First Impression: Tern Castro Duo

By Stephen Haynes

I’ve always been intrigued by folding bikes, much as I am by efficiency apartments, tiny houses, James Bond gadgets and Murphy beds. There is something appealing about a bike that is both practical and fun and can be discretely folded down and thrown in the trunk of your car. It plays to the pragmatist in me while adding a sense of whimsy to the mix.

The Tern Castro Duo does a good job of satisfying these wants and needs by offering a simple bike in a compact package.

The bike folds down small enough to be out of the way in that efficiency apartment or dorm room, but isn’t quite small enough to haul on the bus with you. If you have limited space in your dwelling or are a park-and-ride commuter, this could be your new best friend.

I’ve taken the Castro Duo on many rides both from my backdoor and from the trunk of my small car, folding and unfolding as needed with ease. The folding operation is quite easy by way of two joints: one located in the middle of the frame, the other where the stem meets the headset. The pedals fold down as well, maximizing the space savings.

Riding the Castro Duo reminds me of my first experiences on a bike—when a simple one speed with a coaster brake was all you required to get to the playground or friend’s houses. Tern has attempted to up the ante a bit by adding a SRAM two-speed automatic hub (Hence the “Duo” in the name). While this sounds great in theory, in practice I’ve found it has taken a little getting used to.

Unexpected shifts caught my knees out on more than one occaision early on, but I’ve grown more accustomed to the shifts and am getting better about predicting them, though not expertly just yet. I’ve also learned that by simply disengaging the drive train by quickly back pedaling (not enough to brake), will put you back down into the lower starting gear.

The Casto Duo rides quite nicely though and I have found benefits to having a second speed as well. Coasting down hills doesn’t necessarily mean coasting anymore and on the flats it means not having to spin out in a lower gear. Nice!

The super low step-through, upright riding position, 20” wheels and short wheelbase make it easy to get just about anywhere and be comfortable doing it. This thing is snappy and I’ve been tempted more than once to pretend it’s a BMX bike and launch it in some ill-advised manner.

The Duo’s frame has a built-in rear rack for carrying books, beer, pizza, or whatever; as well as built in front and rear lights. A chain guard means you don’t HAVE to roll up your pants and full fenders will keep those pants clean of street funk.

As if Tern couldn’t make this bike any more practical, they’ve also added a center stand that can be employed whether the frame is folded or unfolded.

The Tern Castro Duo will set you back $800 and for all the practical features that buys, sounds like a steal. Look for my full review in Bicycle Times Issue #16 coming out in April.



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