UPDATE
Finally got around to filling the tires with some sand.
$6 of tube sand weighs 70-75 lbs depending on the moisture content. This is far cheaper than steel weights at about $1.00 a pound.
The hole saw had no problem going though the rubber.
The sand flowed easily in, some dust associated with this, so wear a mask or do it outside.
I had my weight lifting neighbor spot me and did a few reps. The sand plus bar/tires came to 133 lbs. The tires do not spin at all, quite a relief.
Lots more room in the tires, they are only about 1/8th full right now. Temporary plugs in the top fill holes will be replaced with rubber plugs or rubber corks - soon.
Now I have one more exercise to add to my list.
And to top it off, earlier in the day I managed to swim a full lap at the public pool. At my present rate it will be about two weeks until I can do two laps back to back.........something to look forward to. I used to be the fastest kid in the city way back in Jr High school, that was a long long time ago.
