My Specialized Deviant full-facer was in the car a few weeks ago when it got hot… very hot. It was covered up and the sun wasn't on it directly, but the internal car temp was very high and when I used it a few days later, I've found that the outer shell has come unstuck from the thick foam inner shell.

The inner shell is currently being held in place by edging strips in the liner (front, back and sides) and the fact that the outer/inner shells are a good fit together. There's only a small amount of movement, so I haven't been unduly worried that its not safe but it is annoying to have it rattling so much. Upon closer inspection through the vents, I can see several large blobs of glue on the inner shell which must have been softened sufficiently to lose grip on the outer shell.

So, is it unsafe and a write-off? Or what glue should I be using to fix it? Cheers.

Wilko glue form Wilkinson's.

It's your head. Don't risk things with it!

Hmmm – if the liner is undamaged then thats the bit that does the work – all the shell does is hold the liner in place. However the wrong sort of glue could damage it – and as rolf says………….

How old is the helmet?
Ask the manufacturer? Probably the safest bet.

If you do reglue it use as innocuous a glue as possible – silicone sealant? Water based glue? Nothing solvent based for sure

I'd get on to specialized, whilst i'm sure heat damage is not the first thing you think of when designing a helmet. They may well replace it still as thats not good, for a company with all the R&D facilities like spesh.

Good ideas, I'll check with Spec to see if they recommend a glue or are concerned about other issues.

The helmet is a few years old so not under warranty but apart from this problem, its still got lots of life left in it. *Fingers crossed*, its not even scratched yet.

Few years old? Its due the bin then.

I agree with TJ – a few years old means you've already got value for money out of it. Can't believe Specialized would suggest anything other than the bin (particularly given they could attract some liability otherwise). I'd still contact them, as they may do you a deal on a new one.

Actually, Specialized reckon up to 5-6 years for a helmet. (Clicky) Admittedly I think I would prefer to replace mine before that, but this particular helmet is 3-4yrs old with <10 riding days done (its my bike park helmet, I use a XC lid most of the time). I'll contact Spec for their opinion.

What's the worst that could happen?

Response from Specialized:

"You can use any hot epoxy on those pads. Even a hot glue gun would work."

So off to the store to find some hot epoxy….