A challenge for me is not a long distance... if I had the interest to do loooong rides, then it would def be a challenge

But my challenges tend to revolve around 20-50km rides and doing them as fast as I can

Training rides and recovery rides become a challenge in so far as I have to MAKE myself keep the speed down - very hard to travel at 26kms when you want to do at least 32kms

Hills with a gradient of 8% or more are def a challenge, I still weigh to much to be very effective on hills and my aim is always to get up there as quickly as I can cause then it is less time climbing... but we have an 11% climb just before I get home, and at last I can climb that with out feeling like throwing up... so guess I am rising to the challenge

A really interesting thread to read. Thanks all