Made in Australia: Trinity MTB’s Second Prototype, Built for "Downduro"

It was barely a year ago that Trinity MTB made its debut appearance at the Handmade Bicycle Show Australia with a first prototype bike that showed a whole lot of creative promise.

Now the Handmade show has returned for another year, and so has the small team of Trinity MTB. This year they’re showing their second prototype, a bike that engineer Mick Williams somewhat jokingly describes as being built up for “Downduro” (think Enduro, but with shuttles between timed descents). Oh yes, it’s no longer just a joke from Waki.

Trinity MTB is still not ready to put its modular freeride/park/downduro bike on the market, the tease is that there are some big changes still to come before the goal on-sale date of early 2023. While the bike is still expected to change plenty, here’s a look at the latest prototype build.




What’s new?

The new prototype, Prototype 2, builds on general themes introduced in the first. The frame is still constructed with a chromoly 4130 front triangle and a CNC machined rear triangle, all displayed in a raw state. There’s still a high pivot suspension layout and an idler. And the rear shock is still lowly slung in a modular bottom bracket assembly that is designed to fit a regular drivetrain (shown), Pinion gearbox, Effigear gearbox, or Trinity's own derailleur-driven gearbox which remains in development.

However, take a closer look and the specific approach to all of those finer details has changed and progressed. The front triangle now features 3D steel printed lugs at key sections that the 4130 tubes are directly welded to. These printed parts are produced by Australian manufacturer Zeal 3D, and the goal is to clean up and lighten more intricate areas of the bike such as the shock mount, head tube and segments of the split seat tube. Meanwhile, the one-piece CNC-machined 7075-T6 rear-end is intricately latticed on the inner side to save weight.


The shock placement is similar to the first prototype but the suspension system has changed, now running what’s arguably a simpler virtual high pivot layout with a fixed position idler pulley. Trinity MTB claims this approach provides an elongating rear-centre, an optimal leverage curve, and all in a compact package. Rear travel sits at 170 mm as shown (180 mm front), but the company have designed it to be bumped up to 180-195 mm through the use of a longer shock. A coil shock can be used, but it’s only recommended in the longer travel setting.


The bike now rolls as a mullet, with a 29er wheel up front and a 27.5 in the back. And the geometry has been tweaked around that, with a head tube now sitting at 64 degrees (an AngleSet headset can be used) and a not-so-long reach of a 445 mm (medium size). The goal is to offer four sizes, with reach figures going up to 520 mm.

A few other details of note come from Mick Williams’ other business, Williams Racing Products. There’s the previously seen sprag-clutch-based CentreHub crank spider. While up front sits the Stuart stem, which is Lachy McKillop's (@Spinthatup) custom concept with a 44 mm length to match the fork rake, a clean wedge clamp design, and an integrated computer mount.

As mentioned this bike is very much a prototype to test some concepts and help show how things are progressing. And it appears that things are progressing quickly.