38mm, 45psi front, 48psi rear. That's what I've settled on for a bike that spends half its life on smooth principal shared paths and the other half getting shaken around on loose limestone. If you're trying to pick one tyre setup for Perth's mixed paths, the number matters more than the brand on the sidewall, and most people get it backwards.
The question I get asked most at the shop counter, or from mates before a Sunday ride, is whether to run proper gravel rubber or just stick with slicks and cop the rattly bits. Wrong question. The right one is: what's the actual surface split on the route you ride most, and are you willing to compromise on the bitumen sections to survive the gravel ones, or the other way round.
Why tyre choice matters more than the bike here
Perth doesn't have brutal terrain by national standards. No rock gardens, no proper singletrack unless you go looking for it out past the scarp. What it does have is a patchwork of surfaces stitched together on the same ride: smooth PSP concrete, then gravel-topped fire trail, then a stretch of cracked bitumen with tree roots pushing through, sometimes all inside twenty minutes. That patchwork is the actual problem, not the terrain itself.
A narrow slick at high pressure is brilliant on the flat commuter paths and genuinely dangerous the second it hits loose gravel on a corner. A wide knobby tyre survives the gravel fine but turns every bitumen kilometre into hard work, and on a 40km loop that adds up to real fatigue for no benefit. Neither extreme is right for what most Perth riders are actually doing, which is mixed-surface commuting or weekend loops that touch both.
Reading the surface before you inflate anything
I rode the loop through Kepal Road a few weekends back on the gravel bike, partly to check on drainage after some rain, partly because it's a decent stretch to test tyre choice honestly. It's mixed the whole way, hardpack in sections, soft and rutted after wet weather in others. Runs a slick there and you'll feel every stone through the bars. Run something too aggressive and you're working twice as hard once the path firms up again near the road crossings.
Gravel Trail does what it says on the label, and it's genuinely one of the better places locally to test a new tyre before committing to it for a longer ride. Loose in patches, compacted in others, and it'll tell you within the first kilometre whether your pressure's wrong. If you're skidding on the corners at 45psi, drop it. Simple as that.
Coutt Road is the one that catches people out. It looks like a straightforward gravel run on the map but there's a fair bit of loose surface scatter over hardpack, the kind of thing that grabs a narrow tyre and throws the front wheel sideways if you're not paying attention. I wouldn't call it technical. I would call it unforgiving of the wrong tyre choice, which is a different thing entirely.
Bitumen sections: where slicks actually win
On the smooth PSPs, a slick or semi-slick at higher pressure is flat out the pick. Less rolling resistance, no wasted energy pushing knobs through smooth concrete, and honestly it's just a nicer ride. If ninety percent of your riding is commuter path and you occasionally dip onto a formed gravel verge, don't overthink it. A 32-35mm tyre with a light tread down the centre and a bit more grip on the shoulders covers you fine.
Where people go wrong is assuming the whole network is like this. It isn't. The second you head toward the hills or onto anything unsealed, that same tyre becomes a liability.
Gravel sections and the width and pressure numbers that matter
Width does more work than tread pattern, in my experience. A wider tyre run at lower pressure has more air volume to absorb impacts and more contact patch to find grip, without needing aggressive knobs that just add rolling resistance everywhere else. I run 38-40mm on the gravel bike and drop pressure to the low-to-mid 40s in psi depending on rider weight and load. Go much lower than that without a tubeless setup and you're punting on pinch flats, which isn't worth it on rides with any real distance.
Tubeless changes the calculation properly. You can run 5-8psi lower without the pinch flat risk, which on something like Coutt Road or the rougher stretches near Perth Hills makes a genuine difference to comfort and grip. If you're doing enough mixed-surface riding to care about this article, it's worth the conversion.
Perth Hills: the mixed terrain problem in one place
This is where the compromise gets tested properly. Perth Hills throws sealed climbs, loose gravel fire trail, and the odd washed-out section together on the same route, often within a single loop. There's no single tyre that's perfect for all of it, and I reckon anyone who tells you otherwise is selling something.
What I run out there is a 40mm semi-slick, worn centre tread with some side knobs for the loose corners, at around 38-42psi depending on how much climbing's involved. It's not the fastest option on the sealed sections and it's not the grippiest on the loose ones. It's the least-bad compromise, which is honestly the whole game with mixed-terrain tyre choice.
The e-bike question and one honest gripe
I'll admit I'm sceptical of some of the e-bike hire pricing you see around trailheads near the hills. For what you get, a few hours on a hire e-bike costs about the same as a decent dinner, and the tyres fitted on most hire fleets are generic all-rounders that don't suit either surface particularly well. If you're serious about mixed terrain, you're better off on your own gravel setup, even a modest one, than paying premium rates to ride something with the wrong rubber under it anyway.
WestCycle has decent route and safety resources if you're new to the mixed-surface thing and want a sense of where the sealed and unsealed sections actually connect around the metro area. Worth a look before you commit to a tyre and find out the hard way it doesn't suit your usual loop.
Longer rides and the Munda Biddi comparison
If you're building toward something longer, the Munda Biddi Trail Foundation publishes decent surface notes for their trail network, and it's a good reality check for what a proper mixed-terrain tyre needs to handle over distance, not just on a two-hour local loop. Their trail conditions run rougher and more remote than anything discussed here, but the tyre logic scales down fine. Wider, lower pressure, tubeless if you can manage it.
Thats really the whole argument. Dont pick a tyre for the surface you wish you were riding, pick it for the surface you're actually on most of the time, then accept the compromise on the rest. Perth's mixed paths don't reward specialists. They reward whoever got the width and pressure close enough to right and stopped fussing over the last five percent.