Rollcages tubeing, which kind ?

[greenstream]

When reading the Alrc.regulations regarding tubeing for cages it is stated that it could be "Blue Band" to BS1387.

Most people go for CDS overhere (Denmark), but I would like to try other obtions as I understand that CDS requires a drawbender and this and the tube is a little spendy.

So I would like to know what blueband and BS1387 is, perhaps according to DIN or another international standard.

Cheers

Morten

[greenstream]

Well well - the world wide web is a great thing - when used !

Blue Band: DIN2448

BS1387: EN10255:2004

L2 = Light

Medium = Medium

Heavy = Heavy

Please correct me if Im wrong !

M

[Hybrid_From_Hell]

Key differences are strength and weight

Blue band BS1387 Corrus - starts life as flat sheet, is then formed into a tube and welded entire length

As such the strength is poor compared with CDS

also on bending the welds being harder than the steel, can either deform / shows signs of tearing or both

Blue Band is the medium and is heavy red band is the thick abnd silly heavy

48.3mm OD and 3.2mm wall (from memory )

CDS

Is 50.2mm and thinner wall, 2.6mm (from memory again )

Starts life as a draw out tube, bo welds, also reputaed to be a higher grade of metal

No seam weld = stronger, and at 2.6mm wall a hell of a lot lighter

Yer pays yer money.

I have had a big roll in a BS1387 racer and my old hybrid, cage did its job

CDS is better - end of

WELDS qulaity penetration and mounting plates etc are all key to a safe cag whichever you use

Frnakly now with the likes of North Off Road you can buy a CDS cage for not much more than trying to DIY it in Seamed tube, and it will

save you a fortune. Unless you have pratise in tube bending your 1st cage will be a mess !

Been there done that, but that long ago everyone had to make cages !

Nige

[greenstream]

Thanks Nige

Blue Band DIN2448 is OK in Denmark, can get it not welded - but heavy.

BS1387 is not OK as is welded.

CDS is OK in Denmark, not welded - and light.

As per weight, then I'll be shaveing 10 kg. using CDS compared to BlueBand DIN 2448

And this leaves me with the choise of a drawbender.

To buy of the shelf is not an option as its not a standard cage.

Might be looking at it as an investment ;-) and we all start out from somewhere...

[daveturnbull]

What are you using the vehicle for?

Slow events - blue band should be ok, but CDS would be better.

Speed events - don't even think about going anywhere near blue band. I've seen many a bad comp safari roll; red band will save your life, blue band will have you killed. CDS has good lengthwise strength, but the tube will crush easily if presented very suddenly with a large tree.

Do you need a custom cage, or will a pre-bent kit one fit your car?

If custom, as you say you can't bend CDS without some expensive tooling. Red band you can do with a basic hand pump hydraulic bender. The pre-bent kits will nearly always work out cheaper in time & cost of tube.

[greenstream]

Dave

Some of the answers is in the above reply.

Have just discovered that the regulations we use, states that it has to be CDS, all though this is taken from the Rally-guys, where we are organized. But when it comes to construction, then we are using Arlc-regulations - makes you wonder.

M

[Dave W]

The biggest "weakness" of Blue Band other than weight and construction is the formulation of the steel. I can't remember the precise lengths/quantities as it's a loooong time since I looked at this in any detail but from what I remember...

The BS requirement for Blue Band requires a minimum carbon content percentage over something like a 10 metre length (maybe longer). This means that the steel can be inconsistent as the carbon content of the steel can vary considerably along any given length and still meet the BS requirement. The variation in carbon content means that it is acceptable within the blue band specification to have weak spots with very low carbon content. I've seen some evidence of this both when bending it and also in finished cages that have been involved in minor impacts.

I wouldn't use ALRC specifications for anything, the paper isn't even that soft, You'd be better off looking at FIA regulations or MSA unless you anticipate competing in an ALRC event. Most of the ALRC clubs don't even use the ALRC regulations !

[Hybrid_From_Hell]

I wouldn't use ALRC specifications for anything, the paper isn't even that soft,

:hysterical: :hysterical: :hysterical: :hysterical: :hysterical:

[jai_landrover]

I'd rarther a Blueband cage that'll take knocks. Seen a few CDS cages deform badly enough for them to be told to go home and rebuild the cage whereas blueband cage has taken serious knocks and no hit of deformation.

If i was racing out and out weight is a consideration and hitting stuff is to be avoided then CDS but for trials and a bit of racing Blueband all the way the guys face when he was told cage is bent go home and fix it mde my mind up there and then after 2 Blueband cages hit the same tree and bounced around it for a clear and the CDS took what looked like a far less hard a knock and it deformed the main hoop.

[jai_landrover]

So your saying that ALRC idnt MSa regs?

[RedLineMike]

I'd rarther a Blueband cage that'll take knocks. Seen a few CDS cages deform badly enough for them to be told to go home and rebuild the cage whereas blueband cage has taken serious knocks and no hit of deformation.

at last some sense in here,

main reason why my spaceframe is made from blueband instead of cds,

[greenstream]

Hi guys - thanks for all of your replys.

Just to clear thing up

The difference in Red and Blue Band is the wallthickness of the tube ?

Could anyone point me in the direction of FIA and MSA - specs ?

M

[zim]

I've had a number of rolls / backflips in my CDS cage (dan and boothy - keep quiet here !) and it's not deformed. I do have the odd "dink" in places where i've landed on a rock or tree, not sure how a blue band cage would look now - but i'll be staying with CDS on my next one - regardless of price.

G

[RedLineMike]

I've had a number of rolls / backflips in my CDS cage (dan and boothy - keep quiet here !) and it's not deformed. I do have the odd "dink" in places where i've landed on a rock or tree, not sure how a blue band cage would look now - but i'll be staying with CDS on my next one - regardless of price.

G

probably very much like your cage but without the dents & dinks

[landroversforever]

Why not a thicker wall CDS??

[RedLineMike]

cos then the weight saving is lost,

CDS is a "nicer" material than blue band, T45 is a nicer material than CDS, however nice they are & strong they are on paper it doesnt account for the fact we do things to the tube that the manufacturers didnt design the tube to do,

going racing & having an internal cage then IMHO CDS/t45 is as good as it gets, for an external cage then unless you use the thick wall cds you are no worse of using blueband as its much more resiliant to knocks & impacts,

i know of 2 truck cab cages made from T45 that have had to have major repairs to them,

1 vehicle was rolled & the other was lent on a tree hard, if they were blueband or thickwall cds then i very much doubt that they would have needed the repairs,

i am also aware of a cds spaceframe that had a lie down at the decider & resulted in bent sidebars & the tube torn away from the welds,

my own spaceframe which is built from blueband has been over couple o times now & have hit trees "hard" & as yet there isnt any damage or dinks & dents to the tube,

its all swings & roundabouts but to say that blueband shouldnt be used & will get you killed is utter rubbish,

[Hybrid_From_Hell]

Cages from CDS that deform where "Blue Band" would have been "OK" is where a thinner CDS Wall that 2.6mm has been used.

CDS is available in a range of ODs and Wall thickness, std cage spec for a LR would / should be 50.2mm OD 2.6mm wall, And still a wieight save overall, and a huge

strength increase as well. Blue band and red band the difference is the wall, from memory 3.2 vs 5mm ? Red band is super ferkin heavy stuff, roll with a cage built from that

and the earths rotation is lible to be moved a few degress

Blue Band Build cages are often sneered at - no reason, I would rather be in a big roll in a proper built Blue band cage with good gussets and proper welding, than a poorly built CDS one

Nige

[greenstream]

"Cages from CDS that deform where "Blue Band" would have been "OK" is where a thinner CDS Wall that 2.6mm has been used"

Thats what its all about !

Now where to find the MSA ans FIA spec. ?

M

[forkrentfitter]

go on the racmsa website for blue book spec.fia is found in the yellow book,do you know any one who builds rally cars in denmark?they should point you in the direction of the yellow book.

[Dave W]

So your saying that ALRC idnt MSa regs?

No, ALRC made up their own regs. There is some overlap in design as many of the ALRC cage designs were shoehorned into the Blue Book at the last minute when the ALRC suddenly realised all their cages were about to be made none compliant. The ALRC mounting systems and requirements are very different to the MSA and FIA requirements. As an example, my Range Rover was fitted with an FIA and MSA certified CDS roll cage which meant I could take part in Hill Rallies etc... however ALRC regulations meant I couldn't take part in ALRC trials unless I added an additional cage made out of Blue Band and welded a bloody great girder across the rear floor.

The MSA Blue Book is available here...

http://www.msauk.org/site/cms/contentviewarticle.asp?article=1122

[dirtydiesel]

CDS is available in a range of ODs and Wall thickness, std cage spec for a LR would / should be 50.2mm OD 2.6mm wall, And still a wieight save overall, and a huge

strength increase as well. Blue band and red band the difference is the wall, from memory 3.2 vs 5mm ?

Bs1387 medium (blue band) is 48mm od 3.2mm wall 380nm yield

Bs1387 heavy (red band) is 48mm od 3.6-4mm wall 460nm yield

The msa minimum is 350nm

i don't have any exact spec for cds.

I'm pretty sure, 50 x 2.6 cds exceeds 350nm

But..... only when it's undamaged,

2.6mm wall tube deforms alarmingly easily on heavy contact with trees and rocks.

so although a (50x2.6) cds cage will exceed the spec when "new", who knows after a few light rolls and some tree contract?

I believe that for our use* cds is unsuitable.

Our use being multifunctional roll structure, that we expect to sustain multiple rolls as well as hevy contact with trees and rocks.

Cds seems to work harden and crack when beaten badly,

Bowler had to cut the lower cds chassis rail tubes out of early wildcats and replace them with blue band.

Simbugini chassis rails are a single large diameter (80mm?) seamed tube

And the rakeway ridgeback is a cds upper structure built upon a pair of blue band tubes.

[jai_landrover]

OK so ALRC Specs are not MSA but if you build to ALRC Specs you will exceed minimum regs for 99% of the events, Plenty more 6mm plate and stuff but if you build your cage to ALRC Specs you can pretty much take part in any event??? ALRC Regs have been about Donkeys and in keeping the motorsport as cheap as possible with regs that keeps it semi cheap without buying a trophy they arn't too bad.

[jai_landrover]

A friend has just purchased a 90 truck cab and it is fitted with a North Offroad cage. The drivers side and passengers side bars that tie the rear and front hoop together are both bowed in. I know it'd fail any scruteneering event where it matters and by tapping the cage with a screwdriver its most certainly CDS by its tinnyness (thin walled) Its just where the motors have rubbed trees. and theyve deformed. My money is most definatly and always will be with Blueband.

When a rear hoop knocks a tree quite hard it kinked the cage and twists it by cica 3 inch rearward I definatly wouldn't want the job of recaging a motor for a hit that a blueband cage takes weekend in, weeked out, year in and year out for god knows how many years. My 80 inch cage is larger dia blueband than minimum spec but it must have been built circa 1970's/1980's and its taken every knock roll, tree and even by all accounts various comp safari's along the way ever since then by various owners. Nobody can say that that cage hasn't lasted or been up to it. Just a note here I found that the rear mounts have Hard wooden spacers which sounds mad now BUT back in the day was considered a safe method and signed off hell they have done their job. it will be updated to the latest spec for mounts so once again it can takie part but Sorry guys Blue band all the way CDS for a rally car or fast track car fine Offroad comps then Blueband.

I'm still very much surprised that alot of Winch Comp motors get away with the bull cages they get the rear hoop in a king cab is miles behind th edriver. some rear hoops have a bend in them and yet nobody seems to worry. I guess they're not taking part in serious comps or until somone gets hurt. I am friendly with an MSA official that goes to assess events to make sure theyre run according to the regs. If he turned up at a winch comp I guess he'd have a field day.

[Dave W]

I'm still very much surprised that alot of Winch Comp motors get away with the bull cages they get the rear hoop in a king cab is miles behind th edriver. some rear hoops have a bend in them and yet nobody seems to worry. I guess they're not taking part in serious comps or until somone gets hurt. I am friendly with an MSA official that goes to assess events to make sure theyre run according to the regs. If he turned up at a winch comp I guess he'd have a field day.

But then you would think as an "expert" he'd know that cages aren't required for MSA challenge events so his "field day" would make him look like a complete donkey wouldn't it ?

[RedLineMike]

But then you would think as an "expert" he'd know that cages aren't required for MSA challenge events so his "field day" would make him look like a complete donkey wouldn't it ?

beaten me to it,

if you have a manufacturers hard top / roof you technically dont even need a cage, its mearly a recomendation, thus why with a kingcab (i had one) the rear hoop can be in the back & still be perfectly acceptable,