What is wrong (or right) with thighbands?
Taz It seems to me that the current range of thighbands from all makers Tollyboy included are really a bit rubbish. I think in terms of comfort, wearability, security etc they are all lacking.
I'd start the process by looking at garter belt design. I think the locks on the front of the bands have got to go, but it's clear from users here that the bands do have to be removable w/o removing the whole belt. Eg, they're often just used at night. Maybe a step into and pull up design with Tolly style locks on the sides of the waist belt would give lower overall profile?
Jonas No that doesn't work the profile is much smoother but not overall lower. I used the small 4 pin cam locks in an experimental version. Looks better, smoother when the thighbands are not there but no D-ring on the side so nowhere to anchor a handcuff if required. When the thighbands are locked on the lock is about 20mm high and round so still quite bulky.
as an involuntary wearer i have to say that i find them just awful, but i'll try to shed some light on a neutral aspect and that is the noise level, if i don't want to be noticed in public i have to encase the chains in rubber, something could be done about that
Taz From there it is possible to get your leg out of it.
If you connect the chain to the belt (D-ring in the crotch), this is not possible.
Angelina Chains are a problem but also easy which is why I guess they are used by almost everyone. I am away from home at the moment and don't have chain to experiment with but have some ideas on how to stop it rattling. When I can I will try them and see how practical they are. Ultimately the chain needs replacing but then there are problems of connecting and adjusting it.
I can see another advantage (disadvantage) of partly supporting the thighbands from the D-ring at the bottom of the guard. As this is not in line with the centre of hips when bending forward or sitting down it will pull the connecting chains between the thighbands pulling the legs together. Good if this is what you wish to achieve but I guess this support chain gets a lot of urine on it when using the toilet and is hard to clean? If that is the case another design problem that needs fixing.
Jonas Front and back support would look nice when standing but when bending or sitting the front support gets shorter, the rear support gets longer but I guess not by the same amount. Will have to take a whole lot of measurements and think about it. Also whatever is supporting the back of it will get sat on so have to think about that too.
Taz but I guess this support chain gets a lot of urine on it when using the toilet and is hard to clean? If that is the case another design problem that needs fixing.
indeed, i always pee against the chain and have to clean it afterwards, but the problem would be easy to solve if i didn't have to wear this "additional fixation". 
Taz Chains are a problem
Why not use stainless steel ropes? It strength has to be high enough that you can't pull it apart. To withstand tools is another class. A rope doesn't rattle. It's job would be to prevent to get it off.
To hold the bands in place elastic bands in front and back would do it. They do not have to prevent the bands from being removed. They would expand and shorten when you sit down. I suppose if it the same type as on garter belts you will not feel much if you sit on them.
Taz No that doesn't work the profile is much smoother but not overall lower. I used the small 4 pin cam locks in an experimental version. Looks better, smoother when the thighbands are not there but no D-ring on the side so nowhere to anchor a handcuff if required. When the thighbands are locked on the lock is about 20mm high and round so still quite bulky.
As far as I see all women who wears thigh bands wear skirts during this time or be at home. To get the thigh bands on and off would following idea work?
The connection to the CB to hold the thigh band could have an end-device which could only fit in an opening at the waist band from top. At the thigh band would be a look where the cable is connected and hold the band in place. Also it prevent that you move the cable up to get it out of the opening in the waist band.
The fastening system can turn out relatively flat in opposition to a lock. The lock on the thigh bands is hidden by the skirts during the day and at night it does not matter how thick it looks.
To get the thigh bands off you open the lock at the thigh bands remove them and push up the connection cable out of the belt.
Taz I guess a plate over the waist band with a couple of threaded holes, attached by c/s screws from the inside. The hinge could be part of the plate or clamped by the screws.
Joh Yes that will work quite well but then you get the problem of needing a lock on the thighbands themselves further complicating that design. Tollyboy are just plain bands you step into them and pull them up then lock to the waistband. Result simpler bands but a bulkier attachment to the waistband. It is certainly something I need to consider.
Thighbands is a crutch. You don't need them with properly fitted belt.
Joh Stainless steel cable is good and for the force involved you would only need about 1.5mm diameter there is a possible problem. Chain is almost infinitely flexible cable has a minimum bend radius before you start cracking strands in it. It is possible that a sharp pull though the D-rings if the wearer tripped for example might bend it too sharply and crack a strand. These strands are as sharp as needles and cut like a razor. I have the scars to prove it. Whatever connector you put on the end would have to fully enclose the end of the cable not just loop it back and put a crimp on it with the end protruding. It is a good plan and I have built a belt like it in the past but it needs more work it isn't just a drop in replacement. I used very low profile connectors with the cable silver soldered into them where the annealed portion of the cable from the soldering met the non heat affected cable some of the strands cracked with time and flexing.
Taz I would use cable with PE, PU or PTFE jackets.
Soldering is a problem with cables. The flexibility is lost in this area. I would crimp a metal tube, with a thread at it end, on the cable. After fitting the cable trough the waist band screw a metal loop on the end of the cable which need e.g 5 turns. I suppose this is sufficient to get it not off if locked to the thigh band.