I've always loved my G502's shape but I hated the weight. I ended up switching to a similarly modded wheel mouse optical (weighing 62g). So I decided to cut out (literally) all the G502's features I don't use in order to achieve a lighter mouse.
Here's a time lapse of what I did: https://www.youtube.com/watch?v=KAY85p1r9c8
I started out disassembling the mouse completely. This is an impressive mouse. Very little wasted space. Everything seems very strategically placed.
Something Logitech did that I hope more companies start doing is having a teflon piece where the mouse button contacts the micro switch:

So I started out knowing the scroll wheel would have to go. I had already been using a G500/G700 scroll wheel. G502 wheel is 13g, G500 wheel is 11g. Cheap OEM wheels (which I have a ton of) are just 1 gram. Couple that with a blue rubber ring from another cheap mouse and we go from 13g to 2g.
I also removed all components dealing with the infinite scroll feature (since I can't do it anyway with this wheel).
Luckily I have a TON of mice. So I popped out a scroll wheel from a basic OEM mouse as well as a blue rubber ring from a cheap $2 ebay mouse.

The OEM mouse wheel needed a lot of grinding to fit the G502's plastic housing. OEM wheel was too wide, too large of a diameter, axels didn't fit the pin holes, and I needed to shape it such that the blue rubber ring would fit around it.



Scrolls fairly well. Feels far from perfect but I don't use the scroll wheel much in games. I think my axel is slightly off center because each revolution has 1 spot that's slightly harder to turn.
Next I took a dremel to the weight compartment. I cut out a chunk from the mouse body. It's still very structurally sound.

Then I cut off most of the door flap on the bottom that goes over the weights. Since the right side of the plate has a teflon foot I decided to keep that

This door in held in place by two magnets (one on door, one on mouse body). Combined the magnets are only a couple grams but there's no use in having them since I won't be opening/closing the door. Super glue is now holding that right side teflon foot to the mouse body.
I also removed the rear palm rest plate. It's only 5 grams but the mouse isn't uncomfortable without it.
Other parts removed include the two LED light deflectors (one white for the G logo, one gray for the 3 DPI level indicators). I don't care about lights and I only play at 800 dpi. If I ever need to change DPI it only takes a few seconds within the gaming software. With this light gone I also removed the G9 button which I had never used anyway.
I also make my own mouse feet using pure PTFE from ebay. I smoothed the edges of the feet using a dremel with a wire brush.
I'm a little disappointed with how the feet came out. If I switch to this mouse from my current MX510 then hyperglides will be worth investing in.

End result:
Logitech's website: 168g w/ cord, 121g w/o. 37g removed = 84g!



With palm plate on:

Pic of everything that was removed:
Here's a time lapse of what I did: https://www.youtube.com/watch?v=KAY85p1r9c8
I started out disassembling the mouse completely. This is an impressive mouse. Very little wasted space. Everything seems very strategically placed.
Something Logitech did that I hope more companies start doing is having a teflon piece where the mouse button contacts the micro switch:
So I started out knowing the scroll wheel would have to go. I had already been using a G500/G700 scroll wheel. G502 wheel is 13g, G500 wheel is 11g. Cheap OEM wheels (which I have a ton of) are just 1 gram. Couple that with a blue rubber ring from another cheap mouse and we go from 13g to 2g.
I also removed all components dealing with the infinite scroll feature (since I can't do it anyway with this wheel).
Luckily I have a TON of mice. So I popped out a scroll wheel from a basic OEM mouse as well as a blue rubber ring from a cheap $2 ebay mouse.
The OEM mouse wheel needed a lot of grinding to fit the G502's plastic housing. OEM wheel was too wide, too large of a diameter, axels didn't fit the pin holes, and I needed to shape it such that the blue rubber ring would fit around it.
Scrolls fairly well. Feels far from perfect but I don't use the scroll wheel much in games. I think my axel is slightly off center because each revolution has 1 spot that's slightly harder to turn.
Next I took a dremel to the weight compartment. I cut out a chunk from the mouse body. It's still very structurally sound.
Then I cut off most of the door flap on the bottom that goes over the weights. Since the right side of the plate has a teflon foot I decided to keep that
This door in held in place by two magnets (one on door, one on mouse body). Combined the magnets are only a couple grams but there's no use in having them since I won't be opening/closing the door. Super glue is now holding that right side teflon foot to the mouse body.
I also removed the rear palm rest plate. It's only 5 grams but the mouse isn't uncomfortable without it.
Other parts removed include the two LED light deflectors (one white for the G logo, one gray for the 3 DPI level indicators). I don't care about lights and I only play at 800 dpi. If I ever need to change DPI it only takes a few seconds within the gaming software. With this light gone I also removed the G9 button which I had never used anyway.
I also make my own mouse feet using pure PTFE from ebay. I smoothed the edges of the feet using a dremel with a wire brush.
I'm a little disappointed with how the feet came out. If I switch to this mouse from my current MX510 then hyperglides will be worth investing in.
End result:
Logitech's website: 168g w/ cord, 121g w/o. 37g removed = 84g!
With palm plate on:
Pic of everything that was removed:
