Roll cage tube specification thread - MSA & FIA info

Discussion in 'Track Prep & Tech' started by A.N. Other, Oct 31, 2009.

  1. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Agree - 50mm stands out a mile.

    Some non-race cars, ie track cars, are being supplied with T45 at the (paying) customer's request. I believe the cage suppliers can supply whatever's asked of them, because the gatekeepers are the MSA Scrutineers.

    /reaches for Blue Book
     
  2. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Some more info found here:

    http://www.customcages.co.uk/roll-cages/certification

    Also some info on Safety Devices' site here

    I think the the SD page is irrelevant through, because it's all about International Competition, pre and post 1 Jan 2003 (I think the first date is a typo).

    As regards T45 use, it then comes back to what's in article 253 (link in post 1) / or the Blue Book equivalent (ie the first Custom Cages para above).
     
  3. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    From post 1:

    [​IMG]

    Hmmm, 'Minimum'. That's got to be where the answer lies. If T45 is deemed to be above the threshold of the minimum 'material' & 'yield strength', then logically it should be ok? Provided it meets the minimum dia and tube thicknesses given?

    So T45 used in cages not FIA certificated / not given a Letter of Conformity suffers a weight disadvantage, agaist thinner tube used in FIA/Conformity cages?

    So it'll gain the 0.5 kg per metre of tubing (or 10 - 15%) T45 weight saving over CDS which pascal quoted in his Audi thread, but there's no scope to lighten any further through thinner tube?

    I've just checked 1992 and 1997 MSA Blue Books and this text hasn't essentially changed since then.
     
    Last edited: Jun 3, 2011
  4. Hamish Forum Member

    Joined:
    Apr 18, 2008
    Likes Received:
    0
    An interesting question would be who has ever had there cage tubing drilled by the scrutineers?
     
  5. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    From post 1

    Just dug out:
     
  6. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Just to add a little more to the discussion, I came across the ex-Dialynx Audi A4 at the weekend, and the owner kindly let me roam with the camera.

    The first thing that struck me was the diameter of the door bar tube. After looking at many cage tubes, it stuck out a mile as being smaller dia:

    [​IMG]

    Estimated 40mm

    [​IMG]

    But the sticker, bottom right ^^ I believe is the key:

    [​IMG]
     
  7. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    MSA cage certification sticker from Johnny Herbert's Team Dynamics BTCC Civic:

    [​IMG]

    The cage - a combo of diameters involved:

    [​IMG]

    [​IMG]

    [​IMG]
     
  8. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    From post 1:

    Interesting potential developments on this.

    I called the MSA today to ask whether roll cage additions on non-hologated cages still had to be per minimum spec given above. The answer was 'yes', ie every single piece of tube in a non-homologated cage must comply.

    However, tomorrow the MSA are having a meeting to discuss reducing the minimum requirements of additional tubing (ie dashed lines and additions in the Blue Book, diag ) down to FIA-spec.

    The non-dashed lines of the cage in the diags below must be to 45x2.5 or 50x2.0 in the UK:

    [​IMG]

    This is not tabled for amendment.

    However, the FIA allow more flexibility on what is allowed beyond the "main cage" structure (in red):

    This is what the MSA are discussing.

    This potentially means weight can come out of some cages, without the need for them to be homologated.

    The answers on this will be known in the minutes next week, with the following possible outcomes:

    1) Rejected.
    2) Deemed safe, allowable immediately, and reported in the MSA Magazine to competitors.
    3) Put into a consultation period, which coud result in 1), or being implemented from 2011 onwards.

    The upshot of this is that if you are designing a cage now, then stop, and wait to see what happens, because you might be able to install a lighter one :thumbup:
     
  9. danster Forum Addict

    Joined:
    Apr 2, 2008
    Likes Received:
    7
    That is interesting to note the differences between the MSA and the FIA specs.

    With regard to the smaller diameter material allowed for the main cage pre 95 : Is that relevant for cages produced, or homolagated pre 95?
    Does that mean a cage could still be produced in the smaller diameter tubing today as it was homolagated pre 95?
    When I bought a few bolt in cages from Safety Devices back in 97, golf mk2, sierra and pug 205, only the pug 205 cage came with a 50mm main hoop and all other tube for the rest of the pug cage and the entire golf and sierra cages was 40mm.
     
  10. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    I think it's fairly safe to say that the only reason the provision is left for those pre-95 cages is to avoid a retrospective ban on hitherto eligible cars. Any workaround isn't what they're looking to sanction, but if someone can create a workaround, or comes across a cage from long term storage, it might be usable.

    I suspect the cages you got from Safety Devices were MSA certificated or FIA homologated? If so, they sit outside the material specs outlined above, which only apply to non-homologated cages. The minimal non-homologated material specs, per the MSA Blue Book, are the same in 1997 as they were (at least) yesterday.
     
  11. danster Forum Addict

    Joined:
    Apr 2, 2008
    Likes Received:
    7
    Yes, all three cages were homolagated (pretty sure it was FIA) and came with a special sticker and serial no. The sticker was black and silver and about 40mm x 60mm IIRC.

    It will be intersting to hear the outcome of the meeting and if it changes some of the tubing specs.
    It is a bit of a grey area though depending on what race / rally series or event, and scrutineers interpretation of the rules are.
    More than half the race and rally cars I have seen (lots), being built or repaired, fail to comply in some way or another, sometimes very obviously, yet compete regularly so get through scrutineering ok.
     
  12. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    The MSA:


    Definitely. There are the rules, and there are the people that enforce them.

    I remember a Peugeot 205 which had had a sill impact, and the lowest part of the B-hoop had been cut and repaired with new tube :o Newly-built car and the driver was loathed to scrap it. Just an example.

    I have to say some of the scrutineers I've come across weren't the sharpest knives in the drawer. The MSA has a lot of potential liabilty to insure against, and the people on the front line, charged with doing this are lowly paid/volunteers from a variety of backgrounds. Personally, that's not my idea of well-managed risk.

    Anyway the original purpose of the thread was to help people with self-built cages. Seems to have inadvertently turned over a rock in the process!
     
  13. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Latest on this is that the proposal was put forward to allow non-mandatory roll cage tubes (see diag 37 above) to be of a smaller diameter, as per FIA.

    This now moves forward to consultation and *caveat: if successful* a Blue Book amendment may be issued via the next MSA magazine, which could mean it is allowable from that point onwards. If not, 2011.

    So don't build anything new until you read it for certain, but it's worth holding off if you can.
     
  14. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Just to rather belatedly confirm the outcome of this.

    The optional reinforcing members have had the minimum dimensions reduced to:

    38mm x 2.5mm
    or
    40mm x 2.0mm

    This is not in the 2011 Blue Book, appparently because it went through after that was printed.

    The non-optional cage dimensions remain as before:

    Note this is all CDS, covered earlier in this thread.
     
  15. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Following vw_singh's roll cage installation, we now have more insight into the tube thicknesses of a certificated roll cage. The info below shows there are clear weight savings to be had by buying a certificated cage, rather than falling into a situ whereby you have to stick with the stipulated DIY minimums for all tubes outlined in the last post :thumbup:

    More info / full cage installation thread here.
     
    Last edited by a moderator: Dec 21, 2013
  16. 16valver Forum Member

    Joined:
    Jun 30, 2005
    Likes Received:
    164
    Location:
    Aberdeen
    Chris, does whether a car has been previously MSA log booked have any effect on this?

    I.e. one that has been ok to race in the past with that particular cage, is still ok now?

    Ali
     
  17. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    I don't know on that I'm afraid. I can't think why it would be relevant for a non-road legal sprint car (hence log-booked), turned racer.
     
  18. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    These look handy:

    [​IMG]

    Click
     
  19. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Adding this here, as it's been discussed in the past, but I can't recall where.

    A picture I've been looking for for a while, and I screen-grabbed it off a video posted last week. Pretty self explanatory, giving the forces nowhere to go as the front upper turret stay is un supported with a door bar:

    [​IMG]
     
  20. R.b!n_16v Forum Member

    Joined:
    Nov 3, 2010
    Likes Received:
    1
    left suspension strut hit back and took the cage with him... probably would not have happend if the cage wasn't atached to the suspension strut. So you see the construction and placing of the tubing is really important.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice