Buying a Used Mountain Bike in Australia

Before you look at the price on a used mountain bike, work out whether it will actually fit you. Most listings bury that, or skip it entirely. I've paid for the mistake more than once, and it's the reason I now check size before anything else.

The $40 lesson

A couple of years back I found a bike listed secondhand as a "women's bike" at a good price. I read "women's" as "adult size" and messaged the seller for my girlfriend. Same day another listing came up the same size, so I grabbed that one for myself. Paid for both, drove out, brought them home.

They turned out to be 24-inch bikes. Twenty-four inches is a kid's size, roughly ages eight to twelve. "Women's" had nothing to do with whether it fit a grown adult. My girlfriend rode hers once and never touched it again, and mine was never going to fit me either. So I put the pair back up for sale. I'd paid $120 for them and got $80 back. Forty bucks gone, a Saturday gone, two weeks of messaging tyre-kickers to shift them.

Neither listing lied. They just left out the one thing that mattered.

Wheel size and frame size are different numbers

This is what tripped me up. A bike has a wheel size and a frame size, and they are not the same measurement. A listing will happily quote one and stay quiet about the other.

Wheel size is the diameter: 24, 26, 27.5 or 29 inches. Adult mountain bikes run 26 and up, so anything below that is built for a child no matter what the title says. Frame size (small, medium, large) is the part that tracks your height and decides whether the bike actually fits your body. Trek's wheel-sizing guide and frame-size guide lay out how the two work together if you want the full detail.

Get both numbers out of the seller before you do anything. If a listing only says "women's" or "men's," ask.

What size actually fits me

I'm 160cm. A 26-inch wheel is easier for me to throw around at that height. Taller riders tend to prefer 27.5 or 29, which roll over rough ground better once you've got the legs to match. That's my own preference, not a rule. Check it against a proper sizing chart for your own height before you commit to anything.

Message first, drive second

Every bad buy I've made started the same way: driving out to see a bike before I'd checked the basics. Now I message first. Three questions. What's the wheel size, what's the frame size, and can I stand over it flat-footed. If the answers don't stack up, I don't make the trip. That one habit has saved me more wasted Saturdays than anything else.

Check it isn't stolen

Once the bike fits and the price looks fair, run the frame or serial number through BikeVAULT, Australia's stolen-bike register, before any cash changes hands. It takes a minute. An honest seller won't blink. If they get cagey about the serial number, you've learned something worth knowing.

Paying and picking up

Meet somewhere public, in daylight. Look the bike over in person. Keep the payment traceable. Scamwatch has a rundown of the usual buying-and-selling traps: sellers who won't let you inspect, who push a strange payment method, who lean on you for a deposit to "hold" it sight unseen. Any of those, and I walk.

If I'd looked at the photos and the specs together on those two bikes, instead of trusting the word "women's," I'd have skipped the whole mess. That gap is roughly why we're building Bowera: to weigh up the bike in front of you, not the words someone typed above it.