33 replies to this topic

[mini93]

I wouldnt be without my 4 pots! put it like that

[DeadBert]

Hello

Just to drag this one back from the grave as I never actually got an answer so if anyone has any further information I'd be most grateful.

Totally accept the whole standard 2 pots vs alloy 4 pots and that some people think the latter are a waste of money. Loads of topics on this already for people, and myself, to read

However..... that wasn't the question I was asking. I was hoping to find out why KAD brakes are so much more expensive then others, specifically from Mini Spares (as I've already stated I'd rather sell the car than deal with Mini Sport again).

What am I getting for my extra money?

Improved braking performance (compared to Mini Spares alloy 4 pots, not standard brakes)?
Less weight?
Better design?
Or do you simply pay for the brand name?

If anyone has any input I'd be most grateful. I guess I'll go for the KAD ones if I don't hear anything and never find out if I've wasted the extra money

Many thanks

Chris

[matty...]

Ive glad you've brought this back up as ive been thinking the same.

I want the brakes that have the best stopping power, but if the KAD ones are no better than minispares I can't see the point in spending the extra.

Im currently running cooper S brakes, ive tried all different combos of pads and I have never found them that great at all, hence looking for some decent 4 pots!

[Tamworthbay]

Hello

Just to drag this one back from the grave as I never actually got an answer so if anyone has any further information I'd be most grateful.

Totally accept the whole standard 2 pots vs alloy 4 pots and that some people think the latter are a waste of money. Loads of topics on this already for people, and myself, to read

However..... that wasn't the question I was asking. I was hoping to find out why KAD brakes are so much more expensive then others, specifically from Mini Spares (as I've already stated I'd rather sell the car than deal with Mini Sport again).

What am I getting for my extra money?

Improved braking performance (compared to Mini Spares alloy 4 pots, not standard brakes)?
Less weight?
Better design?
Or do you simply pay for the brand name?

If anyone has any input I'd be most grateful. I guess I'll go for the KAD ones if I don't hear anything and never find out if I've wasted the extra money

Many thanks

Chris

Read Cooperman's replies - a man of his experience ought to know what he is on about so I would listen to him. if you still want to buy them then the real questions is 'do I want to pay £150 for the pose value of calipers saying KAD?'

[DeadBert]

I don't doubt his experience and wisdom at all and of course I have read every reply in this thread. If he has tried both KAD brakes and other 4 pots then I'd be most interested in hearing his comments. Again, this is the nature of the question and not whether a standard brake setup is better in terms of braking performance.

I mean no disrespect to Cooperman or anyone else. Advice and experience is always welcome, however in this case the discussion went in a different direction to the initial question.

'do I want to pay £150 for the pose value of calipers saying KAD?'

This is what I'm concerned about. Would certainly be money that could be spent elsewhere!

Thanks

Chris

Edited by DeadBert, 18 July 2012 - 07:33 PM.

[tiger99]

The thing I would be most concerned about is safety. Calipers are highly stressed, cyclically, every time you use the brakes, the perfect situation to create fatigue failure. It ultimately can't be avoided, as aluminium and its alloys, unlike steel, do not have a fatugue threshold and will eventually fail. You are at the mercy of however many fatigue cycles, and at what brake pressure, the manufacturer considered to be necessary, how accurate their calculations were, and how good their quality control of every single casting is.

Alloy may be ok for low mileage track use, but no way would I ever consider it for high milegae use on the road. KAD stuff, grossly overpriced, has not had the millions of miles of development testing which mainstream manufacturers routinely apply to things like calipers.

[Midas Mk1]

The thing I would be most concerned about is safety. Calipers are highly stressed, cyclically, every time you use the brakes, the perfect situation to create fatigue failure. It ultimately can't be avoided, as aluminium and its alloys, unlike steel, do not have a fatugue threshold and will eventually fail. You are at the mercy of however many fatigue cycles, and at what brake pressure, the manufacturer considered to be necessary, how accurate their calculations were, and how good their quality control of every single casting is.

Alloy may be ok for low mileage track use, but no way would I ever consider it for high milegae use on the road. KAD stuff, grossly overpriced, has not had the millions of miles of development testing which mainstream manufacturers routinely apply to things like calipers.

Nothing like a bit of the old scaremongering of alloy callipers!

Companies such as Kad and Minisport will be regularly be improving / testing their products to ensure they are the highest quality, in both performance and safety.
Minisport have been making the 4pots for nearly 20 years, and like any product have developed and improved them over time, and still do, with any problems rectified.

I know over the choice of Minisport/ kad 4pots over an old set of cast callipers, which set I'd be choosing........

Edited by Midas Mk1, 19 July 2012 - 09:52 PM.

[DeadBert]

Good point, never considered this!

I'd be interested to know if anyone (specifically a Mini) has actually had this happen! Whilst possible is this so unlikely that it isn't a concern? After all, Aluminium and Alloy calipers are not just used by after market manufacturers.

We all fill our cars up with highly flammable fuel, but rarely give a thought to the car bursting into flames. I guess this could happen, but the chances are so slim then it no longer becomes a risk.

I think again we're getting away from the initial question. Probably best to let this thread die ungracefully now. I'll get the KAD brakes and live in blissful ignorance that I might have wasted £150

Chris

[tiger99]

There have been reports of alloy caliper failures on this very forum within the last 6 months.

[mini93]

And the standard fit manufacture calipers. such as motorbikes, or high performance cars... no way would they let a car go out with potentialy failing brakes. toyota did that remember and ended up costing them a shed load.

cars have ran alloy sliding calipers for yonks. my peugeot has alloy callipers on the back and before that, 205s have...same caliper design. if they thought there was a stress fatigue problem then they wouldnt have carried on.

etc etc. I see no problem at all using alloy callipers on a mini. They are small, light weight, dont often stop from high speed.
maybe the KAD callipers have the pistons at a further radius. more radial stopping force... but it would be margenal.
My cars ran minisport 4-pots for yonks, before i had it, it was a rally car and used them since mid 90's

[matty...]

Deadbert - I'd like to know the same as you, "why are they soo much more".

It might be worth contacting KAD and asking why they are soo much more than other 4 pots available?

If their calipers are so much better than the rest, they should be more than willing to tell you why.

If the difference turns out to be something minimal like say they are100g lighter (only an example) then its down to the individual to determine whether it would be worth the extra £150.

Edited by matty..., 19 July 2012 - 09:49 PM.

[tiger99]

Mini93, the problem is that the mainstream manufacturers have tested their calipers for the equivalent of hundreds of thousands of miles of hard road use. It is certain, due to economics, that KAD have not, and I doubt that they even know the actual working stresses in a Mini.

The aircraft industry is trying hard to get rid of alloy by switching to composites due to the fatigue problem, however in the meantime it is just about safe because in a large airliner there is redundant structure with additional load paths to hold things together between regular crack inspections if one element should fail. Some parts are changed regularly, based on load cycles, including the bits most similar to a car, i.e. wheels and landing gear components. There is no redundant load path in a brake caliper, nor indeed in the alloy suspension components and even space frame being used by certain manufacturers. Accidents due to failure of these relatively modern vehicles will, quite predictably, start to become significant soon.

Despite the testing, alloy components on mainstream cars do fail with depressing regularity, because of bad maintenance or being overstressed beyond the manufacturers assumptions. The Bini has a nasty problem which BMW have so far done a good job of covering up.

[DeadBert]

I think it's a little unfair to compare aircraft industry to the automotive. It's a different application of the material, subjected to different stresses and will have to go through different testing and certification.

If anyone has any links to topics about calipers failing I'd be very interested. Must have missed them.

Also, are we now concerned about all alloy components? What about hi-los for example? They're alloy but are still extremely popular!

I think I'll contact KAD directly as suggested. Might even be cheeky and ask what testing they do and their opinion on the suitability of alloy for calipers.

[Nick Warwick]

If you can get a good answer out of KAD it would sway me to buy theirs over others.

[donjarr]

So not really relevant, but I bought KAD six pot callipers some tens years ago, no dust seals, no problems and if I remember once in a blue moon I stick a air line on them to clean them, and they stop amazingly well with very little pressure on the pedal, with no servo fitted.

However things you have to bear in mind is grade of aluminium which KAD specify but I couldn't find on miniport or mini spares. Minispares put me off as you have to file the corners off the brake pads to get them to fit which to me says corner cutting on the design. Also compared to both mini sport and KAD the mini spares ones looked to have a rougher not so clean cut finish.

So ignoring the scary mongers and whoa beware alloy callipers, KAD are not a general retailer they only sell stuff they make (plus brakes pads and bits like that) unlike both mini spares and sport which are general retailers, so KAD have to excel on all their products because that's their source of income. Just one duff product from KAD could cost them everything, so quality and workmanship is top of the class. Also just the general finish of their stuff is way above the rest.

So not really relevant, but excluding the first MOT which the guy said the brakes were still bedding in, each year he writes down various specs because like me he is a mini nut and we keep track of stuff, and over the 9 MOTs the brakes have constantly produced 1250kg (it does vary by a kilogram or two either way) per wheel of stopping power on the brake testing machine, which is down to KADS brake bias setup, 6 pot callipers and the same ten year old silicon brake fluid. (I was warned off that by the scary mongers too, lol)

So I haven't owned any of the four pots being talked about, but can say that the stuff KAD make is as good as your going to be able to buy, but the real bottom line is how much do you want to spend?? For me the extra cost of the KAD stuff was well worth it.