I‘ve wanted a motorcycle for a while now and I‘ve been doing a little research. I‘ve read a lot about engine braking but I‘m not entirely sure on what it is. Can someone please explain it to me and list the steps involved. Or a good link about it would be just fine.thanks
As long as they are not so wide that they rub.
Can you drive? it's just turning down the throttle,If you're riding at 3,500 RPM and turn the throttle down to 3,000 the bike gets dragged down to the speed that it rides at 3000, turn it to 2000 and it slows more. It can also be done by downshifting from 5th gear to 4th, the bike at the same RPM,goes slower in 4th than at 5th. Try not to spend too much thought on the physics, get out and play with it.
A scenario: You're rolling along at 50 MPH, and you close the throttle. The engine acts as a brake to slow the bike. Engine braking refers to the engine acting as an air pump and slowing the bike down. Because the butterfly valve in the throttle body is closed, not much air can get into the cylinder as the piston descends, so the piston is sucking against a vacuum, which takes a lot of energy. That energy isn't coming from the fuel, as in most modern fuel-injected engines, if the throttle is closed and the engine is above idle speed, all fuel is shut off to improve mileage, since it's assumed the engine is in braking mode. So, the energy to keep the engine spinning in this situation is coming from the drive train, which is in turn getting its energy from the momentum of the bike. Thus, as the energy is transferred back into the engine from your forward momentum, it slows you down. That is engine braking. Note that on diesels and some newer fuel-injected gasoline engines, there is no throttle-body butterfly valve, so there is very little engine braking.
Good answer but not complete. Most cars have automatic transmissions in the US. (In Europe, you'd be hard pressed to find an automatic. Everyone knows how to drive a stick shift. European cars get their mileage by being small and light.) American cars are heavier and have automatic transmissions. These transmissions are designed to coast when you lift off the gas pedal. So if you want to slow down an American car, you use the brakes. A lot of driving is speed up; slow down; speed up again. If you lift up on an automatic, you don't slow down much. If you lift up on a standard transmission, you get that engine braking you're asking about because there is a one-to-one relationship between the motor and the drive wheels. I reckon you could find an automatic transmission on a motorcycle, but I've never driven one. With motorcycles, you tend to hold a constant speed with the throttle. Need to slow down a bit? Close the throttle a bit. Need to go a bit faster? Open the throttle a bit. BTW, my racing Bultaco had a compression release that worked very well- grab that little lever and the motor acted like a great brake, not locking up the rear wheel, but slowing you down pretty effectively. Don't know what the mileage was, but that was a track bike, and no one cared about mileage. When you ride a bike, you take off using the clutch. When you hit your cruising speed, you use the throttle to go a bit faster or a bit slower. You can use the throttle to go a lot faster, but that's a different matter all together. Be safe!! Many 18-wheel diesel trucks have jake brakes, a feature that releases compression in the head, making the downward stroke into a braking stroke.
