First is saddle tilt- level or slightly nose up so you're not sliding forward.

Second- if your butt wants to be more forward, move the saddle forward to be under it.

Third- if reach is too long (unlikely with such a short stem unless the frame is too big) raise handlebars or change bars to smaller pattern.

Forth- allow some time to develop the flexibility & core strength needed to comfortably hold riding position.

Assumes that saddle height is reasonably good.

Thanks woodcraft for the thoughtful responses!

first, we are level and also tried to adjust slight nose up, no change in the issue.

second, moved the saddle forward, and that also did little! I hit the “stop” zone on the flite and would like to stay w/in OEM standard.

Third, you are correct, the frame is not too big, but here’s the rub, could the stem be too short? It almost seems like lengthening it by 10 or 20 mm could take up that “little hop back” I spoke of.

fourth, yes there is a chance I need training to hold the position but I’m ::almost:: slammed as it is and do not find that flexibility is ever anything that’s an issue for me on the bike. Strength to hold the position may be needed, but if this can be taken care of by altering my “hard” measurements, I would choose that option!

i came here for insights like yours so thanks again for writing. Would love to hear from anyone who has gotten rid of the dreaded hop back with a longer stem.

Experimenting is good but if you tend to move forward then moving the bars forward doesn't seem like a fix.

Raising the bars temporarily can often help fit issues- early season or post-injury, then incrementally lower as fitness improves.

What size is the frame? Short stem, 0 setback seatpost and saddle forward would give a very compact riding position for most bikes/riders.

Having the saddle forward could be part of the issue since setback helps to push the butt back as you put pressure on the pedals.

Backwards of what has been suggested. It's the opposite.
1) Always level your saddle. What level is varies with saddles, which are mostly slightly curved in profile. I level the part where my butt is. The tiniest change can make a big change in comfort. Make tiny adjustments until your butt feels best. It has nothing to do with sliding forward.
2) When you slide forward on the saddle, it's always because the saddle is too far forward, not too far aft. Sliding forward means you're always pushing on the bars to hold yourself in place. Moving your center of gravity back solves this problem. Ideally, your hands should be very light on the bars. Perfect is when you can take your hands off the bars without sliding forward on the saddle. You may need a setback post if you don't already have one. Stay within the markers on the saddle rails. Some say the clamp should be in the middle of the rails, but that's silly. Fit is more important than someone else's aesthetic.

You should be completely at ease on the bike. Your reach is correct when, as photographed from the side, your upper arms make a 90° angle with your torso when your hands are on the hoods or in the drops.

Try using a setback seatpost and longer stem. I've got long legs for my height and a short torso. I have a 25mm setback post and use a -17 degree stem, 110mm length, but I also use short reach bars. With longer reach bars, I'd only use a 100mm stem.

How's your flexibility and pelvic rotation? Sometimes sliding forward is a result of your lower back and pelvis trying to rotate itself back upright, due to tightness and not maintaining a straight lower back.

Alternatively, curved saddle profiles can somewhat stop you sliding.