Lead Shock

Brad Fish · Joined: 03 Oct 2008 Posts: 45

I dug the scales out and weighed my son's JB kart for the first time. I'm having a very hard time wrapping my head around the fact that I need to put 70# of lead on the kart. That's 20# more than my son!

Thank goodness we're running a K80 or it would be worse.

Any advice on location, type, and fastening method for that much lead?

Does it have to be coated or can it be natural?

Scott Boito · Posted: Sat Mar 03, 2012 2:38 pm Post subject:

Welcome to my world! Kieran weighed 50 with gear two years ago, when the K80 was still 250 lbs. His kart weighed almost as much as mine with the lead.

For the lead, I acquired various 5 lb "cupcakes" and use galvanized bolts and double nuts to secure. I add rubber washers to reduce vibration and protect the seat. Here's a pic of how the left side and rear look: https://sites.google.com/a/betteroffracing.com/www/videos/NJPro-2.jpg?attredirects=0

As for the distribution, generally speaking you want it toward the back, with weight distribution around 43% front and 57% rear. For us that meant a huge amount of lead bolted on to the seat and about 20 lbs on the floor board. Last year we moved up to the KT100 and a full-sized chassis and he only gained about 5 lbs, so again the weight was mainly added to the seat.
_________________
KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

Brian Garfield · Posted: Sat Mar 03, 2012 3:12 pm Post subject:

The cakes are common to use, but if you can acquire raw bricks of lead from a manufacturer (that's where we got all of ours), it becomes a lot easier as it's more dense and you can cut/melt to whatever shape you want. Not sure if they'll sell to individuals anymore, but a place called OG Kelly in Tennessee was where I got mine. Back then, it was $1/lb.

BTW, if you have small kids, then JA will actually be worse than JB. Julian had 80lbs when he first started in JA. (never mind the fact that we have always had 80lbs on Lisa's)

Brian

Christian Hubbell · Posted: Sat Mar 03, 2012 9:57 pm Post subject:

Think it's lead shot. Any who, melt some down into a baking pan outside. Beat it with a hammer to add some shape and it'll mount nice to the back of a seat with 4 bolts.

Brad Fish · Joined: 03 Oct 2008 Posts: 45

You are correct. It was a play on words since I'm in "shock" at how much lead I need to buy.
Attempting to be funny.

Christian Hubbell · Posted: Sun Mar 04, 2012 11:13 am Post subject:

Got it now;)

I've seen people use lead sheets to make a removable seat insert, saves you from lifting an extra 15 pounds every time.

Matt Miskoe · Joined: 27 Dec 2011 Posts: 12

Although I have not yet done it, someone gave me the suggestion of removing the rear bumper and filling the frame rails w/ lead shot. I have no idea how much weight you can hide in there or how hard it is to do/remove. I like the idea for how simple it is and that it keeps the weight down low. Not as good as concentrating it in the very center of the cart, but low is better than high.

F1 teams used to get spent/non-radioactive plutomium type materials because they are denser than lead, thus being able to concentrate the weight where they want it. You think lead is hard to come by...

Andrew Peppler · Joined: 08 Aug 2010 Posts: 90

Weight up high is not bad for little guys karting, you want the frame to flex to work.. totally different from cars or F1 with suspensions.

I've got 60+lbs on ours, 40 on the back of the seat, 6 on the left side, 8 underneath the seat between the legs, and 10 lbs on the floor tray near the feat. Yes, it is heavy to lift.

I got my lead from http://www.divers-supply.com/Search.aspx?k=lead%20weight and painted them white per sprint race rules.

Tim Koyen · Advertiser Joined: 26 Nov 2002 Posts: 1557

Karl Hughes · Joined: 15 Aug 2011 Posts: 20

Joe Ricard · Posted: Thu Mar 08, 2012 6:25 am Post subject:

We got smart about adding weight to my son's JB Birel C-28 (cadet)kart. Limited real estate with the smallest seat made.

When I looked for more room I custom made two pucks 3" dia and to the exact thickness of the bottom seat bolts. doesn't affect chassis flex and I was able to easily add 3 pounds in a place normally occupied by 3 ounce plastic spacers.

I an using an old Porsche air cooled cylinder as a mold. this way I can make a 1lb to 9lb puck just by changing the amount I pour in. We also have lead heal stops about 4 pounds each.

Then custom fit the piece under the seat crotch. hammered the snot out of it till it exactly fit the contour and also cleared the ground.

Then two 9 pound pucks up high on the seat back and a couple more 5's on the side aa well as lower seat back.

Yep that little kart is heavy.

BTW thanks for the 10 additional pounds to run the new restricted WF. Very Happy

_________________
Arrow AX-8/ Rotax Sr.

Dale Seeley · Posted: Thu Mar 08, 2012 4:16 pm Post subject:

Write a letter....

Especially when the spec engine comes into play, a spec gear with a reasonable min weight makes a lot more sense.

Brian Garfield · Posted: Thu Mar 08, 2012 5:18 pm Post subject:

You'll never win that argument until they tell the heavy kids that karting isn't their sport.

It's funny, we will be adding less lead to Julian's Spec Miata than the kart....less than HALF the amount.

Brian

Brad Fish · Joined: 03 Oct 2008 Posts: 45

Joe Ricard · Posted: Fri Mar 09, 2012 10:17 am Post subject:

When I need lead I just make the rounds to all the tire dealers. I bring a couple plastic 5 gallon buckets. Usually they let me have all I can carry off.

Then my son sorts through the alloy weights and lead weights. I melt them down, pick out the steel clips and pour.

I have about 150 pounds of assorted pucks. still nothing to what Brain has I bet.
_________________
Arrow AX-8/ Rotax Sr.