Fulcrum Sizes

What tends to be everyone’s preference on fulcrum sizes when stretching? Reading through various threads there is some division on the ideal size. Some folks preferring drum stick type circumference and others preferring anything up to wine bottle size.

Curious as to differences noticed by people who have used both larger and smaller sized fulcrums .

I have been using an aluminium water bottle (filled with hot water for heat) which is 22cm circumference. It has been good but I feel I don’t hit my maximum BPFSL maybe a smaller circumference will be more fruitful.

I use a supplement tub for inverted v and side fulcrum stretches. A tub like you get a pre workout powder in.

For hanging I like a rolling pin or a metal pole (it’s actually an attachment grip for pull downs)

Mine is the back of a chair with rounded edges, about 3/8-inch thick. For me, wider diameter fulcrums are worthless.

More information/opinions about fulcrum diameters? When I hanged over fulcrum years ago I found that larger fulcrums like 45-50mm feel better and seem to target longer area but not as intense as smaller fulcrums.