KCNC Quality

[Johan Bornman]

yes the bars' date=' stems and seat posts are superlight too - all the kcnc parts are made from scandium[/quote']

 

I don't think so. Last time I looked it was aluminium.

Qualify that JB... which parts don't you think? Or is that all?

Can i steal your thunder Johan?

http://en.wikipedia.org/wiki/Scandium - "The primary production is 400 kg"

I dont think they going to waste more than a milligram or two per part, and only for the marketing i guess...

 

He he....the thunder was right there for the taking.

 

I actually thought the annual worldwide output was about 270 kgs. A few years ago I got that figure from a materials book. I suppose they've upped production since then. How did we ever get by without Wikipedia?

 

 

[Pantani]

 

 

How did we ever get by without Wikipedia? 

 

I thought we asked you?

 

[Climate]

I've got to replace my MTB blades and was considering KCNC. What are the opinions on the KCNC blades ... specifically concerned with performance (eg. chain-suck)?

[Johan Bornman]

Come on guys! Did you honestly expect calipers that weigh 30 - 35% less than DuraAce or Record to have the same stopping power? The stopping power of the KCNC calipers are on par with the performance of other light calipers like ZeroG - I've ridden both (as well as Record & DuraAce)

 

The exception may be eebrakes @ about R6k per set:

http://www.eecycleworks.com/eebrake.html

 

Agree that the KCNC brake pads are crap - throw them away & get some Coolstops or Swisstops. 

 

 

 

Christie those eebrakes look awesome but.....

 

If they are as powerful as the website claims, it means their mechanical advantage is higher and they can thus not be used with current brake levers.

 

On the flipside, if they are compatible with current brake levers (I'm talking Shimano front and back and Campag front only), then they don't have the mechanical advantage they claim and stop as well as current Shimano or Campag.

 

Secondly, if they do have the high mechanical advantage, it means the pads have to be positioned closer to the wheel. With today's poofter wheels that bend when you stand, it means the pads will touch when you pump it up a hill.

 

Also those two short arms sweep through a small arc with a high cosine error. The pads will wear quickly from the bottom up and eventually give you pad dive right into the tyre - with extreme wear but nevertheless possible.

 

If you carry on staring at them they go from trick to primitive. That external spring on the front is yuk.....

 

And there are just too many moving parts and pivots.

 

No thank you.

 

Not sour grapes either. Of course I have R6k to throw at experimental brakes.

 

[Johan Bornman]

I've got to replace my MTB blades and was considering KCNC. What are the opinions on the KCNC blades ... specifically concerned with performance (eg. chain-suck)?

 

None of the modern sprocket designs either encourage or discourage chain suck. Chain suck is a function of chainring wear and dirt.

 

Obviously a softer chainring will start to wear quicker and therefore suck quicker but all things equal, all chainrings are equal suckers.

 

 

[singletrackmind]

yup that crank is super light and super smooth but not used for everyday riding as it will be worn after 3 riders and no service to the BB. A few people use them but only for racing with

[Guttersnipe]

I'm no metallurgist, but I have to call bullsh*t on this "its all just marketing" thing.

 

It takes about 10 seconds of googling to find neutral sources of information about the effects of adding small quantities of scandium to aluminium alloys, which are considerable.

 

Also, if you went beyond Wikipedia, you would find out that companies which use the stuff for things like bicycle parts don't use pure scandium from that tiny 400kg annual production when they mix up their alloy. They use a "master-alloy" which they get from a supplier who makes it up using scandium oxide (SC2O3), currently available in reasonable quantities in Russia, where decommissioned military supplies are relatively plentiful. What happens when they run out is another story but there are other sources of scandium oxide.

 

Anyway. From what I understand scandium in very small quantities makes aluminium alloys more weldable and limits the degree to which welding distorts the grain structure of the metal (recrystallisation as the welded area cools makes cracks more likely to form for obvious reasons).

 

Strong aluminium alloys are particularly *** for welding, but adding a tiny dose of scandium to the usual recipe of Al, Zinc, Magnesium, etc, solves that problem.

 

For sports kit like bicycles, tent poles, baseball bats, that means you can make strong tubes that are thinner and lighter, than those made out of traditional alloys, which are more weldable but weaker, and have to be used in fatter tubes - think arse smashing early 90s cannondale.

 

Strong, light, and weldable is also useful for building Mig-29 jets and ultralight handguns ...

 

For a non-commercial, and rather sciency literature review, try this explanation:

 

http://www.home.no/al-sc/papers/Scandium%20in%20Aluminium%20Alloys%20-%20International%20Materials%20Reviews.pdf

 

 

 

And for a marketing tainted, but very clear and sensible explanation relevant to cyclists, the Easton website offers this:

 

 

 

http://www.eastonbike.com/downloadable_files_unprotected/r&d_files/R&D-03%20Scandium.pdf

 

 

 

So, sure, it costs more than gold in its pure form. And sure, KCNC uses aluminium alloys with a tiny percentage of Scandium, as do others, like easton, but it does make a real difference. Again, those "SC" parts aren't scandium in the strict sense, but they are stronger and lighter than traditional, cheaper aluminium alloys.

 

That was way too long, but what I am trying to say is that its silly to just write this stuff off as marketing, although it has obvious marketing benefits.

 

Clearly different alloys have different properties, 7000 series al is great for some applications, titanium is great for others, and carbon for others still. I rather like steel bikes, and I don't think anyone here is going argue that there is no difference between Reynold 853 and 953, for example. "Scandium" seems to make for about the best "aluminium" for some pretty major bicycle applications whatever you want to call the stuff.

 

 

 

R-SYS wheels ... now on those I agree with Herr Bornman

 

 

 

pistadex2009-01-27 12:06:14

[Johan Bornman]

Monsieur Pistadex

 

I think you missread my perspective on thse things. But lets analyse what you say rather than generalise.

 

 

I'm no metallurgist' date=' but I have to call bullsh*t on this "its all just marketing" thing.
It takes about 10 seconds of googling to find neutral sources of information about the effects of adding small quantities of scandium to aluminium alloys, which are considerable.
Also, if you went beyond Wikipedia, you would find out that companies which use the stuff for things like bicycle parts don't use pure scandium from that tiny 400kg annual production when they mix up their alloy. They use a "master-alloy" which they get from a supplier who makes it up using scandium oxide (SC2O3), currently available in reasonable quantities in Russia, where decommissioned military supplies are relatively plentiful. What happens when they run out is another story.

 

[/quote']

 

Just recently the production went up from 270 kgs per annum to today.s claimed 400kgs. If the stuff was stored in a silo in Russia for thirty years with nothing being used up at all, we would sit on a stockpile of 12 tonnes.

 

That's not much, considering how much of the stuff is used in aerospace and the military. And of course we're not sitting on a stockpile, it is rare stuff.

 

Only a fraction of that stockpile is being released and yes, it is available on the open market but how much do you think goes into bicycle parts?

 

The fact that it is available doesn't mean it is used in its pure form and to call something Scandium when it is actually Aluminium, is tomfoolery by anyone's mearure. It's a great scheme though - add two molecules of scandium to each rim and voila, you have a R1300 rim as opposed to a cheap and nasty plain ole aluminium rim.

 

Anyway. From what I understand scandium in very small quantities makes aluminium alloys more weldable and limits the degree to which welding distorts the grain structure of the metal (recrystallisation as the welded area cools makes cracks more likely to form for obvious reasons).
Strong aluminium alloys are particularly *** for welding' date=' but adding a tiny dose of scandium to the usual recipe of Al, Zinc, Magnesium, etc, solves that problem.

 

[/quote']

 

But there is no welding on KCNC parts, that's why they're called kCNC (Computer Numeric Control). They're made up like Meccano set toys from machined parts.

 

Bang goes the welding theory therefore and we're still stuck with marketing tomfoolery.

 

 

For sports kit like bicycle tubing' date=' tent poles, baseball bats, that means you can make strong, tubes that are thinner, and lighter, than those made out of traditional, weaker alloys, that have to drawn into fat tubes - think arse smashing early 90s cannondale.

[/quote']

 

'Ts true. But strong enough is strong enough. Think forged Campag and Shimano. It is strong (stronger than machined KCNC parts for that matter in spite of the latter's exotic herbs and spices.

 

We're still stuck with the marketing tomfoolery.

 

Strong' date=' light, and weldable is also useful for building Mig-29 jets and ultralight handguns ...

 

[/quote']

 

But but but...we're talking pushbikes here.

 

 

So' date=' sure, it costs more than gold in its pure form.

[/quote']

 

Aaah, I think we've arrived a bit closer to its real raison de etre in bicycle usage. On this forum it's commonly known as bling, I think.

 

 

And sure' date=' KCNC uses aluminium alloys with a tiny percentage of Scandium, as do others, like easton, but it does make a real difference.

 

[/quote']

 

I don't think the difference has been stated or proved, unless you're talking about the marketing difference.

 

 

So again' date=' those "SC" parts aren't scandium in the strict sense, but they are stronger and lighter than traditional, cheaper aluminium alloys.

 

[/quote']

 

But they're not. Lighter maybe, but stronger not. Strength on a brake caliper is important in preventing the legs from flexing. The Aluminium alloy with scandium doesn't provide any noticeable improvement in flex. We've seen reports here and it is actually look-uppable in a materials handbook. It may weld easier but as we demonstrated, the problem is not a welding one

 

That was way too long' date=' but what I am trying to say is that its silly to just write this stuff off as marketing, although it has obvious marketing benefits.

[/quote']

 

If you've checked what's on TV you would have written a few more reams.

 

I think you are underestimating the role of Scandium in marketing and overestimating its real structural need. But that's down to opinion.

 

I have seen metals come in and out of fashion. When I was a little tot, I remember my grandfather showing me a few aluminium bolts he rescued from a scrap Spitfire fighter plane.  That was high-tech. I still have to of those bolts in my garage.

 

Later on in life I saw titanium become a fashion metal - half through its excellent medical application and half through its Iron-curtain mystique.

 

Now we're seeing Scandium. Lots of intrigue there. Only 400kgs of the stuff a year and look, my bike's made from it. Whoopee!

 

I'm a fan of appropriate materials for the job.

 

I think you are too:   

 

Clearly 7000 series al is great for some applications' date=' titanium is great for others, and carbon for others still. I rather like steel bikes, and I don't think anyone here is going argue that there is no difference between Reynold 853 and 953, for example.


[/quote']

 

 

[Johan Bornman]

yup that crank is super light and super smooth but not used for everyday riding as it will be worn after 3 riders and no service to the BB. A few people use them but only for racing with

 

I've never come across a rough crank, nevermind a "supersmooth" one.

 

However, I'm astonished that there may be some truth in the fact that someone makes (and a sucker buys) a crank with bearings that last only three rides.

 

But, it's completely immoral not to part a fool from his money.

[straatvark]

 

I'm no metallurgist' date=' but I have to call bullsh*t on this "its all just marketing" thing.

 

[/quote']

 

You are correct. I was to harsh.

 

My point was that a part was not made of pure scandium, as marketing material make people believe.

 

Personally I believe, just as Easton consider it a "waste to use scandium" with 7005 or 6061, that it is waste to use products containing scandium when you are not competing on an international level - ie it is not suitable to me.

 

 

 

[Guttersnipe]

Now this is getting interesting.

 

I suspect we do agree broadly, and not just about what's (not) on TV.

 

So, as far as appropriate materials for the job go, we can probably aren't that far apart on the idea that aluminium alloy with a seasoing of scandium is probably a good idea for a tubeset - depending on what kind of frame you want to build, of course.

 

The leaves the question of whether it makes sense for unwelded tubes, like my KCNC bars (which I like mainly because they have quite a lot of sweep); whether there is really 400kg available annually; and whether "scandium" makes sense for things like brake calipers.

 

Last point first - I'm with you on the brake calipers, I think. In fact, as I understand it, the desirable kind of flex you can get with thinner, but stronger "scandium" tubesets is its principal advantage for building non-arse smashing frames, but brakes probably have rather different engineering requirements.

 

The flaw in the welding argument occurred to me about 10 minutes after I edited my last post. I don't it that ends the story, however, even where bars are concerned.

 

Small amounts of Scandium significantly increase the "yield strength" of the alloy, which means you can have tubes with thinner walls that are just as strong as thicker walled tubes of other alloys. That is a good idea for handlebars and baseball bats (thinner walls, springier bat, ball goes further; thinner walls, lighter bar, bike is lighter and still doesn't break). Sure, strong enough is strong enough, but if stronger means you can go lighter, well then, how strong is too strong?

 

Now, on to cost and the vanishingly small quantities of the stuff that are supposedly available.

 

These sporting goods Al alloys have less than a quarter of a percent scandium.

 

As that paper I posted a link to points out, in high end bicycle parts, materials cost is relatively small proportion of the final cost.

 

This is where the marketing bullsh*t comes in, and where we are definitely in agreement.

 

There are some interesting numbers in the paper on the cost implications of adding 0.2% Sc to Aluminium - it roughly triples or quadruples the price at 2005 levels by adding about $4/kg to the price of the alloy.

 

But the price of Sc master alloy is falling, and new supplies are becoming available which may bring that figure down to $0.8/kg.

 

So, we are almost certainly paying more for the benefit than the materials cost justifies, which is not quite the same thing as paying for no benefit at all.

 

Which brings us to final remaining point, the mythic 400kg. That number refers to the production of the pure metal, but the master alloy is made from the reduction of much more readily available Scandium Oxide. Even Wikipedia makes this clear:

 

"World production of scandium is in the order of 2,000 kg per year as scandium oxide. The primary production is 400 kg while the rest is from stockpiles of Russia created during the Cold War." There is more available, I am pretty sure, in the form of recycled MIGs.

 

When the Russian jets are all melted down, red bauxite will apparently fill the gap at a lower price. So the volume of pure metal on the market is a bit of a red herring.

 

Also, the pure metal may be more expensive than gold, but the equivalent quantity of scandium oxide cost about $2000/kg in 2005, which is a good deal less than gold.

 

In short, it is probably good stuff for both frames and bars, but the upcharge may well be out of proportion to the increase in the cost of the underlying materials.

 

Rims? I don't know, but expect the same "thinner, stronger, lighter, a bit more expensive, and a bit more compliant" logic should apply. Of course the benefits are probably overhyped, as are the prices, but I think the KCNC stuff is pretty reasonable. That said, I'm not about to swap out my campy brake calipers.

 

Ok, I expect you'll knock that one out of the park, but I hope it'll take five minutes, so I'm off to eat dinner.

 

 

 

pistadex2009-01-27 14:06:33

[Johan Bornman]

I think we kinda agree and I think you make some good points, especially the one about "which is not the same thing as paying for no benefit at all."

 

I tend to speak in absolutes to emphasise a point and that gets me into trouble. That statement of yours puts things nicely in perspective....for frames, not the calipers, but you conceded that.

 

But, just to make things interesting, I dont agree completely.

 

By increasing the yield strength you don't necessarilly have a better material for the job. If its strain caracteristics are still poor, you still have a schlapp frame. All the increased yield does is create the permanent deformation at a higher stress point. This is something that isn't necessary in frame building. You want a stiffer material or construction, not higher yield.

 

I still want to get my head around the "master alloy" and Scandium oxide issue. I'm convinced that when they talk about a 400kg yield per annum, that's the stuff that they manage to extract from the scandium oxide raw material. Aluminium, titanium and iron are all basically produced from oxides and I think the availability and abundance of the raw material is not always directly linked to the yield of the final product. Titanium oxide is incredibly abundant but titanium is a different story and expensive to extract.

 

At the end of the day my alloy crusade is one of farting against thunder. It irks me when someone says "this is made of alloy" when they actually mean it is made from aluminium (alloyed or not). However, this stupid "alloy" moniker will stick to aluminium till the cows come home.

 

When they say "scandium" I react the same. It is a little bit like referring to a lump of barbel spawn topped with one beluga egg  as caviar.

 

 

 

 

 

 

 

[Guttersnipe]

 

 

Oh dear, we do agree, but to keep it going for one more round ...

 

I think the thing about adding scandium to aluminium is that it probably improves the strain characteristics of the more standard Al/Zn/Mg alloys because its finer grain structure and higher yield strength let you do clever things in the tube drawing/butting process, but I really don't understand what goes on molecular level well enough to debate that.

 

Anyway, I am going to have my 7005 framed cx bike resprayed and rebranded "Barbel spawn".

[javadude]

I've got Tokens with Koolstop salmon brake pads. I'm 95kg's and the stopping power is acceptable, but not as good as my Chorus skeleton. 

[Montblanc]

I have stems' date=' bars, skewers ,jockey wheels and seat post.

Never had a problem with any of their stuff.

I'm heavy so I havent used their Brake calipers.
[/quote']

 

Your bike must be under weight then!!

 

I agree, i use the calipers and skewers - works 100% . The jockey wheels i did not like to much. If you have a record derailer, why fiddle around! 

[Montblanc]

Now this is getting interesting.
I suspect we do agree broadly' date=' and not just about what's (not) on TV.
So, as far as appropriate materials for the job go, we can probably aren't that far apart on the idea that aluminium alloy with a seasoing of scandium is probably a good idea for a tubeset - depending on what kind of frame you want to build, of course.
The leaves the question of whether it makes sense for unwelded tubes, like my KCNC bars (which I like mainly because they have quite a lot of sweep); whether there is really 400kg available annually; and whether "scandium" makes sense for things like brake calipers.
Last point first - I'm with you on the brake calipers, I think. In fact, as I understand it, the desirable kind of flex you can get with thinner, but stronger "scandium" tubesets is its principal advantage for building non-arse smashing frames, but brakes probably have rather different engineering requirements.
The flaw in the welding argument occurred to me about 10 minutes after I edited my last post. I don't it that ends the story, however, even where bars are concerned.
Small amounts of Scandium significantly increase the "yield strength" of the alloy, which means you can have tubes with thinner walls that are just as strong as thicker walled tubes of other alloys. That is a good idea for handlebars and baseball bats (thinner walls, springier bat, ball goes further; thinner walls, lighter bar, bike is lighter and still doesn't break). Sure, strong enough is strong enough, but if stronger means you can go lighter, well then, how strong is too strong?
Now, on to cost and the vanishingly small quantities of the stuff that are supposedly available.
These sporting goods Al alloys have less than a quarter of a percent scandium.
As that paper I posted a link to points out, in high end bicycle parts, materials cost is relatively small proportion of the final cost.
This is where the marketing bullsh*t comes in, and where we are definitely in agreement.
There are some interesting numbers in the paper on the cost implications of adding 0.2% Sc to Aluminium - it roughly triples or quadruples the price at 2005 levels by adding about $4/kg to the price of the alloy.
But the price of Sc master alloy is falling, and new supplies are becoming available which may bring that figure down to $0.8/kg.
So, we are almost certainly paying more for the benefit than the materials cost justifies, which is not quite the same thing as paying for no benefit at all.
Which brings us to final remaining point, the mythic 400kg. That number refers to the production of the pure metal, but the master alloy is made from the reduction of much more readily available Scandium Oxide. Even Wikipedia makes this clear:
"World production of scandium is in the order of 2,000 kg per year as scandium oxide. The primary production is 400 kg while the rest is from stockpiles of Russia created during the Cold War." There is more available, I am pretty sure, in the form of recycled MIGs.
When the Russian jets are all melted down, red bauxite will apparently fill the gap at a lower price. So the volume of pure metal on the market is a bit of a red herring.
Also, the pure metal may be more expensive than gold, but the equivalent quantity of scandium oxide cost about $2000/kg in 2005, which is a good deal less than gold.
In short, it is probably good stuff for both frames and bars, but the upcharge may well be out of proportion to the increase in the cost of the underlying materials.
Rims? I don't know, but expect the same "thinner, stronger, lighter, a bit more expensive, and a bit more compliant" logic should apply. Of course the benefits are probably overhyped, as are the prices, but I think the KCNC stuff is pretty reasonable. That said, I'm not about to swap out my campy brake calipers.
Ok, I expect you'll knock that one out of the park, but I hope it'll take five minutes, so I'm off to eat dinner.

[/quote']

 

Are we still talking KCNC here.