I put a pair on my wife's Giant and they've worked fine on a mixture of surfaces. They are a nice wide tyre with decent puncture resistance. I was a bit worried initially on some of the gravel cycle paths but it was just me being over protective regarding her riding skills and I should have realised she was more than capable. They won't grip so well when the surface gets loose or slippy, but if you are happy you can handle the bike in those conditions, the tyres should work adequately in them. As you're talking about riding along a canal I think presuming relatively flat and no sharp turns is a fairly safe bet. The ideal option would be something different, but if that isn't an option for you, then the fact is you shouldn't be doing them any particular damage using them there.
