QUESTION: Should you always use both brakes on a road bike? I’ve heard that I should mostly use the front brake, but won’t that cause me to flip over the handlebars? —John K.
RBR’S STAN PURDUM REPLIES: The answer I’m about to give presumes two things: First, that your brakes are working properly. Each brake should engage smoothly, and the lever should bottom out before coming into contact with the handlebar. And second, that you know which lever controls which brake. Usually, bikes sold in the United States are set up with the right lever controlling the rear brake and the left lever controlling the front one. But some people prefer them set up the opposite way. Be sure you know which is which on your bike.
The basic reality of braking is that the front brake alone provides the most stopping power. Using the rear brake by itself will stop the bike, but you’ll go twice as far before that happens. Applying the front brake suddenly in a panic stop situation can cause the bike to stand on its nose and send you over the handlebars, but you can avoid that scenario by simultaneously sliding back as far as you can go on your seat or even behind it, which moves the center of gravity back, and bracing against the deceleration with your arms.
Admittedly, it takes some practice to do that, but it’s worth your time to learn. Try it out in an empty lot, while wearing your helmet.
I typically use both brakes most of the time, and in normal stopping situations, I apply both gently. But in emergencies, it’s best to squeeze the front brake lever harder than the rear brake lever, and be ready to back off the rear brake if needed.
I learned this the hard way. Back when I was still a fairly new rider, I was “flying” down a steep hill when the wind caught the map I had tucked in my handlebar bag and sent it sailing. Not wanting to lose the map, I slammed on both brakes. I quickly found myself lying on the road with some skin missing from one arm and with a pulled groin muscle (the cleat grippers on my new clipless pedals were adjusted too tight and one foot didn’t come out of the pedal right away). My bike was lying farther down the road with a bent handlebar and a new series of nicks and scratches. Thankfully, I was wearing a helmet.
Later, trying to diagnose what must have happened, I came across this from the late, great Sheldon Brown: “Using both brakes together can cause ‘fishtailing.’ If the rear wheel skids while braking force is also being applied to the front, the rear of the bike will tend to swing past the front, since the front is applying a greater decelerating force than the rear. Once the rear tire starts to skid, it can move sideways as easily as forward.” (Brown was a bike mechanic and author with an encyclopedic knowledge of all things bicycle. See his advice about braking here.) I do think that fishtailing caused my crash.
John Allen, another bike tech wiz, who now maintains and updates Brown’s website of bike info, advises that when using both brakes, you should squeeze the front lever three times as hard as the rear, but increase the force on both levers simultaneously. If the rear wheel starts to skid, release the front brake a little and shift your weight rearward. When the rear wheel stops skidding, resume pressure on the front lever. You may need to repeat this front-rear modulation a few times before coming to a full stop. (Allen’s full advice about braking is here.)
The problem with spelling all this out in words is that it makes braking sound like some highly technical procedure that can only be mastered with hours of practice. In fact, it can be learned rather quickly with a little experimentation at slower speeds. And learning it will serve you well when you must decelerate quickly from higher speeds.
Readers, what’s your approach to bicycle braking? Let us know in the comment section below.
Stan Purdum has ridden several long-distance bike trips, including an across-America ride recounted in his book Roll Around Heaven All Day, and a trek on U.S. 62, from Niagara Falls, New York, to El Paso, Texas, the subject of his book Playing in Traffic. Stan, a freelance writer and editor, lives in Ohio. See more at www.StanPurdum.com.
Note on the accompanying article from 2019, “Fix for Larry’s Off-Center Rim Brakes (Sidepull Brakes)”
The pictured brakes are Dura-Ace. They have a special feature with the tiny allen bolt on the top right, visible in the picture.
Obviously, first follow the advice to be sure the brake is tight. Once that’s done, don’t hit it with a mallet and screwdriver. Instead, the small allen bolt is designed to adjust the brake so that the pads are centered around the rim. I think this feature is only on Dura-Ace sidepulls.
“I think this feature is only on Dura-Ace sidepulls”
It’s also on Shimano 600 and Ultegra dual-pivot side-pulls that I have
I have a set of Shimano 105sc brakes on a bike that’s 32 years old and those brakes have the centering screws. I’ve never seen a set of Shmano dual pivot brakes that did not have the centering screws.
On a rim-brake equipped bike, when descending a steep mountain road, I alternate using front and rear, braking as hard as possible for the shortest time, to give the rims time to cool. In general, I drag the rear brake lightly at first, to straighten the bike, then use the power of the front brake to scrub off speed. That light rear-only braking also helps very low-speed control, in parking lots or in dense urban riding.
I’d like to hear Stan Purdum’s comments on this manoeuvre described above:
“On a rim-brake equipped bike, when descending a steep mountain road, I alternate using front and rear, braking as hard as possible for the shortest time, to give the rims time to cool. ”
it seems dangerous. as as every time you go to braking maximum with one wheel only it could introduce the possibility of instability (crashing).
Do rims really heat up that much? Do brake pads lose effectiveness when heated (ie glazing?). Genuinely curious about this. We have one mega hill in my region that tbh is a big challenge to go down (summit climb, down the same road) where. you have to maintain maximum braking for the entire 5.3 km road descent..
Aluminum rims really do heat up a lot with sustained braking. Essentially all of the energy you have from a rolling bike and rider (one half mass times your velocity squared) turns into heat when braking. While your tires might heat up just a bit, nearly all of the heat appears in the rims. While I’ve not measured it, I know from experience that aluminum rims can heat to or near 140 F (60 C) which is a temperature that can burn skin. Next time you get to the bottom of that hill after sustained braking, touch your rims and see what you think.
Regards brake pads losing effectiveness, that depends both on the brand/type of pad and your braking style. This is why the advice is to pump the brakes to let both the pads and the rims cool in between braking pulses.
They sure do! I had a rear tire pop once while descending a long, steep hill.
Feel your rims and/or pads sometime after braking.
Alternating the brakes and hard braking on each separately sounds risky to me. But if it is something one has practiced, it might work OK. I myself, pump both brakes simultaneously going down steep hills, but I put a little more pressure on the front lever.
Personally, I use the brakes as I do on the motorcycle. Brake dabs for small speed changes by the front only. Light to medium braking by front only. Heavy and extreme braking using both. For heavy and extreme braking, a bit of rear brake first to help hold the rear down, then add in front with ever increasing lever pressure until up to desired front lever pressure. The front has the vast majority of the stopping power. The rear can too easily lock up, that being aggravated even more on steeper downhills. Use just enough rear brake to get some deceleration effect out of it when doing extreme braking which is when maximum weight transfer to the front occurs. Any hint of rear slippage, soften the rear brake to get grip back. Never lock your elbows when bracing against the handlebars when hard on the brakes, as that body rigidity too easily causes loss of grip. My opinion is that many riders have never explored and developed good technique for heavy and extreme braking, and leave much shorter braking distance capability on the table so to speak. As an indicator, if your forks don’t flex flex back under braking, the braking force being applied is low.
Please read through this link as it seems to cover the physics, physiology and psychological aspects of braking.
https://www.renehersecycles.com/how-to-brake-on-a-bicycle/
Note particularly his use of the right hand for front brake in one of the photos. He did not mention it specifically that putting weight on the pedals by slightly lifting of the seat with cranks horizontal lowers the effective center of gravity and also allows the tires to better track the road surface.
>>Essentially all of the energy you have from a rolling bike and rider (one half mass times your velocity squared) turns into heat when braking.
Yes now that you put it that way it is a lot of energy is being absorbed. I generally try to do the hard climbs/long brake-free descents direction of the ride circuit so don’t brake nearly as often as people doing the opposite.
Thanks for the interesting feedback today. Lots of niche details to improve braking ability and safety.
I think braking is a personal thing where one finds what works best for them.
I ride mostly on relatively flat roads and use the rear brake almost exclusively for non-panic stops. For panic stops I apply the rear brake first and then the front brake…applying force to both as necessary to stop.
On steep down slopes, I use the same technique (rear gently first and then the front) in short bursts to maintain desired speed.