DIR Return Create A Forum - Home
---------------------------------------------------------
CycleKarts GB
HTML https://cyclekartsgb.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: Tech Forum
*****************************************************
#Post#: 5478--------------------------------------------------
Cyclekart weight
DIR By: RhysN
Date: February 14, 2022, 1:22 am
---------------------------------------------------------
Just in case new(ish) builders have considered the finished
weight and wondering what to aim at.
A few have been built at under 100kg all up. These were not
built with the conventional 75 x 25 frame rails.
One is
HTML https://gittrevillegp.com/2021/09/18/maserati-250f/.
Another is this which I built for Tieton, on the scales which
were subsequently found to be reading high it was just under 90
kg. As you can see, a space frame with stressed alloy skin.
I know of others that have that much on the front wheels alone.
#Post#: 5481--------------------------------------------------
Re: Cyclekart weight
DIR By: TheGiantTribble
Date: February 14, 2022, 4:30 am
---------------------------------------------------------
That Voisen is beautiful, can you remember what thickness
Aluminium you used Rhys?
#Post#: 5482--------------------------------------------------
Re: Cyclekart weight
DIR By: David F-R
Date: February 14, 2022, 4:41 am
---------------------------------------------------------
Very interesting, and, in the case of the Maserati, very
beautiful.
But these are a far cry from the 'Stevenson Formula' and DIY-er
shed build as I understand it.
Does this mean that the level playing field has tilted?
Or will there be two classes in the future, 'Stevenson's' and
'Not Stevenson's'
Personally, when I start building it will be cheap and basic, to
the formula, for the simple fun of it.
Maybe further down the road I may want to explore lightweight,
more radical builds (I do like the balsa/grp body idea - reminds
me of model building in the 50's though we used muslin and dope
[that's cellulose lacquer not drugs for you youngsters] instead
of grp).
The Stevenson's Formula with plywood/aluminium bodies make CKs
accessible to anyone with a few basic skills and tools, where as
in USA, to be competitive, your wallet does the building and
works teams do the sponsoring - all a far cry from the original
ethos.
Don't take too much notice of this rant, I was disoriented when
I got up this morning and clearly exited the bed from the wrong
side.
#Post#: 5483--------------------------------------------------
Re: Cyclekart weight
DIR By: StefanN
Date: February 14, 2022, 5:42 am
---------------------------------------------------------
I strikes me they’re both close enough to the formula even if
not pure Stevenson construction. The wheels, size, engine, etc
are pretty much standard Stevenson.
Rhys’s space frame is square section tube so could all be cut in
the shed and then if you don’t weld ask someone local to.
Admittedly not Stevenson construction, but not big budget.
The Maserati is bolted together (shed friendly) and the body is
wood former with a wood covering with a bit of ali and
fibreglass, which is close to a Stevenson build albeit the wood
pieces are smaller to achieve the shape. The exhausts on the
Maserati are from scrap ali sun chair legs, glued together…and
that is very Stevenson.
If you’re keen to build very light, then it just takes a little
more care, even with a 100% Stevenson design. Use the lightest
ply you can get away with in any part of the structure. I find
it’s a bit like my midriff - the weight creeps on when you’re
not looking! I took 4kg off the Bugatti just by switching to a
smaller (and cheaper) tyre - went from 3.25” to 2.75”. I then
added it back on with all the flumadiddle I added (hand brake,
working gauges, shocks, etc) but then that’s the build I wanted
to do.
Build it low and light enough, and you’ll have a whole heap of
fun.
#Post#: 5484--------------------------------------------------
Re: Cyclekart weight
DIR By: David F-R
Date: February 14, 2022, 6:05 am
---------------------------------------------------------
I'm sure you're right Stefan.
I think that what shocked me was watching a CK Grand Prix in USA
where the lead cars were either pre-built or 'works' team.
Here in the UK builders will do what they can with what they've
got, the more adventurous trying lots of new ideas, and quite
right too.
So, I've had the grandchildren for breakfast (delicious :-) )
and now less of a grumpy old man.
The Maserati looks absolutely fantastic. I would be so very
proud to have built that, and the balsa/grp is a great way to
achieve the complex form (one to consider for the future for
sure).
I'll follow your advice - keep it light and low. I'm now looking
at a '34 Riley Ulster Imp - that is definitely low. Aluminium
sheet over a 3 x 1 steel frame should keep the weight down-ish.
But fun (building and driving) is my main objective. First job -
making a tool to bend the yokes.
#Post#: 5485--------------------------------------------------
Re: Cyclekart weight
DIR By: RhysN
Date: February 14, 2022, 6:09 am
---------------------------------------------------------
I still commend the basic Stevenson, plywood box with added bits
to provide the aesthetics. My ERA was only just over 100kg built
exactly as Stevenson projects, as there was no other website,
social media or anything.
As Stefan has said, when you start adding things the weight very
quickly climbs. Even using 10 mm bolts when 8 is plenty and 6
would probably work just keeps adding bits, let alone heavy
additional things moving from simple to sophisticated adds
weight. (eg diffs). I don't weld, the Voisin was built in the
garden (note not shed as that was full) with an angle grinder,
cordless drill and a few hammers. Yes I did have someone do the
welding but it was all jigged up ready to do so. Adding weight
always adds cost! A piece of 3mm steel (unneeded anywhere in a
CK in my belief) costs more than 2mm. 12 mm ply costs more than
9mm.
I can not agree that your wallet does the building in the
States, sure there are some that buy stuff, but having taken
part there I can assure you that 99% of folks are scrounging
wherever they can, looking for inspiration in skips, plastic
barrels, old car bits etc. I know of no "works teams" in
cyclekarting, anywhere! Nor do I know of any sponsoring, unless
you count being given a bed for the night, or sleeping in a
truck instead of a hotel :) I would really like to be shown the
"works teams" at any event, I have been to several and not seen
that!
Width of both are within the guidelines, as are length, engines,
TAV, steering, and both accepted within the "formula".
Bill, the alloy was all 1.2 mm.
#Post#: 5489--------------------------------------------------
Re: Cyclekart weight
DIR By: StefanN
Date: February 14, 2022, 7:35 am
---------------------------------------------------------
--- Quote from: David F-R link ---
>
> I think that what shocked me was watching a CK Grand Prix in
USA where the lead cars were either pre-built or 'works' team.
>
--- End Quote ---
I’m guessing you’re talking about the Vintage Kart Co in the US
and the Scottsdale GP. Yep those exist but they’re not typical
of the US scene.
#Post#: 5490--------------------------------------------------
Re: Cyclekart weight
DIR By: David F-R
Date: February 14, 2022, 7:44 am
---------------------------------------------------------
Yes, I'm bang out of order, especially as a newbie, making
remarks based on so little knowledge. And I really was a grumpy
old S*D this morning, not my usual cheery self.
I must say in my defence that I based my initial remarks re USA
on a YouTube video that listed CKs in a race as Builder -
(commercial firm) and a couple of 'Works Team's. I'll see if I
can find it.
But, Rhys, I am very pleased and quite delighted to stand
corrected - and your experience is first hand. I certainly
didn't want to offend and I apologies to all for my ill-informed
remarks.
I really like the the whole concept CKs as it appears on this
forum and in the UK. I shall build one and take on board all
that you and Stefan have said about keeping the weight down. I
have much to learn (and some things like over-engineering, to
un-learn)
In that vein, are 8mm bolts okay for the kingpins then, and is
5mm x 40mm too meaty for the yokes?
Any ideas for scrounging 1.2mm aluminium sheet? I'm trying to
think where it is regularly used.
#Post#: 5491--------------------------------------------------
Re: Cyclekart weight
DIR By: RhysN
Date: February 14, 2022, 7:54 am
---------------------------------------------------------
David no offence taken. I did think while driving that you might
have seen Scottsdale and VKC, that was a very commercial
exercise, if my memory is correct it ran twice. You had to use
their cars, again from memory it cost $2500 to take part. Where
the money went????
In regard kingpins, most racing carts use 6mm! I would suggest
8mm is probably a bit more like it although I tend to scrounge
second hand gokart parts, and yet to have had a problem. The
yokes I have here are 5 mm, there's nothing in material between
3 and 5 mm so.....
I have dropped you a message, might be worth a call?
*****************************************************
Page 1 of 1