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Trek Boone 9 review

8 Dec 2015

The Trek Boone 9 would make a fantastic cyclocross racing bike, but more importantly it’s a whole heap of fun.

Cyclist Rating: 
Great fun to ride, Light for a CX bike
Tyres feel slow, over-braked

With the advent of the gravel bike, the cyclocross bike is starting to look a little bit like a relic with its knobbly tyres, lack of rack mounts and high bottom bracket. I’d argue that the cyclocross bike still has a place, but not as a commuting bike anymore - you can leave that to those new gravel bikes. I’d say it needs to exist for thrashing around some woods and, if you get really carried away, for racing too. And for that, the Trek Boone 9 Disc seems perfect.


Trek Boone 9 frame

The Boone 9 is fairly lightweight for a disc equipped cyclocross bike, just 8.3kg for the full build. At the core of that is the 600 series OCLV carbon frame and full carbon fork (with a thru-axle so it should be nice and stiff). Trek claims that the Boone is its smoothest ‘cross bike ever thanks to the IsoSpeed decoupler that gives a bit of bounce to the back end.

The frame is clearly a well thought out ‘cross crusher. The integrated chain keeper is a nice touch as is the weather sealing around the internal cable ports.

Trek doesn’t want it just crashing around the fields of Belgium though, so there are nods to regular usability like two sets of bottle cages and hidden mudguard mounts if you’d like to use it on the commute. 


Trek Boone 9 rear disc

I’m a big fan of discs and, having used them extensively on the Specialized Diverge, I can’t really imagine having a bike to tackle muddy ground without them. At first though, I wasn’t so sure that the 160mm rotors that are fitted were the right choice.

The Shimano R785 brakes are incredibly powerful and it was all too easy to lock the rear wheel. One of my first rides on the Boone 9 was wet and the greasy spots of tarmac mixed into the ride were hair-raising. I became quite nervous applying the brakes and began to really heavily on the rear brake, as a rear skid can be recovered.

After a few more riders on the Boone, I became used to the braking power and was able to modulate a bit more but I remain convinced the Boone 9 is over braked. A drop to 140mm rotors would be a welcome change in my opinion, without sacrificing too much stopping power. 


Trek Boone 9 chain catcher

What more is there to say about Shimano’s Ultegra groupset? The shifts are smooth and precise and, as mentioned, the braking power is huge. The Boone 9 comes with a 46/36 ratio chainset, which combined with the 11-28 cassette can get up all hills that don’t require running.

The Bontrager Affinity Elite wheels are light but still strong enough to cope with all the usual knocks and scrapes involved in cyclocross. I touched the rim down on quite a few rocks and they’ve both remained straight. The Affinity Elites are actually tubeless ready, although they’re not set up tubeless from the factory.

The Bontrager CX3 tyres were slow to win me over, but I came to like them more and more by the end. On the road, the CX3s felt slow and my first forays onto grass revealed little in the way of grip. Head into the mud though, and the tyres come into their own. The tread grips deep mud remarkably well and sheds the sticky stuff well.

taking the Boone off road is a real hoot

The remainder of the Bontrager finishing kit is nice albeit unremarkable with the exception of the IsoZone handlebars, which are incredibly comfortable and a great shape. 


Trek Boone 9 seat mast

For a cyclocross bike, the Trek Boone geometry is low to the ground. This does reduce the ground clearance but it also means one other thing: it’s fast. The 70mm bottom bracket drop on the 50cm is no higher than a road bike and it does make the whole bike feel incredibly stable, especially at speed.

It also means that it’s more stable in the corners and when ripping along through mud. I did strike the pedal once or twice, but it was worth it to feel like a pro the rest of the time.

The rest of the geometry is pretty standard until you come to the front end. When I first took the Boone for a ride I had a peculiar, albeit very distinct, sensation of the front wheel being miles out in front of me. It all felt a bit vague and distant, but I put that down to just new bike feeling. A look at the geometry and I could see it wasn’t all in my head. The same 45mm offset fork is used across the range, so on the 50cm with 71.0 head angle the Boone 9 has a much bigger trail than the others.

The ride 

Ignoring all the little niggles for a time, just taking the Boone off road is a real hoot. Dropping the stem down a few spacers placed my weight over the front end quite a bit more and sorted out that vague feeling in the corners. The front wheel still remained light though and gave the front wheel a brisk feeling that I came to enjoy.

The heavy mud tyres I complained about at first did mean you could realistically ride this bike whatever the weather or terrain, but if your local trails are a bit drier you could swap out to something a little faster.

The IsoSpeed decoupler did seem to make a difference as I wasn’t so battered at the end of rides as I usually feel. The little shroud that covers it did snap though while riding, but Trek said it would be covered by warranty (or for £2.70 if not covered).

The seatmast did also bring about one other issue, as there is a maximum seat height. The max on the 50cm is 72.5cm, which is bang on my saddle height, but it could cause a problem if you want a really aggressive position. Again, these are available aftermarket in different lengths (and setbacks) so it shouldn’t prevent you from dialing in your perfect position.

By the end I came to the conclusion that the disc brakes are just lightyears ahead of cantilevers. Even in the thickest mud and the worst weather, the braking power is never diminished. Add in the large increase in tyre clearance (I never once had to stop because of mud clogging) and you’re on to a winner. 

If your idea of fun is ripping through a forest for hours on end all year round and whatever the weather, then the Boone 9 will suit you right down to the ground.


Trek Boone 9 Disc
Frame Trek Boone 9 Disc
Groupset Shimano Ultegra
Brakes Shimano R785
Chainset Shimano Ultegra 46/36
Cassette Shimano Ultegra, 11-28
Bars Bontrager IsoZone
Stem Bontrager Race X Lite
Seatpost Bontrager Tuned Seat Cap
Wheels Bontrager Affinity Elite Tubeless Ready
Tyres Bontrager CX3 Team Issue
Saddle Bontrager Paradigm RL, Ti rails

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