Helmet Checking

[Mr. Dazzle]

I wouldn't use that Shoei.

You can't see out of it!

[Count Steer]

The mechanism behind stress risers is also a surprisingly powerful phenomena, well worth Googling because the underlying principle for force magnification is actually quite interesting.

S'why glass fails under tension and is incredibly strong in compression. Microscopic surface discontinuities act as stress raisers. Under compression they just close up and you observe the real strength. Toughened glass has quenched surfaces so the surface and the little elliptical 'cracks' are in compression so only act as stress raisers once the compression is overcome. You can flame polish it too iirc.

Once a crack starts to run glass fails catastrophically ie is brittle because there's no way of distributing the energy through sliding planes of atoms 'cos it's amorphous. The energy balance occurs through creation of new surface/air interfaces so the more energy in, the more the running cracks bifurcate so the more bits of glass you get.

Glass composites make the most of the strength of glass and uses a matrix to absorb the energy. If you pull a fibre fine enough it's too small to have the surface imperfections so fibres are v strong too.

All that....and you can see through it too! Cool stuff is glass.

Yrs. Glass Nerd.

[Mr. Dazzle]

Glass fibres always strike me as a bit freaky. You can tie them in knots, knit them and make wool out of them. It's the same glass as you make windows from though, give or take.

Funny thing, scale.

[Bigyin]

Not that I want to start a helmet war and how much is your head worth and crying from the fashion police but
These are 50 quid delivered
https://www.ebay.co.uk/itm/303861575607 ... Sw7dZgEBP9 and get 4/5 on the sharp rating.

They're comfy enough. Are they safe enough?
One of the better (imo) visor attachment systems, durable anyway.

Seen them exact same design and set up under the name of Nitron helmets.

For info i had the flip up version of the Box helmet shown as it seemed a bargain so how bad could it be. I wore it a few times and hated it. Mechanism on the flip up was poor and failed to lock in quite a lot, visor wouldnt seat properly no matter how i adjusted it, vents were shit , the drop down tinted visor was almost clear so useless against sunlight and the helmet just felt cheap and not comfortable at all. It now sits in a helmet bag at work as a "only in an emergency spare" as its ECE2205 certified

[Count Steer]

Glass fibres always strike me as a bit freaky. You can tie them in knots, knit them and make wool out of them. It's the same glass as you make windows from though, give or take.

Funny thing, scale.

That's because of the flaw thing mentioned above. Final glass nerdism - as mentioned above the energy balance on fracture occurs through creation of glass/air surfaces/interfaces. The reason you wet the nick you put in a glass tube before breaking it (as perhaps you would in the chemistry lab) is that the 'surface tension' between glass and water is different from that of glass/air so less new surface is required to maintain the energy balance. You get an easier, cleaner break. The water, in essence, lubricates the fracture.

On topic. The scuff on the helmet chin bar could be smoothed out without losing much in the way of integrity. It would have to be properly coated/sealed - to keep moisture out I think. Same with the scuff on the top. Properly done I wouldn't have a problem using it. Probably keep it as a spare though.

[DefTrap]

Not that I want to start a helmet war and how much is your head worth and crying from the fashion police but
These are 50 quid delivered
https://www.ebay.co.uk/itm/303861575607 ... Sw7dZgEBP9 and get 4/5 on the sharp rating.

They're comfy enough. Are they safe enough?
One of the better (imo) visor attachment systems, durable anyway.

Seen them exact same design and set up under the name of Nitron helmets.

For info i had the flip up version of the Box helmet shown as it seemed a bargain so how bad could it be. I wore it a few times and hated it. Mechanism on the flip up was poor and failed to lock in quite a lot, visor wouldnt seat properly no matter how i adjusted it, vents were shit , the drop down tinted visor was almost clear so useless against sunlight and the helmet just felt cheap and not comfortable at all. It now sits in a helmet bag at work as a "only in an emergency spare" as its ECE2205 certified

They must be different because the box bx1 I've had for at least 5 years is absolutely fine. Certainly no issues with the visor, nor comfort. It reminded me very much of the old shoei I had 15 years ago, a fairly old fashioned design but solid enough. It doesn't have a drop down tinted visor btw.

[The Spin Doctor]

Seen them exact same design and set up under the name of Nitron helmets.

For info i had the flip up version of the Box helmet shown as it seemed a bargain so how bad could it be. I wore it a few times and hated it. Mechanism on the flip up was poor and failed to lock in quite a lot, visor wouldnt seat properly no matter how i adjusted it, vents were shit , the drop down tinted visor was almost clear so useless against sunlight and the helmet just felt cheap and not comfortable at all. It now sits in a helmet bag at work as a "only in an emergency spare" as its ECE2205 certified

Did you mean Nitro?

I have a full face, ACU-approved Nitro for the track and it reminds me very much of my old Arai Giga 2 in terms of shape, fit and comfort. It's extremely well finished, quiet (ridiculously quieter than my Shoei flip) and if I'm picky only the vents don't have the quality feel of the Arai. It was about £80 when I bought it and boxed it for a few years. We also had some of their polycarb lids for the trainees and after two years when we changed them, they were all in far better condition than the AGVs they replaced.

Having said that, when I needed a new flip for work (having abandoned the Shoei as too noisy), I tried a Nitro in a dealers and it was pretty horrid and went straight back in the shelf. I wouldn't have said it was made by the same company.

[Bigyin]

They must be different because the box bx1 I've had for at least 5 years is absolutely fine. Certainly no issues with the visor, nor comfort. It reminded me very much of the old shoei I had 15 years ago, a fairly old fashioned design but solid enough. It doesn't have a drop down tinted visor btw.

It was this one , the SZ-1 .....its now discontinued

Did you mean Nitro?

Yup, my bad, Nitron are the suspension company

We used them for trainess pre covid along with budget Tuzo helmets

[Felix]

I have an Aldi Crivit flip up thing that i use now and then as well as a standard solid one for what brand i dont remember. I have to put them on as its low and i hate not being able to see when riding faster due to eyes watering.

[iansoady]

I've been using Nitro open face helmets for about 15 years and found them comfortable and well made. Never road tested them however. Sadly they seem to have discontinued the x512 model which is the one I like.

Having sadi that I did buy one mail order which had a defective fastening and had great difficulty getting the supplier to replace it. Not the manufacturer's responsibility however.