I used to cycle some 5+ years ago. Started again about 3 weeks ago x 3 times per week. Started at 8 miles and have got up to 20 miles (1hr 40 mins). A friend has asked me to do a charity bike ride - 75 miles in 10 weeks.
I really want to do it but I consider myself pretty unfit. I’ve got 5stone to lose (already lost 3).
YABU - it’s too soon, keep training
YANBU - it will be hard but with training it’s possible