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#51
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Let's do the bunny-hop, was Will a 29er work for collegecampus commute?
On 22 Oct, 15:50, " wrote:
On Oct 21, 11:49*pm, Dan O wrote: On Oct 21, 8:00 pm, Frank Krygowski wrote: On Oct 21, 6:37 pm, RonSonic wrote: Hopping while clipped in is much easier. Apparently BMX and trials guys can make the bikes stick to their feet or something. I can do it a bit without clips, but not nearly as easily or as high. It happens so fast it's nearly unconscious, but I think the physics goes like this: *Rider jumps up, and pulls handlebars up after himself. *Mass center of the bike rises while the rear wheel is still on the ground. *Then the rider pushes down on the bars, to rotate the bike about its mass center so it's horizontal. *The end effect is two wheels off the ground. Good analysis, I think. *I've never practiced it. *I think maybe there's a forward thrust / rotation of the bars component. *Obviously the rider cannot "pull up" on unattached pedals (it's definitely all in the handlebars), but does use the inertia of his body to lift the bike off the ground. As a former BMX racer, current BMX dirt jumper, skate park and street rider and someone with a lean toward trials style on the MTB, I'll chime in here. *I can hop higher on my BMX, no clips, than I can on anything I have with clips. *The way I do it is entirely weight transfer and momentum through the handlebars. *It goes something like lean back, into a manual (wheelie) that you know would loop out. *When the bike passes the balance point, throw all your weight forward (which is now 45 degrees from the ground at a minimum, likely higher, exactly where depends on the bike). The basics can be practiced in a much more mild way. *Lean back and pull up on the bars to get your manual (wheelie) and then shove the bars forward with all your weight and momentum. *It feels more natural to throw the weight forward in relation to the ground rather than the angle of your bike, that's fine for starting out. *The only limiting factor is it will not allow you to hop higher than you can manual. *Be sure you are transferring your body weight and momentum into the bars and over the front wheel and not just pushing with your arms with your weight still back on the pedals. *The reason we're able to control the rear of the bike so well when doing this on a BMX with platforms is there is basically no weight on the pedals at this point, we've thrown all our weight and momentum into the direction we wish the bike to go. *The pins on the platform provide sufficient bite into our sneakers for small adjustments. Another way to practice is to find a small rise, say 4", that is not sharp enough to pinch your rear wheel. *Ride up to it and manual your front wheel on, then throw your weight forward into the bars and lean forward, lifting your rear wheel up onto the rise. *Once you can do this, it's just a matter of speeding it up to hop up the same rise. Then you can work on height. *BTW, practice on things/times/places that won't get you really hurt or damage your bike (i.e. if you think you are hopping 5", don't try to hop a 4" curb at an angle in front of traffic). *You're never going quite as high as you think you are. *The only way to know is to clear obstacles. *You can start with 2x4's on their side, if you're not getting the 3.5" you'll knock it over. *Then 2x6 (for 5.5"), etc. *Once you can clear a section of 2x12 (11.5") consistently you're ready to start looking at larger obstacles. *My current challenge is a downed trash can, it was easy-peasy in my real BMX days but these days I tend to clip the things. snip With a touring/racing bike the handlebars are lower and more stretched out. The usual procedure is to set the pedals level and jump off them while giving an extra bit of lift on the front which you then level out the bike when actually airborne. I wonder if the fore-aft heaving on the bars is actually as effective on a drop handlebar bike when optimally set up for distance riding. I understand that you are simply kicking off the back wheel and you need to get your c-of-g behind the axle so as to be able to push against the ground. |
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#52
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Will a 29er work for college campus commute?
" wrote:
For that ride, personally, I'd want a BMX. wrote: Funny you bring BMX up as there are a TON of them on campus and ridden by younger students. BUT.... I'm a full size adult student! Where do I get a BMX frame and bike that fits a 200 lb adult??! KINK, Redline, many vendors: http://www.kinkbmx.com/home.html http://www.redlinebicycles.com/bikes...evice-complete 20" freestyle are sold by top tube length, not frame size -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#53
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Let's do the bunny-hop, was Will a 29er work for collegecampus commute?
On Oct 22, 11:02*am, " wrote:
Meh... *weight is overrated in this respect. *My 20" BMX is my heaviest bike. *It's also the smallest. *It's also the one I can hop highest, by orders of magnitude. Hmm. I don't think I've ever tried to hop my Bike Friday New World Tourist. And I wonder if it would try to fold itself mid-flight? But I think I've just invented the next radical move for the guys that do that sort of stuff: Jump a Bike Friday Tikit (the quick folding model), fold the bike while airborne, unfold it and land it clean! Who will be the first to try it? ;-) - Frank Krygowski |
#54
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Will a 29er work for college campus commute?
AMuzi wrote:
BMX frame and bike that fits a 200 lb adult??! KINK, Redline, many vendors: http://www.kinkbmx.com/home.html http://www.redlinebicycles.com/bikes...evice-complete 20" freestyle are sold by top tube length, not frame size Thanks Is it NOT possible to raise the seat up high enough for an adult to sit down while pedaling? |
#55
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Let's do the bunny-hop, was Will a 29er work for college campus commute?
Frank Krygowski wrote:
But I think I've just invented the next radical move for the guys that do that sort of stuff: Jump a Bike Friday Tikit (the quick folding model), fold the bike while airborne, unfold it and land it clean! Who will be the first to try it? ;-) Ha ha Good one!! |
#56
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Will a 29er work for college campus commute?
BMX frame and bike that fits a 200 lb adult??!
KINK, Redline, many vendors: http://www.kinkbmx.com/home.html http://www.redlinebicycles.com/bikes...evice-complete AMuzi wrote: 20" freestyle are sold by top tube length, not frame size wrote: Is it NOT possible to raise the seat up high enough for an adult to sit down while pedaling? Sit down?? What's next, a flippy flag? http://www.youtube.com/watch?v=qAn0k9aStqA -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#57
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Will a 29er work for college campus commute?
On Oct 22, 1:58*pm, wrote:
AMuzi wrote: BMX frame and bike that fits a 200 lb adult??! KINK, Redline, many vendors: http://www.kinkbmx.com/home.html http://www.redlinebicycles.com/bikes...evice-complete 20" freestyle are sold by top tube length, not frame size Thanks Is it NOT possible to raise the seat up high enough for an adult to sit down while pedaling? To get a normal leg articulation while pedaling? I honestly don't know, the bikes have changed so much lately checking on mine would be somewhat pointless even if it was on hand, which it is not. In A Muzi's post above mine, the bike shown has the seat in the typical BMX position, slammed all the way down. It's mainly used to grab with your knees while doing tricks, and to sit while coasting. That's the typical BMX style - pedal all out, coast, repeat. My seat post isn't slammed totally into the seat tube, but it's pretty close. Pedaling while sitting my knees end up above the seat. Even if you could raise the seat that much, you'd run into a few problems. 1) your seat would be as high as your bars, if not higher. 2) you'd have very little seat post left in the seat tube, making the frame and/or post very likely to break. If you want to do most of your pedaling while sitting, I'd go back to the MTB idea. Again, I think a 29er would make a fine choice for what you're trying to do, assuming you can hop it high enough. You may consider going a bit small on frame size to make this easier, since your route is short enough it won't bother you as it would on all day rides. My 29er is a bit big, and I wish I'd gone a size smaller. It's a lot of bike to muscle around. BTW, that video Andy posted has a pretty good representation of how I'd suggest learning to hop, on a much smaller scale of course. Manual into throwing it forward, rear coming up late, etc. I can't tell if his rear wheel clipped the quad on the final run or not, but even if it did it would not matter much to him, as his weight is all off that part of the bike at that point. It's the same principle that's allowed me to hit trash cans without consequence trying to hop over them. Another thing worth nothing: The hop everyone including me has described to you is not actually a bunny hop, it's a J hop since the front comes up first. A bunny hop has both wheels leaving the ground and the same time and is not nearly as useful, nor will it allow for the same height or clearing of obstacles. Disregard bunny hops and the term, what you want to do is called a J hop. Can you do this currently with any of your bikes? If not, a 29er may be a lot of bike to learn on, and a BMX would be ideal. If so, find somewhere to demo a 29er and see if you can do it on that, or get ready to practice. If not, a BMX bike would be a great way to learn this stuff. You can pick up something entry level for a couple hundred bucks, if you plan to go with a bigger bike once you get it down. If you plan to stick with it, get something with sealed bearings all over, and a lengthy top tube. Your height, budget, and current ability regarding hops would help us help you here. If I were to suggest something just to learn the basics of how to hop, it would probably be something like this, unless your area has a good craigslist system (I seem to recall you living overseas?) http://www.danscomp.com/101140.php?cat=BIKES The unsealed hubs and low-end everything make that a poor choice long term, but DK is a decent bike and for under $200 with a 20.5" top tube it'd be decent for beating around on and learning. |
#58
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Let's do the bunny-hop, was Will a 29er work for collegecampus commute?
On Oct 22, 12:14*pm, thirty-six wrote:
On 22 Oct, 15:50, " wrote: On Oct 21, 11:49*pm, Dan O wrote: On Oct 21, 8:00 pm, Frank Krygowski wrote: On Oct 21, 6:37 pm, RonSonic wrote: Hopping while clipped in is much easier. Apparently BMX and trials guys can make the bikes stick to their feet or something. I can do it a bit without clips, but not nearly as easily or as high. It happens so fast it's nearly unconscious, but I think the physics goes like this: *Rider jumps up, and pulls handlebars up after himself. *Mass center of the bike rises while the rear wheel is still on the ground. *Then the rider pushes down on the bars, to rotate the bike about its mass center so it's horizontal. *The end effect is two wheels off the ground. Good analysis, I think. *I've never practiced it. *I think maybe there's a forward thrust / rotation of the bars component. *Obviously the rider cannot "pull up" on unattached pedals (it's definitely all in the handlebars), but does use the inertia of his body to lift the bike off the ground. As a former BMX racer, current BMX dirt jumper, skate park and street rider and someone with a lean toward trials style on the MTB, I'll chime in here. *I can hop higher on my BMX, no clips, than I can on anything I have with clips. *The way I do it is entirely weight transfer and momentum through the handlebars. *It goes something like lean back, into a manual (wheelie) that you know would loop out. *When the bike passes the balance point, throw all your weight forward (which is now 45 degrees from the ground at a minimum, likely higher, exactly where depends on the bike). The basics can be practiced in a much more mild way. *Lean back and pull up on the bars to get your manual (wheelie) and then shove the bars forward with all your weight and momentum. *It feels more natural to throw the weight forward in relation to the ground rather than the angle of your bike, that's fine for starting out. *The only limiting factor is it will not allow you to hop higher than you can manual. *Be sure you are transferring your body weight and momentum into the bars and over the front wheel and not just pushing with your arms with your weight still back on the pedals. *The reason we're able to control the rear of the bike so well when doing this on a BMX with platforms is there is basically no weight on the pedals at this point, we've thrown all our weight and momentum into the direction we wish the bike to go. *The pins on the platform provide sufficient bite into our sneakers for small adjustments. Another way to practice is to find a small rise, say 4", that is not sharp enough to pinch your rear wheel. *Ride up to it and manual your front wheel on, then throw your weight forward into the bars and lean forward, lifting your rear wheel up onto the rise. *Once you can do this, it's just a matter of speeding it up to hop up the same rise. Then you can work on height. *BTW, practice on things/times/places that won't get you really hurt or damage your bike (i.e. if you think you are hopping 5", don't try to hop a 4" curb at an angle in front of traffic). *You're never going quite as high as you think you are. *The only way to know is to clear obstacles. *You can start with 2x4's on their side, if you're not getting the 3.5" you'll knock it over. *Then 2x6 (for 5.5"), etc. *Once you can clear a section of 2x12 (11.5") consistently you're ready to start looking at larger obstacles. *My current challenge is a downed trash can, it was easy-peasy in my real BMX days but these days I tend to clip the things. snip With a touring/racing bike the handlebars are lower and more stretched out. *The usual procedure is to set the pedals level and jump off them while giving an extra bit of lift on the front which you then level out the bike when actually airborne. *I wonder if the fore-aft heaving on the bars is actually as effective on a drop handlebar bike when optimally set up for distance riding. *I understand that you are simply kicking off the back wheel and you need to get your c-of-g behind the axle so as to be able to push against the ground. The type of hop I describe is fairly hard on the bike. Most bikes will take it no problem, and the higher you get the easier it is to soften the landing by absorbing it with your body, but I still cringe a bit doing it on my road bike due to the low spoke count and CF fork and rear triangle. I don't mind hopping up onto a curb or something as I'm essentially hopping to the height I'm landing, but I don't like hopping over things (i.e. pothole, debris) just because I'm uncomfortable with landing hard on low spoke wheels. They're probably stronger than I give them credit for, but I know a broken spoke on them would be an issue. On my BMX, which has Peregrine HP 48 superpro 48 spoke wheels, broken spokes don't matter. I've been abusing these same wheels for 12+ years and while they both started as 48's it's probably 47/46 or 46/45 at this point, and they still both run perfectly true. The beauty of such a small diameter wheel, a high flange hub and 48 spokes... What boggles my mind is people who can hop them well from the drops. I have to go to the upper bar section to do it. |
#59
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Let's do the bunny-hop, was Will a 29er work for collegecampus commute?
On 23 Oct, 16:35, " wrote:
On Oct 22, 12:14*pm, thirty-six wrote: On 22 Oct, 15:50, " wrote: On Oct 21, 11:49*pm, Dan O wrote: On Oct 21, 8:00 pm, Frank Krygowski wrote: On Oct 21, 6:37 pm, RonSonic wrote: Hopping while clipped in is much easier. Apparently BMX and trials guys can make the bikes stick to their feet or something. I can do it a bit without clips, but not nearly as easily or as high. It happens so fast it's nearly unconscious, but I think the physics goes like this: *Rider jumps up, and pulls handlebars up after himself. *Mass center of the bike rises while the rear wheel is still on the ground. *Then the rider pushes down on the bars, to rotate the bike about its mass center so it's horizontal. *The end effect is two wheels off the ground. Good analysis, I think. *I've never practiced it. *I think maybe there's a forward thrust / rotation of the bars component. *Obviously the rider cannot "pull up" on unattached pedals (it's definitely all in the handlebars), but does use the inertia of his body to lift the bike off the ground. As a former BMX racer, current BMX dirt jumper, skate park and street rider and someone with a lean toward trials style on the MTB, I'll chime in here. *I can hop higher on my BMX, no clips, than I can on anything I have with clips. *The way I do it is entirely weight transfer and momentum through the handlebars. *It goes something like lean back, into a manual (wheelie) that you know would loop out. *When the bike passes the balance point, throw all your weight forward (which is now 45 degrees from the ground at a minimum, likely higher, exactly where depends on the bike). The basics can be practiced in a much more mild way. *Lean back and pull up on the bars to get your manual (wheelie) and then shove the bars forward with all your weight and momentum. *It feels more natural to throw the weight forward in relation to the ground rather than the angle of your bike, that's fine for starting out. *The only limiting factor is it will not allow you to hop higher than you can manual. *Be sure you are transferring your body weight and momentum into the bars and over the front wheel and not just pushing with your arms with your weight still back on the pedals. *The reason we're able to control the rear of the bike so well when doing this on a BMX with platforms is there is basically no weight on the pedals at this point, we've thrown all our weight and momentum into the direction we wish the bike to go. *The pins on the platform provide sufficient bite into our sneakers for small adjustments. Another way to practice is to find a small rise, say 4", that is not sharp enough to pinch your rear wheel. *Ride up to it and manual your front wheel on, then throw your weight forward into the bars and lean forward, lifting your rear wheel up onto the rise. *Once you can do this, it's just a matter of speeding it up to hop up the same rise. Then you can work on height. *BTW, practice on things/times/places that won't get you really hurt or damage your bike (i.e. if you think you are hopping 5", don't try to hop a 4" curb at an angle in front of traffic). *You're never going quite as high as you think you are. *The only way to know is to clear obstacles. *You can start with 2x4's on their side, if you're not getting the 3.5" you'll knock it over. *Then 2x6 (for 5.5"), etc. *Once you can clear a section of 2x12 (11.5") consistently you're ready to start looking at larger obstacles. *My current challenge is a downed trash can, it was easy-peasy in my real BMX days but these days I tend to clip the things. snip With a touring/racing bike the handlebars are lower and more stretched out. *The usual procedure is to set the pedals level and jump off them while giving an extra bit of lift on the front which you then level out the bike when actually airborne. *I wonder if the fore-aft heaving on the bars is actually as effective on a drop handlebar bike when optimally set up for distance riding. *I understand that you are simply kicking off the back wheel and you need to get your c-of-g behind the axle so as to be able to push against the ground. The type of hop I describe is fairly hard on the bike. *Most bikes will take it no problem, and the higher you get the easier it is to soften the landing by absorbing it with your body, but I still cringe a bit doing it on my road bike due to the low spoke count and CF fork and rear triangle. *I don't mind hopping up onto a curb or something as I'm essentially hopping to the height I'm landing, but I don't like hopping over things (i.e. pothole, debris) just because I'm uncomfortable with landing hard on low spoke wheels. *They're probably stronger than I give them credit for, but I know a broken spoke on them would be an issue. *On my BMX, which has Peregrine HP 48 superpro 48 spoke wheels, broken spokes don't matter. *I've been abusing these same wheels for 12+ years and while they both started as 48's it's probably 47/46 or 46/45 at this point, and they still both run perfectly true. *The beauty of such a small diameter wheel, a high flange hub and 48 spokes... What boggles my mind is people who can hop them well from the drops. I have to go to the upper bar section to do it. You have little time to move your hands at over 30mph. Jumping up 4" is generally little trouble if you practise the procedure on a daily basis. The 12" high jump I'm not sure can be perfomed without prior warning. But practicing this would definitely help in avoiding injury should the need arise to use it in an emergency. If you had more trustworthy wheels what height do you think you could clear on a 'racer'. |
#60
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Let's do the bunny-hop, was Will a 29er work for collegecampus commute?
Slight modification to previous post for clarity.
On 23 Oct, 21:35, thirty-six wrote: Dan wrote: What boggles my mind is people who can hop them well from the drops. I have to go to the upper bar section to do it. You have little time to move your hands at over 30mph. *Jumping up 4" is generally little trouble if you practise the procedure on a daily basis. *The 12" high jump I'm not sure can be perfomed without prior warning. *But practicing this would definitely help in avoiding injury should the need arise to use it in an emergency. So Dan, if you had more trustworthy wheels what height do you think you could clear on a 'racer'? [Be quiet, Ron.] |
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