Gary Fisher Bikes Press Camp: Rumblefish First Impressions

Okay, so now here comes the “big” one. Gary Fisher Bikes newest model in the 29″er line up, the Rumblefish, is a bit of a conundrum on paper. Touted as a step up in terms of travel, it is a bit of a puzzler to learn that it has the same amount of travel as a Hi Fi or the Superfly 100. So, how is this going to be any different than getting a Hi Fi and sticking a 120mm fork on it? That was the question I had going into the camp.

The new 2010 Rumblefish II

What’s The Deal?: So, the lowdown on the Rumblefish in a nuts and bolts breakdown is this: Different aluminum frame than the Hi Fi. Well……..at least the front triangle is different. Fisher used a slightly slacker head angle and different shock mounting points on the Rumblefish necessitating a different front triangle. The rear of the bike is otherwise the same as a Hi Fi. The shock is obviously very different. The DRCV Fox will be mentioned in more detail later. The front end is graced with a Fox F-29 120mm travel 15QR fork, making the bottom bracket height higher on the Rumblefish as well. The Rumblefish II that I rode was bone stock with a mostly XT drive train and Avid Elixir brakes featuring a 185mm front/160mm rear rotor set up.

DRCV: It is what makes a Rumblefish a Rumblefish.

Fox DRCV Rear Shock: Fisher folks stressed that the type of travel that the Rumblefish was going to provide was the distinguishing factor between the Hi Fi/Superfly 100’s and the Rumblefish models. This centers around the DRCV damper fitted to the Rumblefish. In essence, it is an air shock with an extra air chamber. Usually you see this sort of thing as an external unit with some variation on plumbing running back to the main air chamber. Not so with the new DRCV damper which was designed in collaboration with Fox and Trek/Fisher shock guru, Jose Gonzales and his team. On the DRCV, the extra air volume is part of the main unit, making the entire package more compact. The way it works is very unique as well. When the main piston gets to approximately 50% of its travel in the damper, it contacts a “plunger” which activates a valve opening the airway to the secondary chamber of the DRCV unit. Without getting all high tech, this dual air chamber, and the way it works lets the shock ramp up way later in its stroke and provides a much more linear spring rate throughout the midstroke of the suspensions travel. This is an important point I will refer to later.

But that isn’t all. The “Boost Valve” rate on the DRCV damper is set at a much lower rate than on the Superfly/Hi Fi line up of bikes. This translates into a noticeably more plush small bump compliance, and a tendency to bob a bit when out of the saddle efforts are undertaken on the Rumblefish. It is a trade off that Fisher designers thought was a plus on the Rumblefish to keep the feel consistent throughout its range of travel. And really, it fits the purpose of this model much better, in my opinion. It is a “trail bike” after all! Not a hard tail.

Set Up: It has to be stressed that any full suspension bike needs to be dialed in before you ride it to get the correct performance out of the design. The Rumblefish is no exception, and if anything, it is even more critical due to the DRCV damper. To properly charge both air chambers, there are two key elements to the set up procedure. First, the shock air pump that is used must be fully screwed onto the Schrader valve. Since the Schrader valve is specifically designed to allow you to accomplish charging both air chambers at once, it will fail to do so if you only partially screw the pump on. You will see the needle jump on the guage at first, but don’t let this fool you into thinking you have it on far enough to charge both chambers. It is best to screw on the pump all the way to insure you will get the job done right.

Secondly, it is critical to cycle the damper at least 50% of the way through its travel and re-check the sag measurement. The reason for this is that the second air chamber will not equalize pressure with the main air chamber unless the Dual Rate Control Valve is actuated by the plunger. If this step is neglected, you will sense that the damper isn’t set to your weight and that the rear is blowing through its travel. After going through the proper procedure, I found that a front to rear balance was easy to achieve and the bike performed very well on the trail.

The XTR rear derailluer and the 12-36T cassette were welcomed spec on the Rumblefish.

120mm fork, aggressive tires, bigger front rotor, and tubeless Bontrager Rhythm Elite wheels add up to a high degree of trail worthiness.

Other Features: The Rumblefish, being a trail bike, is spec’ed a bit differently than the Hi Fi and Superfly bikes. Here we see the new Shimano 12-36T cassette out back. Bigger brakes, and Rhythm wheels shod with Bontrager 29-3 tires. (The “front” model on both ends) These wheels and tires were set up tubeless on our tester rigs. In a change from the past, the new Rhythm and Race Lite wheels that were featured in the Press Camp will come with the proper rim strips with the bikes to allow consumers to set up the tires tubeless right out of the gate if desired. Good move on Fisher’s part. The handle bars were wider and had more sweep, adding up to a comfortable, slightly more upright position that I thought was excellent for what this model is intended for.

Trail Performance: Okay, enough of the babbling. How did it work? Well, it was a very different feeling bike. It was immediately evident that the Fox DRCV was a whole different animal on this bike. I felt the bike was definitely more sensitive to small trail chatter, and it did feel a bit more like a suspension bike than the Superfly 100 did. This was the lower Boost Valve setting coming into play. Once all the climbing was done, and I was able to breathe the thin mountain air without having to work so hard, the trail turned to a more rock laden, technical type of single track that really showed me the virtues of the Rumblefish’s design. Most medium sized trail obstacles were no match for the Rumblefish and were smoothed out much better than they were on the Superfly 100. Climbing up over some one foot high ledges was amazingly smooth, and rocks in the trail that were fist sized and larger were dealt with in a much more calm and refined manner than with the Superfly 100. Good climbing, just like the Superfly 100, but even bigger obstacles could be approached seated and ridden right over. If anything negative could be said about the climbing performance, it would be that the front wheel tended to wander just a bit more than on the Superfly 100, but I think that is to be expected with the category of bike the Rumblefish is in. (Read: longer fork/slacker head angle)

When things pointed down, the tapered steer tube and massive down tube kept you going straight.

Of course, trail bikes are supposed to descend really well, and the Rumblefish is no exception. The front to rear balance of the suspension was spot on, making riding down unfamiliar trails a lot less stressful. Travel felt very consistent throughout the stroke in the rear. I never could tell if I was bottoming out, or close to it, but afterwards a check of the o-ring on the shock shaft showed I had used very nearly all the travel available. I wouldn’t call it a “bottomless” feeling rear end, but it was super consistent from just off the top end of travel to very near the end of its limit. The Fox front fork was stiff, plush, and smooth as well. I felt I was getting a significant amount of the travel; however, not everyone in attendance was in agreement on that point. Some were saying they felt the Fox F-29 was great feeling fork, but they weren’t getting all the travel they expected, much like the previous F-29 models. Hmm……well, that aside, I thought the example I rode was very well mannered and front to rear performance was spot on with a very linear feel.

Even though the Rumblefish has a slightly higher bottom bracket and a slightly slacker head angle, it is no slouch in the handling department, although its relaxed design was apparent after riding the Superfly 100. They do feel different in this regard, but it isn’t a dramatically different feel, to my mind. The Rumblefish is well suited for trail exploits in the handling department with a nod to slightly more stable handling than a Superfly 100/Hi Fi.

Other Bits: The wheels and tires were excellent on this bike. Tubeless pressures in the low 20’s for me and I was loving the traction and ride feel. The brakes were a real improvement over the old Juicy brake models I have used. They were very easy to modulate, and had lots of “whoa” power when called upon. Of course, the ABP brake pivot was very noticeable in the ride of the Rumblefish, just as with the Superfly 100, it gave a much more rigid and stiff feel laterally to the rear end of the bike, and braking performance was definitely enhanced by this feature. Again, I am very impressed by the improvements to the rear end of the full suspension 29″ers that Gary Fisher Bikes has for 2010.

Conclusions: So, here is the bottom line: While the Rumblefish is a disappointment in the actual measurement in its rear wheel travel, the bike is a huge hit for me in terms of performance. This suspension is really dialed folks. With the massive improvements made to the rear end of the bike, the DRCV Fox shock, and the spec on the Rumblefish, it is going to be a hard bike to ignore for anyone looking for a rig to ride all day on the mountain or in the woods. The shorter wheel base, the longer travel fork, and the G2 geometry all conspire to make this a really fun bike to ride over most trail obstacles the average mountain biker will come across. It really is a different feeling and performing bike than the Hi Fi/Superfly 100, and with so much of these bikes being the same, this alone is an amazing achievement by the Fisher bunch. I would highly recommend that somebody in the market for a trail rig with wagon wheels take a look at the Rumblefish. If you can ignore the 110mm figure for the rear travel long enough to actually ride the thing, I think you might find that it doesn’t matter all that much in “the end”. What does matter is that the Rumblefish is a very capable and highly refined bike that is a great addition to the 29″er line up at Gary Fisher Bikes. Do we need longer travel? Maybe some of us do, but I feel the Rumblefish will take care of a big slice of the trail bike crowd. For those needing/longing for more, we can only hope the next step is a big wheeled Roscoe. But for now, this Rumblefish is pretty dang cool. Color me impressed.

I’ll be back with some more thoughts from the Gary Fisher Bikes Press camp later this week. Stay Tuned!