New Trek road bike with 'IsoFlow' seat tube hole leaked — so, is it a new Émonda or revamped Madone?

With the Tour de France just a month away and one unreleased road bike already doing the rounds today in the form of a potential new Canyon Aeroad, it looks like mysterious new road bike leak season is well under way... and fittingly, the next one we're bringing you news of will almost certainly have a gaping hole in, more commonly known as Trek's IsoFlow bump-taming technology.

The question is, will the new bike be a long-awaited new Émonda, Trek's lightweight model, or a new version of the Madone aero road bike? 

We first reported on this new bike back at the start of the year when pro rider Giulio Ciccone was spotted riding it at a training camp. At the time, we thought it was a revamped version of Trek’s lightweight Émonda, which is overdue an update as the current one is nearly four years old, but it could just as easily be a new version of the Madone, which would make it the eighth generation.

This photo (below) was shared on the Weight Weenies forum and shows the latest Trek road bike retaining the IsoFlow technology and the cantilever seatpost design of the existing Madone model. However, it comes with shallower tubes, likely aimed at reducing weight. It's clearly a recent photo given that the bike is equipped with the newly released SRAM Red AXS groupset. Also, the aero water bottles suggest it's not solely focused on lightweight performance, which could rule out the Émonda theory. 

(666pounder, Weight Weenies)

We first spotted the seventh-generation Madone SLR at the Dauphiné two years ago, although it wasn’t officially launched to the public until a month later. 

The standout feature of that bike was its IsoFlow technology, which involves an interrupted seat tube. Trek claims that IsoFlow provides dramatic aerodynamic improvements – it “smooths air as it moves over the bike and accelerates it through the frame for even more free speed”, according to the US brand – while reducing weight and adding compliance. The cantilever upper seat tube/seatpost design is intended to flex over bumps to smooth the ride.

Like most of the cycling world, we thought Trek would likely extend IsoFlow to its lightweight Émonda platform next. Why? Mainly because the Émonda hasn’t been updated in nearly four years, whereas the Madone got its radical new shaping in 2022. 

The current Madone, that we first spotted at the Dauphine in 2022

> Trek releases radical Madone SLR, its “fastest road race bike ever” 

Although similar to the seventh-generation Madone model (above) in some ways, particularly regarding the IsoFlow technology at the heart of things, integrated cockpit and integrated seat mast, the new bike features shallower tubes across the board. The head tube and down tube are far, far shallower than those of the seventh-gen Madone, and the same goes for the fork legs. 

The lower section of the seat tube wrapped around the leading edge of the front wheel on the previous Madone. That’s no longer a feature here, and the deep seatstays have been replaced by decidedly skinny ones.

What is Trek up to with this design? That’s harder to say because this new bike has yet to be launched and the company has released precisely zero information about it.

Over recent years, Trek has offered the Madone as its aero road bike and the Émonda as the lightweight alternative. However, several brands have moved away from that two-pronged attack (and some, like Pinarello, never went there in the first place). 

Specialized, for example, has been down the ‘one bike to rule them all’ route with its Tarmac SL7 and SL8 – bikes designed to be both lightweight and aero. It claimed a 56cm frame weight of just 685g in its lightest colourway, and a fork weight of 358g.

The seventh-generation Trek Madone SLR was launched with a frame weight of just under 1,000g, and a fork weight of just over 400g.

Trek clearly thought a little extra weight was a price worth paying for the aero gains, but we’d imagine that the tubes have been slimmed down to save grams. That’s speculation, of course, but it’s usually the way of things.

Will Trek have sacrificed aero performance to save weight? The brand will doubtless have a good story to tell and a white paper’s worth of justifications for the changes.

The current Trek Émonda, that is getting on for four years old

> What do Trek’s plans to ‘right size’ mean for the industry… and you?

One final question: where does this leave the Émonda if the leaked bike is a Madone? One final answer: we don’t know. It could be that Trek is putting all its eggs into one basket with the Madone in the same way that Specialized has with its Tarmac, having shelved the aero Venge.

Maybe Trek is merging its lightweight tech and its aero tech into a single platform. On the whole, though, we suspect that the Émonda is too strong a model to let drift; it’s just really odd that the Madone (if that's what this mysterious new bike is) will now have been updated twice since the last Émonda launch. 

Hopefully, everything will be revealed when Trek officially launches this new bike. When will that be? We've asked Trek for comment, and in the meantime we'll be keeping our eyes peeled...