What goes on under the grip

That's disgusting

What brand? Please tell, they can't sue if it's true :)

Or at least, is it described as "carbon" by the manufacturer? Or do they use clever words....

i've found same thing which is probably same brand, I also snapped the same boom in several places on fairly decent crash but no worse than others i've had.

When you pick up one of these booms you wonder why they are so heavy well all of the glass that is hidden is probably why. It's not really acceptable when you buy something marketed as carbon boom, masts at least state percentage & so do some booms.

I'll post pics of remaining bits later.

That's probably no worse than fibreglass boards laminated with black resin, to very closely resemble carbon.

^^^ you are very kind to the manufacturers.......
I am only aware of one boom that says 60% carbon. I am sure he is not talking about that one (cos there would be no complaint there lol)
In the absence of info as to percentage (as your list shows), when they sell a boom as "carbon" you expect it to be all carbon surely?

That expectation is reasonable and comes from the fact the first carbon booms were fully carbon and that persisted for many years. Thus it is a reasonable thing to hope that a boom called "carbon" is 100%....... or has minimal glass and any glass is present along the full length (interwoven, or thin layer over top for abrasion resistance)
A substantial length of glass tube (pretty much the whole arm) is deceptive and cheap.

I have re-gripped a couple of Carbon booms over the years and what I have seen is well, amusing

Another fallacy, a lot of brands say they are "monocoque" construction, maybe after all the bits are glued together

Don't be fooled, they all break some sooner than others though

The worst part after spending huge amounts on a big name branded boom is the grip falling off, clag just doesn't cut it guys

^^^ oh agreed, me too. Had great warranty service from NP and Goya for a start. Exceptional in fact.
Had wonderful treatment from MFC with a small manufacturing issue, Pio answers fast and honestly... and with answers to my questions directed at many companies.

I just meant in this instance - if I bought a boom described as carbon, with no percentage mentioned, and found 2-3ft of arms was pure glass I'd be p!ssed. Badly.

Whist Mat and I where researching how to make our own Carbon boom, we came across a video somewhere showing the construction of a custom Carbon boom by a small, expensive and highly regarded manufacturer in Europe.

The description and video shows the curved arms being initially layed up as a thin Fibreglass base shell which the Carbon is then wound over. I suspect this method is quite common so I would be very surprised if many booms were actually a full 100% Carbon.

Also consider that Masts labeled as 100% Carbon can't possibly be that. Apart from the resin content, there is almost always a small amount of glass thread that holds the unidirectional carbon threads together and often some fibreglass, Dyneema, and/or Kevlar or other hi tech fibres. Perhaps filament wound masts are an exception, but there are very good reasons to reinforce certain areas with modest amounts of other types of Fibres. However, the Carbon content is almost certainly 100% Carbon!

^^^ anything else? cos that looks like it could be 2oz glass over a unidirectional carbon - a perfectly good construction.......

I was expecting to see milky translucent pure glass.

I'm reluctant to cross-section it to find out for sure!!!

If eyes and minds more experienced than I say that this construction is carbon (or some acceptable variation there-of), then I'm a happy camper and apologise for the amateurish 'Dr Google' diagnosis! I hope I've provided some light hearted banter in the process!

How does the 'seam' arise?

Jealous? Remo not putting out anymore?

I dont think anyone mentioned glass tube. Ive got four other carbon booms here & the one that broke is the only one that uses glass like that. I can accept glass used on mandrel but why is top layer there?