Weight, speed and stopping
Road Badge › Know Your Machine › Weight, speed and stopping
Weight, speed and stopping
Both brakes, squeezed early, not grabbed.
1Pushing it up the drive
Switch the motor off and push your bike up a sloping driveway by the bars. You will feel it in your shoulders before you are halfway up.
That is the weight, with nothing helping. It is the same weight the brakes have to deal with, before you add yourself on top of it.
2The weight stays quiet while you are moving
That is what makes it sneaky. The motor carries the extra mass along the road, so nothing about riding it tells you the machine is heavier than the one you learned on. It only ever shows up at two moments: when you want to stop, and when it goes down.
The adult safety guidance says it about carrying a passenger, and the physics is identical for a battery and a motor: extra weight changes the way the machine handles and increases stopping distance.
3And you are going faster than you think
A study that instrumented real bikes in ordinary daily use measured it: riders on assisted bikes averaged 20.5 km/h against 16.6 km/h on ordinary bicycles. The youngest group they measured was everybody under forty, so that is the closest honest figure there is for you, and the trend says teenagers are not slower than it.
Then the physics does the rest. Double the speed and braking distance goes up around four times, because the energy you have to get rid of climbs with the square of the speed. It does not care how easy the machine felt on the way there.
4A stop has two halves
The half where you are still deciding, and the half where the brakes are doing the work.
Only the second band is about brakes. The first one is the last lesson in the badge before this, and both of them get longer when you go faster.
5A junction you usually brake for late.
Pick one.
Yes, and it is the one instruction that survives all the arguing. Nobody can tell you exactly how much further this machine needs, and we will not pretend otherwise — but every source agrees on the behavior: start applying the brakes earlier than you would on a traditional bike. Earlier is free. Later is not.
Braking harder is the option you have least of. The machine already carries more weight and more speed into the same intersection, and the ground you cover while deciding has grown too. The part you can still choose is when you start, and that is the whole answer here.
6How to brake, and the number we are not giving you
Three things every source agrees on.
Use both brakes, every time you slow or stop.
The front one does most of the work.
Squeeze progressively. Never grab.
And one more from the cycling side: straighten up first, then brake. Braking hard while leaned over is how the back end goes.
We are not telling you what share the front brake does, because four decent sources give four different answers, and the truth moves with the bike and the rider. Same reason there is no stopping distance here: two published figures differ by about five times and neither shows its working.
7Two bars, one crossing
A slider from walking pace up to the top assisted speed of your own machine, with a rider approaching a marked crossing. Two bars grow as you drag: the ground covered deciding, and the ground covered braking. No numbers on screen — just the two bars and the crossing.
Drag it slowly and watch which of the two bars grows fastest. That is the square in the physics, drawn.
8Which of these make the stop longer?
Pick every one that is right, then press Check.
Find all 4.
Four things that lengthen the stop, and only one of them is the brakes.
Two of those change nothing about stopping. Colour and a bell are not physics.
9Four words for every stop
Say it out loud, in your normal voice
Both brakes. Squeeze, don't grab.
Say it on your next three stops, in a parking lot, before you need it anywhere real. It is a hands habit, and hands learn it faster with the words attached.
10Before you leave this page
Test each brake alone. Feel the weight.
Stand beside the machine with the power off. Hold only the front brake and push it forward — it should not roll. Then only the rear, and push again. Each brake on its own has to hold the machine still. Then push it up the drive by the bars, so you have felt the weight the brakes are working with.