Kalamunda gets you there faster. Mundaring gets you a better day. That's the short version, and if you want the long version, keep reading, because it depends a fair bit on what's strapped to your bike rack.
I've started rides from both towns more times than I can count, on the gravel bike mostly, sometimes on the old hybrid when I'm feeling lazy about tyre choice. Both are legitimate gateways into the Perth Hills, both sit roughly forty minutes from the CBD if the Roe Highway traffic behaves, and both get spruiked in every glossy brochure about escaping Perth for a weekend. The brochures aren't wrong exactly. They're just not telling you the whole story about surface quality and where the gravel patches turn nasty on a wet corner.
Kalamunda as a Perth Hills start point
Kalamunda is the tidier option. Railway Road through the town centre is well kept, there's decent café density if you need a flat white before you commit to anything steep, and the town itself feels finished in a way Mundaring sometimes doesn't. For a family day out with mixed abilities, Kalamunda is the safer pick. The paths are wider, signage is better, and if someone in your group is on a road bike with skinny 25mm tyres they won't immediately regret their life choices the way they would on some of the rougher fire trails further out.
The catch is that Kalamunda's best riding is really just the entry point to bigger stuff — the Munda Biddi corridor and the escarpment trails that run south. You're not getting a huge amount of variety if you stay close to town. It's a good half-day, not really a full one, unless you're happy to link up longer loops that push well past what most casual visitors have planned.
Mundaring as a Perth Hills start point
Mundaring is scrappier and I reckon that's actually the point. The gravel out this way is looser in spots, there's more genuine climbing, and the Kep Track rail trail gives you a proper long-distance option if you want to actually cover ground rather than loop back for lunch. Tyre pressure matters more out here — I run a few PSI lower than I would around Kalamunda's smoother stuff, because the rail trail gravel and some of the fire access roads get corrugated after dry spells.
If you're basing a whole day around it, the Perth Hills Discovery Centre and Campground is a solid anchor point. It's got the infrastructure to make a full day work, not just a quick loop and back to the car. And if walking rather than riding is more your speed that day, the Rocky Pool Trail is nearby and genuinely worth the detour, particularly after winter rain when the pool's actually got water in it worth photographing.
The bit nobody mentions in the brochures
Here's my mildly unpopular take: Kalamunda's reputation as