Trinity MTB Debuts With a Steel, High Pivot, Gearbox Compatible Freeride Bike

May 7, 2021 at 5:50
by Dave Rome  

Within the ManuFutures facility of Deakin University (Victoria, Australia), surrounded by numerous carbon fibre innovators sits Engineered to Slide, a motorsports fabricator. Between the endless row of metal cutting tools and one fast track car sat a half-finished frame awaiting the welding torch.

That was two days before the Handmade Bicycle Show Australia had opened its doors. By the time the show rolled around Trinity MTB was official and they had their first prototype rolling on two wheels.
Trinity Details

Frame material: 4130 Chromoly front triangle, billet aluminium rear triangle
Intended Use: "hucking triples to flat"
Rear Wheel Travel:170mm (200mm Boxxer fork)
Wheelsize: 29" front, 27.5" rear
Weight: 15.2kg (single speed)
Price: N/A
More info: @trinity_mtb

Three makers who ride

Mick (left) and Nigel (right)

Trinity MTB is a new creation of three friends who all have riding in common and each brings a unique skillset to the table.

Based near to Geelong, Mick Williams is Trinity MTB’s engineer and also runs Williams Racing Products, a young bike component manufacturer who specialises in custom stems and linkage yokes. Nigel is the fabricator and runs Engineered to Slide. Judging by how he left the welding of his only prototype to the day before the show, he’s clearly comfortable with a torch in hand.

Nigel's experience as a fabricator is evident on this frame

Finally, there’s the designer, Chase Warner. Chase is based in California and so wasn’t present at the Handmade show.

Prototype Number One - idea basics

The goal of this first prototype was to create a test mule that could be chopped and changed to experiment and refine the suspension kinematics.

“We’re using a binematic patented by I-Track suspension. It’s a high pivot, but the high pivot moves independently of the axle path,” said Mick of the design. “In short we’re able to get really high anti-squat numbers while still having a high pivot and an axle path that moves backwards. It’s obviously something we want to test a lot, but could also be a bit of a game-changer.”

Trinity MTB has built this prototype with an interchangeable bottom bracket area, something that would allow them to easily produce mounts for the originally intended Effigear gearbox (which wasn’t sent in time by the company), a Pinion gearbox, or just a regular bottom bracket as pictured. For now, the bike is set up as a single speed, something that didn’t faze Nigel and Mick who come from BMX backgrounds.

The complex lattice can house an Effigear, a Pinion or a regular BB as shown.

“There hasn’t been a bike on the market that you could run a gearbox or a standard bottom bracket to do some quantity of testing to do some back-to-back testing to see what works. Work out lap times, efficiency in pedalling and that type of stuff.”

4130 Cromoly and surprisingly light

As shown and currently set, the bike is said to have 170 mm of rear-wheel travel, while the Boxxer on the front is set to 200 mm. In this configuration, the head angle sits at exactly 64-degrees.

The front triangle is made of .9mm thick 4130 Chromoly tubing, with the result being a bike that’s said to weigh just 15.2kg as shown. Of course, that weight is with just a single gear.

“I’m a huge fan of steel bikes, but we understand that aluminium is probably a better material to make them out of,” said Nigel. “I really wanted to start with a steel frame because we could do a lot of changes and modifications to begin with and it gives us some freedom in setting up and testing the kinematics of the bike.”

“From there we’d like to move to aluminium, but we’re also interested in doing a limited run of steel bikes.”

The rear end is currently aluminium billet but there's talk of a full aluminium build in the future.

They may have plans to chop and change the front end, but the rear end was machined from billet aluminium and so changes there are likely to be more costly.

As for when they’ll be ready for sale or at what price? Well, there’s no comment there. “We want to get into the forest on this thing and huck some triples to flat,” said Mick while Nigel nodded.


  • 289 2
 this bike should be named "pinkbike comment section"
  • 23 3
 People laughed about the doughnut too and that seemed a valid concept haha
  • 58 0
 Grim Peanut Gallery
  • 9 0
 pinkbike needs to do a ride comparison between this and the reeb brewser
  • 6 0
 Full house on pinkbike comments bingo!
  • 46 1
 Steel, high pivot, and gearbox. It is indeed the holy trinity.
  • 8 0
 @kcy4130: oh, and it's 15.2 kg
  • 4 0
 pinkbike comment section bikes are taking over ! The reckoning is near!
  • 11 0
 @cougar797: We're not laughing. It's like they listened to everything we asked for...
  • 7 1
 @charmiller: Oh I know. Its just they listened on the other example, seemed like a joke, but then it worked. The PB people know what kind of bike they want for a reason. I personally am all aboard this train in every aspect.
  • 6 0
 so why is everyone loving this but hating on Deviate's high pivot gearbox bike?
  • 1 0
 @hamncheez: The deviate is a super refined looking rig. Its not as slack as I prefer though and I just have a thing for the raw metal builds.
  • 10 0
 @kcy4130: And looks like it'll accommodate multiple water bottles within the front triangle! The Holy Qaudinity?
  • 10 0
 @hamncheez: because Deviate is carbon and carbon is evil dentists' conspiracy. Steel on the other hand is the coolest frame material in the universe. And Deviate is not very pretty. But honestly I was considering it for a while, unfortunately I'm not a dentist.
  • 6 0
 @hamncheez: Because the PB commenters are a fickle bunch.
  • 7 0
 @hamncheez: because not raw ti or steal
  • 8 1
 @hamncheez: cause ....... look at it
  • 5 0
 Is there room for a waterbottle? Oh yes, and waterbottles for all your friends.
  • 9 0
 Looks like a Section. Dibs.
  • 3 0
 @BenPea: and thats without the gearbox...
  • 1 0
 @charmiller: careful what you wish, you might just get it...
  • 2 0
 @toaster29: I may not have read all the words.
  • 2 0
 @hollowing2000: Underrated comment.
  • 1 0
 @johnny2shoes: was that a Richie rude jibe?
  • 7 0
 Shut-up-and-take-my-money Pinkbike legions must have brought down their mail server by now
  • 2 0
 @sjma: just call it the peanut gallery!!!!!
  • 3 0
 Right on! This is the bike the comment section dreams of.

For a huck machine you just need the chain to stay on not a gear box you will rarely shift.

A DH race bike with a gearbox? Now you are talking.

For me I’ll wait for the all-weather, all-mtn, enduro-lite, 29/29’r with 130-150 rear wheel travel model.
  • 3 2

When I was a hucker, I had it in my mind that I’m always going further, faster and higher. Pushing limits and fate.‘I’m going to crash often and bad. It’s just the price of admission. So why would I want a bike made of glass that lasts exactly one crash?

Why is aluminum outselling carbon in consumer DH bikes? Because we know we are going to crash and are not made of money with factory support trucks at the bottom of the hill with spare frames.
  • 3 0
 @adrennan: REEB BREWser wins by the lone fact that it *actually has a gearbox*
  • 135 0
 Steel, high pivot, gearbox, mullet, freeride, dual crown and water bottle space. It's a pinkbike comments section wet dream.
  • 19 0
 Just put a Balfa sticker on the downtube and don't mention the sizes of the mullet wheels and I'd think we just went back in time to 2005.
  • 2 12
flag IluvRIDING (May 7, 2021 at 7:34) (Below Threshold)
 Sorry mate, too heavy for a single speed.
  • 8 0
 How on earth did they hit all these points and miss a dropper?
  • 2 0
 @IluvRIDING: In steel... when they switch to aluminum, it'll be just fine.
  • 7 19
flag DoubleCrownAddict (May 7, 2021 at 10:09) (Below Threshold)
 All it's missing is an e bike motor.
  • 10 0
 If they receiver an order for everyone that said 'give me this and I'll buy it without a thought', this'll be the best sold bike in history.
  • 61 5
 This is the bike that every single Pinkbike bro thinks is the pinnacle of bike design, yet would never be caught dead riding/owning this frame because their Santa Cruz bromad just "rides way too good."
  • 17 2
 Oh I could see me riding this.
  • 9 0
 Santa Cruz bromad pffff the RAAW power Madonna juice "rides way too good."
  • 3 0
 As a pinkbike bro, I found your comment quite funny because as I was looking through it I thought "This is exactly what I've been asking for for years." Ha!
  • 1 1
 As a Nomad owner you're right, you can't even understand how good these things ride On the other side makes my eyes hurt looking at that pile of scaffolding
  • 42 0
 Hey, how many of those little wheels do you want?
All of them.
Ok, all of em then.
  • 46 0
 “Wait, wait. I worry what you just heard was ‘give me a lot of those little wheels.’ What I said was ‘give me ALL of those little wheels.’ Do you understand?”
  • 2 1
 I feel there could be more @sjma:
  • 9 1
 You mean the same number of little wheels as a high pivot derailleured bike?
  • 7 0
 @sjma: “I’ve cried twice in my life. Once when I was 7 and hit by a school bus. And then again when I heard that Li’l Sebastian had passed.”
  • 21 4
 I would sell my sb165 frame for a refined version of this no questions asked. The suspension probably performs incredible. High sprung mass, low unsprung mass, interchangeable drivetrain types, high pivot, decent geo, dual crown compatible, good travel. It's like the best bits of a Zerode, DH bike and Forbidden all rolled into one alongside removable bottom brackets you can upgrade in the future. Make it look a bit nice and out of Alloy or Titanium and I'm down.
  • 1 0
 Fully with you there
  • 5 0
 But is it plush enough for you?
  • 19 0
 The Steve Irwin in the background ftw!
  • 15 0
 "In short we’re able to get really high anti-squat numbers while still having a high pivot and an axle path that moves backwards"

That's not different to any other high pivot: a rearward axle path and potential for lots of anti-squat. The difference would be if they can dial the anti-squat without massive pedal kickback. Which is usually done with an offset idler, which this design also has...
  • 7 0
 Correct. Generating good amounts of AS with less chain growth is a characteristic of all 'high-pivot' bikes, not just i-track configurations. The higher the pivot (real or virtual), the more rearward the axle path, and the more AS that is generated by the axle path alone.
Unless the pivot is really high though, you still need some amount of chain growth to generate a bit more AS and get it into that 'pedals well' range. This is where i-Track becomes very useful; it provides the designer with many options for positioning the idler in a suitable location so that it moves in a way that generates the chain growth you need.
  • 14 0
 What does "hucking triples to flat" mean?

Side note I did my engineering degree at deakin uni in Geelong.
  • 7 0
 So did my friends Bruce, Sheila and Kane. Know them?
  • 5 0
 You know that dumb feeling when you get to the end of an article taking it seriously and then realize it was satire? That line did it.

Then I realized it was real and wondered if I was out of the loop.
  • 3 0
 It means over shooting an already ambitious jump. Or a badly made one...
  • 3 0
 f*ck the Cats and all Abblets : )
  • 12 1
 Correct me if I'm wrong, but wouldn't one want LESS anti-squat on a freeride/DH bike?

I mean, the only reason we all deal with high anti-squat numbers on single crown bikes is because we have to pedal the damn things up hills.
  • 9 5
 Yep. And also the 29in wheel would make it harder to rotate tricks. Not to hate but this is more like a pb comment section build and less a heavy hitting freeride workhorse.
  • 19 2
 @DaFreerider44: plenty of people are throwing spins on 29 these days. freeride doesn't have to equal slopestyle
  • 9 3
 @adrennan: Those guys are all over 6 ft tall. Anybody shorter is going to have a pretty hard time rotating a 3 on 29. I'm 5 10 and you need a ton of rotational force when you account for the gyration effect of the spinning wheels. Trust me I've tried throwing a 3 on a 29er. Even with the mullet setup, it's still a little sketchier for rotations.
  • 8 6
 I think the double crown and single speed on this build give a bit of the wrong impression. It seems these guys, when they say freeride, meant what in these days is called Enduro or super Enduro. A 170mm bike that is meant to be pedaled and the gearbox suggests the same. I'd like to see the concept as a full on Park bike, but I'm pretty sure that's not what they are going for. It's just too ghetto at this point in time to see what this will turn into somewhere down the line.
  • 6 0
 I think it's supposed to be something like a Forbidden Dreadnought on steroids.
  • 25 1
 @Loki87: CNC machined parts by professional fabricators and engineering professors is "ghetto"?
  • 11 2
 Anti-squat doesn't really ever hurt on its own... Unless it comes with the cost of massive pedal kickback. Then for hucking triples to flat it's going to turn into an ankle breaker, unless of course you run a super sloppy hub with like 25 degrees between pickups, and then it only breaks ankles sometimes.
  • 4 2
They said they were missing the gearbox and therefore went with a single speed setup for initial testing.
I wasn´t talking about their fabrication skills, but the way the prototype was assembled. They also stated this proto was intended to be hacked apart and rewelded as necessary. Furthermore, it aparently has been assembled rather hastily if i got that right from the text. Not sure if component choices are due to lack of parts availability, but i wouldn´t put it outside the realm of possibility either. All this in summary suggests to me that this is indeed nowhere near what they´re trying to achieve with this project, but rather a first proto to evaluate nthe validity of the concept. So compared to what their next evolution will most likely look like (gearbox, aluminium, carefully selected components etc) i consider this a rather "ghetto" prototype. No harm meant in calling it that though.
  • 6 2
 @Loki87: You clearly are mistaking prototype for a pre-production model. Early prototypes are quick and dirty test rigs, not polished and dialed ready for mass production. Pre-production prototypes (the last phase) are usually the only ones shown the the public as early prototypes often have looks that only an engineer could love.
  • 2 0
 @DaFreerider44: you just need to pull a nyquist and grab the brakes to stop the rotational force of the wheels. Not that I've ever thrown a 3 in my life...
  • 3 1
 @justinfoil: Well said. For most bike designs, antisquat is generated by chain tension, or chain growth. Too much chain growth and you get pedal kickback, and extra drag on the suspension (see Gwins chainless run).

The I-Track patent claims that by having an idler pulley fixed on the swingarm, lots of antisquat can be generated with very little chaingrowth (think, pedaling pulls the chain downwards on the idler, tugging the swingarm down, counteracting squat) and therefore very low pedal kickback.

I personally think pedal bob is an exaggerated problem. Frame flex, weight, drivetrain and tire selection all have greater effects on pedaling efficiency.
  • 6 0
 It's fantastic to see this project come to life!
Congratulations to the team at Trinity for getting this prototype together against a tight schedule, with a couple of curve-balls thrown in along the way.
The i-Track suspension system is all about providing the designer with options for achieving their design goals. In this case, the high-pivot inverted Horst Link layout provides a rearward axle path without the increase in Anti-Rise (aka 'brake jack') that you would get with a high-single-pivot configuration. Having the idler 'floating' on the seatstay link means that the idler pulley can be positioned in a much more convenient location than it would have to be if it was 'fixed' on the front triangle. Additionally, by making small changes to the idler position (forwards or backwards on that seatstay member), Trinity has the power to test a huge range of Anti-Squat values, so they can arrive at a final product that meets all their expectations. Having the idler mounted in this way has provided flexibility for Trinity, and allowed them to package the suspension incredibly neatly.
Well done!
  • 12 3
 That BB area looks like flex hell.
  • 9 1
 If weldingp0rnhub was a thing, this is the stuff you would find in the homemade/amateur section.
  • 5 1
 I think this is a test rig, so I'll give them a partial pass, but those welds don't look confidence-inspiring.
  • 5 0
 As a fellow Aussie (despite what the little flag next to my user name says) and someone who has followed Nigels journey from back when he was early, early days of his creations (back in The 180sx days, before the ETS Hilux) it’s been awesome to see this one come to life.

The man is a master at what he does.
  • 4 0
 I'm wondering if gearbox DH bikes will be faster. With the gearbox (like Pinion), the suspension would be allowed to work more independently and more efficiently without the drivetrain interfering as much. More active/efficient suspension perhaps would equal faster times? DH bikes are not worried about weight, so added gearbox weight is not really much of an issue.
  • 4 0
 Engineered to Slide builds some super sick drift cars. Really cool to see an overlap between drifting and MTB here. Need to see some of that animal style cross over here though! Where is the glitter paint and stickers?! Coming soon I'm sure
  • 3 1
 Up next, Bosozuku number plates!
  • 5 0
 Finally someone with a different intention on their own creation. If the price is right I would be in the market for one
  • 2 0
 so you buy a bike with this undercarriage, and a few years after purchase, you buy the eeb motor for it that bolts right in, or a gearbox tranny, or whatever..........this interchangeable drivetrain option could be worth following up on....
  • 4 0
 Show it to Jeff Walker, it will surely be featured on Carcass' next album cover.
  • 3 0
 This comment reeks of putrefaction.
  • 1 0
 Doesn't the i-track patent cover the use of an idler pulley attached to a link to control its movement through the travel, not having a "high pivot that moves independently of the axle path" (which I assume just means using a four-bar design instead of a single pivot used by Forbidden, Deviate, Commencal, etc.)?
  • 1 0
 i-Track might have more than one patent
  • 2 0
 Nice idea! but....................Only problem is manufacture & get component parts for bikes?
I take it that could be a problem getting hold of a gearbox to fit the frames, too...................?
  • 1 0
 Aside from all the steel and gearbox goodness I'm excited for a different reason. Mongoose Freedrive and GT RTS suspensions didn't die...they went into hiding and have now emerged with a child. That child didn't inherit a floating bottom bracket (must have been a recessive gene) but did grow a high pivot idler pulley. I hope this design outlives its parents.
  • 4 0
 Reminds me of our old Formula SAE cars. Love it.
  • 1 0
 More like SAE mini-baja. I do get your point though: weld, test, redesign, cut, repeat.
  • 1 0
 @dodgerpuppy: Well, of course in function, but we fabricated 4130 tubes, gussets and thin metal webs like that all day. Being lightweight and strong was our aim!
  • 2 0
 Stoked to see the i track suspension still around. This is basically my perfect bike. I hope it goes into some sort of production run. Maybe with 27.5” wheels? Big Grin
  • 3 0
 Well done legends!!! So good seeing it ready to roll after the hectic month you have had!!
  • 4 1
 I don't think you needed to write "PROTOTYPE" the welds said it loud and clear.
  • 3 0
 is that ship named the "Steve Irwin"? or am i reading that wrong?
  • 10 0
 That's right, it's a Sea Shepherd boat.
  • 5 2
 Unleash the armchair welding experts!
  • 5 0
 I'm so sick of the "online welding inspectors" that have no clue what they're talking about
  • 1 0
 After following Engineered to Slide's drift Tacoma build it was super cool to see him take part in the design and fabrication of a bike!
  • 3 0
 Looks like they decided to remake the GT RTS system.
  • 2 0
 Wow, really impressed ! And great to see a compatibility for both effigear and pinion gearbox.
  • 1 2
 I’m bewildered as to why 29f and 27.5r is referred to as ‘mullet’... mullets are short up front and long in the back. I’d get it if it was called the reverse mullet. The only thing that makes sense is it they’re (the bike culture at the moment) strictly referring to the phrase ‘business up front, party in the rear.’ But even then, I’ve ridden many a 29er that is all party.
Maybe I just need to go try one.
I don’t know why, but it bothers me.
  • 1 0
 i have also been confused always and people call 27.5f 29r "Reverse Mullet"
  • 1 0
 The position of the idler pulley and cranks is a very intelligent move for HP to avoid chain slipping. Salute to the designer.
  • 3 0
  • 2 0
 Engineered to slide! His drift cars and fabrication work is bliss
  • 3 1
 why is micks shirt so tight. Awesome bike i want it
  • 1 0
 Gorgeous. I'd like one with the lower shock cage to resemble spider web, and another web at TT/DT. Rat rod!!
  • 1 0
 Effigear, ha! The Snuffleupagus of the bike industry.
Do they even exist? I dare anyone to try and buy one.
  • 2 0
 That's not a bike, this is a bike. The best thing outta OZ since Sam Hill.
  • 1 0
 Looks like an amazing 1st bike. Love the raw steel / raw aluminum half n half look.
  • 2 1
 Strueth, she's a farkin' beauty.
  • 2 1
 A single speed huck bike sounds rad!
  • 3 2
 I like the Titan frame better than this damn thing
  • 3 4
 The bike looks beautiful but the chain looks goofy with those 2 additional pulleys. Which you technically wouldn't need if you weren't running single speed right ?
  • 2 0
 I think you'd need something to manage the chain growth, and idler is there to limit/prevent pedal kickback.
  • 1 0
 There is no derailleur or chains retention in the rear. With this much chain growth and option to run a gear box they need to run the front chain retention device
  • 2 0
 "POP" nice.
  • 1 0
 Looks like a Crossworx Dash 275 - I love it!!
  • 1 0
 I like it. Be perfect round my way
  • 1 0
 Will Smith and Kevin Kline called. They want their bike back.
  • 2 1
 You could easily fit 3 water bottles on this frame
  • 1 0
 imagine snaggin a rock on those frame openings..
  • 2 1
 This is DCA's dream if only it was an ebike
  • 1 0
 Cant wait to see this in person today
  • 2 0
 Got to see it last night. You're in for a real treat.
And the boys were up for a good chat/discussion about it too.
  • 1 0
 I've often wondered whether we'd ever see an upside-down Horst link
  • 2 0
 This is the way
  • 2 0
 This is the way!
  • 1 0
 love the raw look, I would put an sdg i-fly saddle on
  • 1 0
 I’d take that thing on a date to snowshoe.
  • 1 0
 These guys have reached the pinnacle of bike design. Full stop!
  • 1 0
  • 2 2
  • 1 2
 Impressive, all 3 things I don't want on one bike; steel, high pivot, and a gear box. Thumbs up.
  • 1 0
 I'd ride it
  • 1 4
 That bottom bracket section has no chance of survival in a drop any larger than say 4 feet if you ask me.
  • 2 4
 Neat but no thanks.
  • 2 5
 Room for a Ebike motor too?
  • 1 0
 @nfa2005: Yeah. It's right where the gearbox would go.
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