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  1. #26
    Senior Member randya's Avatar
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    Quote Originally Posted by LittleBigMan
    I'm gonna try Chinese Google first chance I get. I'm gonna see if I can pull up anything significant about Tiennamen Square. My guess is no.
    You're really stretching if your analogy means you think bicycle steering displacement tests would be censored on the US internet in the same way information on Tiennamen Square is censored in China. Or are you trying to get this thread moved to P&R?


  2. #27
    Senior Member John C. Ratliff's Avatar
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    Steering displacement analysis

    Quote Originally Posted by John Forester
    How does your Vision R40 SWB/OSS handle during a steering displacement test at speeds of over 40 mph?
    John,

    I don't have a Vision R40, but I do know that they are a unique bike and can be set up either as SWB/OSS, or LWB/OSS. They can also be set up with underseat steering (USS) in both configurations. There was a great deal of engineering going into those bikes, and I almost bought one but I found out that the company was having trouble. They went under shortly after I did buy a competitor's bike.

    I bought a Rans Stratus, after having test rides on probably 20 different recumbant bicycles over a two year period. My wife did not want me to buy a recumbant, because she felt that they did not look good and more people use an upright bike. I told myself that if I had one more problem (I had already had two which I attributed at least in part to the design of an upright), that I'd get a recumbant. About six months later, I did have another problem, on a bike path. My front wheel got caught in a crack in the bike path's wood planking, at low speed of about 8 mph. I thought I could stop, but I went over the handlebars anyway. Talk about instability, that did it. The next week, after settling with the City of Hillsboro (they replaced my bike's front wheel, and made the bike path so that this accident could not happen again), I put money down on my Rans Stratus. I picked it up later that year (2002, I believe) and now have over 6000 miles on it.

    You asked about a steering displacement test at 40 mph. As a safety professional, I would not ever ask someone to do this kind of test on their own on the road. That could contribute to an accident, no matter what type of bicycle you ride. My wife has a hybrid by Trek which, when I tested it out near my house, wants to pull further into a turn rather than return to the centerline riding. In other words, it takes active steering once a turn is made to get out of the turn. That is not good, and could contribute to a fall. She still likes the bike, and so far we have not gotten a new one for her.

    Concerning steering displacement itself, we can do something on paper which may shed some light on the situation. I just measured my Rans Stratus, and it has a lengeth from the center of the wheel's axle to my handlebar of 36 inches. My wife's hybrid has a measurement of about 12 inches. If we displace the handlebar six inchas at about twelve inches, on paper we got a 26 degree turn of the wheel (I measured using a protractor ). But if we do the same 6 inch displacement of the handlebar for my Rans Stratus, I get only a 4 degree turn of the wheel. It's a distance and lever thing (most engineers would know this too). In other words, displacement of my handlebars on the Rans Stratus is much less of a wheel turning event than the same amount of displacement on my wife's upright hybrid. I have, at something like 25 mph, done a displacement test on my Rans Stratus, and found that it is very stable, even turning the wheel quickly to one side about six inches. This is directly because of the much, much longer wheelbase, and the lower CG on the Stratus.

    Concerning balance on a recumbant, it is different, but you can use your weight to alter the CG. I lean by getting off the seat back, and leaning my body to the side at times. Usually, I do this in slow-speed turns on wet, slippery surfaces. I have found that the Stratus is much more stable on slippery surfaces than any of my upright bikes, and in fact rode it in about 4 inches of new snow this last winter; when cars could not get up the short hill by my home, I pedaled along on the sidewalk beside them. If you get into something where the front wheel of the recumbant slides, you can fall. But the fall is much shorter (I'm lower to the ground), and therefore will not produce the injuries that a fall from a higher height would produce.

    More later, as I'm about to have supper.

    John
    Last edited by John C. Ratliff; 05-06-07 at 07:25 PM.
    John Ratliff

  3. #28
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    For once, I agree with the elderly bow-tie sporting
    pseudo cycling grump, as much as it pains my soul.
    Unbefreakinglievable. The elderly-bow-tie-sporting-pseudo-cycling-grump has found agreement with the helmet-cam-wearing-expert-in-everyformofcycling-and-picturetaking-grump.

    Wonders never cease.
    Last edited by LittleBigMan; 05-06-07 at 08:13 PM.
    No worries

  4. #29
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by randya
    You're really stretching if your analogy means you think bicycle steering displacement tests would be censored on the US internet in the same way information on Tiennamen Square is censored in China. Or are you trying to get this thread moved to P&R?

    I was wondering who would be the first to seize on this unintended coincidence.

    No, no such analogy was intended, thankyouverymuch. The more obvious thing is that Google has its flaws...to say the least.

    If it's not on Google, it doesn't exist.
    No worries

  5. #30
    Ms Congeniality bikingMILF's Avatar
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    Quote Originally Posted by Pete Fagerlin
    That's probably because you lack the basic skills to pilot a "wedgie" at high speeds.

    Just because a five year old can ride a Big Wheel faster downhill compared to a real bike doesn't mean that Big Wheels are the answer to descending quickly.

    For once, I agree with the elderly bow-tie sporting pseudo cycling grump, as much as it pains my soul.

    wow pete, you spread your words of joy and wisdom all over this place, dont you.

  6. #31
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by John C. Ratliff
    More later, as I'm about to have supper.

    John
    John R., don't you eat in front of the computer, like the rest of us?
    No worries

  7. #32
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    That's a straw man that you've created there oh timid frightful of riding on roadways squaw.
    I find you sexy.
    No worries

  8. #33
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    You homosexual comment is a poor cover for your post which was not founded in logic, and refuted by the record (as in posting history).

    You're giving Indians (as in "woo woo" indians aka native Americans vs. red dot Indians) a bad name, fraidy cat.
    Kiss me, you fool!
    No worries

  9. #34
    Ms Congeniality bikingMILF's Avatar
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    Quote Originally Posted by Pete Fagerlin

    Newblet, your handle/user name is disingenuous and your your "observations" are hilarious.

    You must be a riot to know in person. I think I love you.

  10. #35
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    As an on again off again Yankees fan, that would be against my religion, you silly twinkie.
    No worries

  11. #36
    Senior Member Brian's Avatar
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    Wow, A&S is the new P&R.

    My office has a genuine N.Y. Yankees Ave sign, but I'm not taking sides.

  12. #37
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Brian
    Wow, A&S is the new P&R.

    My office has a genuine N.Y. Yankees Ave sign, but I'm not taking sides.
    I lived in Brisbane. Taking sides was not on my agenda at the time.
    No worries

  13. #38
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    I'm much more irreverent in person, especially towards goofy, tacky, chicks who label themselves as "MILFs."
    Who would take the time to get to know you?

    Worshippers, perhaps...

    No worries

  14. #39
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    Hey, if that fantasy makes you feel better about yourself chicken little, I'm happy for you.

    Really.
    yawn
    No worries

  15. #40
    Sumanitu taka owaci LittleBigMan's Avatar
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    pete you got great pics and everything, but your personality sucks
    No worries

  16. #41
    Dominatrikes sbhikes's Avatar
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    Quote Originally Posted by Pete Fagerlin
    That's probably because you lack the basic skills to pilot a "wedgie" at high speeds.

    Just because a five year old can ride a Big Wheel faster downhill compared to a real bike doesn't mean that Big Wheels are the answer to descending quickly.

    For once, I agree with the elderly bow-tie sporting pseudo cycling grump, as much as it pains my soul.
    I mean I go faster simply coasting. The recumbent goes much faster down hill. Both of them do. I believe that is due to the better wind resistance. All weigh about the same. And on all of them, the gearing limits me to being able to pedal the thing any faster.
    ~Diane
    Recumbents: Lightning Thunderbolt, '06 Catrike Pocket. Upright: Trek Mountain Bike.
    8.5 mile commute. I like bike lanes.

  17. #42
    Cycle Year Round CB HI's Avatar
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    Quote Originally Posted by N_C
    The thing is on a bicycle the operator is part of the steering system, a major part of it. But let's give the benefit of the doubt here. Has anyone ever heard of a test lab similar to how cars are safety tested? Where the bike could be rigged to a device that propels it along a track to test steering displacement with a test dummie to simulate a humans weight, etc.?
    Do bicycle manufacturers do stability test, including steering displacement test?

    Yes, many manufacturers do. Some test include riders and some do not and there are different methods of doing different test. Many test are done on roller systems.

    A steering displacement or other stability test do not have to be done to full failure (crash).

    Have you ever taken a bike and pushed it by the saddle, leaned it left and seen how well the bikes rack controls the bike and then brought the bike upright to see if the rack returns the bike to a straight path. If so, you have conducted a simple stability test.

    When I ride bicycles, I do what we are calling a steering displacement test. Not to the point of crashing but enough to tell how stable the bicycle handles. I would rather crash while test riding a bike in an empty parking lot than when riding in the middle of rush hour traffic. Mountain bikers have steering displacement test introduced as a normal part of their off road riding. Such experience helped me avoid crashing when a JAM introduced a steering displacement test on me by hitting my handle bar with his side mirror while traveling at 25 mph on a wet road. (Thank you Trek for doing stability testing).
    Last edited by CB HI; 05-06-07 at 11:45 PM.

  18. #43
    Cycle Year Round CB HI's Avatar
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    Most people would be amazed at the range of testing performed by the major bicycle manufacturers.

  19. #44
    The Site Administrator: Currently at home recovering from a couple of strokes,please contact my assistnt admins for forum issues Tom Stormcrowe's Avatar
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    Quote Originally Posted by randya
    Among diamond frame upright bicycles many varying geometries are possible; steering rake and other design parameters can be wildly different from bike to bike. With recumbents the range in designs is even greater. I don't know how anyone, especially an engineer, can make the types of sweeping generalizations about these two classes of bikes that AJ has made here.
    What I was referring to was the Center of Mass being able to be shifted by standing the pedals, and move back and forth forward and back in reference to saddle position dependent on terrain, etc. Not something you can do on a 'bent. Again, I'm not anti 'bent, my wife rides one. It just has limitations under certain circumstances. The DF has limitations under different circumstances. Different job, different tool, as I said!
    on light duty due to illness; please contact my assistants for forum issues. They are Siu Blue Wind, or CbadRider or the other 3 star folk. I am currently at home recovering from a couple of strokes. I am making good progress, happily.


    . “He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you.”- Fredrick Nietzsche

    "We can judge the heart of a man by his treatment of animals." - Immanuel Kant

  20. #45
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by Pete Fagerlin
    You're giving Indians (as in "woo woo" indians aka native Americans vs. red dot Indians) a bad name...
    "Woo woo" Indians?

    "Red dot" Indians?
    No worries

  21. #46
    Senior Member John C. Ratliff's Avatar
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    So that this doesn't get lost in the information sharing that happened subsequent to it's posting, I'm posting it again here:

    Quote Originally Posted by John Forester
    How does your Vision R40 SWB/OSS handle during a steering displacement test at speeds of over 40 mph?
    John,

    I don't have a Vision R40, but I do know that they are a unique bike and can be set up either as SWB/OSS, or LWB/OSS. They can also be set up with underseat steering (USS) in both configurations. There was a great deal of engineering going into those bikes, and I almost bought one but I found out that the company was having trouble. They went under shortly after I did buy a competitor's bike.

    I bought a Rans Stratus, after having test rides on probably 20 different recumbant bicycles over a two year period. My wife did not want me to buy a recumbant, because she felt that they did not look good and more people use an upright bike. I told myself that if I had one more problem (I had already had two which I attributed at least in part to the design of an upright), that I'd get a recumbant. About six months later, I did have another problem, on a bike path. My front wheel got caught in a crack in the bike path's wood planking, at low speed of about 8 mph. I thought I could stop, but I went over the handlebars anyway. Talk about instability, that did it. The next week, after settling with the City of Hillsboro (they replaced my bike's front wheel, and made the bike path so that this accident could not happen again), I put money down on my Rans Stratus. I picked it up later that year (2002, I believe) and now have over 6000 miles on it.

    You asked about a steering displacement test at 40 mph. As a safety professional, I would not ever ask someone to do this kind of test on their own on the road. That could contribute to an accident, no matter what type of bicycle you ride. My wife has a hybrid by Trek which, when I tested it out near my house, wants to pull further into a turn rather than return to the centerline riding. In other words, it takes active steering once a turn is made to get out of the turn. That is not good, and could contribute to a fall. She still likes the bike, and so far we have not gotten a new one for her.

    Concerning steering displacement itself, we can do something on paper which may shed some light on the situation. I just measured my Rans Stratus, and it has a lengeth from the center of the wheel's axle to my handlebar of 36 inches. My wife's hybrid has a measurement of about 12 inches. If we displace the handlebar six inchas at about twelve inches, on paper we got a 26 degree turn of the wheel (I measured using a protractor ). But if we do the same 6 inch displacement of the handlebar for my Rans Stratus, I get only a 4 degree turn of the wheel. It's a distance and lever thing (most engineers would know this too). In other words, displacement of my handlebars on the Rans Stratus is much less of a wheel turning event than the same amount of displacement on my wife's upright hybrid. I have, at something like 25 mph, done a displacement test on my Rans Stratus, and found that it is very stable, even turning the wheel quickly to one side about six inches. This is directly because of the much, much longer wheelbase, and the lower CG on the Stratus.

    Concerning balance on a recumbant, it is different, but you can use your weight to alter the CG. I lean by getting off the seat back, and leaning my body to the side at times. Usually, I do this in slow-speed turns on wet, slippery surfaces. I have found that the Stratus is much more stable on slippery surfaces than any of my upright bikes, and in fact rode it in about 4 inches of new snow this last winter; when cars could not get up the short hill by my home, I pedaled along on the sidewalk beside them. If you get into something where the front wheel of the recumbant slides, you can fall. But the fall is much shorter (I'm lower to the ground), and therefore will not produce the injuries that a fall from a higher height would produce.

    More later, as I'm about to have supper.

    John
    John Ratliff

  22. #47
    Dominatrikes sbhikes's Avatar
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    Certainly recumbents are not mountain biking machines. You can ride them quite easily on unpaved surfaces as long as they are relatively smooth -- not rocky or excessively steep. But you'd be just as crazy to try mountain biking with a lightweight road bike under those conditions.

    The thing to understand about recumbents is they are just different. It's like how they have all these different kinds of skate boards now. Just another fun bicycle to have in your stable. I've got 3 kinds of bikes now -- trike, recumbent, commuter upright mountain bike -- and think maybe I should have more kinds.
    ~Diane
    Recumbents: Lightning Thunderbolt, '06 Catrike Pocket. Upright: Trek Mountain Bike.
    8.5 mile commute. I like bike lanes.

  23. #48
    your nightmare gal chipcom's Avatar
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    Recumbent is for wussy.
    "Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey

  24. #49
    genec genec's Avatar
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    Quote Originally Posted by LittleBigMan
    Ahh, Google...the new Encyclopedia Brittanica.



    If it's not on Google, does it exist? Philosophically speaking, like the proverbial tree falling in the woods, if nobody hears it, did it make a noise?

    I'm gonna try Chinese Google first chance I get. I'm gonna see if I can pull up anything significant about Tiennamen Square. My guess is no.
    I didn't follow your entire thread, but the first thing on Google when I did the "Tiananmen Square" search was this bit on wiki: http://en.wikipedia.org/wiki/Tiananm...otests_of_1989

    Which includes this pic:

    Now on the flip side I can tell you that when I was in China a few years ago I did some interesting searches using my computer in a hotel, and discovered a number of things that appeared to be blocked... which I had no problem accessing when I used a VPN connection to my home office in the US and then searched again. I had both windows open on my PC... it was rather enlightening.

  25. #50
    The Site Administrator: Currently at home recovering from a couple of strokes,please contact my assistnt admins for forum issues Tom Stormcrowe's Avatar
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    Quote Originally Posted by sbhikes
    Certainly recumbents are not mountain biking machines. You can ride them quite easily on unpaved surfaces as long as they are relatively smooth -- not rocky or excessively steep. But you'd be just as crazy to try mountain biking with a lightweight road bike under those conditions.

    The thing to understand about recumbents is they are just different. It's like how they have all these different kinds of skate boards now. Just another fun bicycle to have in your stable. I've got 3 kinds of bikes now -- trike, recumbent, commuter upright mountain bike -- and think maybe I should have more kinds.
    I think that was what I said, Di!

    Like I said, the wife rides a 'bent!

    Good news, 3 days to our UP tour! Woohoo!
    on light duty due to illness; please contact my assistants for forum issues. They are Siu Blue Wind, or CbadRider or the other 3 star folk. I am currently at home recovering from a couple of strokes. I am making good progress, happily.


    . “He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you.”- Fredrick Nietzsche

    "We can judge the heart of a man by his treatment of animals." - Immanuel Kant

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