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Thread: what are the chances?

  1. #16
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    These were huge trucks carrying big steel bands, whoa! The problem was that my bike was out of tune (heck, the timing has never been adjusted to this day) and my handlebars went into a tank slap mode from the enharmonic vibrations, and started doing hemidemisemiquavers (in spite of the steering damper). In the end, the bike ended up on a flat note, accidentally, but it just needed a pick up to set things aright...

  2. #17
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    Quote Originally Posted by 20774 View Post
    I thought it was the other way around? That's kind of weird...
    I agree with Kurt, at least my bike is more stable on the centerstand unless on softer ground or gravel.

  3. #18
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    Quote Originally Posted by PGlaves View Post
    My guess would be that the two springs had approximately the same number of stretches before they each failed.
    I always thought that the left spring worked more often than the right spring because it was closer to the mount/dismount position - darn !!

  4. #19
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    center stand springs

    The springs wrap around posts, and wear. Sometimes the stand bolts back out, or otherwise loosen, and few owners check for lubrication of the stand at the spring perches and tightness of the bolts, and in some instances the spring gets fouled, and, yes, both can go at the same time.
    Be sure that the fitments are square, nothing is excessively worn, and the stand perch area is lubricated. BE SURE the stand can move fully without fouling anything.
    All this should be on the yearly scheduled service list.

    snowbum
    http://bmwmotorcycletech.info

  5. #20
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    Quote Originally Posted by jimmylee View Post
    I agree with Kurt, at least my bike is more stable on the centerstand unless on softer ground or gravel.
    this debate has been hashed, rehashed and cornbeefhashed to death.

    consider this; on c-stand, you have a very narrow isosceles triangle as your base (one wheel, & 2 contact points that are inches apart at the c-stand). on the sidestand, you have a very much larger triangle to support the bike (2 wheels, and one larger contact point of sidestnad).

    there is no question whatsoever that sidestand is more secure than c-stand. the only time c-stand wins out is for doing work on the bike on solid flat ground (garage, pavement, etc), or when bike is on display (again- solid flat ground).

    the only caveat acting against this is if you have a spring loaded sidestand that when weight/tension on it is released, it folds to upright position. I had a mid-90s Duc like that; remove any weight from the sidestand, and up it came! the "tweak" to remove the "sidestand up" feature was soon employed. some airheads have a similar feature, and disabling it is often done to pre-emptively avoid the windy tipover.
    Ride Safe, Ride Lots

  6. #21
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    Quote Originally Posted by bikerfish1100 View Post
    this debate has been hashed, rehashed and cornbeefhashed to death.

    ....snip....

    there is no question whatsoever that sidestand is more secure than c-stand.
    IMO, there's no question it's a personal observation...I would argue the more secure aspect. In my situation, using non-inch size tires definitely reduced the lean angle of an Airhead on the sidestand. You get one of them more vertical, a puff of wind will blow the bike over self-retracting sidestand or not.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
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    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  7. #22
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    Quote Originally Posted by bikerfish1100 View Post
    this debate has been hashed, rehashed and cornbeefhashed to death.

    consider this; on c-stand, you have a very narrow isosceles triangle as your base (one wheel, & 2 contact points that are inches apart at the c-stand). on the sidestand, you have a very much larger triangle to support the bike (2 wheels, and one larger contact point of sidestnad).

    there is no question whatsoever that sidestand is more secure than c-stand. the only time c-stand wins out is for doing work on the bike on solid flat ground (garage, pavement, etc), or when bike is on display (again- solid flat ground).

    the only caveat acting against this is if you have a spring loaded sidestand that when weight/tension on it is released, it folds to upright position. I had a mid-90s Duc like that; remove any weight from the sidestand, and up it came! the "tweak" to remove the "sidestand up" feature was soon employed. some airheads have a similar feature, and disabling it is often done to pre-emptively avoid the windy tipover.
    I ditto Kurt's observation - non-inch tires or not!

    My experience has been that on solid ground, the sidestand will be perfectly stable unless someone touches the bike. But then you also have the "lean" issue with the boxers. But if I am on stable solid ground, I will always use the centerstand (no "lean" issue, and I think the bike is harder to knock over if someone should try to mess with it.

    The clincher for me, is that I have seen, when using the sidestand on let's say, grassy areas, that the stand will tend to "cut" in to the ground and the bike will "walk" forward to the point where the stand would fold. I had that almost happen. Of course, the centerstand on softer ground would probably not be very good either.

    The issue is not worth fighting about - except for the "lean" issue to boxer engines - but only if there is something to that, and I think there is!

  8. #23
    Registered User lmo1131's Avatar
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    These were huge trucks carrying big steel bands, whoa!
    Dang!! How many steel bands were there on that truck anyhoo ?!?!?!

    "It is what you discover, after you know it all, that counts." _ John Wooden

    Lew Morris
    1973 R75/5 - original owner

  9. #24
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    Ha! You got it!

  10. #25
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    Agreed!

    Paul calls it my mechanic stand because that's the ONLY time I use the center stand!

    Voni
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  11. #26
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    Imagine a football player on the line of scrimmage with his feet together instead of spread out. That's the principal of the wider aspect of using the side stand. On the centerstand, you only have 2 points of contact at the centerstand and one point of contact with the rear tire, and they are all in the same plane, basically. Heck, I've knocked my bike over on the centerstand by just hitting it with my knee whilst mounting.

  12. #27
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    Quote Originally Posted by Weasel View Post
    Imagine a football player on the line of scrimmage with his feet together instead of spread out. That's the principal of the wider aspect of using the side stand. On the centerstand, you only have 2 points of contact at the centerstand and one point of contact with the rear tire, and they are all in the same plane, basically. Heck, I've knocked my bike over on the centerstand by just hitting it with my knee whilst mounting.
    I don't think that analog really works that well. What if you push on the chest of the football player?

    Theoretically, if I can visualize this right, it takes essentially the same amount of force to push a bike over on the center or sidestand...plus or minus. Pick a point to push on. The only way the bike is going to tip over is if the CG gets outside the supports on the ground. So, for the sidestand, you start pushing and only until you get the CG to go beyond two contact points of the tires, then the bike will fall over. Obviously, for the auto-retract sidestand, it's kind of worse, because if you push just a bit and the stand retracts, the only thing keeping the bike up at that point is side pushing force. So for the sidestand situation, you either push for a short period of time, the stand retracts or you continuous push to move the CG beyond the wheels and the bike goes down.

    Centerstand...genereally about the same side force and once the CG is outside the centerstand contact point, the bike will go over. Time might be a factor here. On the sidestand, you have to push for quite a while to get the bike up to vertical (actually, it's taking more force because you're having to raise the CG higher from the leaned over position). On the centerstand, the CG still has to be raised a bit also before it gets outside the contact point. The time of the pushing is probably shorter for the centerstand situation before it gets precarious.

    Consider a Reynolds ride-off stand. The contact points for the centerstand are much wider and the forces to push on the bike have to raise the CG quite a distance before it gets to the point of being outside the contact point.

    As initially suggested, this topic is beat up quite a bit...which approach is better. We each make our choices...if it doesn't work for you, you move on to something else.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  13. #28
    Benchwrenching PGlaves's Avatar
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    Go out and mark the footprints on the pavement.

    Centerstand feet and tire patch.

    Both tire patches and sidestand.

    Then stand back and decide which ought to be the most stable. Consider physics!

    Sure, if you put it on either stand wrong - sidestand leaning to far or not far enough, or centerstand leaning it will be unstable.
    Paul Glaves - "Big Bend", Texas U.S.A
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  14. #29
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    Quote Originally Posted by PGlaves View Post
    Go out and mark the footprints on the pavement.

    Centerstand feet and tire patch.

    Both tire patches and sidestand.

    Then stand back and decide which ought to be the most stable. Consider physics!

    .
    If I do what you say, Paul, sidestand and two tires would be most stable. The distance between each point of contact is much larger, thus leverage required to move it out of stable position is higher.

  15. #30
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    I take into consideration that this topic is pretty much a personal decision.

    My 2 reasons for using the centerstand rather than the sidestand are these: 1) I still take seriously some of the old timer's suggestion that when leaning, the boxer engines will drain some of the oil into the left jug/piston. and 2) I don't want to do ANYTHING to have my Beemer look like a Harley!!!

    As far as the physics go. I can see how the two different methods actually put the three contact points (sidestand: two tires and 1 stand, centerstand: two stand legs and 1 tire patch) with slightly different chances of tipping. With sidestand, two wheels could roll much more easily if ground is not level or if bike is bumped - especially from behind. With centerstand, bike could also be bumped forward and thus get stand to go "over center" but that would take a heck of a bump, but not when bike is not on level ground but facing downward. That is why I always use centerstand and point bike UP, Sidestand in this situation, whether pointing UP or DOWN, would allow 2 of the three contact points to roll. Wow - now that's scary!!

    I really think that we need to have all the owners take a vote and then we can see which stand is the correct one to use! Before someone blasts me, I am joking!!!

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