You could safely say that Mondraker pioneered the long & slack geometry we’ve all come to love, but Ronan Dunne’s race-winning alloy prototype Summum DH bike looks to go even longer! Details are thin, and I only managed to snap some quick racing photos. But there are several interesting updates on this aluminum prototype. And the Irishman had his fork set all the way forward in the longest geo-adjust headtube I’ve ever spotted for his Bielsko-Biała / Szczryk DH World Cup victory…
Mondraker prototype Summum alloy DH bike of Ronan Dunne
The existing alloy version of Mondraker’s Summum DH bike had been raced on the World Cup since 2019. And it got a carbon update with built-in MIND telemetry tracking since 2021. Now, the long-running downhill race bike looks set for another refresh!
And a longer one at that!
At first glance, I wondered why some of the best downhillers in the world from the Mondraker Factory Team were racing on aluminum bikes, when there was a carbon Summum available. But a closer look reveals a lot of sneaky prototype tricks.
Extra Forward Geometry?
What caught my attention was that extra-long headtube.
Mondraker has always been pushing geometry with their long, low & slack Forward Geometry. They literally wrote the standard for stretching out and slacking out mountain bikes, that has since become the basis of what we describe as modern off-road geometry – from XC to Trail to Enduro, maybe even to Gravel, now too. Well, this bike could be a lot longer.
We don’t know anything specific about numbers, but let’s make some assumptions. Current MTB upper headset cups are usually around 50mm in diameter. This then looks like there’s almost another 40-50mm of space behind the headset. (Compare that to most bikes that offer a reach adjust headset that would typically have no more than 10mm of adjustment.) I can’t imagine that Mondraker – early proponent of long Forward Geometry – would go backwards at all. That would mean that Ronan Dunne is likely racing a bike that has 4-5cm longer Reach than before!
It’s safe to say that the final consumer version of this bike won’t have 4+cm of Reach adjustment.
Look close and we can see that it took machining some unique inserts to bolt into this massively long headtube to be able to survive the impacts and abuse of World Cup DH racing. Likely the team riders had several inserts to safely test out the full wide range of reach figures. And probably plenty of angle adjustments, too. There’s a ton of room in that headtube for adjustments!
But the Mondraker Factory Team riders seem to be happy to slam it all the way forward – apparently with a small bolt in the front of the headtube to secure the insert in place (see below).
Reshaped Zero Suspension
Out back we can also see that there’s an updated short-link 4-bar suspension layout, as well. It does look like Mondraker have kept the same Zero Suspension System concept for this new prototype Summum. But now, instead of two separate rocker links on the alloy bike, this alloy prototype features a one-piece rocker link more like the Summum Carbon. Even then, it looks like a longer link overall, that angles the coil shock more forward – like we saw yesterday on the enduro-winning Lapierre Spicy prototype.
Overall chainstay length has probably increased as well on the prototype Mondraker Summum DH bike, because there is now a larger single strut connecting the front of the seat & chainstays – in front of the rear tire. This new rear triangle member replaces the two separate struts found on the current alloy or carbon Summums.
And it also allows Mondraker to move the lower shock mount higher up on the new rear triangle design. We can even see in the side shot (above) that this allows for an easily-accessible flip-chip at the lower shock mount that could tune the bike’s progressive character. Dunne has his shock mounted in the center, neutral position.
The new design also appears to somewhat help protect the shock from mud off the rear tire. But in photos from behind you can also see a set of bolt holes at the top of the new seatstays that may be there to mount a mini fender for even better protection.
Already race-winning next-gen Summum
OK, there’s a lot to digest for an aluminum prototype Mondraker Summum that looks like it will be an evolution of their current race-proven downhill bike.
And this one has already earned its own race-winning palmarès, with Ronan Dunne’s first-ever DH World Cup win.
And you get to go along for the race-winning ride thanks to Dunne and his POV on-board GoPro!
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