4 ms·

How bicycle coaster brakes work (2018)

89 points by Vedor 1mo ago

bariumbitmap 1mo ago
> The disadvantages of coaster brakes are that the pedals cannot be adjusted while standing over the bicycle frame. Another disadvantage not mentioned in the post is that with coaster brakes the pedals can get trapped by the kickstand. I don't remember the details because this was a long time ago, but I accidentally found myself in a situation where I couldn't pedal forward because the kickstand was in the way, and couldn't pedal backward because the brakes engaged. I don't remember how I fixed it.
- pak9rabid 1mo ago
  Probably had to unbolt the brake bar to get it to spin freely backwards?
  - vjvjvjvjghv 1mo ago
    I had this sometimes happen as a kid. I think we mostly solved it with some old fashioned violence.
  - willismichael 1mo ago
    Either that or unbolt the kick stand.
    - SoftTalker 1mo ago
      On some bikes it was welded to the frame.
    - Kaliboy 1mo ago
      My friends. The kick stand stows by moving towards the back, making it possible to push it in during the normal cycling motion. So if its in the way, they're backpedaling. The way to solve it is to lift the bike's rear wheel and pedal like normal. That's it. No unbolting needed.
- thesuitonym 1mo ago
  You can get out of this situation by rolling the bike backwards. Since the clutch is engaged it will also move the pedals in the reverse direction. Thanks for unlocking that memory for me, it's been decades since I had to know that.
  - bariumbitmap 1mo ago
    > You can get out of this situation by rolling the bike backwards A-ha, I think that's why I ended up doing. And thanks to you as well!
  - theodorethomas 1mo ago
    Yes, this is how I used the "handbrake" function to "park" on a steep uphill.
- nkrisc 1mo ago
  You can adjust the pedals while standing, it’s just awkward. Take your weight off the seat, grab the back of the seat behind you and lift enough so the rear wheel loses traction and then you can push the pedals forward a bit. Not ideal, but possible.
jmclnx 1mo ago
These brakes are far more complicated then I was expecting. But do last forever.
- imp0cat 1mo ago
  Really the only downside is that they're prone to overheating in hilly terrain.
pak9rabid 1mo ago
Wow, I was just the other day wondering how these work. Far more complicated than I had expected, but a very cool mechanism!
vantassell 1mo ago
Biggest advantage is that they keep your hands free while braking.
BorisMelnik 1mo ago
I love coaster brakes! its one of the few parts of a bicycle I cannot fix (that, and wheels/spokes/truing)
- asdff 1mo ago
  Wheel truing is easier than you'd guess. Watch the park tool video then just take your time. You can do it on your bike with some jerry rigged feelers (e.g zip ties) attached to your chain stays.
contingencies 1mo ago
Retired cycle tourist here: Australia, China, Laos, France, Romania, Taiwan, Thailand. This is interesting, I recall having some of these as a kid. I'd say the key drawback not mentioned is that, in many riding conditions (such as but not limited to riding when in close proximity to vehicles, riding in high wind, riding in proximity to severe drops or road discontinuities, riding with heavy loads, riding downhill with luggage encountering sharp bends, repositioning legs for a hard ascent, etc.) you cannot always freely alter your physical stance to apply additional pressure to the braking system (as it may upset other concerns) nor can you afford a short latency to reposition to your stronger leg before applying the brake (or a short burst of climbing on difficult terrain). So while functional in most conditions, I'd say they are in fact objectively inferior in terms of latency and control and thus safety and utility in many realistic conditions. What could be an improvement (and may have been made already) is a speed-gated clutch, that is to say, slow reverse is permissible but a burst above the gate speed enables braking. This could solve a minority of the issues in terms of control at the cost of complexity.
- deepsun 1mo ago
  For cycle tourism I would have the coast brake AND a front wheel hand brake. Coast brake is much more resilient to elements (dirt/rain/oil), which is a major thing in bike tourism. And it's much more convenient to have one hand free to use a navigation tool, holding a camera, adjusting luggage, all while being in control of the braking.
  - contingencies 1mo ago
    On resiliency, most people cycle tour with disk brakes. This is primarily because the additional weight of the luggage adds inertia to a downhill scenario necessitating a larger braking surface and better torque control. Whether using vee or disk brakes, you still get redundancy (two wheels means two brakes with two separate control systems) and any experienced cyclist is familiar with compensating for the loss or relative efficiency of two brakes in a failed, fouled or poorly tuned state. Occasionally adjusting a brake is not a big issue, nor is changing a brake pad. Packing a spare set of contact pads is normal in touring. Few cycle tourists seem to optimize for using navigation tools or holding cameras while riding. Oldschool Europeans used to mount maps on their handlebar bags, but I haven't seen that in yonks. It might be common on a short-hop or produced-for-youtube thing, but to my mind it's not really the same mental space as touring, which anyone who has done it would understand: long distances, often daily goals or pre-nav, strong engagement with topographic change and natural environment = ~no need for while-riding lookups. Sure, if the road is well-surfaced and there's nobody on it, or it's a phone-photographed quickie: go for it. But unless it's a fleeting moment, most people I know would stop, have a drink, perform any lookups, maybe take a photo, then set off again. F=ma. Luggage means you have relatively large m. Fiddling with your camera while riding can be a bad idea.
deepsun 1mo ago
> The coaster brake also can be prone to locking up the wheels and causing the tire to skid. For kids this is an advantage, since they enjoy putting bikes into a sideways skid. Damn well it was! I remember we used to play tag on bikes. But when we switched to hand brakes, it became impossible, as you need a free hand and speed control at the same time.
- SoftTalker 1mo ago
  Yep I wore holes in several tires doing skids on my Schwinn when I was a young boy. My father got somewhat annoyed at it but used it as an opportunity to teach me how to change a tire and threatened to withold from my allowance the costs of any more tire replacements. I can't remember if that actually ever happened.
- deleted 1mo ago
  [deleted]
- kqr 1mo ago
  > But when we switched to hand brakes, it became impossible, as you need a free hand and speed control at the same Did y'all have only one hand?
  - usrnm 1mo ago
    Breaking with just the front wheel break is a very bad idea, so you always need the rear wheel hand to break
    - kqr 1mo ago
      What makes the front wheel brake a bad idea? I almost exclusively use the front brake, because that's the one that'll actually stop me. (Source: when I used rim brakes I had to replace the front brake pad three times for every time I replaced the rear brake pad.) I know some people use the rear wheel locking up as a way to sense when they have applied enough front brake, but that's not necessary. It's also possible to learn to sense that directly.
Hobadee 1mo ago
Where is all this love for coaster brakes coming from?! They are, IMHO, one of the worst brakes ever. They have caused me numerous spills and scraped knees (due to the rear wheel locking up and skidding out from under me) and have done the same to my kids. There is virtually no control over them, and they don't allow you to shift your weight around when standing on the pedals to go around sharp corners or off-road. (Nevermind trying to shift your weight backwards when stopping quickly) I have hydraulic disc brakes on my bike, and they are the greatest thing ever! Yeah, they require maintenance, but totally worth it.
- Gualdrapo 1mo ago
  In my experience hydraulic disc brakes require less maintenance than rim brakes. Living on a hill (like I had to go up a ~150m 23% wall to get home, and go braking down it to go places) meant I had to spend frequently on rim brake shoes and, eventually, rims. The frequent rain and mud makes it to the rim brake shoes and diminish braking power if you don't keep them clean. That doesn't happen with hydraulics - clean them with alcohol, bleed them once each year and you're set. I agree, they're the greatest thing ever.
  - CorrectHorseBat 1mo ago
    Hydraulic rim brakes also exist and they are amazing too
  - Swizec 1mo ago
    > The frequent rain and mud makes it to the rim brake shoes and diminish braking power I'll never forget when I was a kid (13 or so) going for a ride in the city during a downpour, slamming on the brakes because a pedestrian stepped out in front of me (mixed pedestrian/bike zone, no cars, we both assumed no-one else was dumb enough to be out), and ... nothing happened. Damn near shat my pants. Luckily the pedestrian saw me and jumped out of the way. In retrospect that was too much downpour. Could literally see water spraying out my brakes. The hot cocoa after was fantastic tho
  - rconti 1mo ago
    I've only once in my life worn out a set of rim brake pads I wore out the thin, small disc brake pads on my gravel bike in the first ~2000 miles. It didn't even _occur_ to me that the sound I was hearing was my brake pads being completely gone on what was a basically-new bike.
dnemmers 1mo ago
"The coaster brake also can be prone to locking up the wheels and causing the tire to skid. For kids this is an advantage, since they enjoy putting bikes into a sideways skid. This seemingly is a one of the requisite skills for youthful riders, especially but not exclusively boys." Very accurate.
zoom6628 1mo ago
Brilliant for folks in flat cities riding to and from work. That's the environment in which they got popular 100y ago. For hills def need rim brakes or discs for flexibility of use. BMX racing in early 80s we used the lightest rim brakes and levers we could find. I had couple of times snapping the levers and even the brake arms before fitting with really strong machined aluminium ones which lasted me 3 years before I stopped riding.
PreownedPlaid 1mo ago
[dead]
c0balt 1mo ago
Coaster brakes are ime one of the best brakes for beginners/intermediates because they can be a reliable backup in addition to rim/disc brakes. Had my rim brakes at least once lose a lot of efficacy during a large downpour and coaster brakes make a great backup for extra breaking power. They sure do like to lockup your rear wheel but that is still better than the alternative of only having very weak rear/front breaks.
walthamstow 1mo ago
Coasters are great if you have good cycle infra, don't go very fast and don't have to go up or down hills. Which explains why they're so popular in NL.
- analog31 1mo ago
  Yes, this illustrates that the merits of a technology are relative to its use. Urban cycling in the US is a whole nother beast. It's dangerous enough without effective brakes.
tokai 1mo ago
If you are skidding out using a coaster brake something is seriously wrong with your bike. Time to go get a hub service done.
edu 1mo ago
Used one once in a rental bike in Berlin, hated it all the time.
Gravityloss 1mo ago
I have biked with lots of coaster bikes and lockup has never been a problem. Like with a lot of things, you just need a little bit of humble attitude and trial and error to get the feel and then once you get it, it gets easier and easier. I don't think they lock up easily at all. Same if you drive an unfamiliar car, it's more bumpy in the beginning but your brain will adapt, especially manual gears. I remember some cars did have terrible clutches and gearboxes and very low torque engines so it felt intimidating as a kid.
kqr 1mo ago
> Many of the front brakes installed on less expensive bicycles are worthless and give riders a false sense of security. You should test the brakes before every ride! The front brake should make it very, very hard to push the bike forward. (The back brake should lock the wheel but the bike will continue to move forward.) That way, you can quickly tell whether they are worthless or provide true security.
wkjagt 1mo ago
I've always found it impressive that such a small diameter brake can brake so strong. Especially considering it's filled with grease.
pmontra 1mo ago
The worst brakes I ever used. They were on a rental bike in a relatively remote area so it could be a matter of maintenance but I remember braking on a 10% slope to lose no more than 50 m of height. I had to lock both my thighs with the same strength I would have used to climb that hill. That vs flexing my fingers with the smallest muscles I have.
wheybags 1mo ago
They forgot the biggest downside: when you REALLY need to stop RIGHT NOW, you're not thinking about what kind of brakes you have. You're running on instinct, and that instinct probably says "do a grabby motion with your hands", but that doesn't work, and you don't brake on time. Source: I have a bike with one coaster brake and one normal one. Have never intentionally used the coaster brake, have used it unintentionally many times.
timonoko 1mo ago
Two speed - Sturmey Archer was the best. No cables, no maintenance. Drove 4000 kilometers at one go and only needed new tire every 1000 km.
kazinator 29d ago
> “Pedal backwards. Really?” That's a good test for blowing the cover of extraterrestrial imposters posing as human beings. They don't know about pedaling backwards to stop a bike, because they were never a four-year-old human. Children's bicycles have coaster brakes. In the USA, a federal law requires them.
- reorder9695 29d ago
  As someone from outside the US, I had only heard of coaster brakes from this article. As a child all my bikes had rim brakes and now my bike has hydraulic discs, coaster breaks seem very strange to me.
  - kazinator 29d ago
    Had them in Europe in the 1970's on kids' tricycles. I remember leaving rubber marks on the pavement by locking these things up hard while turning the steering.

89 points by Vedor 1mo ago

> The disadvantages of coaster brakes are that the pedals cannot be adjusted while standing over the bicycle frame. Another disadvantage not mentioned in the post is that with coaster brakes the pedals can get trapped by the kickstand. I don't remember the details because this was a long time ago, but I accidentally found myself in a situation where I couldn't pedal forward because the kickstand was in the way, and couldn't pedal backward because the brakes engaged. I don't remember how I fixed it.

pak9rabid 1mo ago
Probably had to unbolt the brake bar to get it to spin freely backwards?
- vjvjvjvjghv 1mo ago
  I had this sometimes happen as a kid. I think we mostly solved it with some old fashioned violence.
- willismichael 1mo ago
  Either that or unbolt the kick stand.
  - SoftTalker 1mo ago
    On some bikes it was welded to the frame.
  - Kaliboy 1mo ago
    My friends. The kick stand stows by moving towards the back, making it possible to push it in during the normal cycling motion. So if its in the way, they're backpedaling. The way to solve it is to lift the bike's rear wheel and pedal like normal. That's it. No unbolting needed.
thesuitonym 1mo ago
You can get out of this situation by rolling the bike backwards. Since the clutch is engaged it will also move the pedals in the reverse direction. Thanks for unlocking that memory for me, it's been decades since I had to know that.
- bariumbitmap 1mo ago
  > You can get out of this situation by rolling the bike backwards A-ha, I think that's why I ended up doing. And thanks to you as well!
- theodorethomas 1mo ago
  Yes, this is how I used the "handbrake" function to "park" on a steep uphill.
nkrisc 1mo ago
You can adjust the pedals while standing, it’s just awkward. Take your weight off the seat, grab the back of the seat behind you and lift enough so the rear wheel loses traction and then you can push the pedals forward a bit. Not ideal, but possible.

jmclnx 1mo ago

These brakes are far more complicated then I was expecting. But do last forever.

imp0cat 1mo ago
Really the only downside is that they're prone to overheating in hilly terrain.

pak9rabid 1mo ago

Wow, I was just the other day wondering how these work. Far more complicated than I had expected, but a very cool mechanism!

vantassell 1mo ago

Biggest advantage is that they keep your hands free while braking.

BorisMelnik 1mo ago

I love coaster brakes! its one of the few parts of a bicycle I cannot fix (that, and wheels/spokes/truing)

asdff 1mo ago
Wheel truing is easier than you'd guess. Watch the park tool video then just take your time. You can do it on your bike with some jerry rigged feelers (e.g zip ties) attached to your chain stays.

contingencies 1mo ago

Retired cycle tourist here: Australia, China, Laos, France, Romania, Taiwan, Thailand. This is interesting, I recall having some of these as a kid. I'd say the key drawback not mentioned is that, in many riding conditions (such as but not limited to riding when in close proximity to vehicles, riding in high wind, riding in proximity to severe drops or road discontinuities, riding with heavy loads, riding downhill with luggage encountering sharp bends, repositioning legs for a hard ascent, etc.) you cannot always freely alter your physical stance to apply additional pressure to the braking system (as it may upset other concerns) nor can you afford a short latency to reposition to your stronger leg before applying the brake (or a short burst of climbing on difficult terrain). So while functional in most conditions, I'd say they are in fact objectively inferior in terms of latency and control and thus safety and utility in many realistic conditions. What could be an improvement (and may have been made already) is a speed-gated clutch, that is to say, slow reverse is permissible but a burst above the gate speed enables braking. This could solve a minority of the issues in terms of control at the cost of complexity.

deepsun 1mo ago
For cycle tourism I would have the coast brake AND a front wheel hand brake. Coast brake is much more resilient to elements (dirt/rain/oil), which is a major thing in bike tourism. And it's much more convenient to have one hand free to use a navigation tool, holding a camera, adjusting luggage, all while being in control of the braking.
- contingencies 1mo ago
  On resiliency, most people cycle tour with disk brakes. This is primarily because the additional weight of the luggage adds inertia to a downhill scenario necessitating a larger braking surface and better torque control. Whether using vee or disk brakes, you still get redundancy (two wheels means two brakes with two separate control systems) and any experienced cyclist is familiar with compensating for the loss or relative efficiency of two brakes in a failed, fouled or poorly tuned state. Occasionally adjusting a brake is not a big issue, nor is changing a brake pad. Packing a spare set of contact pads is normal in touring. Few cycle tourists seem to optimize for using navigation tools or holding cameras while riding. Oldschool Europeans used to mount maps on their handlebar bags, but I haven't seen that in yonks. It might be common on a short-hop or produced-for-youtube thing, but to my mind it's not really the same mental space as touring, which anyone who has done it would understand: long distances, often daily goals or pre-nav, strong engagement with topographic change and natural environment = ~no need for while-riding lookups. Sure, if the road is well-surfaced and there's nobody on it, or it's a phone-photographed quickie: go for it. But unless it's a fleeting moment, most people I know would stop, have a drink, perform any lookups, maybe take a photo, then set off again. F=ma. Luggage means you have relatively large m. Fiddling with your camera while riding can be a bad idea.

deepsun 1mo ago

> The coaster brake also can be prone to locking up the wheels and causing the tire to skid. For kids this is an advantage, since they enjoy putting bikes into a sideways skid. Damn well it was! I remember we used to play tag on bikes. But when we switched to hand brakes, it became impossible, as you need a free hand and speed control at the same time.

SoftTalker 1mo ago
Yep I wore holes in several tires doing skids on my Schwinn when I was a young boy. My father got somewhat annoyed at it but used it as an opportunity to teach me how to change a tire and threatened to withold from my allowance the costs of any more tire replacements. I can't remember if that actually ever happened.
deleted 1mo ago
[deleted]
kqr 1mo ago
> But when we switched to hand brakes, it became impossible, as you need a free hand and speed control at the same Did y'all have only one hand?
- usrnm 1mo ago
  Breaking with just the front wheel break is a very bad idea, so you always need the rear wheel hand to break
  - kqr 1mo ago
    What makes the front wheel brake a bad idea? I almost exclusively use the front brake, because that's the one that'll actually stop me. (Source: when I used rim brakes I had to replace the front brake pad three times for every time I replaced the rear brake pad.) I know some people use the rear wheel locking up as a way to sense when they have applied enough front brake, but that's not necessary. It's also possible to learn to sense that directly.

Hobadee 1mo ago

Where is all this love for coaster brakes coming from?! They are, IMHO, one of the worst brakes ever. They have caused me numerous spills and scraped knees (due to the rear wheel locking up and skidding out from under me) and have done the same to my kids. There is virtually no control over them, and they don't allow you to shift your weight around when standing on the pedals to go around sharp corners or off-road. (Nevermind trying to shift your weight backwards when stopping quickly) I have hydraulic disc brakes on my bike, and they are the greatest thing ever! Yeah, they require maintenance, but totally worth it.

Gualdrapo 1mo ago
In my experience hydraulic disc brakes require less maintenance than rim brakes. Living on a hill (like I had to go up a ~150m 23% wall to get home, and go braking down it to go places) meant I had to spend frequently on rim brake shoes and, eventually, rims. The frequent rain and mud makes it to the rim brake shoes and diminish braking power if you don't keep them clean. That doesn't happen with hydraulics - clean them with alcohol, bleed them once each year and you're set. I agree, they're the greatest thing ever.
- CorrectHorseBat 1mo ago
  Hydraulic rim brakes also exist and they are amazing too
- Swizec 1mo ago
  > The frequent rain and mud makes it to the rim brake shoes and diminish braking power I'll never forget when I was a kid (13 or so) going for a ride in the city during a downpour, slamming on the brakes because a pedestrian stepped out in front of me (mixed pedestrian/bike zone, no cars, we both assumed no-one else was dumb enough to be out), and ... nothing happened. Damn near shat my pants. Luckily the pedestrian saw me and jumped out of the way. In retrospect that was too much downpour. Could literally see water spraying out my brakes. The hot cocoa after was fantastic tho
- rconti 1mo ago
  I've only once in my life worn out a set of rim brake pads I wore out the thin, small disc brake pads on my gravel bike in the first ~2000 miles. It didn't even _occur_ to me that the sound I was hearing was my brake pads being completely gone on what was a basically-new bike.

dnemmers 1mo ago

"The coaster brake also can be prone to locking up the wheels and causing the tire to skid. For kids this is an advantage, since they enjoy putting bikes into a sideways skid. This seemingly is a one of the requisite skills for youthful riders, especially but not exclusively boys." Very accurate.

zoom6628 1mo ago

Brilliant for folks in flat cities riding to and from work. That's the environment in which they got popular 100y ago. For hills def need rim brakes or discs for flexibility of use. BMX racing in early 80s we used the lightest rim brakes and levers we could find. I had couple of times snapping the levers and even the brake arms before fitting with really strong machined aluminium ones which lasted me 3 years before I stopped riding.

PreownedPlaid 1mo ago

[dead]

c0balt 1mo ago

Coaster brakes are ime one of the best brakes for beginners/intermediates because they can be a reliable backup in addition to rim/disc brakes. Had my rim brakes at least once lose a lot of efficacy during a large downpour and coaster brakes make a great backup for extra breaking power. They sure do like to lockup your rear wheel but that is still better than the alternative of only having very weak rear/front breaks.

walthamstow 1mo ago

Coasters are great if you have good cycle infra, don't go very fast and don't have to go up or down hills. Which explains why they're so popular in NL.

analog31 1mo ago
Yes, this illustrates that the merits of a technology are relative to its use. Urban cycling in the US is a whole nother beast. It's dangerous enough without effective brakes.

tokai 1mo ago

If you are skidding out using a coaster brake something is seriously wrong with your bike. Time to go get a hub service done.

edu 1mo ago

Used one once in a rental bike in Berlin, hated it all the time.

Gravityloss 1mo ago

I have biked with lots of coaster bikes and lockup has never been a problem. Like with a lot of things, you just need a little bit of humble attitude and trial and error to get the feel and then once you get it, it gets easier and easier. I don't think they lock up easily at all. Same if you drive an unfamiliar car, it's more bumpy in the beginning but your brain will adapt, especially manual gears. I remember some cars did have terrible clutches and gearboxes and very low torque engines so it felt intimidating as a kid.

kqr 1mo ago

> Many of the front brakes installed on less expensive bicycles are worthless and give riders a false sense of security. You should test the brakes before every ride! The front brake should make it very, very hard to push the bike forward. (The back brake should lock the wheel but the bike will continue to move forward.) That way, you can quickly tell whether they are worthless or provide true security.

wkjagt 1mo ago

I've always found it impressive that such a small diameter brake can brake so strong. Especially considering it's filled with grease.

pmontra 1mo ago

The worst brakes I ever used. They were on a rental bike in a relatively remote area so it could be a matter of maintenance but I remember braking on a 10% slope to lose no more than 50 m of height. I had to lock both my thighs with the same strength I would have used to climb that hill. That vs flexing my fingers with the smallest muscles I have.

wheybags 1mo ago

They forgot the biggest downside: when you REALLY need to stop RIGHT NOW, you're not thinking about what kind of brakes you have. You're running on instinct, and that instinct probably says "do a grabby motion with your hands", but that doesn't work, and you don't brake on time. Source: I have a bike with one coaster brake and one normal one. Have never intentionally used the coaster brake, have used it unintentionally many times.

timonoko 1mo ago

Two speed - Sturmey Archer was the best. No cables, no maintenance. Drove 4000 kilometers at one go and only needed new tire every 1000 km.

kazinator 29d ago

> “Pedal backwards. Really?” That's a good test for blowing the cover of extraterrestrial imposters posing as human beings. They don't know about pedaling backwards to stop a bike, because they were never a four-year-old human. Children's bicycles have coaster brakes. In the USA, a federal law requires them.

reorder9695 29d ago
As someone from outside the US, I had only heard of coaster brakes from this article. As a child all my bikes had rim brakes and now my bike has hydraulic discs, coaster breaks seem very strange to me.
- kazinator 29d ago
  Had them in Europe in the 1970's on kids' tricycles. I remember leaving rubber marks on the pavement by locking these things up hard while turning the steering.