UKC

In the scenario where you bail on a trad route, I've always heard it said that you must recover the gear either by abseiling, or by someone else climbing the route.

However, if you've placed good gear, at fairly close intervals, would it be unsafe to downclimb and recover it yourself? Clearly this could be awkward, but I can't see how falling on the same gear would (in general) be any more dangerous when downclimbing than when climbing up. As you remove each piece of gear, you become protected by the piece below.

Not looking particularly to argue for this view, but keen to see if there is anything I've missed/misunderstood.

This is a valid technique, sometimes called down-leading. It's in Andy Kirkpatrick's book Down.

The main issue with this is that downclimbing is hard and slow. Most climbs near my limit where I've needed to bail are much too hard to downclimb. Part of the safety of trad climbing comes from knowing when you're likely to fall off and when you're not, and downclimbing changes the calculus a lot.

That said, downclimbing is a very useful skill and worth practicing.

Yes, it is feasible in the right circumstances if the terrain is easy enough. I did it recently on a seacliff VDiff after encountering a nesting fulmar which was invisible from below. It is psychologically harder as when you remove gear, you suddenly find yourself in a more serious situation, and if any of the gear is stuck, you may not be able to extract it easily or safely. It is also worth bearing in mind that if you have weighted the rope(s), outward forces may have unseated gear lower down. 

"In the scenario where you bail on a trad route, I've always heard it said that you must recover the gear either by abseiling, or by someone else climbing the route."

These are certainly two options, but I'm not sure you 'must' recover the gear this way. It depends very much on the route, the situation and your own knowledge and skills. Down climbing would work if the route is within your ability and you judge it reasonably safe for you to down climb - you've already highlighted the need for good gear at fairly close intervals. 

   A compromise could be to ensure you are 100% happy with the highest piece of gear ( back up as required ) then down climb only leaving the top pieces behind. Alternatively you could be lowered from your highest pieces of gear ( again if you are 100% happy with their placement ). Another option is to make yourself secure and arrange for a top rope to be lowered to you which you can then use for either abseiling, down climbing or being lowered whilst stripping your own gear.

   The ideal is to remove all the gear you have placed and down climbing is certainly an option, good communication with your belayer will help. I don't perceive that you have missed or misunderstood anything and I agree with Suncream about down climbing / leading, it is a great skill to have. I use it a lot in the Alps...

I'll not say which option is less safe, it's very situation specific and tied to your competencies but stripping a route as yoy downclimb or even partially lowering, partially downclimbing can be quite safe if done carefully with sufficient experience.

Jk

I've done this a few times to save leaving gear on the cliff. No reason why not if you can downclimb. One variation; I had to downclimb a pitch that was very loose - so I did not want to sit on any of the gear. Fortunately there was a solid looking rock band in the middle of the pitch. I kept one rope clipped into a nut on that solid rock band as a top rope. I downclimbed taking the rest of the gear out back to the belay, then retreated from there. At the time the gear was sacrificial, but I went back six months later, clipped the nut and finished the pitch.

There is a variation to this involving taking out the gear and jumping off.

If the fall is clean, and the next gear is back on easy ground, then taking a long can get you back into downclimbable territory.

I've done it a few times, most memorable being The Strand at Gogarth. For whatever reason my head wasn't in climbing that route that day, every gear placement was a struggle and never seemed to fit properly so ended up down climbing and taking my gear out.

20 years later I'm hoping this has not blown my on-sight attempt as technically I'm just having a rest

Quite right!

It's not a "must" - there is no obligation to retrieve gear, although it's expensive stuff so obviously you'll want to try to do so if it's possible and safe to do so. However the priority must always be safety, and if you have to abandon gear then so be it, that is sometimes just part of trad climbing. Someone will soon be along to remove it.

I don't think this is an entirely appropriate suggestion on a "Starting Out" forum!!