Yep go for an sj4000 wifi nice bit of kit for the money should see one in your hand with a 32g card an 2 battery's for around the £50 mark make sure it's a proper one not a copy of one they can be had for as little as £25 an are just cheap poo
Have a search and you might find one cheaper. They are great for the cost, have a read of some reviews. Batteries and accessories are cheap to replace. Can't go wrong.
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2004 TTR250. White Brothers E series exhaust, modded airbox, rejetted, 13/48 c&s & many more mods..
I'd get a Drift HD 1080p, its a few editions old now so can be had cheap (£50ish) and is still great quality. More bullet shaped so a bit better for biking. And is waterproof out of the box, doesnt need an extra case of anything. Comes with a remote for the handlebars so you can stop start recording. Been using mine for about 4 years now. Excellent quality!
Go pro session at £149 now! Got me a hero 3 black but if I was to have a second one it would be one of these, much smaller! (Promise I do thane shares trying to sell one!)
Though £149 is a bit more expensive that the above ones
2nd hand then look at VIO POV 1 OR 1.5 I have had one for over 10 years after using them at work [have seen them blown up an still come out working] it's a cable cam but you don't look like a tellie tubbie with it stuck on top of your head an the recorder slip's into a pocket with ease plus it has a remote the 1 an 1.5 are 720 but the video is good it will run all day on 4 aa batteries an a 16g card. I have seen them go on ebay for £50 or less as well I got a 2nd one for £35 on the ebay last year as the cable had broken on the one I had and they wanted £65 for a new cable from the maker.with all the gopro an gopro type cams sj4000 an drift type you need 3-4 batteries for a days run an you are lucky to get an hour an a half out of each battery an at 1030 the 32g cards fill fast as well so as said before new get a Sj4000 2nd hand the vio pov