A few more clues about where you are starting from, how long your trip is, what sort of thing you like, bike, style of accommodation, etc etc would help. I also see on another thread you know about the NC500 - that would be a good start. Nevertheless and assuming starting somewhere south of Glasgow.....

Dumfries and Galloway esp Galloway forest park is good and is a relatively quiet part of Scotland.

Ferry to Arran for a night or two then off the other side to Kintyre.

Head north keeping close to the sea until you run out of options at Durness. You won't be disappointed. On the way you have options to take ferries onto several islands or to make the islands part of the trip - look at Cal Macs hopscotch tickets. Again the islands won't disappoint either.

At Durness take a right and head half away along the north coast and take another right at a Tongue, Bettyhill or Melvich and then generally south to Inverness. Unless you really want to go there ignore a John o groats.

Head east along the moray coast before aiming for the Cairngorms via Tomintoul to Braemar or Ballater (royal dee side). And then south and west towards Pitlochry, blairgowrie and Crianlarich. Then south around Loch Lomond and Glasgow.

There's loads of variants on the above. West is generally best though IMHO.