We have made a number of small modifications to the 2014 KTM 450xc-f now. Most have been aimed at making small contributions to the comfort and ride quality of this race bred bike. As I said previously, the real goal is to see how enduro worthy the xcf can really be.
Each step has been in the right direction. But I was still wondering if we were really going to be able to call it trail worthy. Could the xcf be a viable alternative to the xcw model? If you want linkage and the WP 4CS fork, it is a big question.
The answer to that question turned out to be the flywheel weight. It absolutely changed the character of the aggressive xcf motor. It has gone from hammer to velvet hammer in one simple step.
Even with a quieter, forest legal exhaust and changing the ignition map to the mild setting, our 450 still had a tendency to stall if you got lazy with the clutch hand in technical terrain. It wasn’t so much that the stall would happen often, but that you were always afraid of it happening at the wrong time. I was able to adjust my riding to compensate, but over time it was just more tiring to ride that way.
Steahly offers weight for the new sxf and xcf motors in 8, 12 and 15 ounce sizes. After talking with Chuck Steahly, I decided to go with the 12 ounce version. They call this a “bonded” application. The weight has to be epoxied over the stock flywheel. It is not a difficult process, but does involve a number of steps;
remove stock flywheel
sand and clean thoroughly
slide new weight over stock flywheel
mix epoxy, use supplied syringe to inject epoxy into holes
install set screws
epoxy over top of screws
allow to cure 24hours
bake in oven for 2 hours, allow to cool
weight on left, stock flywheel on right, two parts together in middle
Not having a KTM flywheel puller, I took everything loose and asked the guys over at All American KTM to pull it for me. The rest of the install only required basic tools and know how. The supplied directions were very easy to follow and have good photos for reference. Of course, once it is on, it is there forever.
I don’t really have much experience with adding the weights to bikes. I might have done it to my 1997 RM250, but nothing was going to really help that bike anyway, regardless of what the magazine said.
My first ride on the modified 450 motor was a pleasant surprise. At the moto track the smoother feel let me be more aggressive on the throttle without concern of it getting away from me. I was certainly going faster. For the first time with the 450xcf I finally felt like I could push myself and the bike instead of just riding around.
The real test would come at Tecate. After the positive results at the track I chose to race the 450 for the hare scrambles. Time to judge our progress with the xcf. The motor was an absolute joy to ride. The stalling was almost completely eliminated, therefore I used the clutch far less.
on the line for Tecate Hare Scrambles
Overall I struggled at Tecate, with mile after mile of first gear only terrain, I was a little out of my element and the 450 felt big. I still need to work on suspension set up a bit more for such conditions. But the motor was nearly perfect. With nearly 20 riders on my line, I was 4th to the first turn. Sadly, I was promptly passed my many of those riders. Still, even in tamed down mode, the 450 motor has plenty of power and is now super easy to use.
The Steahly flywheel weight has completely changed my outlook on the 450xcf. I was really doubting that we could have a race bike that would also possess the mild manners of the xcw models, but now I think it is possible. For me the 12 once model seems the correct choice. I probably would not go any heavier. For riders who lean more to the aggressive side, the 8 once might be enough. The motor has certainly lost just a little of that quick snap that it used to have, but for me what it has gained is far more beneficial.