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Discussion Starter · #1 ·
For your collective amusement...


2x2x1/8th box (50.8x50.8x3.125) ad 1/8th (3.125mm) plates.

Plate the tops/sides/faces of the seatbelt turrets (b-pillars) and the boot floor above the rear suspension mounts. One beam across the top of the seatbelt turrets. Two verticals with 45 degree tops ad a top bar for the main hoop. Two rear stays back to the suspension mounts with a harness bar dropped between them. One diagonal running from the top driver's corner to the lower crossbar, and continuing from the lower crossbar down to where the seatbelt turret meets the horizontal bit of the body.

http://www.cosic.org.uk/MarkoStuff/handamx5/chavzda-rollbar/

Deeply deeply ugly, but functional for a cone car/works hack. *Just* clears the roof. A hoop further forward (between the two seatbelt turrent/b-pillar hoops of the soft top) and higher up would be nice, but I don't see an easy way of mounting it without interfering with the seat (driver's shoulder!) or the roof fold (the main hoop would be wider save for the ragtop frame)

Any other (functional) DIY hoops out there?

FWIW: Corbeau buckets are *terrible* seats, steer well clear even if they do fit. They're uncomfortable (all you feel is the tube steel frame of the seat) and dissolve in UV. Scroth harnesses are the tits though - fabulously easy to adjust compared with TRS sets I've had in a past life:

http://www.cosic.org.uk/MarkoStuff/Land-Rover%20T-Series/Series%20Land%20Rover%20T16%20Turbo%20Conversion/target86.html
 

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For the money you saved not buying a TR Lane or a secondhand Cusco for £100 made out of CDS, it hardly seems worth it!

On the positive, I suppose you had some strange sense of achievement from making it!


Though I wouldn't to take a roll in it!

 

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9 points, $20,000 and a lot of happiness.
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Surely if you think your going to need a rollcage that's the absolute last place "money saving" should come into the equation?

Especially looking at those welds


Rich,
Op is in the US not really much point shipping one of them things over when he's got HardDog right on hos doorstep
 

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Discussion Starter · #5 ·
Horses for courses really - the car was a hack-job for tooling about on the airfield near work and the rollbar was a betterthannothingatall-job with a length of box section one afternoon. Serves its purpose for cone-squishing without head squishing, or stopping you dying if somebody gently t-bones you onto your roof in town. You wouldn't use it on track mind! (harnesses were bought for something else and on extended loan)

Works car park... (satellite pic it)
http://maps.google.com/maps/ms?ie=UTF&msa=0&msid=102314509516659045267.000484078bd2a6412fe56

Did take a look at the hard dog kit whilst in the US (I'm UK based now) and wasn't very impressed. Only two of the hard dog bars are worth looking at IMO, and even then they're not inexpensive enough to warrant living with the faults. (as vs having your own bar made by somebody who can bend/weld tubes!) The various "hard bars" are really only any use for show or gentle cone-squishing, and would fold with any real roll.

http://www.bethania-garage.com/images/ab_2.jpg
http://www.bethania-garage.com/images/abx.jpg

Even then they ain't great:

The mountings are poor. The rears pick up on tinfoil rather than the suspension mountings, and the main hoop doesn't tie in the seatbelt turrets/b-pillars properly. (again it picks up on tinfoil - it should pick up on the inside faces of the seatbelt turrets/b-pillars, and the seatbelt mountings themselves with a pair of ears) Not going down to the floor is a good thing though, else you lose too much seat space.

The diagonals don't go to the right places. (they should go the corners of the main hoop like the rear stays do on the X-brace, or right down to where the rear stays meet the floor on the AB2 - pin jointed truss 101 - they've done it that way for ease/cost of fabrication rather than performance) Not killer, but so easily easily fixed.

They're vanilla CDS rather than nice alloy steels (again done for cost rather than performance - which is daft given that 80% of the cost is labour anyway) 15CDV6 is a great alloy steel to use as elongation to failure is huge (it'll keep bending and absorbing energy rather than cracking) and it requires no post-weld heat treatment (unlike the old school 4130 type alloys). Again easily solved.

It doesn't fit the roof particularly well/could be taller. Every inch counts, and if there's room for padding under the soft-top on a bar you're paying real money for then its too short unless you've got a 28" inside leg...

All better than nothing but not ideal.

Haven't seen a Cusco or TR Lane in person yet, and would like to measure one up. The TR Lane looks a good height (might just be the photos I've seen though) and has the belt tie-ins, but the main front hoop mountings are poor and the rear stays are both way too steep an angle and badly mounted.
 

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Discussion Starter · #6 ·
Gix, look at his Avatar and Signature, I don't think he's based in the US...
Was for a while. Older bro' went to work on the west coast, and bought younger bro' an absolute dog of a Miata to roll around in whilst he visited. Younger bro' liked it so much the first thing he did when he got back to the UK was buy an MX5. Now older bro' is back in the UK again and (surprise, surprise...) also looking for a 5!

The 'chavzda' with its $7 paintjob can still be seen in and around Alameda/San Francisco - gave it away when I left on condition that I can always borrow it again if I visit. :)
 

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Gix, look at his Avatar and Signature, I don't think he's based in the US...
Don't really give a shite what his sig says mate, that's a Cali number plate on a car photographed in the US.

 
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