Andrew, this route from the Route Guides passes through Allenheads. Perhaps you'd like to share the source route? 

So that was the route I was using.

Not sure what's happened but it definitely was skipping Allenheads before...

All's well that ends well I guess.

I'm new to this route but it looks wonderful - except the gravelly bits - and like many long distance hike/bike routes I imagine it would provide much greater pleasure doing it with others to share the experience and fun.

I've worked it out.

If you add add via points or overnight stops, it reroutes partially off the c2c route

So for example if you set it to three overnight stops, Allenheads is fine but to the east of Rookhope a bit of the ncn7 gets routed rather than the c2c marked bypass.

Ken, I'm doing the C2C right now with panniers full of camping kit. It's really quite wonderful if a little hilly. 

It's probably not the ideal (first time) route for doing a cycle-camping trip - having to lug the kit up the >3km total ascents and being slightly unstable for taking photos and the gates makes things slightly awkward.

B&B/Bunkhouse/Hotel tour or organised tour is probably the way to go.

The route guides on the site were mostly laid out before the “cycle routes only” routing mode came along. I’ve been working on some code to change this which will mean any editing sticks more religiously to the signposted route, but until then, changing the routing setting to “Routes” will probably remedy this.