Saddle fore aft position - numbness

[Chicken Chaser]

Hoping someone might be able to explain this for me. When i'm riding on the turbo, I can ride for 2 hours with little numbness at a natural cadence for maximum power (around 77-79rpm) up to around 85rpm. Once I start doing high cadence, I find myself shifting forward on the saddle (riding on the rivet if there was one) and spinning the legs up to 100rpm. I can maintain the high cadence but after a few minutes I can feel numbness in my right leg as saddle is pressing inside of my sit bones (due to shifting forward).

Is this a saddle fore/aft positional problem or just an unnatural cadence for me? I've tried 3 or 4 saddles now with and without cutouts and it happens with any of them when doing this.

[Jimbo.]

You're shifting away from your optimal position on the saddle and piling loads of weight onto your barse (presumably) on the narrow part of the saddle.

Or at least that what it seems.

ISM saddles all the way!

[Chicken Chaser]

I cant actually get the required cadence in the same saddle position though, I'm then probably sat on my Perineum.

[upsidedownmark]

Shouldn't be the case - typically you move forward to put out more power; try dropping the resistance further.

Failing that, if you're determined to increase your cadence, do it in steps. Not everyone is suited to riding at 95-100rpm, one size does not fit all. Get to a point where 85 is normal/comfortable, then add 10 and so on..