Velocite Flux review – the extreme XC carbon mountain bike

Yes, I am a Velocite employee, so there will be bias. I will try to stay away from aggrandizing and unsubstantiated superlatives however 🙂

 

Rob Dunnet: Velocite Flux mid flight 

 

The title says “extreme XC mountain bike”. I thus feel that I should address this first. What do I mean by extreme XC? Cross country (XC) mountain bike riding means different things to different people. After all, any riding that is not on the paved road can be considered cross country. Depending on where you live or ride, cross country trails may mean nicely maintained unsealed roads, hard pack trails through meadows and fields or meandering forest trails. XC trails can also mean riding on steep rutted, rooty hiking trails, rock gardens that used to be mining, fire or military roads built by tanks for tanks, or muddy and steep trails where even walking is difficult. These trails are basically downhill bike territory without large drops and with somewhat smaller obstacles – they are the type of XC trail that you see at World Cup XC races.

Here are some example photos from XC World Cup races to better illustrate what I mean.

Houffalize WC: Julien Absolon

Mont St Anne WC: Julien Absolon, Geoff Kabush

 

MTB World Cup 2007 in Offenburg on Flickr - Photo Sharing! - Mozilla Firefox 7202010 61537 PM.bmp  Offenburg WC

Thus, World Cup XC trails are what I call “Extreme XC”. They require high level of skill and just about complete faith in your equipment so that no doubt ever enters your mind. Of course depending on where you ride, you may not think that these trails are that extreme, and that’s great since Velocite Flux is then a perfect bike for you 🙂

Does this mean that you cannot enjoy the Flux on less technical trails or situations? No, you can of course ride the Flux wherever you like, but you may not experience the extent of what the Flux can do during normal riding. It will be easy to notice the frame stiffness and responsiveness. It will not feel like harshness, more like instant response to every pedal stroke and almost telepathic steering response. The Flux will go exactly where you point it with just about no delay. This easily observable characteristic actually does not make it very suitable for casual riding or cruising. It would be like trying to cruise down your favourite city street in a track tuned race car. Flux can be ridden slowly, but it will push you to compete against just about everyone, and you may be cutting in and out of bicycle or motorized traffic a bit more than usual just because you can…I am actually trying to say not to buy the Flux if you intend to use it as a cruising or paved road riding bike. There are both cheaper and much more expensive alternatives that would be better suited for that type of use.

Where Flux begins to shine is where the paved road ends. I ride it on old army roads up the local hill. They were literally built by special purpose tanks, I was not kidding 🙂 . My Flux is set up almost exactly as the Flux Pro XC bike.


 STANDARD SPECIFICATIONS

Frame
Velocite Flux high modulus,
high compaction carbon frame
1.5” tapered head tube
BB30 bottom bracket

Fork
Rock Shox SID XX 1.5” tapered

Headset
FSA No.42/48/ACB

Rear Derailleur
SRAM X.0

Front Derailleur
SRAM X.9

Shifters
SRAM X.9

Brake levers 
SRAM Elixir R, white

Brake calipers
SRAM Elixir R, white

Cassette
SRAM X.0 11-34

Wheels
FSA XC-300S

Tires
Schwalbe Rocket Ron

Cranks
FSA Afterburner 386 BB30

Chainrings
42/27

Bottom Bracket
FSA BB30

Stem
FSA SL-K

Handle bar
FSA SL-K flat

Saddle
Prologo Kappa Pas

Seat post
FSA SL-K

Pedals
none included

Frame size
XS, S, M

Colour
Matt clear coat, white and blue

Weight
9.6kg with pedals

Price
From US$ 2899 (shipping and duties excluded)


The only difference is that I use wider Maxxis High Roller SS 2.35 on the rear and Schwalbe Fat Albert 2.4 tires up front. Flux has plenty of rear tire clearance to go even wider, but the Rock Shox SID XX fork is at the limit with the huge Fat Albert 2.4 tire.

The highlights of the build are the FSA Afterburner 386 BB30 cranks and the Rock Shox SID XX asymmetric (tapered) steerer fork in original SID blue colour.

The cranks use just two chain rings. 27t and 42t. Combined with the 11-34t cassette I have yet to run out of gears climbing or descending. I never missed the 22t granny gear, not really. There are of course moments when I think that shifting even lower would be nice, but being forced to keep the current ratio and just push through the climb works well. The climb lasts shorter since by necessity of keeping a reasonable cadence you end up riding a lot faster.

The fork is excellent. If you also ride long travel all mountain or freeride bikes with high end forks using bolt through axles you will like the SID XX. It compares very well in terms of controlled travel and stiffness, but weighs just 1.6kg. The stiffness is helped a great deal by the oversize, tapered steerer that matches the Flux oversized and tapered head tube. There are lighter XC forks than the SID XX, but they do not offer the same level of stiffness and control and are thus better suited for lighter duty bikes or pavement riding.

trail_rocks_rob

An example of a rocky trail. It is steeper and more rugged than this photo seems to show.

 

On rougher trails the stiffness of the Flux is of great help when climbing. The “trick” with riding a hardtail up steep and rough terrain is to keep the momentum so that your rear wheel does not get hung on a rock which can slow you down or in the worst case completely stop you. Stiffness helps here in that you can easily power over the obstacle by stomping on the pedal instead of trying to lift the rear end by leaning forward and thus stalling against a rock with your front wheel instead 🙂 What makes the powering over rocks easy is that the Flux does NOT deflect sideways when you apply full power to the pedals. Almost all of your energy is instead being transferred to the rear wheel. This is so awesome that even though climbing broken up technical trails is very exhausting for me, I find enough energy to enjoy the sensation of rocketing over small boulders and ledges, up hill. Of course there is no choice since as mentioned, if you do not keep up the speed and momentum, you will stall and fall over.

Of course, where the stiffness of the bike really matters is when you decide it is time to head back down the hill.

Why does the stiffness matter? The explanation is a bit more involved this time, but it is nevertheless familiar to all enthusiast and competitive mountain bike riders. The main benefit of stiffness when heading down hill is that your bike goes straight and does not feel like a headless chicken bouncing all over the place whenever you hit an obstacle. Riding a flexible bike fast is very difficult since you never know where you are actually going and you may either crash, or slow down because you feel out of control.

Here is a more involved explanation of why a stiff mountain bike is a good thing. Every time your wheels hit an object they can either go over the object (rock, root) or slightly to the side of it. If the primary motion allowed by the wheel, fork and frame is up and down, then you will ride over the obstacle, if instead the wheel, fork and frame are not stiff, the wheel will deflect to the side somewhat, resulting in loss of momentum and direction, or in severe cases an over the bars trip. The same thing applies to the rear wheel. Mountain bikes with flexible rear triangles (part of the frame composed of seat stays and chain stays) do not go straight over the obstacle and since you do not steer the rear wheel, this lack of directionality is impossible to correct. Flexible rear triangles are the main reason why some bikes just feel out of control, or do not inspire any confidence. While it is fashionable to make hardtail frames with a degree of vertical compliance it is not possible to make them both vertically compliant and horizontally stiff. All they can achieve is to be relatively more vertically compliant than horizontally compliant, but overall flexible in both directions. This is why if you really must have a bike or frame with a vertically compliant rear end, you should ride a full suspension bike.

 

Velocite Flux rear triangle. It is solid

So how does the Flux feel when you are coming down the mountain? Let’s just say that I am the absolute weak link here. I never managed to push the Flux enough to feel anywhere near losing control or that I am at some kind of a limit. Part of the excuse is that there are many walkers around so running someone over is not what I would like to do. At the speeds that I did manage to achieve the ride was rough – it is a hardtail after all, but never out of control. You can confidently ride over and barge over a boulder or fly off a ledge, the Flux really does not care. Every ride for various reasons (mostly people related) I end up off my preferred line and briefly think to myself “oh crap” before relaxing and just letting the Flux do its bit. When I rode over the unplanned rough section and right now as I am writing this review, I truly cannot recall how it felt. It was a complete non-event. So far it made no difference at all how fast I went over rough or smoother parts of the trail. It also does not care about speed. I have to ride very slowly around hikers in some stages and I never got hung up on a rock or stalled, to my great surprise.

Flux is not a miracle bike, it just follows one simple rule: do not flex. If you have the opportunity to ride the Flux on the trails that suit its extreme performance character, you would be hard to find a more rewarding bike or frame.

Size M frame weighs 1321g, while the complete Flux Pro XC bike with SPD pedals is 9.6kg and costs US$ 2899 online, plus shipping and import duty where applicable.

  • when will flux come with postmounts for the rear brake? 😀

  • We will transition to post mount rear brake around the mid 2011.

  • aha, just what i thought 😀 the placement where you have the disc mount now, is perfect for postmount

  • Endeavour

    I`ve been riding Flux for about 4 months and must confirm the post above – the frame is very stiff and responsive for a mountain one. I’m not that kind of a racer to make some profound analysis, but even for an amateur Flux can be a noticeable advantage during a race.
    Tnx Victor and the whole Velocite team for that stuff 🙂

  • Good revieiw.
    I'm just looking for this kind of bike. But the only thing is that I need a "normal" 44x32x22 chainring. Since I miss one foot on the left. Is it possible to mount this when I want to order it?

    Kind regards, Reitz Bok

  • Hi Reitze. We do not have a normal 3 ring MTB crankset for the Flux, but we can customize the build kit and deliver the bike without a crank set, with or without BB30 to BSA/ISO adapter. You can then use another crankset that suits you better.

    …I still recommend sticking to BB30. There should be several triple ring BB30 MTB cranksets available by now.

  • paul robertson

    My flux has been awesome so far. ive ridden a world cup and a few local and regional races. It fulfills the world cup label with its surefootedness on technical and hard xc courses. For lumpy continually rooty courses a full sus is needed though. Any plans yet? please!

  • …we do have a full suspension mountain bike frame planned. But. It has to be a really good MTB FS frame, not a “me too” and it has to work. As you can see from your experience with Velocite, everything we say about our products’ performance is factually correct for most riders. Thus, when we make a FS frame I need to feel comfortable with claiming that it is the best in class, or best outright. Aiming to be an “alternative choice” is not what we do.

    Achieving this is not easy since many MTB products are actually very good, that is in contrast to the road bike market which is full of really bad ideas and products. This is due to the MTB market not being constrained by too many traditions, or tribes, and due to it being easier to spot badly performing products, so they do not last.

    We have some basic agreements in place for custom, properly engineered full suspension system, and we have some ideas for the frame itself, but it will take a while to get this designed and tested.