The best source locally is Xabia Bikes in Xabia/Javea, you can do rides with them and/or get local routes from them, you can also hire good bikes from them. They have a facebook page. There is a pdf of local routes on their website, but neither of the routes we did appear on their list, so I presume the ones they have published are easy and/or totally legal routes. The best stuff will be word of mouth I suspect.
If you’ve already been to the area, then it all looks as though it should be very good for MTB. unfortunately, the maps are a bit rubbish and there don’t appear to be any local guidebooks, like we have in the UK. But, as in the UK, all the best stuff will be locals knowledge. I’ve heard good things about Guadalest, which is not too far away.
What I know about Jalon, apart from Verdi Vent, which is excellent, we went to the big flea market which is on a Saturday I think. Also, the local Bodegas sells really good cheap red wine in 2L plastic containers. That’s about it.
I’ll try and sort out those two routes for you, probably just a rough line on a map I’m afraid. Both these routes were given to us by the Xabia Bikes bloke. Mugboo^ went out on one of their Sat afternoon rides. I’ve got a load of gps files or something that someone emailed me (might have been portlyone) which I’ll email to you if you want them, but I think they are the same as the routes detailed on the Xabia Bikes website.