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#101
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MTB disc brake caused wild fire
On 2018-04-02 10:37, jbeattie wrote:
On Sunday, April 1, 2018 at 10:31:26 AM UTC-7, sms wrote: On 4/1/2018 9:23 AM, jbeattie wrote: snip And yet, for decades, I rode rim brakes in the rain, mud, etc. The downside was the rim-lathe of grit against aluminum rims and momentary loss of braking, but on a wet surface, the real problem has always been traction. The two times my bike didn't stop in the rain due to brake issues we (1) pulling a trailer with my son in it on poorly adjusted cantis with STI levers, and (2) descending a sled run out of the West Hills with worn and unadjusted pads on cable discs. I stopped and dialed in the pads which solved that problem. In both cases, hard braking would have had me skidding down a wet road or path. I rode maybe 40-50 miles yesterday all climbing and descending on my uber-bike (no instrumentation and no idea of elevation) with direct mount calipers. It was dry, and I didn't give my brakes a moment's thought. My braking issues were all about when I slowed and road surface quality. You may have done this for decades, but you were not having any fun doing so. I have a friend who used to go on and on about the greatness of Price Club (now Costco). I asked him "Tom, how did you survive before Price Club?" His response: "I survived, but it wasn't much of a life." I was riding yesterday on the Synapse that replaced the stolen Roubaix that replaced the Cannondale CAAD 9 that went to college with my son. We're getting all my son's bikes from Utah this weekend, including the CAAD 9 and three other bikes. The Roubaix was recovered. We have way too many bikes! Also coming back is a Windsor Knight -- a $150 frame from Bike Island that I built with a lot of left over 9 speed parts. It was my son's first "fast" bike. I'm going to steal all the parts for my commuter (spares) and Craigs list the frame. The CAAD 9 will probably go, too, since my son wants a disc commuter. He gets pro deal on Cannondale, so he'll probably get a disc bike from them. Anyway, I was riding around on the Synapse which has both discs and UDi2. It was sprinkling a little but not horrible, so the superior braking was really irrelevant. The Di2 was neat because you can climb out of the saddle and buzz through the gears. It shifts really well under load, so doing the long rollers common to the hinterland, it was like taking an escalator up. https://c1.staticflickr.com/4/3539/3...f58a6d14_b.jpg Does this make riding more fun? No! Someone told me that Eddy Merckx said when asked about a giant chocolate desert he was polishing off "Chocolate? No, that's not bad for you. Hills, hills are what's bad for you". ... Well, it beats the sh** out of having to flop down into the saddle and use DT friction shifting. It's also awesome to have so many gears now that I am decrepit. I NEED the gears now, but I could live with cable STI and rim brakes. If you threw me back on my 1976 custom SP racing bike with 52/42 13-21 5sp and a slammed Cinelli stem, I would be demonstrably unhappy -- and walking a lot. That's what I had until a few years ago. Then I hacked a MTB cassette so the largest cog in back was at first 28, then 32. Getting older ... Later I switched the freehub to 7-speed because I crunched my last UG freehub. The upside is that I don't have to hack the cassettes anymore. On the ride yesterday my MTB buddy told me he got an 8-speed 13-50 from somewhere, IIRC under $25. Now that's tempting! I'd even give up my trusty old Shimano 600 derailer for that which I'd have to. I'd probably have to hack the cassette again to reduce it to 7-speed but it sure would make some really steep hills palatable. Those where I now use the MTB instead which has the nimbleness of a tank. -- Regards, Joerg http://www.analogconsultants.com/ |
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#102
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MTB disc brake caused wild fire
On Monday, April 2, 2018 at 2:23:52 PM UTC-7, Joerg wrote:
On 2018-04-02 11:35, jbeattie wrote: On Monday, April 2, 2018 at 9:21:35 AM UTC-7, Joerg wrote: On 2018-04-02 08:57, wrote: On Monday, April 2, 2018 at 4:36:21 PM UTC+2, Joerg wrote: On 2018-04-01 13:53, Roger Merriman wrote: Frank Krygowski wrote: On 3/29/2018 5:34 PM, Roger Merriman wrote: sms wrote: On 3/27/2018 7:39 AM, Joerg wrote: Hydraulics also can suffer from sudden fade and that's scary. Then they require bleeding which, depending on the kind, is a messy business. On mine particularly so because there is no bleed kit for them. Cable disc brakes are fine for pavement riding, just not for heavy duty MTB riding. Avoid hydraulic disc brakes at all costs. Stick to mechanical disc brakes. Which require constant adjustments as the pads wear, have cables that weather eats, etc. All my bikes have disks the CX/gravel/adventure road? Is cable the others are hydraulic. The cable is a lot more fuss, the Hydros just work, once set up you feed them pads which is very easy. Personally as someone who rides off-road plus high (ish) miles commuting disks and preferably Hydro are game changers in terms of performance and maintenance. In terms of stuff like power, there is quite a overlap between the two, my gravel bikes cable disks is about as powerful as the old commute MTB with its older and cheaper Hydro brakes, both are embarrassing weak compared to my Full suspension MTB. "Embarrassingly weak" sounds strange to me. Aren't you really talking about overall mechanical advantage - that is, lever force vs. braking force? Practical braking force, especially off-road, is limited by traction and/or by risk of pitchover. I fail to see why getting that amount of force from a one pound lever force is better than getting it from a two pound lever force. I can squeeze a two pound force all day. Modern MTB’s have much slack geometry, and frankly it’s a fairly green Cyclist who can’t adjust some of there weight, why do you think dropper posts are in use? You wouldn't believe it but someone (Frank?) posted a video here a while ago about a series crash in a steep downhill curve during a Tour de France. The majority of riders who crashed did not scoot behind the saddle for max braking action. These were all professional riders yet they clearly lacked instincts any serious MTB rider has. Joerg telling pro road riders how to brake. That will be the day. Yes, I do know better braking techniques than many of those riders did and would have likely either not crashed or not as hard. I found the video again, it wasn't the Tour de France but a race in Utah: https://www.youtube.com/watch?v=hRM3bFXlyNk If you do not know what the first rider who crashed and some others did wrong I suggest you refrain from MTB riding in the mountains. You are not a better rider than the four-time Irish national road champ and pro-continental cyclist. In terms of power and endurance, or course not. Never. In terms of MTB rider instinct I am rather sure I would. Whenever I see a situation that could go wrong I am behind the saddle. Even if the situation just feels iffy. Mountain is not road. There is no steering with braking, and radically un-weighting your front wheel can result in wash-out on a reversed-bank descending turn. You need to push back on the saddle and maybe straighten your arms but you need both tires and both brakes working for you. The crash in this case was caused by a rider being put over the apex of a turn, allegedly by support vehicle traffic. The rider was going too fast for the turn, and hard, positive braking would have done very little to prevent the crash. Brammeier made a mistake, but I guaranty you that he can beat you down any paved road. Go do some descending with national or world-class road cyclists and then report back. You'll learn just how bad you suck. It is not just the braking phase where he should have gone behind the saddle, it is also the moment of impact. He just goes into the rear left side of the car "as is". I had a similar situation with a VW Polo driver blowing a stop sign, so close that there was no way to stop or slow down much. I instinctively slid behind the handlebar and turned a bit. This resulted in not having an uncontrolled exit from the bike and flying through the air like this rider. Instead, it resulted in my right shoulder blade and side absorbing the brunt of the impact. My upper body smashed the driver side door to the point where the driver could no longer open it from inside but I essentially remained on the remains of my bike (which was pretzeled), lots of bruises but nothing serious. I was able to help the elderly driver get out. He was allegedly bailing out directly across the apex of the turn when a car drove in front of him. He made a forced error in hitting the turn too fast on the inside. He made a split second error on the queen stage of a very difficult race. He was chasing to get back on and was confused by the support cars: He remembers rounding the second last bend before his crash. Then things took a dramatic turn for the worse. “I just remember coming around that corner, it was one of the first corners of the climb on the downhill side and there was just a line of traffic up ahead. This would have been a great time to apply the brakes. Hard. Probably, but better to be on the outside of the turn looking across the apex planning his entry and exit. But he was pushed out of line by a support vehicle. **** happens. “Straight away I saw all the cars and where they were in the road but the traffic threw me onto the wrong side of the road. “So my line was totally messed up around the corner…there was no chance of me making it so I was just looking for an exit plan, really. “I was headed for the bushes but this car just turned right in front of me. “I thought he was going to stop but he just drove around the corner, I hit it and that’s the last thing I remember.” Brammeier was knocked out briefly and doesn’t remember anything until he arrived in hospital “which is probably a good thing”.. “I think at that point, I was out of it, I didn’t really feel any pain or anything. I was just pretty spaced out,” he said of that first night. “When I had my first diagnosis at the hospital I was like ‘****, this is really bad’.” He supposedly felt fine, but I bet plenty of the chasing riders were wiped out. Guardsman is above 9,500, and the descent comes after a grueling climb. That altitude and "full throttle mode" can probably slow someone's reaction. However, I was surprised that many riders did not take instinctive countermeasures at all. Have you ever raced road -- done a 100kph descent? The professional racers are taking counter-measures, but they're not just your one-trick-pony weight back measures. Watch Nibali descend -- he's generally centered over his bike through tight, fast turns. https://www.youtube.com/watch?v=iPHnqI13vPk You would be somewhere in his distant rear view mirror. Counter-measures may in fact be bicycle dependent. Descending a hill not too far from Guardsman Pass, my technique was to squeeze my knees to the top tube and put a little more weight on the front-end because the bike I was riding had a slight front-end shimmy above 50mph. Speaking of, I was descending from Mirror Lake at maybe 50mph behind my son when he sat up in his saddle, took his hands of the bars and started flapping his arms like a bird.. http://farm3.staticflickr.com/2817/9...bc411f31_b.jpg It was precious. On caliper brakes -- no discs. Traffic, deer, mountain lions, zebras -- it was all happening on Bald Mountain. -- Jay Beattie. -- Jay Beattie. I've been on that stretch of Guardsman, and that turn is even steeper and tighter than it appears on video. My son has ridden it many times on caliper brakes and CF rims -- fast, no discs. If you pick a wrong line, you're toast -- no matter how far you scoot back on your seat, and heavy braking even with your weight back will get you sliding sideways down the bank of the turn. And the road has that dusty slough on it. Why did he not go behind the saddle and with his belly onto the seat? It would not have stopped the crash this late in the game but it would have improved the deceleration and reduced the force of impact into the car. Have you ever raced road? Have you descended above 100 kph into a hard left, reversed bank 10-15% descending turn surrounded by support vehicles? |
#103
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MTB disc brake caused wild fire
On Mon, 02 Apr 2018 07:36:18 -0700, Joerg
wrote: On 2018-04-01 13:53, Roger Merriman wrote: Frank Krygowski wrote: On 3/29/2018 5:34 PM, Roger Merriman wrote: sms wrote: On 3/27/2018 7:39 AM, Joerg wrote: Hydraulics also can suffer from sudden fade and that's scary. Then they require bleeding which, depending on the kind, is a messy business. On mine particularly so because there is no bleed kit for them. Cable disc brakes are fine for pavement riding, just not for heavy duty MTB riding. Avoid hydraulic disc brakes at all costs. Stick to mechanical disc brakes. Which require constant adjustments as the pads wear, have cables that weather eats, etc. All my bikes have disks the CX/gravel/adventure road? Is cable the others are hydraulic. The cable is a lot more fuss, the Hydros just work, once set up you feed them pads which is very easy. Personally as someone who rides off-road plus high (ish) miles commuting disks and preferably Hydro are game changers in terms of performance and maintenance. In terms of stuff like power, there is quite a overlap between the two, my gravel bikes cable disks is about as powerful as the old commute MTB with its older and cheaper Hydro brakes, both are embarrassing weak compared to my Full suspension MTB. "Embarrassingly weak" sounds strange to me. Aren't you really talking about overall mechanical advantage - that is, lever force vs. braking force? Practical braking force, especially off-road, is limited by traction and/or by risk of pitchover. I fail to see why getting that amount of force from a one pound lever force is better than getting it from a two pound lever force. I can squeeze a two pound force all day. Modern MTBs have much slack geometry, and frankly its a fairly green Cyclist who cant adjust some of there weight, why do you think dropper posts are in use? You wouldn't believe it but someone (Frank?) posted a video here a while ago about a series crash in a steep downhill curve during a Tour de France. The majority of riders who crashed did not scoot behind the saddle for max braking action. These were all professional riders yet they clearly lacked instincts any serious MTB rider has. I had a look at the video you mention (in another post) and from what I say every one of the riders were sitting back on the rear of the saddle. See: https://www.youtube.com/watch?v=zojjIghKQoM As for being behind the saddle? As the road racers are intent on reducing their ""wind resistance" to a minimum they quite commonly do this by leaning far forward over the bars. And of course the Rodies are traveling much faster then the Dirty Boys, in fact they are often pedaling hard on descents. Again Modern MTB tyres can exert a surprising amount of grip even technical terrain. Has to be said it might be possible for a rim brake in the dry to exert the same force, but once off perfect conditions its performance declines, I have fond memories of glowing forearms from long wet MTB descents. Such descents even on rigid bikes with disks such as my Gravel bike, are far easier and frankly more fun! Also much cheaper because after 2000mi of rough riding with rim brakes the rims might be through and that gets expensive. Even replacing pads is quicker with disc brakes. Drop out the wheel, remove the spring, old pads drop out, scoot in new pads and spring, wheel back in, done. No adjusting, toe-in and all that. The prices are also interestingly different. Not that this matter much but just noting. The lowest cost but well working pads for rim brakes I found are Clarks from the UK, around $4-5/pair. The lowest cost pads with good quality for Promax Decipher hydraulic disc brakes are $2/pair from Hangzhou Novich. -- Cheers, John B. |
#104
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MTB disc brake caused wild fire
On Mon, 02 Apr 2018 14:23:50 -0700, Joerg
wrote: On 2018-04-02 11:35, jbeattie wrote: On Monday, April 2, 2018 at 9:21:35 AM UTC-7, Joerg wrote: On 2018-04-02 08:57, wrote: On Monday, April 2, 2018 at 4:36:21 PM UTC+2, Joerg wrote: On 2018-04-01 13:53, Roger Merriman wrote: Frank Krygowski wrote: On 3/29/2018 5:34 PM, Roger Merriman wrote: sms wrote: On 3/27/2018 7:39 AM, Joerg wrote: Hydraulics also can suffer from sudden fade and that's scary. Then they require bleeding which, depending on the kind, is a messy business. On mine particularly so because there is no bleed kit for them. Cable disc brakes are fine for pavement riding, just not for heavy duty MTB riding. Avoid hydraulic disc brakes at all costs. Stick to mechanical disc brakes. Which require constant adjustments as the pads wear, have cables that weather eats, etc. All my bikes have disks the CX/gravel/adventure road? Is cable the others are hydraulic. The cable is a lot more fuss, the Hydros just work, once set up you feed them pads which is very easy. Personally as someone who rides off-road plus high (ish) miles commuting disks and preferably Hydro are game changers in terms of performance and maintenance. In terms of stuff like power, there is quite a overlap between the two, my gravel bikes cable disks is about as powerful as the old commute MTB with its older and cheaper Hydro brakes, both are embarrassing weak compared to my Full suspension MTB. "Embarrassingly weak" sounds strange to me. Aren't you really talking about overall mechanical advantage - that is, lever force vs. braking force? Practical braking force, especially off-road, is limited by traction and/or by risk of pitchover. I fail to see why getting that amount of force from a one pound lever force is better than getting it from a two pound lever force. I can squeeze a two pound force all day. Modern MTBs have much slack geometry, and frankly its a fairly green Cyclist who cant adjust some of there weight, why do you think dropper posts are in use? You wouldn't believe it but someone (Frank?) posted a video here a while ago about a series crash in a steep downhill curve during a Tour de France. The majority of riders who crashed did not scoot behind the saddle for max braking action. These were all professional riders yet they clearly lacked instincts any serious MTB rider has. Joerg telling pro road riders how to brake. That will be the day. Yes, I do know better braking techniques than many of those riders did and would have likely either not crashed or not as hard. I found the video again, it wasn't the Tour de France but a race in Utah: https://www.youtube.com/watch?v=hRM3bFXlyNk If you do not know what the first rider who crashed and some others did wrong I suggest you refrain from MTB riding in the mountains. You are not a better rider than the four-time Irish national road champ and pro-continental cyclist. In terms of power and endurance, or course not. Never. In terms of MTB rider instinct I am rather sure I would. Whenever I see a situation that could go wrong I am behind the saddle. Even if the situation just feels iffy. It is not just the braking phase where he should have gone behind the saddle, it is also the moment of impact. He just goes into the rear left side of the car "as is". I had a similar situation with a VW Polo driver blowing a stop sign, so close that there was no way to stop or slow down much. I instinctively slid behind the handlebar and turned a bit. This resulted in not having an uncontrolled exit from the bike and flying through the air like this rider. Instead, it resulted in my right shoulder blade and side absorbing the brunt of the impact. My upper body smashed the driver side door to the point where the driver could no longer open it from inside but I essentially remained on the remains of my bike (which was pretzeled), lots of bruises but nothing serious. I was able to help the elderly driver get out. What I can't understand is that with all your vast range of skills and vast knowledge why you aren't leading the peloton in the TdeF. But you are not. Which leads one to believe that you are just another "Monday morning quarterback". Watching the TV and telling everyone how they should have done it. He made a split second error on the queen stage of a very difficult race. He was chasing to get back on and was confused by the support cars: He remembers rounding the second last bend before his crash. Then things took a dramatic turn for the worse. I just remember coming around that corner, it was one of the first corners of the climb on the downhill side and there was just a line of traffic up ahead. This would have been a great time to apply the brakes. Hard. Straight away I saw all the cars and where they were in the road but the traffic threw me onto the wrong side of the road. So my line was totally messed up around the cornerthere was no chance of me making it so I was just looking for an exit plan, really. I was headed for the bushes but this car just turned right in front of me. I thought he was going to stop but he just drove around the corner, I hit it and thats the last thing I remember. Brammeier was knocked out briefly and doesnt remember anything until he arrived in hospital which is probably a good thing. I think at that point, I was out of it, I didnt really feel any pain or anything. I was just pretty spaced out, he said of that first night. When I had my first diagnosis at the hospital I was like ****, this is really bad. He supposedly felt fine, but I bet plenty of the chasing riders were wiped out. Guardsman is above 9,500, and the descent comes after a grueling climb. That altitude and "full throttle mode" can probably slow someone's reaction. However, I was surprised that many riders did not take instinctive countermeasures at all. I've been on that stretch of Guardsman, and that turn is even steeper and tighter than it appears on video. My son has ridden it many times on caliper brakes and CF rims -- fast, no discs. If you pick a wrong line, you're toast -- no matter how far you scoot back on your seat, and heavy braking even with your weight back will get you sliding sideways down the bank of the turn. And the road has that dusty slough on it. Why did he not go behind the saddle and with his belly onto the seat? It would not have stopped the crash this late in the game but it would have improved the deceleration and reduced the force of impact into the car. -- Cheers, John B. |
#105
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MTB disc brake caused wild fire
On Tuesday, April 3, 2018 at 1:18:50 AM UTC+2, jbeattie wrote:
Go do some descending with national or world-class road cyclists and then report back. You'll learn just how bad you suck. Time for an anecdote. I was on ahum spring training trip in Spain two years ago in an area popular to pro riders (Calpe Spain). I was passed on a climb by a Sky rider. Little guy on an expensive Pinarello. At the top he had a **** and came out of the bushes so we started the descent together. It was not a difficult descent but after two hairpins I had to let him go. I had no chance keeping up with him. After the ride I was curious who that may have been so I looked at the Strava flybys and saw that it was Kwiatkoswki who had a 140 km trainings ride that morning. Lou |
#106
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MTB disc brake caused wild fire
On 2018-04-02 16:18, jbeattie wrote:
On Monday, April 2, 2018 at 2:23:52 PM UTC-7, Joerg wrote: On 2018-04-02 11:35, jbeattie wrote: On Monday, April 2, 2018 at 9:21:35 AM UTC-7, Joerg wrote: On 2018-04-02 08:57, wrote: On Monday, April 2, 2018 at 4:36:21 PM UTC+2, Joerg wrote: On 2018-04-01 13:53, Roger Merriman wrote: Frank Krygowski wrote: On 3/29/2018 5:34 PM, Roger Merriman wrote: sms wrote: On 3/27/2018 7:39 AM, Joerg wrote: Hydraulics also can suffer from sudden fade and that's scary. Then they require bleeding which, depending on the kind, is a messy business. On mine particularly so because there is no bleed kit for them. Cable disc brakes are fine for pavement riding, just not for heavy duty MTB riding. Avoid hydraulic disc brakes at all costs. Stick to mechanical disc brakes. Which require constant adjustments as the pads wear, have cables that weather eats, etc. All my bikes have disks the CX/gravel/adventure road? Is cable the others are hydraulic. The cable is a lot more fuss, the Hydros just work, once set up you feed them pads which is very easy. Personally as someone who rides off-road plus high (ish) miles commuting disks and preferably Hydro are game changers in terms of performance and maintenance. In terms of stuff like power, there is quite a overlap between the two, my gravel bikes cable disks is about as powerful as the old commute MTB with its older and cheaper Hydro brakes, both are embarrassing weak compared to my Full suspension MTB. "Embarrassingly weak" sounds strange to me. Aren't you really talking about overall mechanical advantage - that is, lever force vs. braking force? Practical braking force, especially off-road, is limited by traction and/or by risk of pitchover. I fail to see why getting that amount of force from a one pound lever force is better than getting it from a two pound lever force. I can squeeze a two pound force all day. Modern MTB’s have much slack geometry, and frankly it’s a fairly green Cyclist who can’t adjust some of there weight, why do you think dropper posts are in use? You wouldn't believe it but someone (Frank?) posted a video here a while ago about a series crash in a steep downhill curve during a Tour de France. The majority of riders who crashed did not scoot behind the saddle for max braking action. These were all professional riders yet they clearly lacked instincts any serious MTB rider has. Joerg telling pro road riders how to brake. That will be the day. Yes, I do know better braking techniques than many of those riders did and would have likely either not crashed or not as hard. I found the video again, it wasn't the Tour de France but a race in Utah: https://www.youtube.com/watch?v=hRM3bFXlyNk If you do not know what the first rider who crashed and some others did wrong I suggest you refrain from MTB riding in the mountains. You are not a better rider than the four-time Irish national road champ and pro-continental cyclist. In terms of power and endurance, or course not. Never. In terms of MTB rider instinct I am rather sure I would. Whenever I see a situation that could go wrong I am behind the saddle. Even if the situation just feels iffy. Mountain is not road. There is no steering with braking, and radically un-weighting your front wheel can result in wash-out on a reversed-bank descending turn. You need to push back on the saddle and maybe straighten your arms but you need both tires and both brakes working for you. Do some tests, it isn't all that different between offroad and on pavement. It's just that offroad you can wipe out much easier but the physics are the same. The crash in this case was caused by a rider being put over the apex of a turn, allegedly by support vehicle traffic. The rider was going too fast for the turn, and hard, positive braking would have done very little to prevent the crash. It is not about preventing the crash, it clearly was too late for that. It is about reducing the severity of the crash. What is better, smacking into a car at 40mph or at 30mph? ... Brammeier made a mistake, but I guaranty you that he can beat you down any paved road. Go do some descending with national or world-class road cyclists and then report back. You'll learn just how bad you suck. Sure they will beat me in downhill riding technique and pretty much any otehr race-relevant skills. I do not corner well and I also never let'er rip past 45mph on a long downhill stretch. Especially after the last tire blow-out. However, we were not talking about skills to win a race. We are talking about reaction in emergencies and there was a clear lack visible in that video. This is how it's done right: https://janheine.wordpress.com/2013/...-on-a-bicycle/ Clearly some other riders in the video had the correct instincts and posture approching this situation. It is not just the braking phase where he should have gone behind the saddle, it is also the moment of impact. He just goes into the rear left side of the car "as is". I had a similar situation with a VW Polo driver blowing a stop sign, so close that there was no way to stop or slow down much. I instinctively slid behind the handlebar and turned a bit. This resulted in not having an uncontrolled exit from the bike and flying through the air like this rider. Instead, it resulted in my right shoulder blade and side absorbing the brunt of the impact. My upper body smashed the driver side door to the point where the driver could no longer open it from inside but I essentially remained on the remains of my bike (which was pretzeled), lots of bruises but nothing serious. I was able to help the elderly driver get out. He was allegedly bailing out directly across the apex of the turn when a car drove in front of him. He made a forced error in hitting the turn too fast on the inside. And wrong seat position. Afterwards wrong impact stance. He was lucky he didn't hit the car a few feet more forward or he'd have gotten his face cut up by the rack and stuff on top. He made a split second error on the queen stage of a very difficult race. He was chasing to get back on and was confused by the support cars: He remembers rounding the second last bend before his crash. Then things took a dramatic turn for the worse. “I just remember coming around that corner, it was one of the first corners of the climb on the downhill side and there was just a line of traffic up ahead. This would have been a great time to apply the brakes. Hard. Probably, but better to be on the outside of the turn looking across the apex planning his entry and exit. But he was pushed out of line by a support vehicle. **** happens. Right but when it does you need to react right then and there, not seconds later. “Straight away I saw all the cars and where they were in the road but the traffic threw me onto the wrong side of the road. “So my line was totally messed up around the corner…there was no chance of me making it so I was just looking for an exit plan, really. “I was headed for the bushes but this car just turned right in front of me. “I thought he was going to stop but he just drove around the corner, I hit it and that’s the last thing I remember.” Brammeier was knocked out briefly and doesn’t remember anything until he arrived in hospital “which is probably a good thing”. “I think at that point, I was out of it, I didn’t really feel any pain or anything. I was just pretty spaced out,” he said of that first night. “When I had my first diagnosis at the hospital I was like ‘****, this is really bad’.” He supposedly felt fine, but I bet plenty of the chasing riders were wiped out. Guardsman is above 9,500, and the descent comes after a grueling climb. That altitude and "full throttle mode" can probably slow someone's reaction. However, I was surprised that many riders did not take instinctive countermeasures at all. Have you ever raced road -- done a 100kph descent? No, I find that too risky on li'l 25mm tires that can let their 110psi go within a split second. Especially since I don't have medics following me at every turn like these guys do. ... The professional racers are taking counter-measures, ... Many of them clearly didn't in the emergency shown. Some did, and kudos to them. ... but they're not just your one-trick-pony weight back measures. Watch Nibali descend -- he's generally centered over his bike through tight, fast turns. https://www.youtube.com/watch?v=iPHnqI13vPk You would be somewhere in his distant rear view mirror. He sure was in a hurry :-) Sometimes that goes wrong: https://www.youtube.com/watch?v=ua-f0ETXO1Q Looks like he isn't immune either: https://www.youtube.com/watch?v=Cj9lqC2Oick Counter-measures may in fact be bicycle dependent. Descending a hill not too far from Guardsman Pass, my technique was to squeeze my knees to the top tube and put a little more weight on the front-end because the bike I was riding had a slight front-end shimmy above 50mph. Mine does around 30mph but above it eases off again. Speaking of, I was descending from Mirror Lake at maybe 50mph behind my son when he sat up in his saddle, took his hands of the bars and started flapping his arms like a bird. My MTB buddy does that a lot. Scary. http://farm3.staticflickr.com/2817/9...bc411f31_b.jpg It was precious. On caliper brakes -- no discs. Traffic, deer, mountain lions, zebras -- it was all happening on Bald Mountain. -- Jay Beattie. -- Jay Beattie. I've been on that stretch of Guardsman, and that turn is even steeper and tighter than it appears on video. My son has ridden it many times on caliper brakes and CF rims -- fast, no discs. If you pick a wrong line, you're toast -- no matter how far you scoot back on your seat, and heavy braking even with your weight back will get you sliding sideways down the bank of the turn. And the road has that dusty slough on it. Why did he not go behind the saddle and with his belly onto the seat? It would not have stopped the crash this late in the game but it would have improved the deceleration and reduced the force of impact into the car. Have you ever raced road? Have you descended above 100 kph into a hard left, reversed bank 10-15% descending turn surrounded by support vehicles? Why would I even want to do that? -- Regards, Joerg http://www.analogconsultants.com/ |
#108
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MTB disc brake caused wild fire
On 03/04/2018 10:47 AM, Joerg wrote:
On 2018-04-02 16:18, jbeattie wrote: On Monday, April 2, 2018 at 2:23:52 PM UTC-7, Joerg wrote: On 2018-04-02 11:35, jbeattie wrote: On Monday, April 2, 2018 at 9:21:35 AM UTC-7, Joerg wrote: On 2018-04-02 08:57, wrote: On Monday, April 2, 2018 at 4:36:21 PM UTC+2, Joerg wrote: On 2018-04-01 13:53, Roger Merriman wrote: Frank Krygowski wrote: On 3/29/2018 5:34 PM, Roger Merriman wrote: sms wrote: On 3/27/2018 7:39 AM, Joerg wrote: Hydraulics also can suffer from sudden fade and that's scary. Then they require bleeding which, depending on the kind, is a messy business. On mine particularly so because there is no bleed kit for them. Cable disc brakes are fine for pavement riding, just not for heavy duty MTB riding. Avoid hydraulic disc brakes at all costs. Stick to mechanical disc brakes. Which require constant adjustments as the pads wear, have cables that weather eats, etc. All my bikes have disks the CX/gravel/adventure road? Is cable the others are hydraulic. The cable is a lot more fuss, the Hydros just work, once set up you feed them pads which is very easy. Personally as someone who rides off-road plus high (ish) miles commuting disks and preferably Hydro are game changers in terms of performance and maintenance. In terms of stuff like power, there is quite a overlap between the two, my gravel bikes cable disks is about as powerful as the old commute MTB with its older and cheaper Hydro brakes, both are embarrassing weak compared to my Full suspension MTB. "Embarrassingly weak" sounds strange to me. Aren't you really talking about overall mechanical advantage - that is, lever force vs. braking force? Practical braking force, especially off-road, is limited by traction and/or by risk of pitchover. I fail to see why getting that amount of force from a one pound lever force is better than getting it from a two pound lever force. I can squeeze a two pound force all day. Modern MTB’s have much slack geometry, and frankly it’s a fairly green Cyclist who can’t adjust some of there weight, why do you think dropper posts are in use? You wouldn't believe it but someone (Frank?) posted a video here a while ago about a series crash in a steep downhill curve during a Tour de France. The majority of riders who crashed did not scoot behind the saddle for max braking action. These were all professional riders yet they clearly lacked instincts any serious MTB rider has. Joerg telling pro road riders how to brake. That will be the day. Yes, I do know better braking techniques than many of those riders did and would have likely either not crashed or not as hard. I found the video again, it wasn't the Tour de France but a race in Utah: https://www.youtube.com/watch?v=hRM3bFXlyNk If you do not know what the first rider who crashed and some others did wrong I suggest you refrain from MTB riding in the mountains. You are not a better rider than the four-time Irish national road champ and pro-continental cyclist. In terms of power and endurance, or course not. Never. In terms of MTB rider instinct I am rather sure I would. Whenever I see a situation that could go wrong I am behind the saddle. Even if the situation just feels iffy. Mountain is not road.* There is no steering with braking, and radically un-weighting your front wheel can result in wash-out on a reversed-bank descending turn. You need to push back on the saddle and maybe straighten your arms but you need both tires and both brakes working for you. Do some tests, it isn't all that different between offroad and on pavement. It's just that offroad you can wipe out much easier but the physics are the same. The crash in this case was caused by a rider being put over the apex of a turn, allegedly by support vehicle traffic.* The rider was going too fast for the turn, and hard, positive braking would have done very little to prevent the crash. It is not about preventing the crash, it clearly was too late for that. It is about reducing the severity of the crash. What is better, smacking into a car at 40mph or at 30mph? ************************* * ... Brammeier made a mistake, but I guaranty you that he can beat you down any paved road. Go do some descending with national or world-class road cyclists and then report back. You'll learn just how bad you suck. Sure they will beat me in downhill riding technique and pretty much any otehr race-relevant skills. I do not corner well and I also never let'er rip past 45mph on a long downhill stretch. Especially after the last tire blow-out. However, we were not talking about skills to win a race. We are talking about reaction in emergencies and there was a clear lack visible in that video. This is how it's done right: https://janheine.wordpress.com/2013/...-on-a-bicycle/ Clearly some other riders in the video had the correct instincts and posture approching this situation. It is not just the braking phase where he should have gone behind the saddle, it is also the moment of impact. He just goes into the rear left side of the car "as is". I had a similar situation with a VW Polo driver blowing a stop sign, so close that there was no way to stop or slow down much. I instinctively slid behind the handlebar and turned a bit. This resulted in not having an uncontrolled exit from the bike and flying through the air like this rider. Instead, it resulted in my right shoulder blade and side absorbing the brunt of the impact. My upper body smashed the driver side door to the point where the driver could no longer open it from inside but I essentially remained on the remains of my bike (which was pretzeled), lots of bruises but nothing serious. I was able to help the elderly driver get out. He was allegedly bailing out directly across the apex of the turn when a car drove in front of him. He made a forced error in hitting the turn too fast on the inside. And wrong seat position. Afterwards wrong impact stance. He was lucky he didn't hit the car a few feet more forward or he'd have gotten his face cut up by the rack and stuff on top. He made a split second error on the queen stage of a very difficult race.* He was chasing to get back on and was confused by the support cars: He remembers rounding the second last bend before his crash. Then things took a dramatic turn for the worse. “I just remember coming around that corner, it was one of the first corners of the climb on the downhill side and there was just a line of traffic up ahead. This would have been a great time to apply the brakes. Hard. Probably, but better to be on the outside of the turn looking across the apex planning his entry and exit.* But he was pushed out of line by a support vehicle.* **** happens. Right but when it does you need to react right then and there, not seconds later. “Straight away I saw all the cars and where they were in the road but the traffic threw me onto the wrong side of the road. “So my line was totally messed up around the corner…there was no chance of me making it so I was just looking for an exit plan, really. “I was headed for the bushes but this car just turned right in front of me. “I thought he was going to stop but he just drove around the corner, I hit it and that’s the last thing I remember.” Brammeier was knocked out briefly and doesn’t remember anything until he arrived in hospital “which is probably a good thing”. “I think at that point, I was out of it, I didn’t really feel any pain or anything. I was just pretty spaced out,” he said of that first night. “When I had my first diagnosis at the hospital I was like ‘****, this is really bad’.” He supposedly felt fine, but I bet plenty of the chasing riders were wiped out. Guardsman is above 9,500, and the descent comes after a grueling climb. That altitude and "full throttle mode" can probably slow someone's reaction. However, I was surprised that many riders did not take instinctive countermeasures at all. Have you ever raced road -- done a 100kph descent? No, I find that too risky on li'l 25mm tires that can let their 110psi go within a split second. Especially since I don't have medics following me at every turn like these guys do. * ... The professional racers are taking counter-measures, ... Many of them clearly didn't in the emergency shown. Some did, and kudos to them. ************************* ******** ... but they're not just your one-trick-pony weight back measures.* Watch Nibali descend -- he's generally centered over his bike through tight, fast turns. https://www.youtube.com/watch?v=iPHnqI13vPk* You would be somewhere in his distant rear view mirror. He sure was in a hurry :-) Sometimes that goes wrong: https://www.youtube.com/watch?v=ua-f0ETXO1Q Looks like he isn't immune either: https://www.youtube.com/watch?v=Cj9lqC2Oick Counter-measures may in fact be bicycle dependent.* Descending a hill not too far from Guardsman Pass, my technique was to squeeze my knees to the top tube and put a little more weight on the front-end because the bike I was riding had a slight front-end shimmy above 50mph. Mine does around 30mph but above it eases off again. Speaking of, I was descending from Mirror Lake at maybe 50mph behind my son when he sat up in his saddle, took his hands of the bars and started flapping his arms like a bird. My MTB buddy does that a lot. Scary. http://farm3.staticflickr.com/2817/9...411f31_b.jpg* It was precious. On caliper brakes -- no discs. Traffic, deer, mountain lions, zebras -- it was all happening on Bald Mountain. -- Jay Beattie. -- Jay Beattie. I've been on that stretch of Guardsman, and that turn is even steeper and tighter than it appears on video. My son has ridden it many times on caliper brakes and CF rims -- fast, no discs. If you pick a wrong line, you're toast -- no matter how far you scoot back on your seat, and heavy braking even with your weight back will get you sliding sideways down the bank of the turn. And the road has that dusty slough on it. Why did he not go behind the saddle and with his belly onto the seat? It would not have stopped the crash this late in the game but it would have improved the deceleration and reduced the force of impact into the car. Have you ever raced road?* Have you descended above 100 kph into a hard left, reversed bank 10-15% descending turn surrounded by support vehicles? Why would I even want to do that? So that it would make more sense when you criticize professionals doing that... |
#109
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MTB disc brake caused wild fire
On 2018-04-02 17:13, John B. wrote:
On Mon, 02 Apr 2018 07:36:18 -0700, Joerg wrote: On 2018-04-01 13:53, Roger Merriman wrote: Frank Krygowski wrote: On 3/29/2018 5:34 PM, Roger Merriman wrote: sms wrote: On 3/27/2018 7:39 AM, Joerg wrote: Hydraulics also can suffer from sudden fade and that's scary. Then they require bleeding which, depending on the kind, is a messy business. On mine particularly so because there is no bleed kit for them. Cable disc brakes are fine for pavement riding, just not for heavy duty MTB riding. Avoid hydraulic disc brakes at all costs. Stick to mechanical disc brakes. Which require constant adjustments as the pads wear, have cables that weather eats, etc. All my bikes have disks the CX/gravel/adventure road? Is cable the others are hydraulic. The cable is a lot more fuss, the Hydros just work, once set up you feed them pads which is very easy. Personally as someone who rides off-road plus high (ish) miles commuting disks and preferably Hydro are game changers in terms of performance and maintenance. In terms of stuff like power, there is quite a overlap between the two, my gravel bikes cable disks is about as powerful as the old commute MTB with its older and cheaper Hydro brakes, both are embarrassing weak compared to my Full suspension MTB. "Embarrassingly weak" sounds strange to me. Aren't you really talking about overall mechanical advantage - that is, lever force vs. braking force? Practical braking force, especially off-road, is limited by traction and/or by risk of pitchover. I fail to see why getting that amount of force from a one pound lever force is better than getting it from a two pound lever force. I can squeeze a two pound force all day. Modern MTBs have much slack geometry, and frankly its a fairly green Cyclist who cant adjust some of there weight, why do you think dropper posts are in use? You wouldn't believe it but someone (Frank?) posted a video here a while ago about a series crash in a steep downhill curve during a Tour de France. The majority of riders who crashed did not scoot behind the saddle for max braking action. These were all professional riders yet they clearly lacked instincts any serious MTB rider has. I had a look at the video you mention (in another post) and from what I say every one of the riders were sitting back on the rear of the saddle. See: https://www.youtube.com/watch?v=zojjIghKQoM You need new glasses :-) As for being behind the saddle? As the road racers are intent on reducing their ""wind resistance" to a minimum they quite commonly do this by leaning far forward over the bars. And of course the Rodies are traveling much faster then the Dirty Boys, in fact they are often pedaling hard on descents. They were not pedaling into the cars and motorcycles. There is a time to be pedaling hard and trying to produce as little wind resistance as possible. Then there is a time where crash mitigation techniques are paramount and those were clearly lacking with some riders. [...] -- Regards, Joerg http://www.analogconsultants.com/ |
#110
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MTB disc brake caused wild fire
On 2018-04-03 07:52, Duane wrote:
On 03/04/2018 10:47 AM, Joerg wrote: On 2018-04-02 16:18, jbeattie wrote: [...] Have you ever raced road? Have you descended above 100 kph into a hard left, reversed bank 10-15% descending turn surrounded by support vehicles? Why would I even want to do that? So that it would make more sense when you criticize professionals doing that... Read more comprehensively. Then you'd know exactly what I criticized and that it's not the above. -- Regards, Joerg http://www.analogconsultants.com/ |
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