How the Hell do I get this over to Ds?

[solo]

Ds will be 12 next month; his grandma has just bought him a new bike. He now wants to go out on it without his helmet as the other arsey kids will take the p ~ which I know they will, but I want him to be safe.

We are just at loggerheads over this. He says he'll stay on the green with no helmet on, but if he wears one, he wants to go off to a local park which I don't want him to do as there are some undesirables there and he's more likely to end up bikeless there.

I ride a motorbike; I wear a helmet (obviously) when I do and so does he when he's on the back and says he wouldn't dream of not doing so.

How do I get this all over to him? I've been straight with him about the facts and possibilities of head injuries and even fatal injuries, but he thinks his street cred is more important.
I'm going to lose it soon and ground him and he finished a 9 week grounding just yesterday...ARGHHHHH!!!

Any idea's on just how to get over to him would be gratefully read and digested.

Ps. I may not be able to come back to read any answers until late tonight or tomorrow.

Actually, I've stuck to my guns today and after about 6 hours, he's relented and is out on his biuke wearing his helmet. [grib] Maybe it'll catch on!

Google images, there's some nasty pictures there.

We all wear helmets and have a very firm rule "no helmet, no bike." Tough I know and sometimes they try to grind me down 14 and 7 but I just stick to my guns.
The only exeption to the rule is when we are on a campsite and they ride on the grass and hardly any cars around.
Well done for sticking to it today, you have won the first battle in what could be lengthy war.

show him pictures of Race across America, the Tour de France etc - they all wear helmets... for good reason --- and a few pictures of head injuries might get the point across if all else fails.

I showed my kids the xray of DH's leg complete with broken tib and fib and metal pin and screws - he got hit by a car, hit and run, about 15 years ago. "This is what happens when you get hit by a car children, so what do we do? We look and L I S T E N.... lol"

I'm quite lucky with my kids, well it's pretty harsh for me to say lucky actually; allow me to explain...

I love my kids to go out cycling, they enjoy it and do it frequently so myself and my wife want them to wear helmets at all times. We had to be quite forceful with our 12 year old son, who, as usual, said it wasn't cool (I can actually relate, I always hated wearing my helmet when I was a kid).

I was talking to a friend of mine about it just casually in conversation, and he replied with "I never did tell you how I lost my sight in my left eye, did I?" It turns out he fell off his bike when he was 13 and cut off his optic nerves going to his left eye. He very kindly offered to speak to my kids about it, so we thought about it and then I let him.

Basically, he got my kids together and, in a quite down-to-earth manner, explained that he too hated wearing helmets too when he was young but then went on about his accident. Now my kids insist themselves to wear a helmet, even the 12yo (who even tells his mates the same story, and they all wear them now too!)

So maybe a little bit of scare-tactics? Perhaps it's a bit unorthodox, and I was worried that it'd put them off cycling; but the results are fantastic!

Thank you all for your ideas.
I caught him out twice with the straps up and tucked into the grooves and I told him he was grounded for a week...he's now sworn to wear it properly. We'll see!

I am going to do some googling for some graphic scarers too.

Whilst I was calling for him to do up the straps the first time , one of the younger girls was listening in, so I told her that one of my friends Ds ended up with his brain on the pavement (I made this up btw) and that's why he (Ds) has to wear it...I went on to say that she too should be wearing one. He reply was that she was old enough now not to have to wear one!!! she's about 9. I said 'Oh! I must be too young then!' This is part of the reason why kids don't want to wear them, because it's not cool and because they are 'big enough'. Makes me mad!