Thanks for the comments guys.
I'll try and answer all your questions.
I have been using Mid Sole Cleats for for around 4-5 years now and I have been moving the cleats further and further back over the years until where they are now being the best position.
Technically they should go on your heal because that's where the power is coming from, but cycling like that would look and probably feel very silly.
I have raced and won races using my cleats like this, so it doesn't really affect my cycling in any way other than it feels a lot better and a lot more powerful.
As for toe overlap, its never really been an issue, you get used to it very quickly and its not like you're pedalling through dead turns all the time when you're on the bike anyway. Plus, smaller riders have managed to put up with overlap forever anyway, and they seem to be fine.
My only drawbacks to Mid Sole Cleats is that I have had to sell all my bikes and get smaller frames (I needed to drop my saddle height by around a few inches) and I couldn't use my shoes any more, hence the modifying of any shoes I could find.
So my 9 year old Trek 5200 was sold and so were both my Sidi Energys
I now use a Chinarello 47cm with a 160mm stem!
These are VERY stiff and there is hardly any flex when I put them over my leg and push down on both sides.
Believe it or not, but actually these football boots were surprisingly stiff already, just the front part/toe was flexible.
My first attempt at football boots were a very flexible pair of Nike R9's and you could basically bend them in half, you can't do that with the F50's.
Those were a bit of a nightmare to do with all the studs in the road and trying to slap the carbon on around them. I picked them because they had the flat bit where my cleat would go.
Those are my every day winter training shoes at the moment, as they're a size bigger and my heated insoles fit in them nicely
plus, having the laces means I haven't needed to tighten straps during a ride, a bit of a pain if you have overshoes on.
I can't remember how many layers went onto the R9's, but they are not flexible and I REALLY use huge gears up hill in training, and if there was going to be an issue with stiffness or carbon breaking, it would've happened a long time ago with those.
Buying the carbon etc...
Its just basic carbon (3k 2/2 Twill 195gsm) you should be able to buy locally, many starter kits should have more than enough to several soles.
I have learned that it is cheaper to buy thicker weave than build up several layers of thinner stuff.
For these, I used 7x 195g, so that's 1365g. I have just got some 650g carbon in the same weave and it was only a few pounds more expensive, which I don't really understand why!
It wouldn't make the sole thinner, just cheaper to do.
I am planning on using UD (Unidirectional) carbon on the next pair, as there is no need to worry about sidewards flex and so I should be able to use less, but I will still put a piece of 2/2 twill in top for looks.
Preparing the carbon to apply on the sole.
I have a flat piece of MDF and lay a strip of thin pallet wrap (PR) down (resin wont stick to that), then put a strip of carbon on that (smaller than the pallet wrap), brush on the resin, another piece of carbon, resin, carbon, resin etc... until all 7 were down, then what I'd do because I dont have any vacuum bagging equipment, was to put another piece of pallet wrap on top of that and then use a roller to force out any excess resin (you only want around 24% resin to carbon for strength). Not a great technique, but the best I can do with what I have.
When it is all squashed, you can quite easily get a pair of normal scissors and start trimming it a bit.
You don't want to go to mad trimming in case you mess it up, you can trim the rest after it has hardened with your drill.
All you do to apply is to peal off one side of the PR and then plonk it down on the sole.
Before I did that, I stuffed my shoe with socks and had some weights ready to put on top to help squash it together after I had wrapped the whole shoe with PR to keep everything in place.
I found that putting the shoe on a thick towel helped make sure it was even pressure all around.
When dry, you now have to cut the excess off which for me, was both side of the arch where the shoe curves in, and then a rub down with wet & dry before a clear coat to make it look better.
I could've spent ages making my soles flat and showroom like, but there is a limit to how much time Im prepared to waste on something that isn't too important, maybe on another pair though!
My other project Im doing right now is a nice pair of carbon mud guards for my road bike (I really needed them the last few days!), I hopefully will have them finished shortly
Oh, and I have just won another two pairs of F50's for less than what I paid for these, but for both! You've gotta love ebay sometimes