The death of rim brakes?
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The death of rim brakes?
Frank Krygowski wrote:
On 3/10/2019 6:15 PM, Roger Merriman wrote: Frank Krygowski wrote: On 3/10/2019 3:51 PM, jbeattie wrote: On Sunday, March 10, 2019 at 8:22:10 AM UTC-7, Frank Krygowski wrote: On 3/10/2019 11:07 AM, wrote: On Sunday, March 10, 2019 at 2:34:24 PM UTC+1, wrote: I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal. Deacon Mark Try to find a ATB without disc brakes. I think that is also gonna happen with road bikes. Fashion is weird and powerful. For off road, discs are clearly better. It is not even debatable. Discs are better for some road applications as well... Agreed - but what is the magnitude on "better"? As I've said, we're deep into diminishing returns on bikes. Sales literature pushes people to buy a 17 pound bike instead of a 19 pound one, so the bike+rider weight diminishes by 1%. Get Dura-Ace instead of 105 because the shifts are 20 milliseconds faster. Ditch your front derailleur and reduce your aerodynamic drag. In real life, stopping "better" almost never means anything practical. but clearly rim brakes are fine for dry weather road riding with aluminum rims. I'm sure they will be around forever. Yes, and those of us who don't have to do panic stops in the rain on 10% downhills don't have to respond to this market churning. I have a Gravel bike, it replaces the CX bike. At that size of tyre your on canti which for a CX race is fine, but rapidly feel underpowered on big hills even in the dry, on tarmac. Discs make 30-40mm road bikes much less of a compromise. I agree that in the dry rims particularly good dual pivots are great brakes but unless that’s your Sunday best bike that only sees dry roads, it seems foolish to plan for best case. Well, the rim brakes on my various bikes are the ones that were used for _every_ case since 1976. The only brake failure I ever experienced was before them, on my first super-cheap 10 speed with chrome steel rims, during a pouring thunderstorm. I had to overshoot the turn I was planning to make. I don't care if people prefer discs. But it bothers me when manufacturers or others start implying that rim brakes are inadequate for even ordinary riding. I think it’s been more rider than manufacture lead, partially if you’re grown up with MTB which have had big stonking Hydro systems for years, I can remember a number of younger guys with their first road bike commenting on the lack of brakes in comparison. Stuff changes roadies do tend to be generally more conservative than MTB so I’d not be surprised if rim brakes survive in some form, after all you can get rim braked MTB still only cheap hardtail but it’s been 15/20 years now? So I could see rim brakes surviving in some form, apart from anything else there is a lot of road bikes with rim brakes out there! But I could see even a few new bikes which aren’t BSO like MTB using rim brakes being continued to be made if only niche. Roger Merriman |
The death of rim brakes?
On Sun, 10 Mar 2019 20:21:40 -0400, Frank Krygowski
wrote: On 3/10/2019 5:52 PM, wrote: On Sunday, March 10, 2019 at 8:34:24 AM UTC-5, wrote: I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal. Deacon Mark One of my issues is that I realize we will have rim brake bikes for awhile but I just hope to keep the nice looks and basic set up. If it is not broke don't fix the puppy. The one item I have never experience is the idea on a long descend you can blow a tube. In the flatlands that to me seems impossible. To blow a tube on a long descend does the speed have to be really fast like about 40mph or say at 25mph for a long time. The biggest descend I have done is about 7% grade total for about a mile and the last say 1/4 mile is got to 9%. I could easily feather the brakes to avoid heat but maybe my experience is really limited for true mountain riding. Can you just pull the brakes up pretty good to get to a speed that is comfortable. In my case this descend got me to about 43mph my top speed for sure. Had the it been longer I don't know long I could have continued before I got to damn scared. Long, long ago I read a technical article in some bike magazine. (There used to be real technical articles in bike magazines.) This one was about brake energy (or really, power in the engineering sense of work per unit time) and temperature rise during long descents. The article explained that the braking power depended on brake force and speed. For any given hill, you could always use the brakes to go super slow. Brake force will be high, but speed will be low and power will be low, leading to less temperature rise. Alternately, you could descend very fast, braking only lightly or not at all. Brake force will be low or zero. (There's also more aerodynamic cooling.) This too will lead to less temperature rise. The author claimed, using lots of calculations summarized in graphs, that the greatest temperature rise occurred by using the brakes to keep the speed about 30 mph or 50 kph. Trouble is, this is exactly the speed lots of cyclists choose for long descents. Any slower and they feel like slugs. Any faster and they get scared. I blew only one tire on a downhill, on the rear of our tandem, creeping down a short ( 1/10 mile) steep grade well over 10%. We just rode the bike to the bottom and I changed the tube. But I can see it would be a problem if the front tire blew. Phuket, Thailand has several extremely steep hills on the western side of the island, steep enough that it is difficult to push a bike up them. Out of curiosity I did push the bike up one and coasted down the eastern side. Having read all the hoopalla about the rims getting hot and tires blowing I stopped about half way down and felt the rims... they were, perhaps, a bit warmer than ambient temperature. But. As the east side of the hill is a series of "S" turns one can't just coast down the mountain but must slow down every hundred yards or so to make the next corner so my braking was a series of pretty hard brake applications followed by, perhaps, an equal period of coasting. I have since used that method when descending hills and an occasional check shows that the rims do not get excessively hot. -- Cheers, John B. |
The death of rim brakes?
On 3/10/2019 10:10 PM, John B. Slocomb wrote:
On Sun, 10 Mar 2019 20:21:40 -0400, Frank Krygowski wrote: On 3/10/2019 5:52 PM, wrote: On Sunday, March 10, 2019 at 8:34:24 AM UTC-5, wrote: I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal. Deacon Mark One of my issues is that I realize we will have rim brake bikes for awhile but I just hope to keep the nice looks and basic set up. If it is not broke don't fix the puppy. The one item I have never experience is the idea on a long descend you can blow a tube. In the flatlands that to me seems impossible. To blow a tube on a long descend does the speed have to be really fast like about 40mph or say at 25mph for a long time. The biggest descend I have done is about 7% grade total for about a mile and the last say 1/4 mile is got to 9%. I could easily feather the brakes to avoid heat but maybe my experience is really limited for true mountain riding. Can you just pull the brakes up pretty good to get to a speed that is comfortable. In my case this descend got me to about 43mph my top speed for sure. Had the it been longer I don't know long I could have continued before I got to damn scared. Long, long ago I read a technical article in some bike magazine. (There used to be real technical articles in bike magazines.) This one was about brake energy (or really, power in the engineering sense of work per unit time) and temperature rise during long descents. The article explained that the braking power depended on brake force and speed. For any given hill, you could always use the brakes to go super slow. Brake force will be high, but speed will be low and power will be low, leading to less temperature rise. Alternately, you could descend very fast, braking only lightly or not at all. Brake force will be low or zero. (There's also more aerodynamic cooling.) This too will lead to less temperature rise. The author claimed, using lots of calculations summarized in graphs, that the greatest temperature rise occurred by using the brakes to keep the speed about 30 mph or 50 kph. Trouble is, this is exactly the speed lots of cyclists choose for long descents. Any slower and they feel like slugs. Any faster and they get scared. I blew only one tire on a downhill, on the rear of our tandem, creeping down a short ( 1/10 mile) steep grade well over 10%. We just rode the bike to the bottom and I changed the tube. But I can see it would be a problem if the front tire blew. Phuket, Thailand has several extremely steep hills on the western side of the island, steep enough that it is difficult to push a bike up them. Out of curiosity I did push the bike up one and coasted down the eastern side. Having read all the hoopalla about the rims getting hot and tires blowing I stopped about half way down and felt the rims... they were, perhaps, a bit warmer than ambient temperature. But. As the east side of the hill is a series of "S" turns one can't just coast down the mountain but must slow down every hundred yards or so to make the next corner so my braking was a series of pretty hard brake applications followed by, perhaps, an equal period of coasting. I have since used that method when descending hills and an occasional check shows that the rims do not get excessively hot. Omega and others make temperature indicator dots. They turn black and stay black when their rated temperature is reached. https://www.omega.com/pptst/TL-C5_LABELS.html They're single use products. Back when Jobst was with us, there was talk of sticking these on some rims and doing tests, but I don't recall if anyone actually did that, or what the results were. -- - Frank Krygowski |
The death of rim brakes?
On Sunday, March 10, 2019 at 11:46:16 PM UTC-4, Frank Krygowski wrote:
Snipped Back when Jobst was with us, there was talk of sticking these on some rims and doing tests, but I don't recall if anyone actually did that, or what the results were. -- - Frank Krygowski Jobst and Carl Fogel are both missed. Cheers |
The death of rim brakes?
On 3/11/19 1:24 AM, Frank Krygowski wrote:
On 3/10/2019 6:38 PM, wrote: On Sunday, March 10, 2019 at 4:48:00 PM UTC+1, Sir Ridesalot wrote: On Sunday, March 10, 2019 at 11:22:10 AM UTC-4, Frank Krygowski wrote: On 3/10/2019 11:07 AM, wrote: On Sunday, March 10, 2019 at 2:34:24 PM UTC+1, wrote: I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal. Deacon Mark Try to find a ATB without disc brakes. I think that is also gonna happen with road bikes. Fashion is weird and powerful. -- - Frank Krygowski A few years ago I nearly bought a new disc brake equipped MTB when my buddy bought his Da Vinci disc brake equipped MTB. However, after having seen how his bike ate disc brake pads I decide not to replace my old MTB after all. I wonder how the cost of replacement disc brake pads over a number of years compares to the cost of a new rim over those same number of years? I've never worn out an MTB rim but my buddy was going thorough a pair of disc brake pads every week or so and that was just from riding or paved roads or crushed limestone stone dust rail-trails. He was NOT using the brakes all that much either. Three bicycle shops here in town could not figure out why his bike ate pads so fast and that includesÂ* the shop that specializes in cyclo-cross and MTB trails and has a cyclo-cross team. Just weird. Rim brakes are fine for a lot of bicyclists yet it seems that once again a choice will eventually be denied to consumers. On top of that, if your present bicycle is equipped with racks you'll most likely have to buy new ones that are disc brake compatible if you do buy a new bike. Those new racks aren't that cheap either. Cheers That is an unusual wear of pads. I've said this before, but if you're heading out on a long tour with a disc brake bike, take extra pads. We hosted a guy whose pads suddenly wore out during a tour, leaving him without brakes until he could find a bike shop on his route. I'm wearing out discs (every 4 years) faster than pads. What am I doing wrong? |
The death of rim brakes?
On 3/11/19 1:10 AM, Frank Krygowski wrote:
snip Well, the rim brakes on my various bikes are the ones that were used for _every_ case since 1976. The only brake failure I ever experienced was before them, on my first super-cheap 10 speed with chrome steel rims, during a pouring thunderstorm. I had to overshoot the turn I was planning to make. I don't care if people prefer discs. But it bothers me when manufacturers or others start implying that rim brakes are inadequate for even ordinary riding. Why did we ever move away from chromed steel rims? Cheap and easy to manufacture, lasted for ever (you still see them about!) and looked great! |
The death of rim brakes?
On Mon, 11 Mar 2019 07:13:52 +0100, Tosspot
wrote: On 3/11/19 1:10 AM, Frank Krygowski wrote: snip Well, the rim brakes on my various bikes are the ones that were used for _every_ case since 1976. The only brake failure I ever experienced was before them, on my first super-cheap 10 speed with chrome steel rims, during a pouring thunderstorm. I had to overshoot the turn I was planning to make. I don't care if people prefer discs. But it bothers me when manufacturers or others start implying that rim brakes are inadequate for even ordinary riding. Why did we ever move away from chromed steel rims? Cheap and easy to manufacture, lasted for ever (you still see them about!) and looked great! And you had to drag your feet to stop :-) -- Cheers, John B. |
The death of rim brakes?
On 3/11/2019 2:13 AM, Tosspot wrote:
On 3/11/19 1:10 AM, Frank Krygowski wrote: snip Well, the rim brakes on my various bikes are the ones that were used for _every_ case since 1976. The only brake failure I ever experienced was before them, on my first super-cheap 10 speed with chrome steel rims, during a pouring thunderstorm. I had to overshoot the turn I was planning to make. I don't care if people prefer discs. But it bothers me when manufacturers or others start implying that rim brakes are inadequate for even ordinary riding. Why did we ever move away from chromed steel rims?Â* Cheap and easy to manufacture, lasted for ever (you still see them about!) and looked great! I suspect the main reason was weight. But there were tremendous differences in braking when wet. The incident I mentioned was an example. The rain was pouring down heavily. I coasted down a slight hill intending to turn right into a little road at the bottom. But the brakes had no effect for perhaps five seconds or more. I rolled right past that little road. Those were probably the worst style of chrome steel rims. They featured little pits on their braking surface, perhaps intended to provide roughness and aid braking, I don't know. But they acted as little water reservoirs, keeping the brake pads from wiping the rims dry. I've heard that there were hard-to-find brake blocks that worked well with wet chrome steel rims, but I've never seen them in the flesh, let alone tested them. -- - Frank Krygowski |
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