Not surprisingly, this has led to vastly divergent impressions of the overall package, as the ATK has generally not faired well in the press. This dichotomy, coupled with the inherent peculiarities of the no-linkage chassis, served to increase time and effort needed to get things dialed in. It took longer than usual to properly set up the 260LQ. That's perhaps why, at least in part, all of the other tests or reviews panned it unmercifully. Truth is, our first couple of rides on the 260 weren't much different. Stiff suspension action and questionable power had us wondering what we had got ourselves into. However, rather than whining and shoving the LQ into a dusty corner, we gave it a chance, taking the time to figure things out and dial it in proper, the end result being a competitive, raceable mount with a distinctly different performance envelope. In the case of this ATK260, patience truly is a virtue.Cool Stuff
We finally got our chance, taking delivery of a new '96 260LQ this past April for a long term test on our own East Coast turf. The good news is that the ATK LQ models come stock with some of the finest hardware you'll find anywhere, short of a factory works racer. Additionally, ATK will practically custom build the bike for a particular customer, adding or removing options to suit, swapping gearing or tires, etc. This impressive list of trick features includes Talon billet hubs front and rear, DID O-ring chain, Talon/Answer Radialite rear sprocket, Pro Taper handlebars, the latest WP fork with high and low speed compression damping, WP rear shock, shroudless 3.1 gallon fuel cell, machined billet triple clamps, quality Dunlop tires front and rear, and an innovative vacuum-actuated, adjustable power valve. Our scoot was also outfitted with the optional enduro headlight and tail lamp.
While the ATK literally reeks of quality custom hardware, it unfortunately has its share of warts too. For the most part, these are features that basically require further "refinement" to improve performance and longevity. Near the top of that list is the thin gage steel used on the frame (for tabs, gussets, etc.) and swing arm. This allows many mountings (fenders, side covers, etc.) to flex or bend out of shape, giving the bike an overall weak and vulnerable look. Older ATKs used to come with trick-looking utilitarian chromoly swing arms--what happened? Speaking of vulnerable, the pipe sticks out like a neglected hernia to the front and right side of the motor, begging to be mashed. Similarly, the chain guide is a disaster waiting to happen, constructed from thin gage aluminum that won't stand up to hard pack ruts, let alone rocks. For the most part, everything can be fixed, its just a matter of deciding where to start.
As usual, our testing regimen included riding and racing the ATK in a variety of terrain, from the sands and swamps of South Jersey, to the Maryland loam and Appalachian highlands rocks. We started off by leaving the bike stock and made changes and refinements as circumstances dictated. First impressions almost always start with the motor, the ATK being no exception. The Rotax powerplant is slightly under square with a 69.8mm stroke and 67.75mm bore (67.5mm for the 250). Straight from Utah, the motor starts easily in spite of a smallish 125 sized kickstarter and quickly achieves a nice steady idle. The head has an integral thermostat, facilitating motor warm-up. The motor uses a Mikuni TMS 38mm carburetor, which is the pilot-less model that surfaced some years back. Factory jetting uses a 350 main, the double tapered 6DGY4-56 needle with the clip in the #2 position, a "G" slide, and the air screw set 1.5 turns out.
In this state of tune the motor ran well, except for a deceptive leanness discovered on the top end. Deceptive because there was no overheating, pinging or rattling. We solved this by bumping the main to a 370, which now provides good performance throughout the power band. Sound abatement is handled by a lengthy extruded aluminum silencer (without spark arrestor). The exhaust note is acceptable, perhaps a bit noisier than the KTM or Husky 250, but still less than any closed-course 250. Large capacity radiators never spewed a drop in defiance of our worst abuse. The motor employs a vacuum-actuated adjustable power valve that uses exhaust gas pressure against a variable spring tension to effect valve opening timing. An external plastic cover located just above the head pipe permits the adjustment, using a threaded plastic plug that can increase or decrease the spring tension. Standard position is with the adjuster nut flush with the power valve cover, with two full turns of adjustment possible in either direction from the standard (flush) position. Turning the adjuster out decreases the spring tension holding the valve closed, thus allowing the power valve to open sooner. Conversely, turning the adjuster in increases spring tension and holds the power valve closed longer.
With the above jetting and the power valve in the standard position, the motor is a real sleeper, with practically no grunt off the bottom, a decent midrange and fair top end runout. The lack of bottom end was really frustrating in high-traction sand conditions, as the motor resisted getting into the more powerful midrange, despite repeated clutch feathering. Like lower horse power bikes (read: 125s), proper gear selection was imperative.
Our first attempt to get some bottom end out of the motor started with a gearing change. The 260 came to our doorstep with a 15 tooth countershaft sprocket (despite the claimed 14/48 stock gearing). We procured a 14 tooth sprocket and were disappointed to find that gobs of bottom didn't instantly materialize, and now we had to shift a whole lot more, to boot. Next step was power valve fiddling. According to the owner's manual (and conventional wisdom), decreasing the spring tension would allow the power valve to open sooner, improving throttle response at low speeds. We cranked the power valve adjuster screw out the full two turns and prepared to have our arms yanked out.
Conventional wisdom be damned, this yielded a motor with no discernible bottom end and a very electric power delivery throughout the rev range. Instead of getting a stump pulling farm implement, we ended up with a blender on two wheels. This proved very effective in the slimy mud and sharp rocks of this year's snotty Ridge Run Enduro, but still didn't provide the desired effect. Coincidentally, the 260's pipe bit the dust big time at the Ridge, the victim of a high speed slide through a rock garden, so we used that opportunity to try one of Rich Daily's Dyno Port torque pipes for the ATK. Now we were on the right track, as the Dyno Port pipe provided a marked improvement in low end, however it was still nowhere near the output of most other enduro 250s.
We tried raising the needle to see if a little more fuel would get things kicking, but this resulted in a blubbery output that hinted of plug fouling. Finally, we bucked conventional wisdom and adjusted the power valve for maximum spring tension, two turns in from the standard position.
Surprisingly, this resulted in a distinctive improvement in power at low RPM, providing more bottom end grunt and facilitating the transition into the midrange. This state of tune is a nice compromise between the raw berm blasting power needed in high traction situations and the friction hunting finesse needed for slick mountain rocks.
Are we totally satisfied with the motor now? Yes and no. Clipper ran the ATK up in New Hampshire this past weekend and came back raving about the perfect power delivery. For rocks and the slick stuff, this is it; this is the bike. Most agree, however, that South Jersey sand will still demand a little more punch. We're at odds where to proceed next, however, the engine's specs list a seven to one compression ration for the Rotax powerplant, significantly lower than most other dirt two strokes. Perhaps some head work to increase compression will spice things up. Another possibility are intake tricks, a switch to a RAM valve and some aftermarket reeds. These projects are underway and we'll keep you posted.
The ATK comes with a six speed gearbox, joining Husky as the only manufacturer shunning five speed trannies. Shifting was somewhat notchy, especially when new, but has improved as the motor has broken in. When new it was near impossible to shift the motor into neutral while idling. Now, with a bit of a drill that includes revving the motor and rocking the bike, neutral can most times be had. Still a chore, however, compared to most other mounts. Clutch action is good as the Rotax engine permits in-gear starts under any condition.
Handling and Suspension
Handling was a real wild card in this project, as the new frame (for '95) and inherent linkless rear suspension design adds considerably to the puzzle. The 260LQ does have a couple of things going for it, most notably the svelte 235 pound weight (wet, no gas), making it among the lightest enduro bikes on the market. Prior to testing, the rear sag was set to 375mm; an amazingly easy chore thanks to the linkless shock access. The factory delivered the bike with the forks raised one notch (approx. 5mm) in the triple clamps. Our testing found that the steering was a little slow in this position, with the tendency to wash the front wheel on occasion. To compensate, the fork was raised to just shy of the second notch, the maximum amount before the rebound adjuster contacts the handlebar. This made the ATK a better turner without making the straight line stability any worse than it already was. More on this later.
The fork found on the '96 ATKs is the latest WP that employs a neat approach to provide adjustable high and low speed compression damping. This is accomplished by simply valving the left and right fork legs differently, the right (brake) side oriented toward low speed damping requirements, the clutch side intended to take care of high speed hits. The fork provides six clicks compression damping adjustment and 24 click rebound. We changed the fork oil a couple of times, settling on Spectro 85/150 (very light, approximate 2.5 wt.) cartridge fork oil filled to a 130mm height. This is a good idea with any new bike, as all too often forks arrive from the factory with contaminated oil and inconsistent oil level (especially WP forks). While the forks were apart, a couple of plastic preload spacers were removed to minimize fork preload. The shock is a WP unit as well and provides six compression damping adjustment positions and eleven on the rebound side.
Out on the trail, the ATK provided good steering manners, exceptional suspension plushness both front and rear, and the well-known WP responsiveness to even minor changes in clicker adjustments. With a single click of any adjuster, suspension action could be tailored to meets the chosen days challenges.
This adjustability is key in light of the wide variety of terrain that we typically see in a given month. One of the most revealing traits of the ATK's WP suspension components was the break-in required in order to achieve proper suspension action. Again, our first few rides were not fun, the stiff shock and fork fighting us the whole time. Fortunately, after a couple of hundred miles, things loosened up considerably, providing a plushness that reacted to the smallest of root, rocks and braking bumps, without undue harshness or bottoming.
Overall we're very pleased with the current suspension setup and overall handling, however, there are a couple of problems. On the minor side, the WP fork has this intermittent habit of deflecting sideways in the rocks. This is by no means an all-the-time thing (not like the older forks), however, it's the unexpectedness that scares you. On the more serious side, the ATK is one of the most vicious head shakers in recent memory. As with most head shakers, the problem occurs mostly at speed when letting off the throttle. This was sometimes severe enough to lead to rear end swapping along with the front end shaking. We fiddled with fork position, rear sag, and even tightened down the steering head bearing to no avail.
Fortunately, we had a WER steering damper left over from a previous installation on a KTM. Installation of the WER steering damper was a snap, using a KTM RXC thumper mounting kit and requiring absolutely no drilling. The transformation was profound. With the WER steering damper installed, and the damping set at minimum, the ATK became stable as a battleship, with no sign of the previously chronic head shake. This thing really works. While we hate to admit that a three hundred dollar add-on is the only solution to any problem, this is one of those cases.
For the record, the suspension settings we settled on for the oil viscosity and air chamber size previously mentioned are: fork low speed compression (brake side); the factory recommended settings are the number two or three position--in our testing we preferred the number one clicker position. Fork high speed compression (clutch lever side)came from the factory set in the number four position, while TR testers preferred the number one slot for rocks, number two for sand. Fork rebound is set from the fully out (ccw) position, the same on both sides. Here we settled on the number six detent. Shock compression damping comes set in the number three position from the factory; which was confirmed as the trick setting once things break in. Prior to break-in we ran things a bit softer, in the numbers one or two positions. Finally, shock rebound came from the factory set at four, and TR riders bumped it to six.
Rounding Out the Package
The ATK comes with Dunlop intermediate terrain tires, a K490 front and K737 rear. These tires provided good longevity over a wide variety of soil conditions. Braking is accomplished using quick change Brembos, the same setup common to late model KTM and Husky dirt bikes. As with these other brands, the Brembos are good performers, providing excellent feel and the right lever (pedal) effort, both front and rear. Our persistent complaint is the questionable pad life exhibited at the rear, which of course is easily solved with a change to an aftermarket sintered metal pad.
The rear end of the bike is shod completely in KTM plastic. Both side panels and the rear fender assembly are right out of a '95 (white) two stroke parts bin. The seat is a KTM clone as well, although much softer. The Pro-Taper handlebars are a mixed blessing, confounding the mounting of handguards and enduro equipment. Instead, we substituted a set of factory KTM handlebars mounted using clamps from a twin shock Honda XR200 (a perfect fit). We'll save the full sized Pro Tapers for hare scrambles. Handle bar controls and levers are Magura, the clutch lever being an older design sans the trick quick adjustment feature. Thin wall DeCrosser grips offer a good feel to the hands while the KTM look-alike seat offers a welcomed improvement over the rock-hard 96 KTM seats.
Light weight tabs are used for mounting of side panels, rear fender, rear master cylinder, etc., and flex whenever subjected to any load. The rear master cylinder mounting in particular, has the tendency to get bent into the frame, misaligning the pedal-driven push rod. This required regular straightening (a simple tug) to realign the master cylinder with the brake pedal, and will surely lead to eventual cracking and failure. We'll beef up the bracket next time we visit Shawn's welding shop. The steel swing arm is constructed from similar thin gage steel painted a charcoal gray color that again looks cobbly. While we experienced no damage/failure to the swing arm, it is however, susceptible to corrosion as ours chipped some paint off near the chain rub block and proceeded to rust.
Show or Go?
What's it all add up to? By now we've spent nearly three months fiddling with our not-so-new ATK. From all of the work and observations presented herein you might be wondering was it worth it. Yes, we think it is. While the ATK may not be as refined as some other machines as delivered, we've succeeded in honing the 260 into a fun-to-ride race mount capable of bringing home the plastic, just like any other quality bike. Unfortunately, we had to change the pipe and install a steering damper to do it. It is an odd machine, but it is also a collection of some of the best components available to off-roaders, and it definitely weighs in as one of the lightest enduro/cross-country bikes you can buy. Spend a little time with it, and you'll probably like it fine. We do.
Manufacturer: ATK Model: 260LQ Engine Type: Liquid-cooled 2 stroke Displacement: 251cc Bore/Stroke: 67.75 X 69.8mm Transmission: Six-speed WR Gearing: 14/48 Chain: DID o-ring Tank Capacity: 3.1 gal. Carburetion: Mikuni 38 TMS Ignition: SEM CDI 160w lighting Forks: WP Model 5 Suspension Travel: 300mm Front Brake: Brembo hydraulic disc Front Tire: Dunlop 490 90/90X21 Rear Suspension: WP Super Adjuster Suspension Travel: 345mm Rear Brake: Brembo hydraulic disc Rear Tire: Dunlop 737 120/80X18 Seat Height: 37.2 in. Wheelbase: 58.5 in. Ground Clearance: 13.5 in. Claimed Dry Weight: 235 lbs. Suggested Retail Price: $5995