How to conserve energy when braking?

nolight

I live in a city with many traffic lights and has to stop often. Saving energy during braking at each stoplight helps in the long run.

What is the most efficient way to brake a road bike so that least energy is required to bring the bike to a stop at red lights? Like finger placement, power control, speed control when approaching green light etc.

Also should I change to lower gear ratio before braking?

kayakerchris

If you dont start moving you wont waste any energy stopping!

Nancy Luger

When coming to a stop I always stop pedalling before the bike comes to a complete halt. I apply the brakes gradually using the minimum force necessary. I feel that stopping pedalling saves the most energy, as my legs are no longer rotating and using energy to propel me in a forwards direction.

The energy used by my fingers in pulling the brake lever a few millimetres is negligible, so finger placement, in terms of energy conservation, makes no difference. Considering the expenditure of energy used via the fingers applying the brakes probably uses more energy in the brain. Writing this has probably used more energy than a lifetime of pulling my brake levers.

MountainMonster

Are you really asking how to save energy with your hands while braking? Wow. Just 1 finger

sub55

walk

TakeTurns

When you see a red, time your stop so that the lights will likely change by the time you reach them. So basically roll you way slowly, tap the breaks if necessary.

nolight

Ok so I should stop pedalling earlier and let it slow down so that I can minimise the use of brakes.

When I do that, does it help to be on lower gear ratio (Does it slow down more like a car's engine brake)? Likewise when I press the brake is it more efficient if I am on lower gear ratio? Or not much difference?

Also I am considering whether I should change to lower front gear when stopping. I don't like the inconvenience of having to change up again after accelerating.

nolight

kayakerchris wrote:

If you dont start moving you wont waste any energy stopping!

Your suggestion is reasonable, but I discovered that I failed to get to my target destination if I do that .

iPete

Buy a fixie.

No really, you'll find you no longer bomb it between lights slamming on the brakes.

jibberjim

What are you actually trying to optimise. If you're not skidding, there's no difference in energy saved no matter how you stop the bike, but I think your question is really something else.

arthur_scrimshaw

The best way to conserve energy (unless you RLJ which I'm not endorsing) is not to stop, so maybe timing the lights is a way forward?
You could just grab hold of the nearest vehicle as it pulls away and let go when you reach optimal velocity? Or you could just mtfu and think of the fitness benefit you're reaping from the start/stops?

Slack

Is this a wind up? If it's not, I suggest you engage the services of a scientist.

nolight

iPete wrote:

Buy a fixie.

No really, you'll find you no longer bomb it between lights slamming on the brakes.

I used a hybrid bike before and it indeed seems less energy is needed to brake than road bike, maybe due to flat handlebar brake lever, slower speed to brake from or weight of the bike. But it takes far more energy to move forward which is a bigger problem .

nolight

jibberjim wrote:

What are you actually trying to optimise. If you're not skidding, there's no difference in energy saved no matter how you stop the bike, but I think your question is really something else.

Just the energy needed to stop the bike, be it body control, strength control, timing of lights or whatever, in order to conserve energy in the long run.

I know the energy to move forward is more significant, but when you have to stop frequently in a busy city, the energy to stop is in fact quite significant since it adds up. Stop pedaling earlier at redlights for example can already save quite significant energy.

Peddle Up!

This?

nolight

Arthur Scrimshaw wrote:

The best way to conserve energy (unless you RLJ which I'm not endorsing) is not to stop, so maybe timing the lights is a way forward?
You could just grab hold of the nearest vehicle as it pulls away and let go when you reach optimal velocity? Or you could just mtfu and think of the fitness benefit you're reaping from the start/stops?

Yes not stopping is indeed the most energy efficient method since no energy is required for braking, and momentum is maintained! I am learning to time redlight better that means I don't slow down as much if I anticipate it is going to turn green soon.

But green light is what is giving me problem. I have no idea when it is going to turn orange. It is probably something I can work on as well, finding the optimum distance before the traffic lights to start accelerating if it is still green and still keep me safe. Finding the optimum distance to start to stop pedaling before that.

cougie

Are you perhaps over thinking this ?

Just anticipate when the lights will change so you don't accelerate up to a likely red.

Its necessary sometimes to change down a gear before you stop just to help you get going again - but that depends on you and what terrain and gears you are on.

The bike doesn't do engine braking -so that's irrelevant.

Anyway - why are you bothered about energy ? Its only a tiny bit. The more energy you burn - the more cakes you can have. It's simple.

Pross

'kin hell - I thought every possible question had been covered on this forum until now!

lotus49

Anticipation.

If you can time it so you don't have to stop so much the better. Otherwise coast as you see you will have to stop anyway.

I'm still a bit baffled by what you,are trying to achieve though. Are your fingers getting tired?

Gizmodo

nolight wrote:

Ok so I should stop pedalling earlier and let it slow down so that I can minimise the use of brakes.

When I do that, does it help to be on lower gear ratio (Does it slow down more like a car's engine brake)? Likewise when I press the brake is it more efficient if I am on lower gear ratio? Or not much difference?

Also I am considering whether I should change to lower front gear when stopping. I don't like the inconvenience of having to change up again after accelerating.

Unless you are riding a fixie then you have a free-wheel which means when you stop pedalling the gears have nothing to do with it. So no, it makes no difference what gear you are in when slowing down, and no, it is not like a car where the gears assist in slowing you.

You should be in the gear that you need to start off again, depending on your speed when you accelerate.

This must be a wind up! Changing gear is an "inconvenience" and using the brakes takes too much energy! You're having a giraffe.

nolight

lotus49 wrote:

I'm still a bit baffled by what you,are trying to achieve though. Are your fingers getting tired?

cougie wrote:

Anyway - why are you bothered about energy ? Its only a tiny bit. The more energy you burn - the more cakes you can have. It's simple.

The slowing down doesn't actually take that much energy. But I find that trying to bring the bike to a complete stop and then bringing my leg down to support the bike while sitting on the saddle somehow takes some amount of energy. During this act I also have to press down on the hood quite hard to bring my leg down.

John.T

Troll alert.

Slack

nolight wrote:

The slowing down doesn't actually take that much energy. But I find that trying to bring the bike to a complete stop and then bringing my leg down to support the bike while sitting on the saddle somehow takes some amount of energy. During this act I also have to press down on the hood quite hard to bring my leg down.

You are such a comedian. Come on, own up to your wind up!!

nolight

Ok you got me. I realised it is not THAT much of a problem, maybe because I am learning to time traffic lights and easing off on the pedals earlier.

But there is one situation which still uses significant energy: when the traffic lights are downhill. Just like a lot of energy is needed to accelerate uphill, a lot of energy is needed to brake downhill. If you don't believe, just imagine you have traffic lights (even if there are none) in the middle of a downslope at your location and you have to stop in the middle of the slope. You will have to brake a large part of the way to bring the bike to a stop, requiring quite a lot of force on the hood.

This is where having to stop and not having to stop will make a big difference!

NewTTer

Now i fully understand why the victorians put people away in sanitoriums, are people like this safe to be out and about

southdownswolf

I reckon that more energy has been wasted reading and replying to this thread than I would "waste" on an average ride braking....

kayakerchris

If you get a dynamo hub for the front wheel you will be able to scrub off all your speed just by turning the front light on!

nolight

After much extensive research in this topic, I found out another adjustment that helps: the angle of the saddle. My saddle had been pointing downwards, causing me to slip down and putting a lot of pressure on my arms when braking :oops: .

In summary, tips to conserve energy while braking:
- Time the lights! Sounds common sense but helps a lot. Look far to analyse the lights. If light is red for a long time, you may want to stop pedalling and prepare for the light to turn green so no braking is necessary. If light just turned green, you know you can safely pedal hard to beat the light before it turns. If light has been green for a long time, you may want to ease up on pedalling and prepare for the need to brake until you are a safe distance which you know you can beat the lights, so that no unnecessary use of brakes.
- Saddle should not point down too much which causes you to slide down and waste energy on the arms.
- Seat near the back of the saddle to move body weight back to help in slowing down.
- If bike approaching stoplight is still quite fast, drop the speed down to walking pace with gradual braking before attempting to bring it to a stop (no stop is the best though if you can time it). Hard braking from high speed is more energy draining.
- However, the moment just before stopping (walking pace already), if you know you are going to come to a stop for sure, squeeze brakes (esp front) HARD at the last moment to bring the bike to a stop once and for all. Better to squeeze hard one time than many small squeezes which wastes more energy than the 1 time squeeze.

Paul E

Use a parachute or an anchor

rolf_f

Just carry a short stout stick with you and slip it gently into the spokes when you want to slow down. Get's it all over with very quickly......

Yes, braking on a descent can be tiring - but not when approaching the average traffic light on a descent. Knackering braking is descending Harknott pass where you are up to 30mph approaching a hairpin on a broken road surface if you even lift off the brakes for a moment.

briantrumpet

Rolf F wrote:

Knackering braking is descending Harknott pass where you are up to 30mph approaching a hairpin on a broken road surface if you even lift off the brakes for a moment.

Ha, I'll admit to being a complete wuss descending Wrynose going east - hands hard on the brakes the whole time - was glad to get off the steepest bit. A bit of a waste of all that climbing effort.