Camera recommendations?

i have a drift ghost x on my helmet, but you can attach it to the bars with kits if needed. Battery life is 5 hours, or 8 hours if you buy the bigger battery pack. 1080p. paid 110 quid. not very big either. About the length of my index finger. 

I have a couple of Polaroid Cube cameras on my bike, they're only £35 each. They'll do 1080p30 and overwrite old files. I use a USB power bank to get round battery issues.

The problem with cameras is the battery life - You can use the go-pro and the associated knock offs on Amazon, but you will get an hour at best out of them on max settings - The advantage of the Cycliq cameras is you will get at least 5 hours out of one on the max settings and as posted below mine sits under my Garmin mounted out front and I don't notice it. I won't go out on a training ride or commute without my Fly 12 or 6.

There's no way I'd put a go pro on my head after the Schumacher accident.

I use https://www.mobius-actioncam.com/faq/ this camera on my helmet and one on the seat post. I use the 2 cameras on all of the fleet. They're cheap but give good quality shots and I run them from external batteries as many of my rides are around 3+ hours.

I've got a GoPro Hero 3 mounted the same way as the Fly12 (in the photo; under the Wahoo computer).  Has given me great service for many years (bought 2015-good investment) primarily to record memorable rides (normally classic alpine climbs); I turn it off/on to preserve battery life and reduce the amount of editing needed to create a short movie.  As a front security camera it isn't great as it doesn't record over footage (loop) and the battery life is limited if you run it continually; new GoPros could be better and spare batteries are easy to carry.  GoPro picture quality is excellent; mine hates the cold which reduces the battery life.  Also good for recording other crazy activities.

For commuting security I've used a Fly6 on the rear which has been excellent, although my original packed up after 2-3 years so needed replacing (reliability is important as these things aren't cheap).  New Fly6 reliability good so far.  I had a Drift Stealth 2 (helmet mounted-discontinued as far as I can tell (reliability poor)) for 2 years but the battery has died (internal; no recognised replacement, although some on-line replacement 'hacks' - safe?...don't know).  Helmet mounted was good as it recorded where you are looking (potentially straight at the a##hole motorist threatening you).  I'm inclined to get a Fly12, based on the strength of the Fly6, and mount it under the computer as there aren't many decent low profile (reliable?) helmet cameras out there as far as I can tell.

I guess the Aldi (Balco) action camera will be too big? But at £50 I'd love to know if anyone has experience of it on a bike.
https://www.aldi.co.uk/balco-4k-ultra-hd-action-camera/p/700972317715600

I had a Fly 12, it did what it did OK & I didn't have any issues like some others but it was simply just too cumbersome IMHO. I had it mounted the same as Spangly but cos of it's size it just got in the way of the cables on my bars when I was trying to switch it on or charge it.

Sold it & got a GoPro 2018 which is much neater. You can just about squeeze 2 hours battery life which is a bit of a bind if you're doing a ride longer than that as you end up carrying spare batteries which I wanted to avoid but I'd rather have that than the Fly 12.

The Fly12 can be made to look quite elegant, at least I think so.