Wake Style Boards
Thickness of
the core determines flex in a sandwich construction, so you generally want
a thin section in the tip to binding area and thicker section over the stance.
As wakestyle boards generally have a wider stance a lot of the board will be stiff
over most of its length. This helps maintain the rocker line but means that more flex has
to
be incorporated in the tip area. With full carbon, the board needs to be 3mm or less to
give
discernible flex in this area
2005
.
One of the first full carbon wakestyle boards I made in 2005.
I left it in Antigua for testing, but it proved to have too little rocker,
too stiff and too fat in the middle
which quote: "....really messed up the ride"
Mistakes were made with some of the early versions, which had too little rocker
and too much use
of high gsm (weight) grade carbon combined with graphite rails made the boards
heavy and stiff.
Later boards used a lot less carbon, more natural rocker line and had thinner tails
with a simpler
rail construction and a DuraSurf base.
This form of construction was quick, effective (using prepreg carbon)
and relatively cheap compared to earlier designs and production boards .
However by the end of 2007 there appeared to be no great demand for this type of
board in the UK,
so I completed one last version for Ally Beaven who was after a wakestyle board and
had previously
been testing CKB landboards.
2008
The large natural rocker line on Ally's CKB Wakestyle board
I have used some of the
conclusions and implemented them in a prototype carbon board (pic above) which Ally Beaven is testing.
2010
Wakestyle 137x43 with 2.5 inches lift at tips completed June 2010
This board features slider type inserts for variable adjustment of stance and boot
positions.
It was was made inverted on the rocker table to give a flat top surface.
It uses 3 solid carbon longerons with reduced thickness solid carbon tips and quad concave
at tails.
Graphite/ Epoxy base and rails it is quite flexy for a carbon board.
Finless but can be drilled to take fins as this area is solid carbon.
Shown with Ronix Cells.
As this style of riding has now gained more interest in the UK, I have collected
together
some of the information, theory and practice I have used over the years.
THEORY How does a Kiteboard work?
For Kiteboards one can probably apply some of the physics of
planing motion in sailing craft.
The dynamic lift needed for that state of motion (called pure
planing or skimming)
can be better understood by studying the following figures"
Fig a Flow under the board
Due to the slowing of the water flow under the board, the kinetic energy
of flow in any one area is converted to pressure p, which is exerted
perpendicularly to the bottom
The over-all effect of these partial pressures p can be represented as
a 'resultant normal force' N.
The highest pressure will be at the stagnation point St,
where the water flow is completed arrested and the magnitude of its
velocity is zero.
Fiq b Pressure distribution along
the centreline.
Ahead of the stagnation point a small amount of water is thrown forward as spray.
Fig c - The schematic pressure
distribution on the bottom
Traced where the lines, which record the magnitude of the pressure,
are less concentrated towards the edges.
There is some leakage of pressure here, revealed externally as spray
thrown out sideways.
This leakage will be greater in the case of a narrow board.
Both side and forward sprays from a board in planing motion is a sign
of dissipated
energy or a form of resistance to motion.
Of course a kiteboard is rarely used flat on the water,
but the above analysis holds for
the board on its rail, (but it will have an asymmetric pressure pattern).
Here the rail ( & fins) become like a keel with the pressure preventing
sideways slip against
the pull of the kite and enabling the board to make progress up wind.
Subtle differences to the geometry & physical behaviour of the board along with
rider style
and kite power will all contribute to the performance the rider feels he is getting
from his
board. Below are some posting about these factors by members of the Kitescoop
forum.
Ref. C.A. Marchaj's "Sailing Theory
& Practice" page.267
"The Hydrodynamic resistance of the hull" in Planing craft." :
PRACTICE
Most of the following can be found on Kitescoop
if you dig out the old posts.
However for ease of reading I have
compiled a collection of them here by kind permission of Adam ( Kitescoop Admin )
The following topics were discussed (click to goto the section)
1 Straps/ Bindings
2 Rocker
3 Flex
4 Channels
5 Concave
6 Custom versus Production
7 Fins
8 GENERAL
DRE( Drizzle)
Had to ride straps for a long time if i wanted to do well on the tour and when i was over
the judging and over riding the way that ppl wanted i switched to bindings fulltime. I
have to say that it is definitely easier to learn tricks in straps. simply because of the
weight factor.You can ride with less power which makes it easier to pass the bar and with
less weight on your feet you can pull youself to the bar easier as well. But when it comes
to landings and hitting rails bindings definitely take win.
2 cents... cha ching
DRE
oh.. did i mention that it just feeeeeeels so right in bindings that it cant be wrong
Inept Fun
Not to mention style with bindings compared to straps,I think bindings definately do make
some tricks more difficult,but why would you want something to be easy? The style factor
is definately worth it. Ride bindings...
Jon Modica
This is what id do if i were you. wait for a good day. like a really good one ride apart
of the day bindings and apart of the day straps decide what you like better. and then do
it. if you feel better doing one you'll be happier in the end, trust me.THE BEST PART
ABOUT OUR SPORT IS THE ABILITY TO RIDE WHATEVER THE F&$^ KIND OF BOARD WE WANT!!!!!!
wakeboard, surfboard, skimboard, snowboard, and even a fuc#*in 2by4 its all fun,
just in different ways
Nik (Waterman)
dont want to tech out here too much but your board setup for bindings makes a big
difference.
If you are riding similar boards but just switching from foot straps to bindings you will
definitely feel bogged down with the boots on. A bindings board should be at least 40cm
(mine is 43cm) wide and have a more natural rocker line (more curve between the feet) to
be efficient. That is why custom boards are a lot more important in this respect. (dont
look at Dre as an example-he throws down on 2x4; but his customs from Sean Ordenez were
the inspiration for getting me back on bindings) Since going to a custom board I ride
bindings only; never went back to foot straps.Foot straps feel so "puny" after
riding bindings properly. You need to also to have an aggressive style. It is "full
throttle" type of riding. Unhooking fully powered and throwing down without fear of
consequence is the key attitude to have.
Dereck Camacho (Dereck)
Waterman is right on here.. You can not compare if you like bindings or straps on the same
board....
If you want to try bindings, to take advantage of the bindings you have to have a board
that is designed for this.. Wide, curvy rocker and a harderned flex between the feet for
POP... Then you will get the height and rotation and really feel the benfit of
bindings...If you were to try and ride this board with just straps fully powered up you
will feel like you are holding on to the back of a car going fast on a skateboard with
loose trucks!! Like wise, if you take a board that is tuned for straps and controlable
with your ankles and you bolt on some bindngs it would be like trying to pick your nose
with boxing gloves on. Two different boards.. When I worked with waterman on the
development of my THUG, I reliased it was apple and oranges...So it all depends on what
you want to do...... Pick one or the other, of have 2 different board set ups if you
really want to do a side by side test.... But as far as choosing what is right for you?
Whatever one you have more fun on...... I say!
But yea, I agree, you got to have attitude as well to work bindings!!
DC
Murphycj
I wanted to go wider on my elements so just t-bolted through them...only option really
Dereck
nope....... get a board made for you. A lot of production companies do not go wide on the
inserts because they will have to change the glass lay up of the board and make is stiffer
in the middle to acommidiate the wide stance, and they stay away from this because the
weight of the production board is already high and it will make it heavier. Even if you
just put t-nuts to make your stance wider, yes you get a wider stance,
custom T-nuts
but there are things happenind to the flex and rocker of the board that makes it a
diferent board.....
ask around youyr local area, any custom builder ( if they have experience with wake style
ridiers and boards) can put the inserts where you want them.... it makes a difference if a
board is built with this in mind rather then just modifing something.... But hey, don't
let it keep you off the water.....if you gotta put t-nuts on your flip flop to get a
session in..>DO IT!!!!
Adam (Adamski)
you know i never actualy thought of that. thanks for clearing that up for us. I always
wondered why companies were so hesitant to put wider inserts. to the "non
shaper" it would seem like a realy simple thing to add, but i guess theres alot more
to it. i guess they will have to put more thought into the initial design of the board if
they want to have a realy wide stance. its all about R&D i suppose
ROCKER
Kitesurfrabbi
derek how much rocker do you put into your boards?
Dereck
It all depends on a lot of elements, riders weight, board length, width, stance how the
stars are allined
(ok joke) but remember, I am custom... from begining to end, so there is no set number I
can give you.
Also, It is not just the tip height rocker ammount that counts, it is the curve and how
the rocker is
used that is ultra important.. I have tested boards with the same total rocker height on
the tips but
with different curves and they are totally different... that's where my buget goes, in
trying different
boards that basically look the same but have different rocker curves, flex
properties..etc..etc...
just different boards trying to get things right before I settle on a design...
But I don't want to look like am giveing you some spin and not answering your question,
so here is the rocker amount of my personal THUG...(again, remember it will vary from
board to board) ...
My THUG (seen in the picture on my avatar) is 140 X 43 and it has just a touch more than 2
1/2 inches tip
rocker each end...( Approx. 5 " running the length of the board) I will look and see
if I have a better
picture of this board... My PLAYER boards (for freestyle/straps have less )
Hope that helps..
DC.
Kitesurfrabbi
you know back in the days when i was building boards myself i thought that elliptic
rockers worked best
for overall performance. but i know there are thousands of elipses with the same tiphight
on a given boardlenght but nevertheless 2,5 inches is quite high and thats actaully
more than the mission or the element have. it's interesting to hear that your boards are
rockered that much and you get some good lightwindperformance out of them. thanks for
sharing your knowlege man!
CKB...
ref. rocker on sliders
slight concave in middle giving it a sort of flattened centre rocker , the idea
being to help stay on the track
Is this dumb or do you need the natural rocker anyway to keep balance?
Dereck
I found the continous rocker is better for the overall ride.Providing better carve and
stability at higher speeds.. For wake style boards I will do what ever I can to make the
rider feel that they can go as FAST as thay can and still have positive control...and
continoul rocker gives this effect..What I found with the flatter rockers on a wake style
board,is that while they are fast, they become difficult to land blind tricks and land
from high speed mega rotation tricks etc.etc.( I observed this from watching video of the
guys in antigua.. not from personal experience..The only high speed mega rotation landings
I go the board is going in one direction and me skimming on my ass in the other direction
) But give your board a try...Being all carbon,
I am sure it will have loads of energy and might work.....
nice work!!
DC.
CKB
Thanks DC.
I can see now, that a continous curve will smooth out high speed landings by distributing
the pressure better. I guess flattter rocker means more unpredicable pressure release.
Nik(waterman)
Dereck and I worked on quite a few prototypes with the THUG before we found the rocker
line that "felt right".The bottom design started out way too complicated. We
ended up boiling it down and down to the simplest of shapes and rocker profiles. I cant
provide any more detail than that
(or else I would have to kill you).....The bindings just simply "overpower" the
subtle affects of most bottom shapes which are more noticeable on foot strap boards . So
keep it simple and remember "rocker line is king".
CKB
Ok, that's no concave with natural rocker then!!!
Dereck
ok, back to the flex thing.... in short....and in general. flex makes up for design
flaws...so by adding some flex in a board, you can get away with bad rails, unproven
rocker templates,etc.etc.... that is why you are seeing most of the production companies
having more flex in their boards..basically, it makes a shit board FEEL ridable... I think
most of the production board companies are putting the cart in front of the horse in terms
of design.. with the current construction method that EVERYBODY is using, it is so cheep
and cost effective that they have not been pressured to make a better board and pay
attention to flex....it is easier to just make these boards with lots of flex and then
spend money marketing it to tell you how good it is. It is that simple.... good for me as
a custom builder, but bad for everyone that spends their hard earned cash on a production
board expecting to get their moneys worth...But don't get me wrong....you DO NOT want a
solid stiff board. You want some flex but not so much that it changes the fundermentals of
the board like the rocker line and twist. (Twist is a big over looked factor...take any
pop out board with ABS rails and twist it from tip to tip and see how everything
changes..) And as mentioned eariler, less flex is better on bindings boards... flex
absorbes energy, and you all the energy you can handle with bindings (to a degree)..and
for footstrap boards, adding some controlled flex helps the allround performance like up
wind chop etc.etc.
got some more info on my site if you want some bed time reading.. sorry to take so
long to reply... I am in Antigua and the wind is distracting me big time!!!
CHANNELS
Kitemulisha Quote:
"What is you opinion on the Nobile 666 boards compared to the Element 134..
From a design point of view? "
Dereck
Ok, I am not a big fan of boards with channels like the element...Great for wake boarding
but for kiting I personally find it kills the feel of the board, it stiffens it too much
and where you want some flex, like in the tips, where the channels are the deepest, it is
the stiffest... Also I find it adds a lot more drag due to the added wetted surface...If I
am going to add so much wetted surface in a board, I perfer it be used in a way that it
makes the board more efficient like just widening etc.etc. Some guys like the feel of a
lot of drag because it keeps the lines tensioned and the pull constant, but you can
achieve this with more attention to rocker line and profile and yet still have a very
slippery fast board.....(anyway, that's a whole other subject.)
I have never ridden the 666, but I went on to the web site and had a look at it to see
what it is about....
Not a bad looking profile, but it is the same stamp out construction that all the
production boards are using
and that turns me off a bit, espically if you want to ride wake style with bindings.. I am
yet to see a production board made this way that can handle the twist and flex demanded
from the powered riding with bindings... That is proberbly why they only offer a 132 X 40
as they biggest board in this model....a bit to small I think for this style of riding....
Most of my orders for wake style boards are at minimum of about 135 X 42/43.... and a
little stiffer than my free ride boards... To answer your question, the stiffness of the
element would suit wake style more, but with a lot of unwanted and unnesserary added drag
and requireing more power.... the 666 because of the common constructon espically with the
thinner sections near the edges..( the :3D mould shaping" as they call it) makes for
a very soft edge that does not suit wake style but will feel coushie for freeriding... I
do not want to sound too negitave, that is not my intent.. these companys make great stuff
for a very general market and for the most part do a great job at it..... but If you are
getting a steal of a deal on any of these boards, go for it.. Of not, look for your local
shaper and tell him/her what you need and get what you want for the same money or less!
Safe flying..
DC.
Kitehigh911
Ref Concave ??
does concave help go upwind and what is the advantage to having board with concave? Is it
faster?
Dereck
I could give you the long or short answer.
Short answer...... YES. it does appear to go upwind a little better.
Is it faster? Not necessarily.
Slightly longer answer...
Upwind performance on a kiteboard (on most water vessels) is similar to racing sail boat
hull design.
Going upwind is all about increased wetted surface. But increasing wetted surface also
increases parasite drag, so the goal is to increase wetted surface without too much of an
increase in drag and a concave is an effective way to do this on a kiteboard....But as I
said above, the increase in wetted surface also increases drag, which, if you are going
for speed is not what you want, so that is why a flat board can be faster than a
concave board. But kiteboards at present are not judged on speed. So the concave is really
used for other reasons. What a concave does as well is give you a bigger angle (edging
angle) for a similar deck angle so the edging properties appear better... also giving more
control........ I use the word 'appear' purposely here. But in the big picture, there are
so many variables that can over come the advantages or disadvantages of having a concave,
like personal technique, kite trim, fin position and so on.. that you can easily get
carried away being forcused on one thing while there are many other things to consider..
So because a board has a concave, do not assume that it will go upwind better than a flat
bottom board. And do not assume that a flat bottom board is faster than a concave board.
What is more important is the rocker line..Rocker line is boss in a kiteboard....Making a
concave kiteboard is more forgiving in that you can get away if the rocker line is not the
best, but on a flat bottom board, it is more critical and the rocker line has to be 'right
on' and you can achieve the same upwind abilities without the additional drag...
Rocker like is everything... but that's a whole new story for another day........ But
again, the nature of kiteboarding has it that there is so many variables and it is a sport
where the equipment is judged on personal preference in terms on what you like best, what
works for you and what will allow you to improve and add to your 'style factor'....Style
factor is big (that too is another topic to get into on a windless day).....
That is why I believe that there can never be one board that is the best for everyone, but
I believe that everyone can have a perfect board. That's where I put my energy, finding a
way to make a board that will allow you to push your limits... All my riders ride totally
different boards, and they all rip!! It's not just the board, it is how the board works
for them...I'll stop there cus I don't what TheKooK to send the geek squad for me after
talking all this tech babble!
Respect
DC.
Dez
did anyone ride the liquid force fish with a kite? i know its got a ton of rocker but its
hella wide and maybe with boots it will be fine....can just imagine it would have sick pop
Dereck
yea, remember, unlimited power behind a cable / boat is a big difference than having to
generate your
own power behind a kite... Boat/ cable....lots of drag is good (ie lots of constant curve
rocker, channels etc.etc ).....behind a kite, it has got to be more efficient.. That's why
wake board designs are very easy, heck you can buy a wake board at wall-mart and have
loads of fun behind a boat...a lot more thought has to go into a kite board.
Quote: (PussInBoots)
Dereck, do you mean to say that the channels on the Element make the board slow? as a
result need more wind? Everyone's saying that this board has fantastic pop but i seem to
need TONNES of wind to do that..technique maybe..
Dereck
yes, lot of drag...Thats why it needs so much wind to get going...and that is why when you
do have tonnes ofwind it can give you good pop because of the drag, you can load up the
lines and gets lots of tension
on your lines and it is that increase of tension and then the relaese from the water that
gives you pop.....
but with so much drag, it is too much work... you can get big pop a lot easier with a
board with less drag
IF the rocker profile is done right....that is a rocker profile that will allow you to
load up and tension the
lines without realeasing from the water before you are ready for it..... if the rocker is
not right, you will
find as you bare off then carve into the wind to load up the lines the boards pops out
before the lines are
really tensioned up, so you Pop, but fizzle very soon after resulting in not getting too
much height........
PussInBoots
Quote:
By off the shelf you mean productions?
Dereck
yes, that is right.. Pirate Dave calls them 'pop outs!'
re 'custom' meaning the cabrinha 'production' board called 'custom' (could never figure
that out marketing I guess... ), they would feel good with straps, but most of the boards
made with that mass produced layered construction, routed out ABS plastic rails with a
layer of glass on the top and bottom, you will find they twist under the pressure of
riding with bindings, so it will be a bit spongee....... not all the energy is being
transfered from the board, the board is absorbing some of that energy...... you can get
away with some of this energy absorbtion riding with straps, but with bindings you need a
little more response.... also you will find they do not offer wider stance options because
the board negitave bends with a wide stance.......(so be carefull just adding t nuts for a
wide stance, you may change the rocker line and kill the feel of a board.) most of them
are all being made in the same place so with just a few small differences, they are
basically the same and would ride the same..... SO if you could pick one up for $200 -
$250 go for it, it would be worth it....But for around $600, do a little more looking
around. Maybe your local shaper can make what you want for the same price ....or less...I
keep my boards less $$ than production boards....... (Thank goodness I don't have to spend
masses of money on marketing so I can keep my cost down.... ) Again, I am not knocking
production boards...they make some good stuff and they are who keep this industry going,
so we all need them around, but generally, it's ok to ride anything if you are just
putting around, but when you want to excell, and start asking these kinds of questions
your equiptment becomes more important......
good luck...
Jason_ssr
I have a custom from Waterboards, and it gets MEGA pop on flat water, but doesnt like the
superchop I
gotta ride in around here. Little to wide and flat for the choppy gusty conditions I have,
and add
a super wide stance, and it gets hard to bury a corner when you need to. but on flat water
it is amazing.
Dereck
hey, anything will ride good in super flat water!. That's easy!
try it.... next time you got butter flat water and some wind, try a cooler lid!! Ok I was
board
Generally, the best production board is the cheapest one.....They are mostly all the same
construction
and feel the same... the difference are the super cool graphics. Just look for a size you
want and go for it...
if the inserts are set up from the factory for a wide stance I would suggest that one,
there is a reason if
a production board company does not put the inserts too far apart...
( they all know that riders perfer wider stances.....) ..with a wider stance than was
intended for a particular
pop out board, there is too much negative flex and the board will tend to break in the
middle off flat
hard landings or mistimed landings on that slider, (And carefull, they will not honor the
warantee if
you have added inserts) and the board will also have a tendency to 'cup' when riding
making the front
end closer to the water and making it really suck in chop where 90% of us ride ......in
chop............
arr'ite!
Jason_ssr
I think it would be awesome to be on the testing/proto team for a custom builder.
But, when your just going with your best speculation and telling a builder to build
"this" or "that",
you dont get to weigh the pros and cons of your decisions until its too late.
I use my custom as a lightwind board because it goes early, rides smooth, and has awesome
pop.
But when the wind picks up (as does the chop) I switch to the LF board.
Dereck
yea, the more info you give us (the shaper) the better...
It also helps to have a look at the other riders that ride for that particular shaper and
see if any
of them have the style you are looking for....see if the shaper has some experience making
boards
for that particular style of rideing.... cus yea, a board for bindings with a wide stance
should
have loads of rocker. The wider you go, the more rocker you can put.. After listening to
my riders
and hearing their feedback when I was developing the THUG, we settled on a particular
rocker curve,
and I got to admit, when the first one came out the vacuum bag, it look liked it had WAY
too much rocker...
but I booted and powered it up it bacame an animal!
So Jason_ssr, you are right, communication with your shaper is key, see if he/she
understands what you
want before you comit.... But even with the pros it may take a few boards to really dial
into what the rider wants...For my team riders, I pretty much know what they expect from a
board so I just try and give them that
and then some MORE!
DRE
the first sick custom board i rode was a Jimmy lewis. as soon as i jumped on it was was
like this is the shit..so later down the line when i got sponsored and could afford to buy
some boards i contacted him and ordered 2 boards. being a pretty well known pro i thought
he woulda hooked me up with a bro deal.
since i would be promoting his shit... NOT Jimmy. he charged me $750 per board...
anyways..
got the boards and they were pretty sick. but i broke the first one in the first sesshion
and the next
one broke within the first week.. so i contacted jimmy and told him there must have been
somethin wrong
with the boards and i wanted to work somethin out. he was like, well im sorry but the
boards were fine and
YOU broke them because YOU landed too hard on them and that i wasnt his tester so i dont
get boards replaced for free. so i was like fuk jimmy.. im over that guy. and thats when i
started getting my boards made by Sean Ordonez. Sean is a really cool guy. he let me crash
on his couch the first few times i came to maui and he's got some serious talents when it
comes to shaping. i hear that Jimmy now puts a disclaimer on his boards sayin he is not
responsible if his boards break. so for the past two and a half years i been developing
boards with Sean. i would tell him some dimensions and what i like the board to feel like
and then he would put the gravy into the foam. then i would ride it for a while and tell
him what its doin and what i'd like to change and he would tweak it. at first my style of
ridin was really into doin big jumps and dangle shit cause thats what u had to do to do
good on the PKRA (and basically you werent gonna get paid or recognised unless you did
good on the tour) so my boards were small (120cm) so i could hold alot of kite. but as i
started to get over riding for judges on the PKRA and felt like i needed to ride more for
myself, i started to ride with my kite lower and ridin more wakestyle. so then i started
askin sean to make my boards a bit bigger and wider and put in dem ingredients to get
MAAAAD pop. luckily my ridin along with some of the other guys on the tour influenced it
to change and see wakestyle riding as the highest scoring style on the tour so that
allowed me to stay in the game and keep doin well otherwise i woulda been doin really bad
in the contests cause i was gonna ride how i wanted to anyways. over the years my boards
went from 120cm all the way up to 133cm. when i got to the 133 we pretty much designed the
sickest board to do wakestyle on footstraps. then the landings started to get crazy hard
and i could hold on with straps anymore so i went back to da roots...bindings. and so Sean
had to build even bigger boards to accomadate the extra weight an shit. so basically we
kept goin up in size until we came up with the magic board. it was an all black 138cm x
41cm... dat board was da shizznit. cabrinha now makes a board that is really close in
outline and rocker to the all black 138 and thats the board i ride now. cause its free and
when i get a new board its the same board so i know it. and i can hit rails or whatever.
arrite.. im over this post. i havent wrote this much since i was in school
Nik (waterman)
... that Custom 38 is the HEAVIEST production board for its size that I have ever
ridden.
It feels like "a couple midgets hangin on to both your ankles" [dre; circa
spring 05]. Supposedly the new Customs are lighter but trust me; that is one heavy ass
board. My bindings board works in gusty, choppy, crappy and great conditions.I am never
for want of extra kite power compared to strapped riders.
Get a custom made board by a reputable builder that knows wake style (read; DC) and you
will be very happy.
FINS
Raider
Hey Drizzle, what size fins did you put on your 138?
thx
DRE
1 inchers... hey! its not the size that matters, its how you use it
GENERAL
DRE
Theres all sorts of boards and bindings out there tho. its good to try differnt styles an
shapes so you can
get a feel for what suits your style of riding or your preference. Just make sure the
board is pretty wide and bigger than you would normally ride with straps. anyways dats my
scoop.
dre
Photos by Dereck published a while back on the Scoop
Inserts
Always seem to give problems
I now make my own from A4 Stainless Steel as brass ones can corrode over
time
Wide base to stop pull-out
Blind tapped M6 thread
Extra carbon over inserts & fins for support and to prevent pull-out