Adding weight to the engine’s flywheel is an old trick that went away. Back in the days, we used to add weight to the flywheel of snappy barking two-stroke motocross bikes to make them work off-road. These days our bikes are already smooth and torquey and adding flywheel weight brings even more of that goodness.
Adding extra weight to the flywheel gives the bike more rotating inertia. The engine spins up slower, giving more traction and a feeling of smoother power delivery and it also makes the engine revs drop slower, giving less stalling and a greater ability to roll over obstacles. All this makes it a great improvement for hard enduro and technical riding.
I made the first few batches of these weights myself after trying many different sizes and weights to come up with what I think is the perfect setup. Not too heavy to make the bike boring to ride but enough to get all the benefits we want. Personally, I’m stoked on these and wish I had gotten on to this earlier!
I've got a local engineering friend making them for me now, always great to keep it in the motorcycling local community!
Installation is easy. Heat the weight up either by popping it in the oven or using a gas torch and then drop it over the flywheel so that it sits up against the starter motor drive teeth. Once it's cooled it will shrink in place and you then add the grub screws with some Loctite and tighten to 6nm.
These will fit all KTM and Husqvarna 250 and 300TPImodels. It will not fit the latest TBI models