Not sure if you are thinking of fly or spinning/bait or both.
For fly I have a 10ft Shakespeare Expedition in high modulus carbon - its not actually telescopic but is four piece so fits on the rucsac - comes in a nice olive cordura hard case so you just strap it on the side. The Hardy Smugglers are very nice, but very, very expensive.
For spinning I did have a £8 Shakespeare Firebird telescopic in glass fibre. Fits in the bumbag, let alone the rucsac. After years of abuse, the kids finally broke it. I'm now using an unbranded cheap made in China equivalent. Works fine.
I believe there is a combined fly/spin rod, but never tried it.