Tire balance

Long ago I was told that tire manufacturers would weight one side of a tire so that it would balance the extra weight of the tube's filler. That you could tell where the extra weight is because it would be opposite the sidewall label. But I always marked this down as an old wive's tale because it never balanced my wheels.

Yesterday I installed a new compact crank and in testing it, the rear wheel was exceptionally out of balance on the workstand. A thought occurred to me. I stripped the tire off and placed the sidewall label opposite the filler - magic - it spun smoothly.

This seems a little silly to me since it is a whole lot easier to line the label up with the filler, but what is, is.

 

Several manufacturers offer balanced rims and Silca offers aero valve stem covers and a counterweight to be placed opposite the aero covers.

Every race team on the planet and every racer from lowly CAT 5's to TDF winners will tell you to locate the tire's label with the valve stem.

I'm not saying what you did wasn't 'real', but I have never heard of tire manufacturers selling a tire to offset stem weight. Will stay tuned to the opinions to follow.

 

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Balancing my wheel made a detectable difference in the ride.

Check this out:

View: https://www.youtube.com/watch?v=dcgiUcbS64c

 

Prior to this post, the only reasons I'd heard for putting the valve stem at the label were that it makes it easier to find the valve stem and it "looks pro". While I'm not disputing your claim that moving the label changed the balance of your tire, I suggest that it's a coincidence. If a tire manufacturer actually did weight a tire opposite the label, they would certainly make that well known so people wouldn't accidentally put the weighted side at the valve stem and make any imbalance worse. Also, with as weight conscious as cyclist are, I just don't see tire companies adding weight to their products.

That said, I've found that balancing wheels can make a big difference in how the feel at high speeds. This was particularly pronounced with tubulars, which are often much heavier at the valve.

 

I suspect you're right and it was only a coincidence. The front wheel wasn't balanced correctly either but I balanced that with the speedo magnetic placed opposite the valve.

 

cyclintom, thanks for the great video. It describes what I've been doing for the last 10 years or more. When I've talked about this problem in the past, I've mostly been ignored here. Forum members have said things like "doesn't matter as bikes don't go fast enough", or they don't have springs like cars so balance isn't important.

Maybe the video will convince a few people to check their wheels. At least I don't feel totally alone in the woods now!

Note, I also think it's outrageous that expensive wheels aren't balanced at the factory. My DT RR1450 wheels were well-balanced (before wheels and tires), but the other wheels I have were not. In particular, the cheaper rims with heavy plug joints opposite the valve stem hole have been significantly out, requiring lots of extra weight around the valve stem.

 

Didn't the valve counter-balance the (hollow aluminum) plug?

I descend regularly at 40 to 55 MPH on sew-ups and clinchers. Never felt an out-of-balance wheel-tire-tube condition.

 

No, the Circuit rims took a good bit of soldier wire on either side of the valve to bring into balance. The plug was pretty heavy on those wheels. The DT RR1450 and Mavic Kysrium Elite wheels I use now have welded rims, and the balance is much better on those. Seems just a small amount of weight is needed to correct for the tire imbalance after mounting.
Last year I recall checking the balance on three of my regular buddies bikes. I had them hold the rear wheel off the ground while I cranked the wheel up by hand in a big gear. None of those three had much vibration, so they pretty much thought I was making it all up. You can easily repeat the test, same thing the guy was doing in the video.

I did intentionally unbalance a front wheel last year by moving the magnet 180*. The imbalance produced was noticeable with the bike on the stand, but not huge as I left the other soldier wraps alone. Then coasted down my home hill at 38-40 mph . Thought I could detect a rougher ride, but it wasn't that big an effect. Will readily admit this wasn't a scientific test.

 

After looking at a video somewhere they were talking about how the rolling resistance of a wider tire running a lower pressure was less than a 23 mm at 120 psi. So I've ordered a set of 28's. Since I'm running Campy CX wheels I won't have any problems with the tires fitting the rims. The only problems I foresee is fitting a 28 through the road brakes. But I'm running Campy skeleton brakes on the Pinarello and they seem to have a lot of clearance. So I'll keep the group appraised of what's going on.

 

What I find odd is that this was never a serious problem with older road rims and tires now suddenly this issue has popped up, I think it may be due to the newer deep dish rims having a lot more material there is potential for the rim not to be perfectly balanced. You will find that the heavier the wheel/tire combination of a car/truck, plus all the suspension components, plus the mass of the vehicle, the more weight is usually used to balance the wheels, but most of that weight added is due to imperfectly made tires as they all are, but the larger the tire the more any imperfection is exaggerated.

The only time I ever had an issue is when I located my computer magnet on the same area that the valve stem was, so I relocated it and problem gone. Back in the days before deep dish rims any unbalanced situation, if any, was minor, and we found that by moving the tire 1/4 a turn at a time on the rim would eventually balance the rim, or narrow it down so the next time you move it you may only have to move it an 1/8th of a turn, so this could be utilized today.

Watch this video and I will point out something:

View: https://www.youtube.com/watch?v=dcgiUcbS64c
Note as he's goofing around trying to balance this wheel where the tire's label is...yup, it's directly opposite of the valve stem, if he had moved the tire instead his balance issue may had resolved itself.

Here's another balance video:

View: https://www.youtube.com/watch?v=YhaUfda6aSY
In this video note where his computer magnet is...it's located about a 1/4 of turn from the valve stem, next note where he puts that clunky counter weight...yup directly opposite of the valve stem right where he should have first located the computer mag! Also in this video I cannot tell where the label of the tire is so I can't comment on that, but once he had moved the computer mag to the correct position and checked the balance he then should have tried to move the tire on the rim to see if that would have taken out any other balance issues.

The other issue with these balancing videos is that we don't ride our bikes upside down! So a lot of this is simply do nothing mumbo jumbo, unless you can feel it while riding it's not a concern. Read this article for indepth detail about balancing: http://yarchive.net/bike/wheel_balancing.html

 

Thread drift: The best reason imho for putting the valve stem at the label is for when you get a flat: Once you've found the hole in the tube you now know exactly where to look on the tire for that piece of glass, metal, etc. E.g., if the hole in the tube is at the 3 o'clock position relative to the valve, you know the puncture occurred at the 3 o'clock position relative to the label and can examine the tire at that spot.

(Obviously this requires that you make these determinations before completely removing the tube from the tire. And it only applies to clinchers.)

 

Interesting. I need to balance my wheels. I remember when I got them and notice this. I took the wheels back to the the bike shop thinking they were out of true, but it was balancing all the time. I knew I wasn't crazy. Does anyone know of counterweights that go on the spokes. I know you can maybe use a magnet, but I was thinking of something other than those.

Thanks...

 

did you read my previous post? if not please do,

If the wheels are that far out of balance that a simple change as I mentioned fails to work then there are only two reasong for such a large imbalance...rims were not made correctly, or the tires were not made correctly, if you never had that issue before with the same rims and put on new tires and wham your rims are now out of balance and you tried the suggestions I mentioned earlier then the tires are of poor quality. If you have used these tires before and got new rims and you tried all my suggestions, then the rims was not made properly. With the advent of deep dish rims people are running into more issues with imbalance especially lower priced rims, but even my low price semi deep rims (Shimano RS500) I have no issues with imbalance, but those are only 35mm the imbalance possibility increases as they get deeper, but even a well made rim should not have that happening, so if your are high quality then I would take them back to where you bought them and explain your situation.

 

Froze, I took the wheels back to the store and they took care of them. I purchase these wheels (Profile Design Altair 52) and tires (Continental Grand Prix 400) at the same time around 2013. The Profile Design are probably not the high end wheels (don't really know), but were about 40%-50% off when I purchased them and better than the wheels I had, while the Zipps were at around $2k. I was just getting back into biking and did not want to spend $2k for wheels at the time.

 

Froze, not sure how you define "large-enough" imbalance. I'm sure you know that no wheel is perfectly balanced and round, nor is any bike tire. So it's just a question of degree of out-of-balance or runout that is acceptable (or noticed). Some of us are more critical than others, or maybe just like to have the smoothest ride and road grip possible. Why assume my wheel/tire is "good enough" when it's so easy to check and correct at home? If I can see the vertical shaking when running up the rear wheel to 30 mph on the stand, that's not a wheel I want to take down 40-50 mph descents.

Many popular-priced rims are made with plug joints. My old Velomax Circuits, which were excellent in terms of build quality and durability were in this category. The aluminum plugs certainly caused a heavy spot at the joint (opposite the valve stem hole). After the rear finally failed at 30K miles (with no truing needed ever) I sectioned the rim to see the plug. It was thick-walled and about two inches long; no wonder it gave the rim considerable imbalance.

Of course, when you buy new tires for your car they are always balanced after mounting. Some new car tires come marked for both the heavy spot and the high spot with red/yellow dots on the sidewalls to allow for indexing on the best place on the rims. This doesn't mean the tires are poor quality, just acknowledges the fact that a perfectly round and balanced tire or rim cannot be made, or at least not mass produced at a competitive price.

 

People are getting fanatical about nothing for the most part. To repeat myself from my earlier post: The other issue with these balancing videos is that we don't ride our bikes upside down! So a lot of this is simply do nothing mumbo jumbo, unless you can feel it while riding it's not a concern. Read this article for indepth detail about balancing: http://yarchive.net/bike/wheel_balancing.html Please read that website, this will explain what I'm trying to convey to you and others here.

 

OK, that article certainly clears everything up. We don't ride bikes upside down, and our tires are a lot harder than car tires due to the inflation. Got it!