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#272
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Why do some forks and frames have brake rotor size limits?
On 2017-10-31 07:23, wrote:
On Monday, October 30, 2017 at 3:40:30 PM UTC-7, Joerg wrote: On 2017-10-30 15:10, Doug Landau wrote: On Monday, October 30, 2017 at 2:16:43 PM UTC-7, Joerg wrote: On 2017-10-30 14:04, Doug Landau wrote: On Monday, October 30, 2017 at 1:58:51 PM UTC-7, Joerg wrote: On 2017-10-30 13:17, Doug Landau wrote: On Monday, October 30, 2017 at 9:39:55 AM UTC-7, Joerg wrote: On 2017-10-29 12:57, wrote: On Sunday, October 29, 2017 at 10:02:12 AM UTC-7, Joerg wrote: On 2017-10-29 09:45, wrote: On Saturday, October 28, 2017 at 8:09:18 AM UTC-7, Joerg wrote: And grandpa has driven his cars without safety belts yet survived ... For people who do not shy away from unpaved roads or use a lot of singletrack and ride in the rain there is a much more extreme issue: Wet mud. There is NO brake the is proof against wet mud. In fact it is perhaps worse on a disk since the additional pressure of the pads can turn the silicon present in most muds into cutting instruments that on rim brakes cuts into the rubber show rather than the hard and thin disk pad. Actually, no. I've had mud literally dripping from the calipers which had become barely recognizable brownish blobs. The only thing that happens is that they make an awful grinding noise just like muddy rim brakes do. With the two major differences that they still come on full force immediately and that this grinding does not eat up aluminum. Aluminum as one of the braking surfaces plain does not make any sense, certainly not in a muddy environment. A downside of bicycle disc brakes is that in contrast to most motor vehicles the rotors have "vent holes" and weight weenie spiders. This results in rather fast heat-up and in "brake mousse" when you plow through thick vegetation on an overgrown trail. Mashed star-thistle and other weeds get shredded and a sort of pulp develops which cakes up in the holes of the rotor. It doesn't diminish the brake force but lets of a bad stench. One of the reasons why I carry a Swiss Army knife in a pocket. Not in a pannier, so I can whip it out in seconds. This also helps in poking out the giant mud clump that forms behind the BB and can prevent the rear wheel from turning. Joerg - that additional noise is wear. Sure. However, the rotors last thousands of miles, cost around $20 and take only minutes to change. The pads cost $2/pair for ceramic-based material (like motorcycles have) and last around 1000mi depending on turf and weather. That is way more hassle than with a motor vehicle but way less hassle than swapping out a shot rim. I started riding again in fall 2013, using an older model MTB with almost zero miles on it. By the end of 2013 it had around 1000mi on it and the front rim looks horrible. The problem in our area is this: Mud contains granules of decomposed granite. Rubber pads need water diverter grooves and the granules lodge in these grooves. They also pierce the rubber itself and lodge in there. When pulling the lever that lets of a horrid grinding noise. Coming down a hill you have to keep the brake engaged and you can literally hear the rim being tortured all the way to the bottom of the hill. On flat surfaces you have to stop and pry out the granules. On a rainy day that means stopping every few miles. I stand by my opinion that rim brakes are inadequate for any serious MTB riding. That is the reason to use Kool-stop Salmons. The compound will not let granules lodge. So then why does it on my road bike? I use Koolstop up front, black and salmon. Gravel flakes embed in both when I travel gravel roads or unpaved sections during soggy weather. Plus they have grooves which is where they mostly embed: http://sheldonbrown.com/harris/images/brk14.jpg -- Regards, Joerg http://www.analogconsultants.com/ Take a pic next time until then we don't believe it We? Are you now spokesman for the whole NG? Was there a party convention with flags and brass band that I missed? Yes. The election that decided this NG's creation. Ah, a Chinese style coronation :-) ... Now quit yer whining and take the goddam pic. Can you tell me how when the weather is bone dry for months? ... This will be of interest to many here. The salmon koolstops and their resistance to embedding rocks are part of the lore of this group, and salmons are popular out of proportion here. Maybe there are versions with li'l gremlins in the grooves that shovel all the dirt out that gets in. Mine don't have those gremlins. ... Now quit complaining about a little effort to do your part, and show us pics of granules embedded in your salmon. See above. And it better rain hard soon because my black/salmon Koolstops are very close to worn down and I certainly will not replace them with new Koolstops. They wanted $17/pair for the MTB version last time I looked. Not going to happen. IME Clarks work just as well, last as long and cost only $4/pair. In terms of grinding after mud exposure I found there was hardly any difference between Koolstops and Clarks. My Campy brake pads appear to be perfectly smooth. Do they need grooves to work properly? Probably not and I've had pads without. My Koolstops and others that I have seen do though, for whatever reason. -- Regards, Joerg http://www.analogconsultants.com/ |
#273
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Why do some forks and frames have brake rotor size limits?
On 11/1/2017 3:27 PM, Joerg wrote:
With me that happened yesterday. School bus from the other side, driver backed out of driveway with gusto into the school bus' path, the bus driver swerved around and into my lane. If I had been lane center I'd be in the hospital or morgue today. I don't think I'd have ended up in the hospital just because I rode at lane center. I know about steering a bike. -- - Frank Krygowski |
#274
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Why do some forks and frames have brake rotor size limits?
On 2017-11-01 13:00, Frank Krygowski wrote:
On 11/1/2017 3:27 PM, Joerg wrote: With me that happened yesterday. School bus from the other side, driver backed out of driveway with gusto into the school bus' path, the bus driver swerved around and into my lane. If I had been lane center I'd be in the hospital or morgue today. I don't think I'd have ended up in the hospital just because I rode at lane center. I know about steering a bike. Except when it's too late to get to the side or as in this case off the road. But I know, you are superman and can easily put on a kilowatt or two to do this uphill. -- Regards, Joerg http://www.analogconsultants.com/ |
#275
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Why do some forks and frames have brake rotor size limits?
On Wednesday, November 1, 2017 at 12:30:19 PM UTC-7, Joerg wrote:
On 2017-10-31 07:27, wrote: On Monday, October 30, 2017 at 3:53:11 PM UTC-7, Joerg wrote: On 2017-10-29 17:09, Frank Krygowski wrote: [...] It doesn't pay to be timid. Man up. Why take the risk when there are alternatives such as this? https://goo.gl/maps/XJk1gMRC2eA2 A bike lane plus segregated bike path plus bicycle bridge, all seamlessly connecting to the Folsom bike path system and the American River bike trail. Plus a lot of parks. That area is a cyclists paradise. During rush hour it gets quite busy. So what you're saying is that the percentage of bicyclists deaths can be changed from nearly nothing to nothing? It isn't nothing. About one a month in our local paper. However, again, this is not only about deaths but also serious injury. I personally knew people who have had that happen, usually by being hit from behind. One woman wasn't able to ride for years because she ended up underneath a Ford F-150. Later she never regained her old performance level because some stuff didn't heal. I'm certainly not saying that injuries aren't serious. Apparently the pain I presently have in my right arm was caused by that crash I had in July. It didn't bother me until maybe a month ago. Now I have to go through physical therapy to try and quell the pain in my shoulder from a torn ligament. These sorts of things will always be around. The safest you can ever hope to be is 100 times less safe than you would like to be. https://www.youtube.com/watch?v=xdWsSB9QGkY It is somewhat strange to me that no one seems to know why brakes react the way they do. "disk brakes have more modulation". Well that's because a rim brake has more leverage. There is a wider distance between application of the disk brake and the full lock position. I don't have any trouble with brake cables or quick releases making noises. Looking at the available disk brake videos I have questions as to the techniques they used to make these tests which showed good rim brakes measurably less effective than disks. https://www.youtube.com/watch?v=xdWsSB9QGkY https://www.youtube.com/watch?v=uHFSSXOSnxs I was incorrect about increased drag from disks: the difference was too slight to mention. https://www.youtube.com/watch?v=HXQuSnKkS-I My personal experiece with disk brakes is not particularly good. On the heavy Trek HiFi they were very good. On my Redline Cyclocross bike they are all hell and gone too powerful. I installed these when the Shimano cantilever brakes on my Ridley couldn't stop a caterpillar in full flight. Later I installed TRP 9.0 V-brakes on the Ridley and even though the Ridley is a lot heavier than the Redline, the braking was much more predictable and powerful. |
#276
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Why do some forks and frames have brake rotor size limits?
On Wednesday, November 1, 2017 at 12:35:34 PM UTC-7, Joerg wrote:
On 2017-10-31 07:05, wrote: ... As for your opinions on safety I can understand your position after seeing how much weight you carry. The difference isn't that large. 20-30lbs in extra bike equipment, water and whatnot. It's peanuts. You talk about 30 or 40 lbs as if it's chickenfeed. My C40 was about 17 lbs ready to ride and my Basso about 24. It took me several months to get used to that weight difference. My Pinarello is 2 lbs lighter and I can sure tell the difference. |
#277
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Why do some forks and frames have brake rotor size limits?
On Wednesday, November 1, 2017 at 12:35:34 PM UTC-7, Joerg wrote:
A lever is never supposed to bottom out before the brake force on respective wheel is maxed. If it did then he'd have faulty brakes and I am sure he'd not have posted this. The guys look like serious cyclists who know this. How old are you again Joerg? With even the old Campy brakes it was possible to bottom out the levers often without locking the wheels. |
#278
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Why do some forks and frames have brake rotor size limits?
On Wednesday, November 1, 2017 at 1:02:54 PM UTC-7, Joerg wrote:
On 2017-11-01 13:00, Frank Krygowski wrote: On 11/1/2017 3:27 PM, Joerg wrote: With me that happened yesterday. School bus from the other side, driver backed out of driveway with gusto into the school bus' path, the bus driver swerved around and into my lane. If I had been lane center I'd be in the hospital or morgue today. I don't think I'd have ended up in the hospital just because I rode at lane center. I know about steering a bike. Except when it's too late to get to the side or as in this case off the road. But I know, you are superman and can easily put on a kilowatt or two to do this uphill. I don't ride with the big group anymore. I got tired of every ride being a race. But I would ride with the moderate group and once in awhile I'd get ticked off at the leaders riding away like that and I would ride up to them on an 8% climb after they had a quarter mile head start. But that was also when I could go from 15 mph to 32 mph to get through lights on busy streets. I think I can only do a sitting sprint to 25 mph or so now. But part of that may be the heavier bike with less aero position. |
#279
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Why do some forks and frames have brake rotor size limits?
On 2017-11-01 13:39, wrote:
On Wednesday, November 1, 2017 at 12:35:34 PM UTC-7, Joerg wrote: A lever is never supposed to bottom out before the brake force on respective wheel is maxed. If it did then he'd have faulty brakes and I am sure he'd not have posted this. The guys look like serious cyclists who know this. How old are you again Joerg? With even the old Campy brakes it was possible to bottom out the levers often without locking the wheels. I clearly consider that a faulty brake system. In Germany they would instantly disqualify a motor vehicle with such a flaw and not even let you ride it off the TUEV test site. -- Regards, Joerg http://www.analogconsultants.com/ |
#280
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Why do some forks and frames have brake rotor size limits?
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