How about describe the feedback on those 90/10 tires. How fast can you go through loose rock? What gear can you safely run in? Does the front of the bike want to wash out? Are you standing or sitting? When going through a loose corner are you able to steer with the throttle? Or do you slow way down and turn your bars in the direction of the turn?
I'm not going to lead my wife through any significant loose rock that will give her a problem. 90/10 tires are perfect for that.
I'd have no problem running those up to 70 MPH or more, on the wet dirt roads around here. Which is
probably more that I'll ever put her through. 90/10 tires are perfect for that.
My wife is not aggressive off pavement, so if she's in a loose corner, she's already pretty cautious and probably not slowing down much. 90/10 tires are perfect for that.
She likes to stand. Has learned that getting off the seat makes her feel way more comfortable when the ride gets a little shaky. 90/10 tires are perfect for that.
She might try to steer with the throttle on her XT250. Definitely more spirited there, but still not what anyone would call aggressive. 90/10 tires are not perfect for that bike, and it doesn't have them.
For me, when I took her BMW to "test" it on a dirt road for her, the road had a light sheen of mud from the rain the night before. I tried pretty hard to get it to slide around, it didn't want to. I'd throw it from side to side with the throttle nearly pinned and it hooked up so well I was actually surprised to look back and see I was leaving a trail behind me. After a few runs back and forth I handed the bike back to her and told her, "you've got nothing to worry about with these tires, don't spend a second thinking about it."
Overall, I know what kind of places I'm going to put her, and those tires are not a concern. Sure we could end up some place I'm not expecting, but she's smart, cautious, and follows the riding directions I give her extraordinarily well (I stress
riding directions). If it looks like too much, I always offer to take her bike through it. 95% of the time, she declines that offer.
I intend to keep her on the same Bridgestone Battlax A41 tires as long as they keep making them. I think it's the prefect tire for what she's going to ride...which includes a good amount of easy dirt.