LEGO Weights are available from LEGO Education. They are not cheap:
$10.00 for two weights. My two teams used them last year to balance the
robot (keep the drive wheels on the mat) when the robot was carrying
objects. The product ID is W779936.

Here is the website to the part:
https://www.legoeducation.com/store/detail.aspx?ID=908&bhcp=1 

Bill

-----Original Message-----
From: First Lego League Discussion
[mailto:[log in to unmask]] On Behalf Of Robert Haskins
Sent: Monday, November 03, 2008 10:54 AM
To: [log in to unmask]
Subject: Re: [VADCFLL-L] where to find lego weights

I don't know if you have access to the mission tabletop pieces from
2006, but one of the missions that year used a couple of Lego weight
pieces that my team is using on their robot this year.

On Mon, Nov 3, 2008 at 10:38 AM, Burke, Stephanie
<[log in to unmask]> wrote:

> My team needs to sue some counter weights, and just rereading the 
> rules see that we can't use extra RXC or other type motors, even if 
> just for weight and not used as a motor which is what they had come up

> with as a solution.  Does anyone know where to find these locally in 
> NoVa (preferable Manassas/Warrenton area)?

______________________________________________________________
To UNSUBSCRIBE or CHANGE YOUR SETTINGS, please visit
https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or
leave the list".

If you want to join the VADCFLL-ADMIN-L mailing list - to which FLL
administrative announcements will be distributed - visit
https://listserv.jmu.edu/archives/vadcfll-admin-l.html and select "Join
or leave the list".

______________________________________________________________
To UNSUBSCRIBE or CHANGE YOUR SETTINGS, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".

If you want to join the VADCFLL-ADMIN-L mailing list - to which FLL administrative announcements will be distributed - visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html and select "Join or leave the list".