Alright, mate, so you're wrestling with that '87 Raleigh Maverick, eh? Classic bike, those. Now, about that 1" Tange quill stem, those nuts can be a bit of a pain. Generally, you're looking at a 32mm spanner, but here's the thing: those old bikes, they can have their quirks.
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First off, don't just assume it's still the same size. Seven years is a long time, things can change. Grab a measuring tape and double-check that nut. You don't want to be stripping anything.
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Secondly, you're gonna want a proper headset spanner. Those regular wrenches are often too thick, they just won't fit in there. A headset spanner is thinner, designed for this exact job. It'll save you a lot of grief.
If you're still scratching your head, honestly, just take it to a bike shop. They'll sort it out in no time. Or, look online for a headset wrench. It's a handy tool to have if you mess with bikes a lot. But yeah, those old bikes, they've got their own personalities, you know?