Reviewed by Brandon Turman // Photos by Courtney Steen and Brandon Turman
com·pul·sion |kəmˈpəlSHən| noun
1 an act of compelling : the state of being compelled
2 the action or state of forcing or being forced to do something; constraint
3 an irresistible urge to behave in a certain way
We've got to tell you, we gave into the Compulsion. Every time we ride it, we have the irresistible urge to go fast, pop off the bonus lips on the side of the trail, and hoot and holler. It wasn't without a few tweaks to the stock build, though…
Two months ago we first swung a leg over it, and today it's time to fill you in on how it performed in the long run.
Compulsion LT 1 Highlights
- Carbon fiber front triangle, aluminum rear
- 150 or 160mm (6-inches) of travel
- 1 1/8 to 1 1/2-inch tapered headtube
- 66.75 or 67.5-degree head angle
- 17-inch chainstays
- 13.6-inch bottom bracket height
- Standard threaded bottom bracket shell with ISCG mounts
- 142mm rear spacing with 12mm through axle
- Weight: 28.9 pounds (13.1 kg)
- $6,199 MSRP complete // $3,099 frame only
For 2013, Felt Bicycles has re-introduced the Compulsion line to the United States marketplace, and they took the opportunity to revamp it in a number of ways - the front triangle is now made from carbon fiber, and the bike has been lowered, slackened, and even made a touch longer than its predecessors. The original Compulsion had 145mm of travel and a 69-degree head angle. Careful to consider the balance between high-speed stability and low-speed maneuverability, it now boasts 150 or 160mm of travel along with a 66.75 or 67.5-degree head angle. All changes for the better.
Molding the front end from carbon saved nearly half a pound (~200 grams) compared to the aluminum front triangle while offering a 5% increase in torsional stiffness, according to Felt. That's pretty substantial. Well-versed in the art of carbon, their construction technique for the Compulsion follows their own "MMC" (Modular Monocoque Construction) process, which essentially means they mold major sections of a frameset and then join them together. Felt says that "having larger one-piece sections gives designers the ability to reduce excess material and optimize each section for specific engineering demands." For the Compulsion, they took full advantage of this by wrapping additional layers of higher strength carbon fibers in impact-prone areas, including the bottom bracket, downtube where rocks are likely to kick up, and top tube where the shifters might hit.
Felt also improved the rear end stiffness and strength through the use of all-new links and hardware, revised pivot placement, and tweaked tube shapes. A 142x12mm E-thru Shimano rear axle helps keeps things nice and tidy as well. Grabbing ahold of the rear end, we're certainly impressed by how stiff it is. All told, Felt says the bike is lighter, stronger, and stiffer than ever before.
At first glance, the Compulsion looks like it uses a four-bar linkage suspension design. Look closer. See the vertical orange link near the seat tube? That's the Equilink, and the key to Felt's proprietary suspension system. First introduced in 2007, this Stephenson-style six-bar linkage system is claimed to disconnect drivetrain forces from bump absorption forces. How? Felt says that under power or weight transfer, the force from chain tension attempts to pull the lower link downward while the upper link attempts to pivots upward. Because the two links are connected by the Equilink in precisely calculated positions, the opposing forces effectively cancel each other out, "equalizing" the system (hence the name). Ultimately this means the suspension is unaffected and able to absorb impacts while pedaling.
The Compulsion uses sealed cartridge bearings in the main pivots and DU bushings in the Equilink and rear pivots, the latter of which are intended to save weight and increase longevity of the system due to their element-prone locations.
Cable routing is dialed thanks to a combination of internal and external routing options, plus it's possible to run cables above or below the downtube depending on drivetrain needs. Want to run Hammerschmidt? They've got you covered. With proper length cables there's very little cable rub and the front end is nice and clean.
Finally, the Compulsion offers great mud clearance, which is certainly something to consider depending on your local trails and conditions. We appreciated it a few times.
On The Trail
Like we mentioned before, we've had the bike for a few months. In that time we've been able to ride it on just about every type of trail imaginable - from high-speed descents to grueling hour-long climbs, slogs through the mud, techy rocky sections, and jumps and drops of various sizes, this bike has seen it all.
By putting the bike in the shorter 150mm travel position, it drops the bottom bracket by about 10mm and slackens the head angle from 67.5 to 66.75-degrees. This is a quick change we'd highly recommend, simply because it gives the bike a more capable feel, especially on the steeps. While it's unfortunate that a travel reduction occurs in this mode, in our eyes it's well worth the 10mm lost. As an alternative, the semi-integrated headset allows the use of a Cane Creek AngleSet for an additional +/- 1.5 degrees of head angle adjustment.
To really see this bike's potential, we immediately swapped out the stock stem and bars for a shorter and wider setup. At 700mm skinny (or less on some sizes), the stock configuration simply didn't cut it. After the slight modification, body position was very well balanced and the overall cockpit length felt just right. Save this component spec oversight, which it honestly is for a bike of this nature, the Compulsion is ready to attack out of the box.
Jumping into rough bits is a breeze. It handles large repeat hits like a champ, allowing you to keep your focus while looking a long ways down the trail.
Taking off down the trail, the Compulsion has a relatively light feel to it. Conversely, it's also quite surefooted. The combo of the two makes for a bike that rides in a comfortable manner midway between "playful" and "ground hugger." This is in part due to the bike's stiffness and in part due to the suspension behavior. The bike just feels solid beneath you, and flex isn't an issue anywhere in the frame. In fact, the rear end is among the most laterally stiff of all the bikes we've ridden in the all-mountain category. While it's not the most playful bike we've ever ridden, it's still relatively easy to move around, manual, and change lines at a moments notice.
Technical sections require no extra thought or odd body positioning, and the somewhat steep head angle helps improve handling in slower situations. When the trail turns really steep, we would appreciate a slightly slacker setup, but Felt struck a good balance for manageable handling at all speeds.
Not your typical all-mountain bike test, we know, but this mountain happened to include a few fun jumps. The Compulsion ate them up.
FOX CTD Float suspension front and rear handles bump duties. Given the option between the travel adjustable Talas fork and the fixed 160mm Float, we're pleased with Felt's decision to use the latter. The moderate head angle and 73.5-degree seat angle don't really require a dropped front end on climbs, and the improvement in damping is noticeable in the Float. We ran the fork almost exclusively in the middle 'Trail' mode with an additional 10-15psi over FOX's recommended setting.
The bike maintains a nice progressive leverage curve throughout the entire range of travel, which makes for a ride that's responsive to inputs and pumps well. The benefits of the progressive system really shine through when jumping, cornering, and in big compressions where good support is needed.
Small bump performance is good, especially when the rear shock is set to 'Descend' mode. At 25-30% sag, we actually preferred to ride without any pedaling platform on the rear shock. The Equilink suspension system works as advertised, creating a bike that pedals very well independent of the suspension setup. In this configuration there is ample traction on climbs and the bike is far more active. Cycling the linkage without the shock in place revealed that the rear end is aligned well and there is little to no binding, even with DU bushings at some of the pivot locations.
Standing up and mashing on the pedals was surprising, especially in the larger of the two chainrings. It's easy to really get up and go with a few solid pedal strokes and there is little to no noticeable suspension bob. It also pedals quite well over rough sections. This gives the Compulsion an assertive feel and allows you to gain speed quickly. Once up to speed, it maintains that speed well. Enduro racers, take note.
Considering it's a 150/160mm bike, sustained climbing was pretty painless. Power transfer is good, it's easy to get front end up while seated or standing, and we never noticed any odd pedaling characteristics in either chainring.
Shimano XT bits cover the bike from head to toe, and they help create a solid, reliable package. In a few months of hard riding, the XT brakes never gave us any issues, providing ample power at all times. Save the very rare dropped chain after a large hit or overly rough section, drivetrain performance was dialed as well. There was some slight chain slap on the chainstay, but slightly elevated seatstays help to quiet everything up.
After a handful of big hits and dozens of rocky sections, the XT wheels are slightly abused, but nothing a good truing session couldn't fix. Going tubeless was easy with the WTB Bronson tires, though one burped tire at a reasonable pressure left us hurting on the ground.
Tire wear and traction in most conditions was respectable. Really opening it up on high-speed sections did reveal one issue, though - the Bronson's soft corner knobs can create a squirly, confidence-zapping, uncontrolled feeling when in rough turns and in sustained chatter. Loose over hard trails were also a little sketchy at times.
Aside from a bar and stem swap, we also changed out the seatpost and saddle. The stock Crankbrothers Kronolog was very hard to actuate, robbing us of some potential fun, and the Felt saddle left something to be desired on long rides.
Long Term Durability
Two months and a few dozen rides in, the Compulsion seems to be holding up well. One initial maintenance concern was the use of DU bushings in the Equilink and rear-most pivots. Granted most riding was done in dry, dusty conditions, but we never experienced any play or stiction. As a preventative measure, grease ports on the Equilink facilitate easy maintenance and flanged Acetyl thrust washers shield the bushings from early abuse. The dropout pivots are shielded in a similar manner.
The carbon front triangle shows no visible signs of wear or concern, but we did encounter something rather unnerving while bolting on a bottle cage. Our metal cage was slightly bent, and while grasping ahold to bend it back we noticed a fair amount of flex in the carbon material surrounding the bottle mounts. Given the impressive fatigue life of carbon, this doesn't seem like much to balk at, but it certainly made us wonder. As mentioned previously, Felt assured us that the front triangle tested 5% better than the aluminum version in lateral stiffness tests, and our on-trail experiences coincide. If anything, just be careful not to put a lot of sideways force on the bottle cage while transporting or picking up the bike.
Also, be sure to keep an eye on pivot bolts, especially the lower front triangle pivot. This particular bolt seemed to constantly loosen itself, but at least Felt made it easy to tighten thanks to wrench flats on the driveside. Keeping pivots snug, clean, and well-greased will also help prevent the slight creaking that seemed to work its way in over time and echo through the carbon front end.
What's The Bottom Line?
Felt finally did it. They finally made a truly aggressive bike. The Compulsion LT 1 is a bike perfectly suited to riders that like to really get after it on the trail and have some fun rallying the rough stuff. Yeah, we had to make a few minor component swaps to get there, but the base package wasn't far off from ideal. It's a very efficient pedaler, offers great support through the entire range of travel, and is reassuring hit after hit. Bottom line? It will compel you to open it up just a little bit more, and you'll be happy it did.
Check out www.feltbicycles.com for more specs and explanations of the technologies used in the Compulsion frame.