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#841
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"Actually you are the first person to bring up this issue"
Tom Sherman wrote:
carlfogel wrote: Dear Jobst, Here's a double-size picture of the rocket recumbent with dreadfully artistic lines and angles calculated off x-y pixel positions. If anything, it looks as if it would brake even better than I originally thought--about a 50 degree angle from COG to contact patch versus 61 degrees for the upright with an almost identical wheelbase in "Bicycling Science." http://home.comcast.net/~carlfogel/download/rocketdia- http://home.comcast.net/~carlfogel/download/rocketdia- gram.jpg or http://tinyurl.com/yrtgohttp://tinyurl.com/yrtgo Possibly the recumbent that you remember wasn't quite identical to this one? Dear Carl, The seat height will be about an inch lower than the top of the seat cushion for an average rider (and lower for one who consumes an excessive amount of sucrose sweetened torroidal foods). As for Tom's elusive blue Dragonflyer, there are a dozen lurid views he http://www.ihpva.org/incoming/2002/D....ihpva.org/in- coming/2002/Dragonflyer Yes, double-checked that one. (Sorry about my incorrect corrections of addresses.) This picture gives an almost side-view: http://www.ihpva.org/incoming/2002/D...tp://www.ihpv- a.org/incoming/2002/Dragonflyer/df2.jpg Weird-lookin' thing! But you must appreciate the OEM custom Phil Wood hubs (each worth at least 4 Roadmaster Mt. Fury's). -- Tom Sherman - Quad Cities (Illinois Side) Dear Tom The Fury Roadmaster, however, is still in production Carl Foge - |
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#842
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"Actually you are the first person to bring up this issue"
Tom Sherman wrote:
carlfogel wrote: Dear Jobst, Here's a double-size picture of the rocket recumbent with dreadfully artistic lines and angles calculated off x-y pixel positions. If anything, it looks as if it would brake even better than I originally thought--about a 50 degree angle from COG to contact patch versus 61 degrees for the upright with an almost identical wheelbase in "Bicycling Science." http://home.comcast.net/~carlfogel/download/rocketdia- http://home.comcast.net/~carlfogel/download/rocketdia- gram.jpg or http://tinyurl.com/yrtgohttp://tinyurl.com/yrtgo Possibly the recumbent that you remember wasn't quite identical to this one? Dear Carl, The seat height will be about an inch lower than the top of the seat cushion for an average rider (and lower for one who consumes an excessive amount of sucrose sweetened torroidal foods). As for Tom's elusive blue Dragonflyer, there are a dozen lurid views he http://www.ihpva.org/incoming/2002/D....ihpva.org/in- coming/2002/Dragonflyer Yes, double-checked that one. (Sorry about my incorrect corrections of addresses.) This picture gives an almost side-view: http://www.ihpva.org/incoming/2002/D...tp://www.ihpv- a.org/incoming/2002/Dragonflyer/df2.jpg Weird-lookin' thing! But you must appreciate the OEM custom Phil Wood hubs (each worth at least 4 Roadmaster Mt. Fury's). -- Tom Sherman - Quad Cities (Illinois Side) Dear Tom The Fury Roadmaster, however, is still in production Carl Foge - |
#843
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"Actually you are the first person to bring up this issue"
James Annan wrote:
Tony Raven wrote: Specialized have already had a recall for mounting tab failures. When? If you mean the recent recall of bikes with too large a rotor installed, there were NO failures and no evidence that there ever would be any failures. The problem was merely that the combination had not been properly checked. Puts the current situation regarding disks and QRs into context, don't you think? James I should choose my words more carefully. I should have said that "Specialized have already had a recall for _potential_ mounting tab failures" The CPSC release said: Hazard: During heavy braking, the brake tabs on the front forks could break off, possibly causing a loss of control and fall from the bicycle. Tony |
#844
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"Actually you are the first person to bring up this issue"
James Annan wrote:
Tony Raven wrote: Specialized have already had a recall for mounting tab failures. When? If you mean the recent recall of bikes with too large a rotor installed, there were NO failures and no evidence that there ever would be any failures. The problem was merely that the combination had not been properly checked. Puts the current situation regarding disks and QRs into context, don't you think? James I should choose my words more carefully. I should have said that "Specialized have already had a recall for _potential_ mounting tab failures" The CPSC release said: Hazard: During heavy braking, the brake tabs on the front forks could break off, possibly causing a loss of control and fall from the bicycle. Tony |
#845
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"Actually you are the first person to bring up this issue"
in message , Chris Malcolm
') wrote: Simon Brooke writes: in message , Tim McNamara ') wrote: Ummm, no. The limit of braking power is not the force with which the brake can clamp onto the rim, but the coefficient of friction between the tire and the riding surface. Clean dry pavement offers a higher coefficient of friction than dirt with the same tires, although perhaps pumice or slickrock might equal or exceed cement pavement. Speaking as someone who regularly rides both types of bikes, I don't agree with you. Mind you, I could be wrong - the caliper brakes on my road bike are single pivot and not especially clever. I don't know the extreme limits of braking on either system, since I'm now to old and have too much respect for the fragility of my skull to just slam on the anchors and see what happens. But I do know that I can stop shorter - a lot shorter - on my hill bike than on my road bike, on the same road and braking from the same speed. I presume that on both bikes you can brake hard enough to skid the front wheel. No idea. I don't do so; perhaps I could, but like I say I have no interest in the 'ejector seat' technique of coming to rest. If you're higher off the ground on your road bike it won't be able to stop as fast. Don't think so. The saddles on all my bikes are the same height, modulo normal suspension compression; likewise the handlebars. However the angles on the hill bikes are a lot slacker, and I do habitually slip off hte back of the saddle to brake hard on the hill bikes. So perhaps the difference is just that I get my CoG further back. -- (Simon Brooke) http://www.jasmine.org.uk/~simon/ There's nae Gods, an there's precious few heroes but there's plenty on the dole in th Land o th Leal; And it's time now, tae sweep the future clear o th lies o a past that we know wis never real. |
#846
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"Actually you are the first person to bring up this issue"
in message , Chris Malcolm
') wrote: Simon Brooke writes: in message , Tim McNamara ') wrote: Ummm, no. The limit of braking power is not the force with which the brake can clamp onto the rim, but the coefficient of friction between the tire and the riding surface. Clean dry pavement offers a higher coefficient of friction than dirt with the same tires, although perhaps pumice or slickrock might equal or exceed cement pavement. Speaking as someone who regularly rides both types of bikes, I don't agree with you. Mind you, I could be wrong - the caliper brakes on my road bike are single pivot and not especially clever. I don't know the extreme limits of braking on either system, since I'm now to old and have too much respect for the fragility of my skull to just slam on the anchors and see what happens. But I do know that I can stop shorter - a lot shorter - on my hill bike than on my road bike, on the same road and braking from the same speed. I presume that on both bikes you can brake hard enough to skid the front wheel. No idea. I don't do so; perhaps I could, but like I say I have no interest in the 'ejector seat' technique of coming to rest. If you're higher off the ground on your road bike it won't be able to stop as fast. Don't think so. The saddles on all my bikes are the same height, modulo normal suspension compression; likewise the handlebars. However the angles on the hill bikes are a lot slacker, and I do habitually slip off hte back of the saddle to brake hard on the hill bikes. So perhaps the difference is just that I get my CoG further back. -- (Simon Brooke) http://www.jasmine.org.uk/~simon/ There's nae Gods, an there's precious few heroes but there's plenty on the dole in th Land o th Leal; And it's time now, tae sweep the future clear o th lies o a past that we know wis never real. |
#847
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"Actually you are the first person to bring up this issue"
Simon Brooke wrote:
in message , Chris Malcolm ') wrote: Simon Brooke writes: in message , Tim McNamara ') wrote: Ummm, no. The limit of braking power is not the force with which the brake can clamp onto the rim, but the coefficient of friction between the tire and the riding surface. Clean dry pavement offers a higher coefficient of friction than dirt with the same tires, although perhaps pumice or slickrock might equal or exceed cement pavement. Speaking as someone who regularly rides both types of bikes, I don't agree with you. Mind you, I could be wrong - the caliper brakes on my road bike are single pivot and not especially clever. I don't know the extreme limits of braking on either system, since I'm now to old and have too much respect for the fragility of my skull to just slam on the anchors and see what happens. But I do know that I can stop shorter - a lot shorter - on my hill bike than on my road bike, on the same road and braking from the same speed. I presume that on both bikes you can brake hard enough to skid the front wheel. No idea. I don't do so; perhaps I could, but like I say I have no interest in the 'ejector seat' technique of coming to rest. If you're higher off the ground on your road bike it won't be able to stop as fast. Don't think so. The saddles on all my bikes are the same height, modulo normal suspension compression; likewise the handlebars. However the angles on the hill bikes are a lot slacker, and I do habitually slip off hte back of the saddle to brake hard on the hill bikes. So perhaps the difference is just that I get my CoG further back. -- (Simon Brooke) http://www.jasmine.org.uk/~simon/htt...org.uk/~simon/ There's nae Gods, an there's precious few heroes but there's plenty on the dole in th Land o th Leal; And it's time now, tae sweep the future clear o th lies o a past that we know wis never real. Dear Tim and Simon A couple of side-view pictures of bicycles and either riders o suggestions about COG would be worth thousands of words A typical paint program will let you draw admirably straight lines, an programs like MB-Ruler 0.93 on this freeware page provide a transparen onscreen protractor and ruler http://www.ramlende.com/graphics.htm Haven't had so much fun since they took the scissors away from me i grade school I'd be happy to host any pictures for comparison and even do the work o drawing and measuring angles The chief area of debate would likely be the center of mass Don't eat the paste Carl Foge - |
#848
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"Actually you are the first person to bring up this issue"
Simon Brooke wrote:
in message , Chris Malcolm ') wrote: Simon Brooke writes: in message , Tim McNamara ') wrote: Ummm, no. The limit of braking power is not the force with which the brake can clamp onto the rim, but the coefficient of friction between the tire and the riding surface. Clean dry pavement offers a higher coefficient of friction than dirt with the same tires, although perhaps pumice or slickrock might equal or exceed cement pavement. Speaking as someone who regularly rides both types of bikes, I don't agree with you. Mind you, I could be wrong - the caliper brakes on my road bike are single pivot and not especially clever. I don't know the extreme limits of braking on either system, since I'm now to old and have too much respect for the fragility of my skull to just slam on the anchors and see what happens. But I do know that I can stop shorter - a lot shorter - on my hill bike than on my road bike, on the same road and braking from the same speed. I presume that on both bikes you can brake hard enough to skid the front wheel. No idea. I don't do so; perhaps I could, but like I say I have no interest in the 'ejector seat' technique of coming to rest. If you're higher off the ground on your road bike it won't be able to stop as fast. Don't think so. The saddles on all my bikes are the same height, modulo normal suspension compression; likewise the handlebars. However the angles on the hill bikes are a lot slacker, and I do habitually slip off hte back of the saddle to brake hard on the hill bikes. So perhaps the difference is just that I get my CoG further back. -- (Simon Brooke) http://www.jasmine.org.uk/~simon/htt...org.uk/~simon/ There's nae Gods, an there's precious few heroes but there's plenty on the dole in th Land o th Leal; And it's time now, tae sweep the future clear o th lies o a past that we know wis never real. Dear Tim and Simon A couple of side-view pictures of bicycles and either riders o suggestions about COG would be worth thousands of words A typical paint program will let you draw admirably straight lines, an programs like MB-Ruler 0.93 on this freeware page provide a transparen onscreen protractor and ruler http://www.ramlende.com/graphics.htm Haven't had so much fun since they took the scissors away from me i grade school I'd be happy to host any pictures for comparison and even do the work o drawing and measuring angles The chief area of debate would likely be the center of mass Don't eat the paste Carl Foge - |
#849
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"Actually you are the first person to bring up this issue"
Hello everybody,
A typical paint program will let you draw admirably straight lines, and programs like MB-Ruler 0.93 on this freeware page provide a transparent onscreen protractor and ruler: http://www.ramlende.com/graphics.html Haven't had so much fun since they took the scissors away from me in grade school. I'd be happy to host any pictures for comparison and even do the work of drawing and measuring angles. The chief area of debate would likely be the center of mass. On the MB-Ruler hompage http://www.Markus-Bader.de/MB-Ruler/index.htm the update to MB-Ruler 1.3 (with screen loupe, RGB picker and multi monitor support) is already available. Bye Markus |
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