is it the bike, or have I gone mad

I rode the 'blade the other day - the first time in *ahem* a while[1].
It felt odd, as if there were something up with the tyre pressures,
but a manual (attempted squeeze test) check showed they were still at
least "full of air".

What it actually felt like was that it was much slower steering than I
remember, and it also felt as if I were riding across a slope - it
seemed to be happier turning left than right.

I had exactly those symptoms on the Zed. It was low pressure in the front
tyre.

yeah, yeah - I'll check at the weekend - it does seem the mostly
likely cause of the problem.

Nononononononononononono!

It's... Umm... Err...

It's sublimation of the front wheel and steering head bearings. That's
it.

All you need to do is take it out on a really tight bendy road and ride
it flat out. A road with stone walls at either side works best
because... because... they retain the airflow so that the sublimated
matter is dispersed efficiently.

Don't touch a thing, just keep it nailed down a really twisty road.

Trust Me(tm).

As much as I do trust you uncle, I'll see what happens to someone this
weekend when I pass long this gem. If it's as you say, the first thing I'll
do is bin me tyre pressure doobrie.

Tyres will feel "full of air" when they have 10~15psi in them. You
really need to check them properly. It's the most likely cause of the
sensation you experienced, and also the most likely thing to have
happened when the bike's been stood for 9 months.

Indeed. Recently my bike seemed very slow to turn into corners. Somehow [1]
the rear tyre had lost 20psi. At 16 psi it looked and felt okay.

[1] there were also 2 slash marks in the outer tread blocks so I suspect
tampering whilst parked up in Monmouth. TFF for trailie block tyres as the
chunks of rubber removed were not part of the main carcass.

OK - I'll check them.

The frame's bent - I'll give you 50 quid for it.

I'll top that - Ł60. And I'll even come and collect it.

done[1].

[1] please note Ł3450.00 administration fee.

Any idea what could cause this, as it was perfectly fine the last time
I had it out.

[1] about 9 months[2].
[2] I've been very busy this year.

you're pregnant and I'll be your agent

can't be - I've had the snip.