Automatic dynamic balancing is proven physics that used in everything from washing machines to industrial equipment. It's even used on, wait for it, truck tires.
Warning: This is a long read but may be of interest to some people.
After getting several flats this year I decided to break down and finally start doing my own tire changes. One thing I looked into was balancing.
When I first read up on Dynabeads I got the impression they were snake oil because it's somewhat counterintuitive to think that throwing some magic beads inside your tire will balance it.
So I decided to poke around and read numerous posts about Dynabeads in all sorts of forums. Just about everyone who has actually tried either reports good results and extended, more even tire wear or, worst case, no change but the vast majority of users of them are believers. There's also quite a few shops out there that recommend (and of course sell) them.
There are, of course, naysayers with arguments like "If they're so great then why don't manufacturers use them?" "I've been a mechanic for 20 years and the way we've always done it is fine." "It's physically impossible because /insert reason here./" Interestingly, none of these people seemed to have actually tried an automatic dynamic balancing(ADB) product like Dynabeads or Ride-On.
After reading so many positive reviews I came to the conclusion that there's some real physics to ADB because quite a few users reported noticeable vibrations going away when using Dynabeads and it's hard to write off testimonials like that to a placebo effect.
My next objective was to get a physical understanding of what was going on to satisfy the engineer in me. I found a couple of YouTube clips that show ADB in action.
Here's a demonstration of a truck wheel balancing product that conceptually applies the same physics:
Here's a demo of Dynabeads in a plastic bottle:
In addition to how ADB is used in a variety of different trucking tire applications (like Equal and XactBalance) I found that it's used in other applications as well:
- Tires on US Air Force jets.
- Keeping industrial fans balanced between cleanings. The fan blades pick up dirt and get out of balance between cleanings so ADB is used to keep the fan assembly in balance as it collects dirt. There's some other industrial applications as well.
- Most modern washing machines have a ring of liquid around the tub to compensate for unbalanced loads.
Anyhow, the bottom line for me is that ADB is not some form of snake oil.
If you want to get deep into the math and physics of it:
http://rsta.royalsocietypublishing.org/content/366/1866/705.full.pdfSo, now that I've decided that ADB is real, what product to use? Here's the options I've found:
- The cheapest way to get ADB is to add antifreeze to your tires and I saw several mentions of that on car forums. Antifreeze is good because it doesn't freeze and doesn't break down. BUT, this is NOT suited to motorcycle use because if you get a puncture then you're pissing slippery liquid on your tire tread. But I thought I'd mention it anyhow though because it's another implementation of ADB in vehicle tires.
- Dynabeads: Little ceramic beads that roll around in your tires.
http://www.innovativebalancing.com/motorcycle.htm- Ride-On Tire Protection System: This is a liquid which also serves an as automatic sealant for punctures.
http://www.ride-on.com/motorcycle-formula-mot.html- Several guys over on ADV have had good luck using 0.12 gram Airsoft pellets.
I think all of these have some common pros:
1) You don't need a static or dynamic balancer and those damned wheel weights that leave adhesive crap on your wheels.
2) Dynamic balancing for the life of the tire as opposed to using wheel weights which only truly balance the wheel/tire assembly when it's mounted. Aside from the fact that ADB products keep your tires in balance as they wear this should also improve (reduce) tire wear for longer tire life.
3) Easy for the DIYer.
They all have some common cons too:
1) Some tire manufacturers will void your warranty if you use these products. I'm not sure why other than it's another out for them financially. I've seen no posts where anyone claimed that an ADB product ruined their tire. Personally, given the level of quality of tires today this isn't a big concern to me. Also note that Dynabeads or Airsoft pellets can be poured out and leave no trace and Ride-On simply washes out with water so how would they know anyhow?
Specific pros and cons:
DynabeadsPros:
1) Can be re-used if you're careful unmounting your ties.
Cons:
1) A little pricey for what you get IMO.
2) I suppose it could get messy if you're not careful revmoing the tire.
3) It's pretty rare but these are small enough to get caught in the end of the valve core when you're refilling and leave the valve stuck open so your tire completely deflates.
(Image borrowed from MOA forum.)
This isn't the end of the world but it'd probably be a good idea to have a valve core remover in your tool kit just in case to rectify the situation. The company that makes Dynabeads also sells "filtered" valve cores that eliminate the risk of this occurring.
4) Since they're little balls rolling around they will come to rest at the bottom of the tire at every stop and your wheel isn't actually balanced again until the wheel gets spun up but at lower speeds balancing isn't that critical and most tire wear occurs at higher speeds anyhow. It's only 1 ounce in the front and 2 in the back and none of the reviews I read indicated they felt anything off at lower speeds.
5) If the air from a compressor has a high degree of humidity, these can supposedly bunch up. Not sure how much of an issue that really is though.
Airsoft 0.12 gram pellets: (most of the posts I read guys were using 1 ounce in the front and 2oz in the rear - similar to Dynabeads)
Pros:
1) Readily available and inexpensive. (I bought 1000 (about 4 ounces - there's 236/ounce) for $4.75 shipped on eBay.)
Cons:
1) Unlike Ride-On and Dynabeads which can be added by removing the valve core, these are larger so you need to install them prior to setting the bead.
Ride-On TPS:Pros:
1) Easy to install. You just remove the valve core and squirt it in.
2) Seals punctures up to 1/4" diameter. (Only in the middle third of the tire since it's a liquid.)
3) Fairly clean. It's a "green" liquid that washes out with water.
4) Not as "dynamic" as Dynabeads so doesn't collect at the bottom of the tire on every stop. (Though I'm not conivnced that's really an issue with Dynabeads for reasons already discussed.)
5) Since it's also a sealant it reduces the little bit of air you lose over time.
Cons:
1) The most expensive alternative.
2) If the bike sits for an extended period then you need to ride 3-5 miles to get it properly redistributed when the tire warms up. (You also need to do this when it's initially installed.)
ConclusionSince I generally ride my RS and LT on longer rides and had 3 flat tires on the LT last year, I plan to try Ride-On on those bikes. Since I use my K75 for running errands and around town stuff I plan to try some Airsoft pellets on that bike.
JMHO.
YMMV.
