Joined: Jun 19, 2003
Posts: 16913
Location: Winchester Springs, TN
Posted:
Sat May 16, 2015 4:41 pm
CB1100F wrote:
toonces wrote:
OK, then please explain the physics. The physics I'm accustomed to say that you have to form a "couple" by adding weight opposite from the heavy side. On a static balancer, the center of the heaviest half settles to the bottom.This is because by definition there's 180 degrees of wheel and tire above the spindle and 180 below. If you turn the wheel by 90 degrees, this same heavy spot applies a torque (technically a "moment") to the wheel. Because it's at 90 degrees, the lever arm component of the torque is at its greatest and the moment is maximized.
Now with the wheel again at 90 degrees from settled, add 1/4 ounceof weight at a time exactly opposite the heavy spot until the wheel no longer tries to settle. Now you've applied an equal but opposite torque to cancel the original torque.
Everyone's opinion on these "magic bb's" working is by the "seat of the pants". Plenty of tires are close enough to neutral balance as mounted, without any weight, to feel "fine" while riding. This does not mean the magical dynabeads are doing anything.
If anyone can show a real world demonstration of balancing a tire by adding beads, I'll buy you a case of beer.
OK, going riding now,
Toonces
Not taking a side, but I would take the beer if this counts?
Also, I would expect water to do the same thing in the video above. Should be easy enough to try.
Ok, just tried it. Not sure what happens, but it's like in the video.
The empty bottle will wobble and spin pretty quickly as speed increase. Adding water lets it definitely remain much more stable at the same speed. Also it takes more speed to throw it off. The empty bottle has a high speed(frequency) wobble the water filled is a much lower speed wobble.
I suspect the added mass of water does it on such a small scale. The empty bottle weight was 17g with water 75g. Speed was few hundred RPM, both could spin up at low speed setting went to high speed to induce wobble.
So I was spinning a lot more water than bottle.
FWIW. I would think the bottle experiment is not analogous to a tire.
If a 20lb tire (320oz) needs 1oz of beads that's a 320-1 ratio. for the bottle at 17g the would be .05g of water. like a few drops.
A few drops had no effect.
So, next time someone is going to change a tire, remove all tire weights or add some if needed to induce a wobble. Add an ounce or so of water and go for a ride and see if the wobble is gone.
_________________ Glenn
´83 CB1100F,´94 Wife
Catchy phrase not included.
Outback_Jon Red CB1100F
Joined: Sep 09, 2005
Posts: 9162
Location: Cairo, NY
Posted:
Sat May 16, 2015 9:23 pm
CB1100F wrote:
toonces wrote:
OK, then please explain the physics. The physics I'm accustomed to say that you have to form a "couple" by adding weight opposite from the heavy side. On a static balancer, the center of the heaviest half settles to the bottom.This is because by definition there's 180 degrees of wheel and tire above the spindle and 180 below. If you turn the wheel by 90 degrees, this same heavy spot applies a torque (technically a "moment") to the wheel. Because it's at 90 degrees, the lever arm component of the torque is at its greatest and the moment is maximized.
Now with the wheel again at 90 degrees from settled, add 1/4 ounceof weight at a time exactly opposite the heavy spot until the wheel no longer tries to settle. Now you've applied an equal but opposite torque to cancel the original torque.
Everyone's opinion on these "magic bb's" working is by the "seat of the pants". Plenty of tires are close enough to neutral balance as mounted, without any weight, to feel "fine" while riding. This does not mean the magical dynabeads are doing anything.
If anyone can show a real world demonstration of balancing a tire by adding beads, I'll buy you a case of beer.
OK, going riding now,
Toonces
Not taking a side, but I would take the beer if this counts?
Also, I would expect water to do the same thing in the video above. Should be easy enough to try.
That was going to be my next post, Glenn. I just got off a sixteen hour shift (no overtime, too) when I responded, though.
That said, when I static balance my tires, with those valve stems, they have needed in the neighborhood of 1.5~2 oz (in one spot on the tire) to get to anything near balanced. For me, that's far enough out to avoid any "seat of the pants" claim.
CB1100F wrote:
If a 20lb tire (320oz) needs 1oz of beads that's a 320-1 ratio. for the bottle at 17g the would be .05g of water. like a few drops.
A few drops had no effect.
I think that's why they put the weight on their bottle in the video.
All I can say is, it works for me. And I know dozens of other guys that use it too.
I have a box of stick on weights that I no longer have a need for. And after tonight, I'm off for a few days. If I get a chance, I'll stick a couple of ounces on and see if I get any shake, or if the beads compensate.
Also, if I'm not on a tight schedule next time I replace a tire, I'll take it for a spin with no beads, then add the beads later.
_________________ Molon Labe
toonces Rest in Peace
Joined: Jun 29, 2004
Posts: 513
Location: littleton, massachusetts
Posted:
Sun May 17, 2015 12:51 am
The spin the bottle with a drill test starts with something grossly out of balance,
adds a handful of beads that get somewhat evenly distributed by centrifugal force
and creates a "less" out of balance condition (but still out of balance, you can see it
shaking in the video). So it's sort of diluting the effect of the stuck-on weight.
If you were to add a small metal hoop around the end of the bottle, equal in weight
to the beads, you could stick the weight on in the same location and get the same effect
as in the video. No hoop = big imbalance, with hoop = less imbalance.
Here's a real world test that would definitely tell the story:
- put a wheel and tire on a spin balancer (we already know the fuzzy little magic balls have to be going 25? MPH to do their thing)
- spin it up, it will tell you how much weight to add, and where to add it
- add the weight, spin it up again, if you got it right the machine will indicate the wheel is properly balanced
- remove the weights and spin it up again. If the machine is working correctly it will tell you the same as above, how much and where
- now, instead of adding the weight, add the furry fucking magic balls. I will GUARANTEE you that the tire will NOT be properly balanced
it's simply impossible.
If I had a spin balancer I'd do it, but again, it ain't gonna work. The case of beer offer still stands.
Toonces
Pete83 CB1100F
Joined: May 29, 2004
Posts: 2261
Location: Fond du Lac, Wisconsin
Posted:
Sat Dec 31, 2016 3:39 pm
I'm looking at getting my own tire changer, four bikes, soon to be five on the road and at $40 a change (or much more if I have the dealer remove/re-install the wheels from the bike) it won't take long to pay for itself.
In doing my due diligence by searching before asking, I came across this thread.
I'm looking at the No Mar Cycle Hill, along with the accessory to use your vehicle receiver hitch for stability. I need something like that because I have absolutely no space for any sort of permanent mounting of the changer in my garage.
Does anyone have first hand experience with the No Mar Cycle Hill? I need it for Sport Touring, Cruiser and Adventure (currently a DL 1000 V-Strom). There's a good YouTube video of two funny Canadians doing a V-Strom rear tire and that changer seemed pretty effortless once they got their lube on.
_________________ 2005 Honda ST1300
2007 BMW R1200 GS Adventure
STDocLizard Twinstar
Joined: Jun 23, 2008
Posts: 231
Location: Hampton, N.J.
Posted:
Sat Dec 31, 2016 11:08 pm
NoMar Jr. Pro with a Marc Parnes Balancer works for me and has paid for itself over the years. A good pair of tire irons is a nice addition to getting last 60 degrees of the top bead seated over the edge of the rim not to mention using the "Yellow Thing."
_________________ FRIENDS DON'T LET FRIENDS EARLY APEX.
toddk CB1100F
Joined: Mar 25, 2004
Posts: 2322
Location: Saratoga Springs, New York
Posted:
Sun Jan 01, 2017 12:42 am
I use SteveG's setup works great. The key is to get the bead into the drop center on the opposite side that you are working on. I use a clamp to hold it in place.
Toddk
Pete83 CB1100F
Joined: May 29, 2004
Posts: 2261
Location: Fond du Lac, Wisconsin
Posted:
Sun Feb 12, 2017 1:55 pm
Bought the No-Mar Cycle Hill Tire Changer at the Motorcycle Show in Chicago yesterday, from No-Mar themselves in their booth and carried it home in our Acadia.
Got them to throw in the "YellowThing" bead keeper. Now I need to buy the Marc Parnes wheel balancer and I'm all set.
Anyone coming thru Fond du Lac, WI and needs a tire changed, let me know....
_________________ 2005 Honda ST1300
2007 BMW R1200 GS Adventure
cagefree Twinstar
Joined: Jan 01, 2016
Posts: 55
Location: Temecula Ca
Posted:
Fri Feb 17, 2017 5:33 pm
f4fast wrote:
Harbor freight has a cheap balancer that works well. $50 Harbor freight has tire spoons as well for $10. They also sell a contraption to break beads on mc tires but I've never tried it.
I use 6" c-clamps to break the bead, and pieces of old leather (shoe or jacket) as a guard to protect the rims while I spoon them on and off.
Small diameter is the hardest..My buddy Jim has a 130/80-16 on the rear of his 750C and that was difficult.
Motion pro just came out with these and they look good to me
Breaking the bead is the most challenging part in my eyes.
I agree with Toonces assessment....I've also used contraptions to break a bead.
Ive got the HF bead breaker and balancer and both work great. I use tire irons and sliced pieces of garden hose to protect the rims from damage. Also lots of soapy water and leaving new tires out in the sun for a while really help them mount much easier.
http://www.motionpro.com/motorcycle/partno/08-0546/?gclid=CLXvvark_b0CFWuhOgod8jwA0g
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