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New Tires and Mounting

Started by Red Diamond, Thu 20, May 2010, 19:55:37

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Red Diamond

Today I mounted two new tires on the 2k Tourer, my first tire mounting. My question for those who do mount their own tires is this, I mounted the tires with the supposed light spot at the valve stem. Some has said that they find the heavy spot on the wheel and mount the light spot to that point. There are painted dots on the wheels of the Valkyrie, a white dot on the 99 and 2K, and a black dot on the anodized aluminum wheel that look like chrome wheels. Has anyone ever determine whether these dots are the heavy spots of the wheels?The chrome looking wheels I purchased from Pinwall with good E3's already mounted, so I haven't mounted the other set on the 99 Interstate. Would be good to know what those dots are for before I mount the other set. TIA

If you are riding  and it is a must that you keep your eyes on the road, you are riding too fast.

John U.

If you do your own mounting and balancing, the best way is to put the empty wheel on the balancer. The heavy spot is not always where you'd think it would be.
If you're using Avons there is no spot on the tire. I rotate the tire on the rim before I air it up to find the best balance. You will probably have to clamp the rim to do this, the tire resists rotating.

roboto65

What I always have done is line the dot up with the valve stem for some reason that is what I heard you are supposed to do never had one out of balance when i got done but I also run Dynabeads !!
Allen Rugg                                                       
VRCC #30806
1999 Illusion Blue Valkyrie Interstate
1978 Kawasaki KZ 650 project

DFragn

Quote from: roboto65 on Thu 20, May 2010, 23:38:51
What I always have done is line the dot up with the valve stem for some reason that is what I heard you are supposed to do never had one out of balance when i got done but I also run Dynabeads !!

My wheels heavy spots are about 8" - 10" from the stems.
Valve stems are only assumed to be the heavy spots. Perhaps on steel car rims, but rarely on aluminum cast wheels.

Knowing the true heavy spots makes weighted balancing easier.

roboto65

What makes balancing easy is ceramic beads   :cooldude:
Allen Rugg                                                       
VRCC #30806
1999 Illusion Blue Valkyrie Interstate
1978 Kawasaki KZ 650 project

lacon

99,
For what it's worth, the first time I changed my tires, I balanced the bare wheels with temporary weights, marked the inside, & noted the weight & location relative to the valve stem in my records.  The paint dots do indicate the heavy spots.  Not even close to the valve stems.  My rear is 42 grams out, which seems like a lot to me.  Front is not as bad with 14 grams.  It would be nice if I could easily permanently balance the bare rims in some way, as I think the weights go as much or more for the rim than the tires.   I've gone to Avon's now, so dosen't mean much anymore as they don't have dots.  
Maybe next time I'll have some patience & try to find the heavy spot on the tire & align it with the rim, but i doubt it.   In my thinking, I would have to seat the bead, tape the temporary rim balance weights in the proper place, then check the balance.  Mark the tire light spot, break the bead, & rotate the tire to line up the spots, re-seat, & final balance.

I just mounted a new Avon Cobra on the rear (replacing a Venom), I was suprised at how much easier the Cobra mounted that the Venoms of past.  Just a coinsidence? Or is the bead maybe a tad bigger?  

Red Diamond

#6
Quote from: lacon on Fri 21, May 2010, 06:15:24
99,
For what it's worth, the first time I changed my tires, I balanced the bare wheels with temporary weights, marked the inside, & noted the weight & location relative to the valve stem in my records.  The paint dots do indicate the heavy spots.  Not even close to the valve stems.  My rear is 42 grams out, which seems like a lot to me.  Front is not as bad with 14 grams.  It would be nice if I could easily permanently balance the bare rims in some way, as I think the weights go as much or more for the rim than the tires.   I've gone to Avon's now, so dosen't mean much anymore as they don't have dots.  
Maybe next time I'll have some patience & try to find the heavy spot on the tire & align it with the rim, but i doubt it.   In my thinking, I would have to seat the bead, tape the temporary rim balance weights in the proper place, then check the balance.  Mark the tire light spot, break the bead, & rotate the tire to line up the spots, re-seat, & final balance.

I just mounted a new Avon Cobra on the rear (replacing a Venom), I was suprised at how much easier the Cobra mounted that the Venoms of past.  Just a coinsidence? Or is the bead maybe a tad bigger?  
That's what I was thinking Lacon, if indeed the dot on the rims is the heavy spot, then why line up the light spot on the tire (in this case a Dunlop E3) with the valve stem. Why not line up the light spot with the dot. It just seems to make since to me if the heavy spot is already marked on the rim. I've found this spot marked on all my rims, it has to be there for some purpose. Maybe I'm wrong.
Incidently, the tires for my Interstate are Avon Cobras.

If you are riding  and it is a must that you keep your eyes on the road, you are riding too fast.

roboto65

Heres a copy and paste and the web page I got it from just a little searching

The dots actually serve a very important purpose in ensuring accurate installation. The red and yellow dots help installers find a tire's high spot, low spot and light point for consistent balancing.

According to Bridgestone, "The difference between the high and the low is called radial runout. Using sophisticated computer analysis, engineers have found that a graph of the force variations looks a bit like a wave, as does a graph of the runout variations.

By simplifying the graphs to what is called their "first harmonic," it's possible to find the place on the tire where, on average, the force variation is greatest. That's where the first harmonic curve hits its high point. And, it turns out that the first harmonic high point for the radial runout coincides pretty well with the first harmonic high point for radial force variation.

Now wheels, especially steel wheels, tend to have the same kind of high and low spots as tires. In fact, many steel wheels are marked with a dimple that indicates their low spot. So, if you could match the high point on the tire to the low point on the wheel, these forces would, to some extent at least, cancel each other, and you'd expect to get a smoother ride and maybe improved wear.

Some original equipment manufacturers are doing this kind of match mounting when they mount tires and wheels on new trucks. The tire is marked with a red dot at the high point, and this is matched with the low point dimple on steel wheels. On steel wheels without a low point dimple, and on aluminum wheels, the red dot is matched to the valve stem."

A yellow dot indicates the light balance point on the tire. In order to minimize the amount of weight needed to balance a tire and wheel assembly, match the light balance point to the wheels heavy balance point, which is normally located at the valve stem.

In a situation where a tire has both a red and yellow dot, the red dot takes precedence and should be mounted to the wheel low point dimple or valve stem.

http://www.tireteam.com/blog/?p=797
Allen Rugg                                                       
VRCC #30806
1999 Illusion Blue Valkyrie Interstate
1978 Kawasaki KZ 650 project