I’ve seen this TR Lane roll bar and it says it can fit under a hardtop but my head is less than an inch from the roof and is over the top of the seat as I am 6ft tall and so with a helmet on would still be in danger of some ground-to-head action, is there a seat and harness combination which will allow me to stay below the roll hoop and so not have my head explode like a melon on contact with the tarmac in the event of a roll?
http://www.ebay.co.uk/itm/MAZDA-MX5-DAYTONA-ROLL-BAR-TRL-PERFORMANCE-/200795713355?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2ec05b6f4b
Are there any other hardtop friendly alternatives to this particular design of the TR Lane bar, as it doesn’t look like it would ‘go with the flow’ if the car rolled, it looks as though it would ‘dig in’?
Check out Peleton72’s guide to roll bars its handy . Also get in touch with TR lane themselves they have a great line of products and are very helpfull, i’m also tall and they do make a bar that fits under a soft top that is slightly higher . Ive tried a bucket seat and because of the box section in the floor they just dont fit low enough. The standard seat actually sat me the lowest .If a seat manufacturer made a bespoke seat that dips behind the box section then i’m sure a good inch or more could be found, most bucket seats are flat bottomed and only fit as low as the box section . It is a difficult car to get low enough in if you are tall and still need a roof to fit to keep out the rain .
good luck and if you find a bespoke bucket seat on your travels let me know 
I had a look at the guide but I couldn’t see exactly where the head of the person who sat in there would be, on your TR Lane bar where does your head sit in relation to the top of the bar?
I’m just worried that in the event of a roll the standard seatbelt wouldn’t hold me firmly enough to prevent my head going over the rollbar. I know it’s all ‘worst case scenario’ but I don’t want to bother buying a TR Lane bar if it doesn’t work even hypothetically. I’ll send them an email about it.
A couple of quick pics for you .
One of the line from the roof to the roll bar with me sat in the car at six foot tall . Also personaly i prefere at least this roll bar with its diagonal cross brace and four legs (i dont really like the single hoop one on e bay ). If you are doing track days then i would also recomend a harness to hold you in place and not just the standard seat belt .
This is all a compromise as i also need a roof to go up . Another make of bar will be no better hight wise,because if you need a roof to fit ontop you are simply restricted in how high you can go by the roof. A full cage is the safest with a proper race seat and harness but then you can’t put a roof up in the rain . It all depends and what your going to do with your car.
Although ive got the full harness for track days ive kept the standard belt for easy road use .
That’s perfect, thanks very much!
I think if I got the roll bar I’d also get a bucket seat as I would worry about the shoulder of the harness coming off in a violent roll or side impact. Tim said he would get back to me tonight about the roll-bar but, as you said, there isn’t a perfect option when you have to take a hardtop/softop into consideration as well. Is yours a TD bar?
My bar is a GP with cross brace and also the harness bar is fitted.
Just to add an edit . I’m Sure i read somewhere that its possible to take out the box section in the floor and then bolt straight to the floor saving you an inch or so in head room . You may need to strengthen your floor anyway if bolting in an aftermarket seat, so it might be worth doing some homework to find if the box section can be removed. This would make a difference when buying as seat as to wether you buy a side mounted or bolted in from underneath type of seat. (i’m sure somebody on here will know ) . have fun anyway
Depends what you want from your roll protection, but that is a good looking bar, cobra/jaguar style.
Will it offer protection in a roll? Got to be more than the windscreen pillar alone but yes, if you’re planning on going trackside and manage to flip the car in the gravel, no amount of steel tube is going to stop the car sinking in and your head meeting terra-frma.
Maybe you should look at it like this; if, IF, your car was to turn over, anything that keeps you away from the ground is a good start. And TR Lane is a good place to find that good start…
I think I’m right in saying that all Tr Lane bars are compatible with soft and hard tops, I have their full cage and can still get the roof up.