airplanes are made from CF and CF variants, same with F1 car chassis. CF composites are remarkably strong and useful materials. Its properties must be required though.

[keithu]

Motorcycle chassis are tuned to behave as a spring mass damping system for a variety of reasons that do not exist in a bicycle chassis.

I'm no engineer but I question this statement. Bicycle frames are expected to damp vibration and shock forces, especially in the case of road bikes where there is no other suspension besides the wheels. A bicycle's frame has a huge affect on comfort, and to a lesser degree​ efficient power transfer.

[nsmiller]

All the pros I see are wearing Shoei or Arai, which don't have any CF helmets listed at Cycle Gear that I can see.

[aeg]

All the pros I see are wearing Shoei or Arai, which don't have any CF helmets listed at Cycle Gear that I can see.

I don't think they are wearing the same Shoei or Arai we can buy at the Cycle Gear. 

[koth442]

Motorcycle chassis are tuned to behave as a spring mass damping system for a variety of reasons that do not exist in a bicycle chassis.

I'm no engineer but I question this statement. Bicycle frames are expected to damp vibration and shock forces, especially in the case of road bikes where there is no other suspension besides the wheels. A bicycle's frame has a huge affect on comfort, and to a lesser degree​ efficient power transfer.

You are correct. My statement was very poorly worded.
 
The engineering required to properly manage shock and vibration in a bicycle frame is not as complex as a motorcycle. Ie.) the bicycle doesn't have 100 pound 75 ft-lb motor strapped too it. Furthermore, a motorcycle carries MUCH more energy than a bicycle. Kinetic energy is 1/2*mass*velocity^2 and momentum is mass*velocity. A motorcycle weighs 50-100 times more. Plus how much faster a motorcycle can go. 
 
Hopefully that clears up my ambiguity.