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CDS Vs BB


Warthog

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My point is if you can buy a CNC bent hoop, out of CDS for £100, why spend time messing about knelt on your garage floor trying to bend up an inferior product that probably wont fit right anyway. It just seems like a waste of time and money.

I agree with 'White 90' in that some people might buy a good quality cage in kit form, then mess it up because they can not weld properly.

As far as you not needing as strong cage for slow speed events, I would guess that rolling down a steep bank or off a ledge could have a similar effect to a much faster roll when comping

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Ok, I guess it's just different perspectives - which is cool.

For me, there is no 'messing about on the garage floor trying to bend up an inferior product that probably wont fit right anyway'. I guess anyone making a cage is gonna spend a few minutes figuring out how to bend tube correctly? It's not exactly tricky to make stuff that fits right (in fact, it's surprisingly easy, I found). For me, 100 quid for a bent tube is a waste of money. Different perspective. :)

Sure there are cases where the energy of the impact isn't related to the initial speed (i.e. involving falling). Plenty of BB cages have rolled down banks. No problemo. I wonder if you aren't underestimating it's strength a bit? I would expect scaffolding to split.

I know it sounds like I'm singing the praises of BB - I'm really not specifically a supporter of it, I just think in most cses on a forum like this one, it's plenty. Rolling down banks & off ledges are cases I would include in this, personally.

Al. :)

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Yes Geoff I mean proffessional cage suppliers that bent and fitted the cages.

on one the owner took the car to D44 to have the welding redone as it was so shoddy

the other didn't weld the bars on the chassis where it couldn't be seen and no screen bar

this was a cage costing in excess of £1000

if I ever get another cage

North offroad in Stockton on Tees will be geting my money

shaun builds superb cages for a reasonable price.

and if you want different he'll do it.

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Totally agree with what's been said - if the design or fabrication is poor then, no matter what material you use, the cage won't be any good.

Yes, for what we're doing BB is OK strength wise BUT its heavy. If you can afford it then CDS is better as you can make to cage lighter. T45's awesome but for, IIRC, £20+ a meter you really need to think its worth it to use it.

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Out of interest exactly how much lighter, for two lengths of similarly strong tube, is CDS than BB? Even just a % would be worth knowing. I'm guessing it's not a massive amount.

I think sometimes people forget that off-roading isn't rocket science, and most people's vehicles are more tractor than rocket. :ph34r:

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I think sometimes people forget that off-roading isn't rocket science, and most people's vehicles are more tractor than rocket. :ph34r:

Amen.

As someone familiar with both, I can promise one is trickier than the other! :P

The weight saving can't be too much - my whole chassis won't weight that much! BB always seems suprisingly light when you pick up a long (or short) bar of it...

Of course, even if you only save 10 or 20 kilos, that's still 10 or 20 kilos. Just depends how much that weight is worth to you. If you are that nit-picky when it comes to chassis weight, you'd better make damn sure the rest of the car fits the bill, or the whole argument falls apart. :ph34r:

Al.

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Well…………… mine is made from CDS and was supplied pre-bent. It needed a little fettling to get the right fit and the welding is down to me ………… primarily for the reasons cited in White 90’s post and also building the cage onto the vehicle is the only way to get a decent and aesthetically correct fit.

Also it must be remembered that EVERY roll is driver error , no ifs and no buts …… its driver error :rolleyes: . However, none of us are perfect and its better to spend some extra £££ on ensuring the best safety for both the occupants and vehicle for when that moment of error comes our way. :D

CDS used to be about £15 / metre ………… how much is it now ? :unsure:

Ian

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Right, CDS seems to be getting a positive feedback. So where would i aquire a "Flat Plack kit" with all bends etc Ready to Weld together and mount" for a truck cab?

Whitbread are doing BB flat pack kits ready to weld/mount for just under £400. Now they seem to be happy using BB?

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Just thought I'd throw my tuppence worth in here,

CDS started being used in rally cars to reduce the weight and the cage designs are calculated in conjunction with the body of the car.

The idea is that when, not if, the car has a woopsy, the body and the cage absorb the impact.

This does not hold for off roading in any discipline, where the idea was to withstand the impact, so they could be righted and then carry on.

Having been competing in all forms of Off Road motorsport for over 20 years and officiating at rallys for the past 10 + years, I'ld sooner be in a BB caged vehicle than CDS.

Bob

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Just depends how much that weight is worth to you. If you are that nit-picky when it comes to chassis weight, you'd better make damn sure the rest of the car fits the bill, or the whole argument falls apart. :ph34r:

For me, a lot of those arguments fall apart the moment you go into the mud - you can stick 10 or 20kgs of mud into the gaps on a LR very easily - wheels, chassis rails, traps in bodywork... not to mention all the protection gear people bolt on (6mm plate steering guard anyone?), the heavy winches & batteries, spare half shafts, etc. etc.

If people were seriously concerned about weight they'd take a long hard look at their trucks and remove all the bits that serve no useful purpose.

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Just thought I'd throw my tuppence worth in here,

CDS started being used in rally cars to reduce the weight and the cage designs are calculated in conjunction with the body of the car.

The idea is that when, not if, the car has a woopsy, the body and the cage absorb the impact.

This does not hold for off roading in any discipline, where the idea was to withstand the impact, so they could be righted and then carry on.

Having been competing in all forms of Off Road motorsport for over 20 years and officiating at rallys for the past 10 + years, I'ld sooner be in a BB caged vehicle than CDS.

Bob

I am sorry but have to dissagree, Rally cars do not just use CDS because its lighter, they use it for the same reason the MSA banned Blue Band for rallying. CDS and T45 are stronger and more consistent in there reaction to an impact. For you to say that the properties required for a rally car 'do not hold for off roading in any discipline' is just wrong. You have clearly never traveled down the Cat.1 tracks used in the British Off-Road Championships, or seen the after effects of an 80mph roll on them. Just go on Ben Gott's website and watch the video of his roll which I think was at Radnor.

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For me, a lot of those arguments fall apart the moment you go into the mud - you can stick 10 or 20kgs of mud into the gaps on a LR very easily - wheels, chassis rails, traps in bodywork... not to mention all the protection gear people bolt on (6mm plate steering guard anyone?), the heavy winches & batteries, spare half shafts, etc. etc.

If people were seriously concerned about weight they'd take a long hard look at their trucks and remove all the bits that serve no useful purpose.

Fridge, I totally agree; it's not much in the scheme of things; 30kgs if you're lucky. However that's all high up weight and so makes the truck more stable.

Yes, the mud thing is a real issue. I'm doing / have done a lot of work to try and cut down the mud traps.

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Whitbread didnt do cds when I worked there, coz he hasnt got a mandrel bender. All of my comp motors have been mede with bb. I've stuffed it on its roof once or twice and never had a problem with the tube. My next motor however will be done in cds coz ive bought a mandrel bender.

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For me, a lot of those arguments fall apart the moment you go into the mud - you can stick 10 or 20kgs of mud into the gaps on a LR very easily - wheels, chassis rails, traps in bodywork... not to mention all the protection gear people bolt on (6mm plate steering guard anyone?), the heavy winches & batteries, spare half shafts, etc. etc.

If people were seriously concerned about weight they'd take a long hard look at their trucks and remove all the bits that serve no useful purpose.

I dont agree with the first bit; Because if you manage to save 500 kg on your landy; adding 20 kg of mud, still results in a 500 kg lighter landy afterwards. A lot of landys are prepared very heavily, but if you design things well, there is no need for this.

I am getting a bit fed up with people saying weight is not important because the car is heavy already; all preparations add weight so if you manage to do something that loses weight all the better.

Daan

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Daan, I'm not saying weight isn't important, I'm saying that:

a) A small % weight saving at a big % cost increase is not necessarily money well spent, especially if it's the difference between bending some BB yourself for the cost of materials, or paying someone else to bend some CDS for materials + labour + delivery.

b) You can save a lot of weight far more easily on an average Landy by unbolting a lot of the bling that people feel they need.

If you can save more than a few Kg's by changing the cage material I'd guess you're doing pretty well, if you can do it for a reasonable £ per Kg then you're doing even better. Personally, even £100 on the cost of a cage is money I could better spend elsewhere on the vehicle to greater effect.

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Hello,

I have been reading this forum for a while- and this post has real interested me.

What bender would suit the bending of 2 and 3inch BB and CDS tubing?

I am planning on purchasing a machine mart bender and some tubela formers and attapting the machine to suit. Would this allow me to bend both bits of tubing perfectly.

I completely agree that the design of the cage is more important than the material used. In most cases proper design can allow smaller diameter and thinner tubing to be used.

From simple analysis most rollcages are built out of LR design considerations rather than mechanical strength. Look at US motors.

Paul Leworthys motor from Zeal Steel has taken alot of the US engineering features on his space frame chassis.

Anyhow will my idea of a tube bender work???

cheers

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