I always feel like I'm sliding forward on my saddle after a while so I always take an allen key with me and occasionally slacken the front bolt off half a turn and tighten the back bolt up the same but still feel like my bum bones aren't where they are supposed to be. Anyhow today I found an 8" spirit level, I put it on a slightly angled piece of wood then turned it 180º to check its accuracy. When I put the one end on the nose of the saddle there was a good ½" gap over the cheek area of the saddle so why do I keep sliding forward ? I've done the old knee over pedal at the 3 o'clock position (albeit on my own) and that looks OK. I think that's why my hands are aching after a while as I seem to be pushing my self back all the time. Any suggestions ? start from scratch ? Saddle height is OK as I can just about tippy toe on one foot when I stop. Saddle, for what it's worth is a Tioga XC and the bike is a CB hybrid.