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How bicycle coaster brakes work (2018)

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Re: How bicycle coaster brakes work (2018)

#11

Post by nkrisc »

bariumbitmap wrote: post #2

> 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 c…

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.

Re: How bicycle coaster brakes work (2018)

#12

Post by contingencies »

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.

Re: How bicycle coaster brakes work (2018)

#13

Post by deepsun »

contingencies wrote: post #12

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 wit…

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.

Re: How bicycle coaster brakes work (2018)

#14

Post by deepsun »

> 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.

Re: How bicycle coaster brakes work (2018)

#15

Post by Hobadee »

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.

Re: How bicycle coaster brakes work (2018)

#16

Post by asdff »

BorisMelnik wrote: post #8

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

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.

Re: How bicycle coaster brakes work (2018)

#17

Post by contingencies »

deepsun wrote: post #13
contingencies wrote: post #12

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 wit…

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.

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.

Re: How bicycle coaster brakes work (2018)

#18

Post by Gualdrapo »

Hobadee wrote: post #15

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. (…

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.

Re: How bicycle coaster brakes work (2018)

#19

Post by analog31 »

contingencies wrote: post #12

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 wit…

Daily urban commuter here. I've had coaster brakes in the past. Bendix, Shimano, and Sturmey-Archer. I was attracted to the simplicity and lack of exposed cables. All were well maintained, by me, on wheels that I built.

Concurring with what you say, I learned all of the obscure failure modes of coaster brakes the hard way. Today I would not put them on anything but a maybe a kids' bike or beach cruiser. You can't guarantee that your feet will be in the right place at the right time to stop the bike.

Among other failures, I've experienced coaster brake "fading" on a descent when my house was at the top of a hill.

Adding a front brake is an improvement but not a panacea. You really need reliable two-wheel braking. It's not just for redundancy but for actual control of the bike during hard braking.

Re: How bicycle coaster brakes work (2018)

#20

Post by CorrectHorseBat »

Gualdrapo wrote: post #18
Hobadee wrote: post #15

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. (…

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 t…

Hydraulic rim brakes also exist and they are amazing too
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