Used to take our two collies out all the time, one of ours would run himself ragged without complaining – I think his longest ride is about 50km…
But… I wont take him out on anything hardpack now, or any length over 20km. It really is just too high impact on their joints, and I’d rather have a healthy active dog for longer.
I should also say he’s bred for working and agility, with an exceptional hip score – but I’m still more reserved with him now.
Soft, local trails for a couple of hours are spot on really.
With regard to taking him out, is he good off lead? how’s his recall?
I’d be looking for a strong recall first, then take him out for a walk with the bike and just see how he reacts to it without you riding it… then ride with him. If you ride slow enough, and do whack him, he’ll soon give you distance – without you actually hurting him.
Try not to stop too suddenly on fast descents, or you may find he stops with you and pulls something.
I may sound cautious, but riding with your dog his high impact for long periods of time; so just be sensible and start off small and easy.
In terms of wearing them out, I find my very energetic collie is far more tired from 5-7 hours walking in the hills compared to when he’s been 4 hours out on the bike. Even more so if we’ve been working his brain.