BMW G450X Project, Part 3

Jun. 16, 2010 By Dan Paris
Our project BMW G450X has led a tough, but short, life. In its 30-odd hours, this particular motorcycle has been on the podium of the EX class at the Montreal Supercross, with then BMW Canada (now Husqvarna’s) Guy Giroux in front of 45,000 people.

Our project bike was formerly on the podium at the Montreal Endurocross.

At Montreal, Giroux raced the bike with a Honda CRF450R fork, triple clamp and front wheel. The stock Marzocchi Shiver forks are fussy to set up, flex and tend to blow seals easily. When we got the bike the Marzocchi forks were back in place, albeit with much-stiffer-than-stock springs. The Ohlins shock had also been fitted with a stiffer spring, along with revalving by Pro Tech suspension. The bike had been badly beaten up at the Montreal race, after which it was basically hosed off and put away wet.

Our first date: a big bike on a little track.

The first time we rode the G450X was at an indoor motocross track, with Pro MX’er Jason Michael working the controls. He dug Giroux’s suspension settings and the engine’s low-end torque. The brakes were awesome too, and the bike didn’t feel heavier than any other 450 off-road bike. But we noticed right away this was a difficult motorcycle to work on. Five bolts with cap washers just to hold on the seat? Three bolts with cap washers to access the airbox? C’mon.

The first time we trail rode the BMW was in the snow. Just as BMW claimed, it got surprisingly good rear wheel traction.

Our first ‘real’ ride on the bike was in a couple inches of snow. In those slick conditions, we were impressed with the smooth power delivery and great rear-wheel traction. The BMW’s countershaft sprocket and swingarm pivot are inline, which helps keep chain tension constant and is also supposed to improve traction. It evidently works, but the bike also exhibited some weird manners we blamed on the slippery conditions. The ergonomics also felt wrong. We called Giroux, who told us, “Yeah, they are like that. You get used to the stinkbug thing after a while. Just learn to ride the bike and after a while you’ll start to like it.” Umm … ok.

Hangin’ it sideways. The BMW was too tall and simply didn’t have enough beans to make a competitive ice racer.

We spent the rest of the winter trying to figure the bike out while we blasted around on the ice with Fredette Racing Products studded tires. The transmission was gappy, with a huge spread between second and third gear. The BMW was also slow even with the EFI in the ‘high’ 50-odd horsepower position, and the gigantic stock muffler and tall gearing made the bike about a match for a good running 250F motocrosser. Every 450F race bike walked all over it. It also did a few weird handling things that we chalked up to the ice conditions or tires.

When spring came, we got some real trail and motocross time on the bike. We were struggling to understand its idiosyncrasies and capitalize on its strengths. We found that the BMW G450X to be incredibly sensitive to minor chassis adjustments, like rear suspension sag, fork height or axle position in the swingarm. We’ve noticed that with a couple recent test bikes, like the Husaberg FE570 and Yamaha YZ450F, as well. The “airbox up front/seat under the fuel tank/engine at a weird angle” machines are all very fussy.

The bike looks slim and aggressive but it just feels weird. You get used to it, eventually. As we learned how to properly set up the geometry and suspension of the BMW, it became quite a good handling machine.

We’d heard horror stories of poor BMW handling, but our bike’s suspension wasn’t stock and it really didn’t handle all that bad, though it never gave us much confidence either. We ended up with the forks raised 5mm in the tripleclamps, the rear wheel shoved as far forward as possible in the axle adjuster slots, handlebars in the forward position and 95mm of race sag. All of a sudden the BMW turned, and it turned well. Everyone who rode the bike remarked about its cornering prowess. It did headshake at speed over rough terrain, but no worse than a KTM or Suzuki. The newfound steering precision was well worth the trade off in less-than-rock-solid stability.

Around this time, about 20 hours, some problems started to show up. Blown fork seals, wheel bearings falling apart, swingarm bearings prematurely wearing out and fuel injection issues. The guys at Budd’s BMW took the frustrating bike off our hands and promised to make it right. They replaced the front and rear wheel bearings, the swingarm bearings, fork seals, repaired some faulty computer wiring and reprogrammed the throttle position sensor. While they were at it, we had them install a two-tooth bigger rear sprocket in an effort to tighten up the gap between second and third gear.

The Akrapovic muffler was light, quiet and woke up the sleepy engine.

When we got the G450X back from Budd’s it was like a new bike. It ran stronger, felt more solid and the gearing change reduced the need to slip the clutch out of tight corners. When we installed an Akrapovic titanium slip-on the performance of the bike shot up yet another level. The bike would now rev out, felt more powerful everywhere and the reduction of five pounds of highly placed lard could be felt immediately. We were on the fast track now!

Personal funny story: When trail riding the bike, I tried to climb a new hill that had foiled me for months. During one attempt I looped the bike over and bounced down the hill with the BMW in hot pursuit. We came to a very abrupt stop courtesy of a large maple tree, and it hurt. Lots. I wiggled out from beneath the bike, threw away my helmet and slid to the bottom of the hill on my butt. I was doubled over, pacing back and forth and trying to regain my composure when the cell phone in my tool belt rang.

“Hello?” I whimpered. With impeccable timing Giroux was on the line.

‘Eh Dan, it’s Guy. Hey, you crying or something?’

“Not really,” I lied. “I’m just trying to walk off a crash.”

‘Is my old bike ok?’

“Well, umm … right now it’s lying upside down halfway up a hill, pissing gas all over the place …”

Anyway, Giroux forgave me for tweaking his bike, and his input has been instrumental in getting handling and maintenance issues sorted out.

The Yosh pipe was a little heavier and a lot louder, but on the MX track we loved the extra snap it provided at the bottom of the powerband.

Once I recovered, we took the bike up another notch with a Yoshimura exhaust system, which was slightly heavier and much noisier than the Akrapovic system but made a big difference in low- to mid-range torque and throttle response. The bike actually ripped! A new set of Dunlop Geomax MX51s further tightened up the handling. Giroux was right – the more we rode the bike more we came to like it and think we could actually race this thing!

We thought we were ready to race until our bike once again developed fuel-injection problems, this time just days before the start of the Cross Country series.

A week before our scheduled ‘trial by fire’ at round-one of the Ontario Cross Country Championship, the BMW puked again. It had been running great, the suspension was dialled in and it handled very well. But when it got hot the bike began to sputter, misfire and refuse to start. We finished a very technical trail ride exhausted, because the bike would only run from about 5000 rpm up. Riding a race-stiff 450F through rocky, trials-type terrain by holding it wide open and working the clutch is not easy, physically or mentally! In case you are wondering, the clutch, which is smaller than normal and runs directly off the end of the crank, handled the abuse just fine.

Back to Budd's, where this time they diagnosed a bad low-speed throttle-position sensor and temperature-sending unit. While they were at it, they replaced a crushed header pipe (no comment…) and tidied up some EFI wiring. We rode it during the week on the motocross track and everything seemed just fine, so we enlisted Matt McCarthy (who normally races a Suzuki RM250) to race the bike that Sunday. He was stoked at the opportunity to race the Beemer; after all, the bike ripped! On the other hand, at this stage our confidence level in the BMW’s reliability was not real high, and two-plus hours at race pace seemed like an awfully long time.

Race day. The final test. Like always, the BMW attracted a ton of attention in the pits. It looks so interesting and serious compared to ‘normal’ enduro bikes, so it feeds a crowd wherever it goes. We had reinstalled the Akrapovic muffler, not only to smooth out the power but mostly to get us through the sound test. Now picture this: Dead engine start. Fourth row. The five second board goes up … wrrrr, clunk … the BMW doesn’t start.

Matt McCarthy recovered from a dead-last start to bring our BMW project full circle, with the bike once again on the podium!

In the pits we hung our heads in despair. By the time the bike finally fired up, the rest of the class was two full turns ahead. Matt took off into a huge dust cloud, riding blind and balls out. By the time the pack came back around after the first lap, 10 miles later, the BMW was about 12th overall! Matt and the Beemer had literally passed 50 riders on the first lap! He kept it pinned, stopping on the third lap for fuel. It was nearly empty. A good thing about the G450X is how easy it is to fill the small gas tank quickly. As rehearsed, Matt slid up on the seat while I popped off the gas camp and dumped a gallon or so of gas into the tank in a couple seconds.

Matt roared off, still holding third place. The fourth and final lap was a 10-mile bar-banging battle for second with a rider on a CRF450R. On the fast, wide-open course, neither bike had an advantage in the straights, and the two riders swapped position several times until the BMW quit while going into a turn. It took several very reluctant cranks before it re-fired, leaving Matt finishing in third by a mere three-second margin. Our bike now had just over 30 hours on it.

So what did we learn? The BMW G450X is competitive, but we already knew that from watching European riders like Juha Salminen take second in E2 class at the World Championships last year and Canadians like Giroux, who finished fourth overall in the 2009 Canadian Enduro Championship. But the BMW is finicky to the extreme. Minor service items are a nuisance, and major ones are all but impossible for the home mechanic to repair. But the bike can work, and when it works, it works surprisingly well.

BMW took on a huge challenge when they went up against the established off-road racing motorcycle manufacturers. They compounded that challenge by starting with a “clean sheet of paper” design, and then further compounded it by making the motorcycle street legal. They took on too much, too soon. Mission impossible, you might say. But still, the bike works. It’s a shame if this is the final year for the G450X under its current guise, but then again the new Husqvarna TC450F shares the BMW’s engine and much of its groundbreaking engineering. So it’s pioneering spirit lives on.

We had mixed feelings when it was time to give the G450X back to BMW Canada. The bike frustrated us with reliability and fussy set-up issues, but on those days when everything was right the bike was really fun to ride.

Thanks to BMW Canada for the long-term loan of the G450X, Guy Giroux for the tech tips and John Parker and the team at Budd’s BMW for keeping it running. We’d also like to thank Fredette Racing Products, Dunlop, Ame, BMW Motorrad Accessories, Moose Racing, Akrapovic and Yoshimura for helping us get our bike dialled in and Matt McCarthy for putting it on the podium! Newsletter
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