Because CT uses Open Street Map data, most of which is supplied by volunteers, I wouldn't be willing to give a "rock solid" guarantee on road surface. 

Mind you, I wouldn't give it for any bike route planner and CT is better than most in my opinion. 

My experience in mainland Spain is that there are a lot of roads that might well be "paved" and were once paved, but would be stretching the limits of most people's definition of paved in their present condition. 

You could use the "Street view" or even the Photos option (where Street view isn't available) to check out your route in advance.

Alternatively, have a look on either RWGPS or Komoot for the routes that others have created before. I'm not familiar with the Komoot method but RWGPS can sometimes throw up some interesting options. Of course, you're still not sure of the surface unless the creator makes it clear. Whether you can download the route or not, depends on your subscription. 

Hope this helps

Thankyou HobbesOnTour, that is very helpful! I thought I was probably asking a bit too much of the app. I have been told there is a printed map showing all the road bike cycleable roads and lanes on the island so hopefully if all else fails I can cross reference any routes I make with that map.

Thanks again, 

Nick

Hobbes is spot on in that c.t is only as good as the surface info that’s in OpenStreetMap – and that varies from country to country.

In the UK or Germany it’s very reliable. In (mainland) Spain it’s mostly there but a bit patchy. In the rural US, OSM’s data is terrible, but c.t does a lot of heavy lifting to work around that.

Briefly eyeballing Majorca it looks broadly reliable, but possibly some of the ‘service roads’ (which c.t tries to avoid in any case) might be missing surface information. So I think you should be ok, but it wouldn’t hurt to give any routes you plan an extra once-over using the Street View link from c.t. 

Thankyou Richard for your help. Couldn't do without your app.