Giant and Liv have finally unveiled their new Trinity and Avow time trial and triathlon bikes, and with it the last bastion of rim brakes in the WorldTour has officially fallen. Of course, we knew this was coming ever since we spotted Jayco-AlUla’s Luke Plapp riding an early prototype version of the new Trinity at the Tour de Romandie last April. But still, if it feels like Giant is late to the disc brake TT bike party, you are not wrong. There is, though, a good reason they’ve shown up fashionably late.
The Trinity was last updated way back in 2016, and has since proven one of the fastest and most successful time trial bikes ever. With multiple World Championship and WorldTour wins on the bike, Giant was understandably reluctant to mess with a winning formula.
But nine years is also an eternity in aero development. New discoveries and technology continue to push the sport forward, and that time has come to integrate those into the Trinity. Today Giant and its sister brand Liv unveiled the new Trinity and Avow. Here’s what the brands claim they have done to ensure the new formula is just as successful as the predecessor.
A quick note: I was not at the launch event in Australia, nor have I had a chance to ride the new Trinity yet. As such, what follows is detail gleaned from the press release circulated by Giant and Liv and from our own Dave Rome, who did attend the launch event. A detailed review with an analysis of the various new features will follow if/when Giant provides a review bike.
There’s a tried and tested formula to making a hit TT bike: make it more aero and more stiff. Giant, though, has added versatility and adjustability, along with a smidgen of comfort, to the new TT bike equation, including making the new bike much more accommodating to rider position changes.
With all that in mind, Giant claims the new Trinity Advanced SL improves upon its predecessor because it is lighter, more aerodynamic, offers greater adjustability, and more compliance.
Giant also claims the new Trinity and Avow framesets, which double up to be used as UCI-legal TT bikes or triathlon-specific rigs depending on the spec used, are also 558 g and 433 g lighter, respectively, than the previous generation models. This weight saving was achieved through the use of higher-grade Advanced SL carbon and improved construction methods. Of course, we’ve heard overall weight savings claims previously which are later tracked back to new wheels or components rather than the actual frame module. Not so with the new Trinity. Giant claims it has saved 120 g from the frame, 130 g from the fork, 109 from the ISP clamp, 209 grams from the AeroVault integrated fueling system componentry (not UCI-legal and so not applicable to the TT version), and, finally, trimming 26 grams from the aero handlebar.
Those are considerable savings to find in a frame that Giant claims retains the same stiffness characteristics as the outgoing model. That similar stiffness – when combined with the weight saving – results in a 12.6% bump in stiffness-to-weight ratio. In the pre-Tour Down Under press event where the bike was unveiled, Plapp went a step further, saying the new bike felt noticeably stiffer. That’s perhaps an indication of how that stiffness-to-weight ratio affects overall feel, or an indication of the stiffness of the new Cadex wheels announced simultaneously and covered below (Cadex is Giant’s in-house wheel and component brand).
It’s 2025, though, and we know stiffness isn’t everything. Giant claims it has increased compliance in both the new aero extensions and the new seat post on the Trinity and Avow to enhance rider comfort and reduce fatigue. Specifically, Giant and Liv say, the new armrest designs offer 28% more compliance (over the outgoing model) to better absorb bumps and vibrations traveling up through the front end of the bike.
The seatpost has also been redesigned to offer a whopping 100% greater compliance (over the outgoing model), which Giant claims results in smoother pedaling and better power transfer with less fatigue over long distances. 100% is a big number and, if I wasn’t already eager enough to review this bike, I am even moreso reading that claim.
Perhaps more impressively, in a sign of how frame manufacturers have progressed in recent years, those weight savings come despite the shift from rim brakes to disc brakes. The result is a new disc brake TT bike which, if the claims prove accurate, is lighter than the rim brake model that immediately preceded it.
All that said, and much more importantly, how does the new disc brake Trinity compare to the outgoing rim brake bike in terms of aerodynamics? Very favourably, say Giant … unsurprisingly!
Specifically, Giant claims the new Trinity Advanced SL offers a 5.9 watt aero advantage over the previous generation. Again, Plapp seemed to take that claim take a step further, saying the aero gains from the new Trinity were immediately obvious on his first visit to the South Australia Institute of Sport wind tunnel with the new bike, where he did his testing and bike fitting.
There was, as you might expect, plenty of discussion of the usual CFD analysis and wind tunnel testing suspects when it came to how Giant achieved these aero gains, with the brand claiming not a single tube profile carries over from the old bike to the new bike, despite how similar they look.
This development process looked at the distinct airflow conditions each part of the frame encounters, with Giant then targeting better integration between the bike and rider. The most obvious updates are the new wider- and deeper-profile fork blades, the new head tube now with distinctive angular shaping on the sides, and new seat stay profiles. The down tube, seat tube, and seat post were also refined. The fork was also designed with an angled shape at the bottom to better integrate and shield those pesky disc brake calipers – thus, the claim goes, reducing the aero penalty from them. (If we’re permitted a brief pat on our own back, all of which we had spotted after Plapp’s first outing on the new bike last year.)
With the design complete, everything was tested in the wind tunnel using a dynamic mannequin with what Giant claims are “anatomically correct” articulating legs.
There’s still much debate over best practice in wind tunnel testing, with valid arguments to be made for testing bike only, bike and rider, bike and mannequin, or even bike and half mannequin as some brands use. For its part, Giant chose a mannequin for the precise repeatability it offers over a movement-prone human, and one with articulating legs so as to measure the interaction between rider and bike during pedaling. As for the tests, Giant stated it tested across yaw angles ranging from -20 to +20 degrees: perhaps relevant for those racing Kona Ironman and its coastal crosswinds, but a much broader range than time trialists will see.
Triathletes get the aforementioned AeroVault integrated fueling system (because cyclists aren’t allowed to easily hydrate, as mandated by the UCI), which Giant claims also contributes to improved aerodynamic performance. This system includes an 850 ml (size M and L) or 700 ml (size S) reservoir on the down tube, a straw near the aero extensions, and a bento box on the top tube designed to hold up to six gels.
Regardless of your sporting code, that reservoir is key, though, as Giant claims aerodynamic gains that stem from optimising airflow around the down tube, which are enhanced even further when equipped with the AeroVault hydration system.
Whatever the level of gain, the rider is still the largest source of drag. As such, optimising (or, alternately, compromising) the rider position atop the bike will always elicit greater gains (or losses) than any component update ever could. With that in mind, Giant has incorporated enhanced adjustability into both the Trinity Advanced SL and the Avow Advanced SL Tri framesets to aid riders in finding their optimal fit for aero and comfort.
This adjustability comes from the new armrests offering 24 times more positional options than its predecessor and a new seat post with four offset options (up from two on the outgoing post), which increase the total seat post offset range from 40 to 51 mm. The aero extension stack, reach and width options are also extended. Total spacer stack range goes from 60 to 80 mm, reach has increased from 60 mm to 75 mm, elbow rest width options increase from six to eight and finally, overall extension width options double from two to four. The new bars also now offer three armrest angle options (0, 10, or 15 degrees).
Crucially, these adjustments can be made using simple spacers and a two-bolt mechanism thanks to the move to a mono riser-style extension mount on the new bikes. The cockpit is also designed to be travel-friendly, with the ability to remove the entire extension set at the clamp bridge via just two bolts. Combined, these extra fit options should mean it is not only possible, but easier to adopt a range of positions.
All told, the new Trinity – and, to a lesser extent the new Avow which is not quite identical to the Trinity – may look like its predecessor, but it’s clear the bikes come with subtle but significant updates. The new positional options may prove most valuable to the most performance-minded riders, but those same riders may well be wondering if Giant have left some gains on the table here.
For instance, for all the talk of aero gains, there was no mention of harnessing the new aspect ratios permitted by the UCI since the last Trinity update. Giant has stuck with the bayonet fork steerer concept, but there was no mention of reducing its width or reducing the width of tubes elsewhere. There was no mention of reduced frontal area nor maximising the newly permitted (in terms of the Trinity timeline) 8:1 aspect ratio.
While other TT-focused bikes have sought to greatly increase the flow-smoothing surface area by utilising the new rules to adopt deep tube profiles, Giant has actually adopted a shallower seat tube profile, while the bottom bracket shell looks largely similar. That said, what is the best seat post aero concept remains hotly debated, and so profile depth alone does not suggest Giant hasn’t also found an aero gain. It does, however, suggest this may be one area Giant has focused on maximising weight savings rather than aero gains.
There’s also the fact the Cadex tri bike is also still a thing and will remain in the Cadex range. Is that the dedicated all-in-on-aero platform complementing an all-arounder approach with the new Trinity? The difference seems at least partly based on event distance; the wild-looking Cadex will continue in production, aimed at competitors in Ironman-distance events. As a non-swimming dedicated roadie, that worries me a bit. The Trinity was always among the fastest of UCI-legal TT bikes, and it may well prove it has retained that positioning, but it’s not immediately clear Giant has prioritised that with this update. Giant, Liv, and the Jayco-AlUla men’s and Liv-AlUla-Jayco women’s riders will be hoping this is yet another reminder that we can’t see aero.
New wheels
Alongside the new frames are two new wheels from Cadex: the Max Aero Disc and the Aero 4-Spoke, both said to be lighter, stiffer, and, you guessed it: faster than their predecessors.
The Max Aero Disc is Cadex’s lightest-ever disc rear wheel with a claimed weight of 1,000 grams. To achieve this weight alongside what it claims are better aerodynamics, Cadex used an integrated design combining light and stiff carbon spokes, hubs and rims with a thin aero cover made with a 1K carbon fibre weave. That 1K weave cover is said to shed 150 grams alone, while featuring a wider 22.4 mm internal width, tubeless straight side (hookless) rim. Cadex claims this overall construction not only produces a lighter wheel but also sees lateral stiffness increased by a claimed 54.3%, with a 20.2% boost in transmission stiffness compared to the previous generation.
Available as both front and rear wheels, the Aero 4-Spoke WheelSystem features a 50 mm profile up front and 65 mm at the rear with, as the name suggests, a four-spoke design. Cadex claims the four-spoke design results in better crosswind stability, and its own wind tunnel testing suggests the new four-spoke front and rear combination surpasses the aero performance of competitors’ rear disc/deep front combinations in headwinds, and achieves lower side force drag in crosswinds, although no details on this testing were provided.
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