The surface of the inside of my helmet, and some of the adjustment band has become sticky and seems to be in the early stages of dissolving. The only possible cause I can think of, given that its not been that hot, is that a liberal application of sun screen to my head may have caused a reaction. The helmet is a standard Hex, and the sun screen alcohol based. Either that or maybe I have acid sweat!

Any one else similar issue, and if so suggestions on how to avoid stripy, helmet ventalation slot sized, sunburn stripes please.

It’s your sweat mate…its quite corrosive. Happened to a few of my lids…and just noticed it also strangely on a arcteryx climbing jacket i’ve had a few years.

I carry on using mine for a long time after it gets sticky…but eventually its time for crash replacement land.

My old Hex did that too. It lasted ages after I first noticed it though. Got retired after about 5yrs use.

Edit: just noticed that in my new Hex the rocloc is all solid plastic rather than rubbery. Might not get sticky.

you had insect repellant on?

Not insect repellant but factor 50 sunscreen. The helmet is still tacky which suggests a chemical reaction which is ongoing. Covered the patches in chalk in the meantime.