Arriva Buses Wales - Bangor Depot

[Quackdave]

RE: Arriva Buses Wales - Bangor Depot
Help - am I missing something obvious here?

During my research into Bangor's DAF/Lowlanders, I found that it appears not to be particularly unusual for them to turn up on the 5 (e.g. 4188, 4189), and I seem to recall in the days of the Olympians that I also saw a fair few photos of those on the 5/X5.

However, when I actually went on a 5 yesterday (on a Pulsar), I noticed that on the way through Conwy, it passes under a 12' 0" arch, which is a good foot and a half lower than a low-height double-decker (even Barton's unique Dennis Loline wasn't that low). Furthermore I can't see any alternative route out of Conwy for the westbound service that doesn't also go under a 12' 0" arch, since Upper Gate Street and B5106 Llanwrst Road (*) also have them, and Berry Street is one-way eastbound. So, other than going via the A55 tunnel and missing out six stops, I'm at a loss as to how these vehicles can be used on this route.

Can anyone put me out of my perplexity?

(*) EDIT: Llanwrst Road is actually 12' 9", apologies