Used with GSX-R125 Grip power that does not feel like a mock-up at all
I used it with GSX-R125.
The standard size is 90/80-17 but I changed the size up to 100/80-17 and reversed the rotation.
The rotation is reversed to prevent the block from collapsing, but please don't copy it.
The BT-39SS is a high grip tire that is well known in the Mini bike race.
To put it bluntly, the grip is so high that it doesn't feel like a mock-up at all, and the handling is so good that you can run through the corners with the line you have in mind.
If you're in doubt, you can't go wrong with this one.

