It is common practice for racers to worry about the weight of their motorcycles and their performance. Bikers always do their best to play with these two and make sure they get the best fit because in as much as they reduce the weight, it also comes along with safety issues which should be controlled in the best way they can.
Generally, the idea is that when the bike’s weight is reduced, there is a greater acceleration achieved from every horsepower that the engine produces. In addition to that, you can also get a better suspension reaction and handling too if the weight is removed from places that the bike’s suspension doesn’t carry.
In motorcycles, there are 3 classes of weight or better still, three types of mass to be more specific. There is the sprung mass, unsprung mass and the rotating mass. The one we are going to be focusing on is the unsprung mass. It’s the weight of the parts of the bike that are found between the suspension and the road.
Generally, this includes parts such as tires, rims, wheel bearings, axles, swing arm, lower half of the forks and shock, brake rotors and calipers, rear sprocket, and part of the weight of the chain. What makes this mass different is the fact that though it is so close to the ground, it barely affects the center of gravity of the motorcycle, the bike suspension rather moves this mass up and down quickly so as to maintain contact between the tyre and the road. So, the less this unsprung mass is, the less the suspensions have to control. As such, it is more ready to react to road conditions.
So if you envisage working on the tires so as to reduce the mass, you should know that in as much as the bike turns easier with lighter wheels due to the reduced gyroscopic effect they produce, this in turn can make a bike that was already quick-steering become more unstable as it is ridden over rough surfaces. So if you really want to go for lighter carbon tires, upgrade your suspension to one that provides a wider range of adjustment.
Another area where most riders look to having some mass reduction is with the chain and sprockets. For instance, if you are to change the chain and make use of a 415 series chain and sprocket, it drops the mass by 2.5 lbs and the downside of it is a reduction in the life expectancy of the bike too. For those who like specifics, this change is equivalent to about 67% of the horsepower being transferred to the rear wheel, a much faster acceleration and improved corner as well as handling speed.
In a nutshell, the parts that make up the unsprung mass can be modified with keen attention paid to the bike performance, so as to get the most efficient bike with a lesser weight. Here are some key points to keep in mind.
● When choosing the parts for the lesser weight, go for components that will give an additional overall benefit. For instance, if you are going for lighter aluminum sprockets, also do well to adjust the motorcycles gearing too.
● You should aim at being cost-effective. Which is why it is advisable to begin with the parts that have the biggest influence but least cost price.
● The fasteners used in the motorcycle can be replaced with corresponding ones made of aluminum or titanium which are relatively lighter. If all of them are replaced on the bike, you are sure to have saved about 1.5 kg.
● For the braking system, if you go for a six-piston caliper then you are sure your discs have a narrower swept braking area. As such, they will be lighter.
Other less conventional methods to reduce the motorcycle’s mas are described below .
● Using a shorter exhaust pipe that is made of quality material is a guarantee lighter weight too.
● You may also want to go for aftermarket rims that are lighter.
● If you are the type who doesn’t carry passengers but your bike has space for that, you could either swap or shorten the seat, as well as remove the foot pegs.
● If you ride with a toolkit, you may want to lose it too. Likewise, for the operator’s manual.
Pic Source: Malfegor