RACE•TEST: Polaris Outlaw 450MXR, 525IRS & 525S; Mods, performance & results

If you are into sport riding, Polaris has you covered with their Outlaw lineup. For cross-country or woods riders, they offer the 525IRS, track tamers have the 450MXR, and grand prix/desert/dune fanatics can choose the 525S.
Over the last year, we tested each of these machines alone, and in shootouts with mostly positive results. During that time, we also race tested each of the Outlaws in their proper discipline, again with favorable results.
This month we are going to tell you how each of the three Outlaw sport quads performed in competition with Editor Brad Howe at the controls. We are also going to show what modification we did to each machine, and  how they worked.

We headed to New Berlin, New York, to compete at the Unadilla round of the Grand National Cross Country series. Unadilla’s tough and mud-ridden course made for challenging real estate to test the independent rear suspended Outlaw 525.
The 525 IRS needed a bit of suspension tuning for the rough nine-mile course, so we decided to re-valve the front Fox podium shocks to Howe’s weight specifications. Ronnie Wilson, of Polaris R&D, did the labor work for us.
The Outlaw features very lightweight steering. The best aftermarket product for racing the Outlaw is a steering stabilizer. We called upon Precision Stabilizers and their $485 damper for our Outlaw.
G.P. style front and rear bumpers from Rath Racing were also installed. Not only were they great for tight tree bumping and grinding, they served as excellent grip handles for getting unstuck. Trust us, in a GNCC event, there is a good chance of getting caught up.
Nerfbars are excellent for safety and keep debris from getting caught up in between your tires. They also provide the rider with another grab point when stuck.
The IRS Outlaw was the right choice for Unadilla. Many straight axle units were getting hung up in deep ruts, but the high ground clearance of the IRS kept Howe clear. The Unadilla course was not short on off-cambered corners and hill climbs, where the IRS was also very beneficial. The revalved front shocks worked great, although we would have appreciated a little more testing and fine-tuning before we hit the track. The steering stabilizer from Precision was Howe’s saving grace. “From slick high speed surfaces to whooped-out and rutted trails, and just plain running into things, that stabilizer worked flawlessly!” he said.
The 525 KTM powerplant provided more than enough power for the tight trails. Gearing felt great, and we were able to lug our way around the course with very little shifting in the tighter sections.
We grooved our rear Maxxis Razr treads for the mud, and the setup worked well. Even on the slick surfaces, there was plenty of traction! We lowered the air pressure from seven to six pounds in the front, to help with cornering as well.
When racing the two-hour GNCC events, we learned the value of being prepared. In a mud race like Unadilla, hand guards should top the list of upgrades for any Outlaw 525 IRS. Other than that, the IRS Outlaw was very impressive in nearly stock form. It was good enough to help Brad finish 17th overall out of 200-plus riders.

To get an idea of how the stock Polaris Outlaw 450MXR feels on a racetrack, we entered it in a GNC ATV MX National event at Round 8 at Red Bud Track and Trail in Buchanon, Michigan.
A very gracious Daryl Rath, his wife Jennifer, and his team of mechanics prepared our Polaris Outlaw 450MXR for the motocross portion of our race tests. Being one of the largest suppliers of aftermarket Polaris products, Rath had what we needed to get our MXR through AMA Tech.
We ran a fully stock unit, with the addition of Rath Racing Pro Peg nerfbars ($349), front MX bumper ($89) and rear MX grab bar ($69). Both the front and rear bumpers come with a bolt-on number plate, so we were ready to go.
Much like the majority of ATV races, a tethered kill switch is mandatory to race. Pro Armor was the company of choice in this area. Their switch retails for 40 bucks, and is used by many top racers, including Daryl Rath. Rath pre-installed the unit for us, and gave great directions on the easiest way to install it. The Outlaw’s throttle features an electronic override switch.
To install the kill switch this way, you disconnect, or in this case, snip the brown and green wire from this override switch. Connect the green wire to one end of the kill switch, and the brown wire to the other. Note, this will eliminate the override feature. If you do not want to do this, a kill switch is easily installed by connecting one wire of the kill switch to the running wire off of the on/off switch on the handlebars. You will then have to ground the other kill switch wire to the frame.
The Red Bud motocross track was incredibly rough for the stock Outlaw MXR. Much like the 525 IRS and S, the steering effort is very easy, causing excessive feedback in rough situations. A steering stabilizer was needed, but was not installed for this test.
Polaris needs to live up to the name of the MXR. Since they offer both forms of the 525 for trail riders, we aren’t quite sure why they didn’t turn their 450 into an actual race ready “MXR” machine. The 450MXR does offer good front Podium shocks from Fox Shox that are preload and compression adjustable. However, our list of changes for Polaris would include a wider, longer-travel front suspension setup, with fully adjustable shocks, like the high/low preload adjusts found on the new KTM 450/505SX and Yamaha’s YFZ450R. We would then match the front with a wider rear axle, and add nerfbars, and an integrated kill switch like that of KTM’s XC and SX machines.
The 448cc liquid-cooled KTM mill provided us with plenty of overall power for the track. The air box and stock exhaust need to be upgraded, and we will show you how to do this in a future issue (Project Outlaw 525 S).
It’s not all bad news for the Outlaw 450MXR. The overall feel and comfort level of the MXR is great. It is very comfortable to ride, and with good suspension, it will be a competitor. The brakes work great, the Magura Hydraulic clutch is very soft and smooth, and the Maxxis Razr tires provide great traction and control.

The independent rear suspension found on the 525 IRS is excellent in the mud, off camber corners and deep ruts. This machine was built for the GNCC series.

A local Taft, California, round of the WORCS series was what we needed to test our upgraded Polaris Outlaw 525 S. We have been constructing a Project version of the straight axle Outlaw for months, and this race gave us the final ingredient needed to complete it. We also learned a few things after the first two parts of our Outlaw race tests, and we were able to upgrade a few areas for the race.
Fox Evol float shocks were installed to improve the stock setup. The rear of the Outlaw is already equipped with a Fox Podium shock. To upgrade this unit, we shipped it to Fox. They offer a complete reconstruct kit for all Podium shocks, including a spring change and a re-valve.
A Precision steering stabilizer ($485) again graced our Outlaw racer, this time mounted to a Rath Racing steering stem. This strong stock length stem was equipped with 1-1/8 inch bar mounts, which allowed us to install Fasst Co’s Flexx handlebars ($329). The Flexx handlebars worked great to absorb shock and vibration that is transferred to your hands, arms, elbows and shoulders otherwise. Learning from our Unadilla mistake, we installed a set of Cycra M2 handguards. These large red molded plastic shields kept the mud and debris off of our gloves.
We replaced the stock Maxxis treads with ITP’s GNCC style tires. We ran 20-inch treads with bead locks in the rear, and 21-inch with non-bead locks in the front.
The Honolulu Hills course provided high-speed terrain with lots of hill climbs and descents, with whooped-out corners and breaking bumps. The 525 S was a good choice for this segment of racing. Just ask WORCS great Doug Eichner; he made the switch to the Polaris team a couple of years back, and he rides the S for the bulk of the series.
This was the best handling Outlaw of the three. However, if the Fox floats were installed on both the 525 IRS and 450MXR, we would almost guarantee better race results. The stabilizer worked great, and the Flexx bars kept us free from arm pump.
The 525 powerplant is fast, but jetting problems led to a lack of power and an overall bad day of racing. We installed a Rath racing designed airbox fix it before the race. This setup includes a K&N filter and a list of cuts for the stock box. This setup has been tested and proven by the Factory Polaris race team, but was not working well for the high speed Taft track. We will be re-testing this unit with Rath, and will feature it in our Project Outlaw in a future issue.

After three rounds of racing, in three different states, on three different Polaris Outlaw machines, we came away pleased with our results. A few modifications from Rath Racing, Fox Shox, Precision steering stabilizers, Cycra, Fasst Co and ITP allowed us to compete in all three events.
The 450MXR needs to be turned into a “race-ready” type ATV, especially since Polaris already has two very capable trail quads in the 525 S and IRS. With many modifications, including long travel suspension, the 450MXR could be competitive, but why not make the upgrades so the owner doesn’t have to? Suzuki (LT-R450, KTM (450SX), Can-am (DS450XMX) and Yamaha (YFZ450R) have already hit the market with a racer of their own. The 525 IRS is our favorite Polaris Outlaw. The Unadilla track we raced on was smooth sailing with the independently sprung rear end. The power is more than enough for tight trails, and is explosive down the straights. Get a steering stabilizer, and you are set with this mostly stock racer. The 525 S is the ATV of choice for WORCS champ Doug Eichner, but his unit is fully modified. We left our unit stock width with Fox Floats, Eichner hooked his 525 S up with Lonestar Racing’s long travel A-arms and wider axle. Tune in for a look at our Project Outlaw 525 in an upcoming issue. This includes much needed airbox mods, suspension upgrades and a bunch of other cool stuff.

If it wasn’t for the rough ride, the 450MXR had plenty of power to contend in the C class. Step up in classes, and you will need more juice.

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