Bicycle Mechanics - Checking Spoke Tension on a working rim

Hi All,

I am putting the finishing touches on my touring bike (bike camper) and I'm going to get the wheels on the truing stand and do them up...I've done this before and have built wheels etc.. but this is my first touring bike and I will be loaded, so I want to make sure that the wheel's won't break and leave me stranded (particularly the rear wheel). My rims are old Aluminum Araya 27" rims 36 spokes 3 cross. They are pretty true right now (a few adjustments needed of course). If this was a town-ie bike I wouldn't even bother taking the wheels off and checking them, but like I said I don't want to be stranded. So, what are the signs that I need to fix the tension of my spokes? I know there's a tensionometer (can't afford) and there is a musical thing (tone deaf)..So when I grab a spoke how can I tell if it is too loose?

Any advice is appreciated.

Brian

Hi All,

.... what are the signs that I need to fix the tension of my spokes? I know there's a tensionometer (can't afford) and there is a musical thing (tone deaf)..So when I grab a spoke how can I tell if it is too loose? If you haven't got the experience, haven't got the ear and can't afford the tensiometer - then I'd say you're all out of luck.

I guess that if you're really stubborn you could bodge up some sort of rig that'd allow you to hang 100-something kilos from a spoke to allow you some sort of vague comparison.

If it's (understandably) that important take it to your LBS. Explain your needs and that you want them to true and properly tension the wheel. Would be best if they do have a tensionometer of course. Other than that it's not possible to convey how much tension is right.

Are you truly that tone deaf that you can't hear the difference between a dull low tone and a more musical mid range tone? You don't need to be able to tell the difference between a middle C and a C# but most of us that can at least enjoy music can hear a difference of an octave. And that's the sort of difference you're looking for. And once you have the spokes set properly to that sort of tone by a shop that knows their stuff you can tap the spokes with a plastic screwdriver handle and get a feel for the tone. Also while you're at it squeeze the spokes together and get a feel for now much they deflect and how spongy or tight they feel. Between the tone and the "elasticity" of the feel of the spokes you should be good if you can remember what they should be like. Obviously to get the spokes set in the first place you'll need to take at least one wheel in and have it tuned up. Then either get the second one done at the same time or use the tone and feel of the one freshly tuned wheel as a guide to tune and true the second wheel.

If you truly can't hear the tones and you don't trust yourself to evaluate and remember the tension from the springiness of the tuned spokes then there's really no alternative. You'll just need to suck it up and take your wheels in from time to time to have them tuned by a good shop. Or else bite the bullet and fork out for a tensionometer. And if you won't be doing such things resonably often it's unlikely that your memory will recall the right feel or the right tone. So again you're stuck with the tensionometer or paying a shop to re-tune your wheels once every few thousand miles.

So what are the signs that you guys notice that makes you check the tension o the wheel. I just don't get these responses. People assume too much about other people's abilities on this blog. I just want to know what makes you go to the tension-O-meter in the first place? There are objective signs that a wheel is too loose? aren't there? I feel like some of you may pay the LBS too much money a year for labor!

That's the thing. Until the spoke acually makes rattling sounds you CANNOT TELL directly. You MUST HAVE a known good wheel with the spokes tightened and trued properly as something to compare your other wheel(s) to.

Long before spokes get too loose the rim will begin to run out of alignment with side to side wobbles that make the rim begin to scuff the pads. But even then this is just the beginning of it. A rim can run out (wobble) enough to scuff both brake pads at different points in one rotation without the spokes being below the recomended range of tension. But equally true is that a wheel can show little or no runout but the spokes are ALL well below the minimum tension needed for a long life under heavier loads.

So until you have a properly tuned wheel to compare it to and assuming you can remember the feel of the tuned spokes and the musical note they make when tapped there is no way to directly tell if your spokes are out of the proper tension range. Even if you figure out some sort of home made tensionometer substitute to remove the guesswork you STILL NEED A KNOWN GOOD WHEEL to calibrate your home made tensionometer.

In other words as the old saying goes "you can't get there from here pardner".

So what are the signs that you guys notice that makes you check the tension o the wheel. I just don't get these responses. People assume too much about other people's abilities on this blog. I just want to know what makes you go to the tension-O-meter in the first place? There are objective signs that a wheel is too loose? aren't there? I feel like some of you may pay the LBS too much money a year for labor!

You can't see, smell or taste tension. You can measure it with a gauge, of by feel with your hand if you have a basis of comparison, or by sound, again if you have a basis of comparison. Without some way of measuring, there are no obvious of a slack wheel until it's so slack as to be hopeless.

As you said in the OP, if this were a townie it wouldn't matter, but since you're planning a long tour, you should assign some value to peace of mind, or reduced risk of failure and stranding and let a pro take a quick look. Or you might go to where a bunch of bikes are locked (you're in Madison, so there's plenty) and compare the tension of your spokes to those on other wheels. You don't have to match it exactly, just get into the same range.

If I had the wheel in my hands I could make a judgment call in a few seconds, but there's no way to do this over the net, nor can I convey what something feels like, nor can I have any idea of your skill or income level, so my advice is decide for yourself whether to go ahead as is and risk it, or spend a few bucks to reduce (not eliminate) the risk. Beyond that, I've no idea what you expect from us.

Checking spoke tension is not "black magic". There are several good techniques that do not require a doctorate degree in mechanical engineering.

Start at the rear wheel, drive side, where the two spokes intersect. Support one of the spoke with your thumb, and the other spoke with your index and middle fingers. Now use your thumb, index, and middle fingers to spread apart the two spokes so that they no longer make contact. If these two spokes are adequately tensioned, then you will need to exert a good amount of force to spread the two spokes. Repeat with the other spokes on the drive side of the rear wheel.

If you come across a pair with low tension, then tighten all the spokes on the drive side by 1/4 turn, check dishing, and re-true wheel if needed. Repeat this until the low tension region go away. Apply a drop of oil to the thread and base of nipple to reduce friction. Stop tightening if you feel that the spoke wrench is about to round off the nipple.

Do the same for the front wheel, except that you want to tighten all spokes by 1/4 turn, then check for proper dishing.

Hmmm, the OP first said he's tone deaf, can't afford a tensionometer, and doesn't have experience. Then he said he thinks bike shops charge too much to do it for folks who lack all three. And he's going on a bicycle tour to the back of beyond loaded with camping gear??? Something's gotta give here. He needs to sit down with a knowledgeable friend who can show him hands-on, in person, no charge, how the tension of a properly built wheel feels. Furballi and BCRider have given about the next best thing, OP. Go to it and practise.

Furballi, that's all fine and good. But without a known properley tensioned pair of spokes to go by for comparison he's got nothing to base the results of his testing on. If he just goes by the tightest pair on the wheel they could still all end up too loose, just right or too tight. There's just no way to know or determine if any given pair is good without either a tensionometer or a skilled wheel builder to show him what's what.

Conspiratemus got it right when he wrote that "something's gotta give here". In some way, shape or form the OP is going to have to pay the piper at least this one last time as the cost of learning the skill and gaining the experience to be able to do the work himself in the future.

http://www.parktool.com/images/products/productimages/det_TM-1_2005726_46736.jpg

End thread.

for me, when I squeeze 4 spokes white knuckle hard, but not as hard as I can they deflect less than 1/4in. These spokes are something around 110kgf.

PS. This is why the imperial system was dropped, because one foot isn't one foot.

^ Nice benchmark, really. I think any attempt to quantify what "by feel" is, is a good thing. Without claiming it makes a tensionometer an unnecessary extravagance, I propose a new measurement system: 1 AEO unit is the spoke tension that gives the deflection as defined above.

But not all of us go "white knuckle" with the same hand pressure..... So again this is only as good as the old cubit unit where the length depended on the forearm of the guy doing the measurement..... :D

If Drwecki was a sneaky sort he could squeeze and tap some spokes in a bike shop to get a feel for the give and tone of the wheels there. But again this pre-supposes that the bike(s) that he checks out are set within the correct range of tension.

But knowing something is a cubit long, while not as good as knowing it's 45 cm long (my cubit), is better than knowing only that it's "umm, sort of that long...you just have to know from experience." It's a start in communicating a standard.

(Yes, I know, Operator will be saying, "Get a tensionometer, fer chrissakes." And he's right. Even though I don't have one.)

... If these two spokes are adequately tensioned, then you will need to exert a good amount of force to spread the two spokes. ....

This would work fine if we all had calibrated fingers.... But I can tell you straight off that between a manual laborer, someone like a guitar player and your average office rat, the concept of "good amount of force" will vary far too much for this to serve as a valid comparison.

http://aebike.com/product/park-tm-1-tension-meter-for-checking-tension-on-spokes-sku-tl7426-qc30.htm

The only other way is to tension and stress relieve until the wheel goes out of true and then backing off the tension and retruing. This is not a good method on a used wheel.

+1 to Furballi, for keeping it simple. It's a bit curious to me how the early track bikes kept true wheels without a Tensionmeter. I suspect learning the sound and feel of proper tension is enough for all but the lightest most technical set ups. Just an opionion.

+1 to Furballi, for keeping it simple. .. Simple is easy, once you have the experience. But if you haven't got the experience, then you need something else to act as a comparison. Besides, what do you know about the upkeep of old track bikes? Track hubs also tend to be zero dish, making them less critical to begin with.

So what are the signs that you guys notice that makes you check the tension o the wheel. I just don't get these responses. People assume too much about other people's abilities on this blog. I just want to know what makes you go to the tension-O-meter in the first place? There are objective signs that a wheel is too loose? aren't there? I feel like some of you may pay the LBS too much money a year for labor!

Someone who doesn't have a fair amount of experience and knowledge isn't going to HAVE a ready-made answer handed to them. That knowledge comes from experience.

People assume a certain amount of knowledge based on what a person is doing or trying to do; someone who's lacing up and truing wheels has the experience to AT LEAST have been exposed to the ideas of the tensiometer, or the 'musical' plucking of the spokes.

Objective signs of LOOSE SPOKES (not a loose wheel, different problem) are having to re-true a wheel frequently, snapping/popping noises coming from the wheel as it rolls, things like that.

Personally, I have yet to pay the LBS a dime for labor; but I would not hesitate to do so if there was a concern I wasn't capable of handling, or had doubts about. You express your significant concern about not being stranded due to broken spokes or a collapsed wheel, yet you want to complain about people who suggest you take it to the experts?

You do what you can; if that leaves you short of where you want/need to be, you "call the guy". In the meantime, if you want more expertise, you go about getting it yourself, and that usually means trial and error. I got where I am with bike mechanics by T & E, with a certified mechanic looking over my shoulder; now, though not certified, I'm a shade better than he is!

Besides, what do you know about the upkeep of old track bikes?


Wow, what the f*@#* was that for? I said I found a pair of old true rims, I infered that racers and for that matter all cyclists kept their rims true long before Tensionmeters for bicycles existed. Relax, if you own a meter, that's OK, use it, enjoy it, it's great!

See ya, I'm goin' for a ride.

Wow, what the f*@#* was that for? . .

Sorry, I didn't mean to offend you.

. ..I infered that racers and for that matter all cyclists kept their rims true long before Tensionmeters for bicycles existed. .

Sure they did.
The point I was trying to make was that you don't know how much trial and error the people maintaining those bikes had to go through before the got enough experience to get it "right".

Sorry for flying off, misunderstood! Your right experience is what will get Drwecki through his wheel build. I hope he has time to put alot of 20 & 30 mile rides in before he goes off on a tour.

FWIW Drwecki, as a former "self proclaimed tone deaf youth" I was taught that nobody is tone deaf, it is something that is learned through....you guessed it.. experience!

Have fun, tune your wheels, ride, break spokes and learn.....it's all great fun!

Thanks Furibal... I got it. Appreciate your helpful insights! And I also appreciate the white knuckle technique and the bike shop spy suggestion thanks... Will have freewheel remover and extra spokes on me so I also thank the guy with the break it and learn suggestions.. I will have a tent so if I do break down FTW I'm staying the night in my portable house!

Tap.Tap.......clunk,clunk or ding,ding ???? :) Too easy..

Brian, I just yesterday finished the same task you're on with similar 27" 36 spoke wheels. More or less the same method as what Furballi described. There were a couple of spokes that just werent as taught as the others, but not making noise when ridden. As most of the spokes were fine it was noticeable when the loose ones were checked.

Brad

PS. This is why the imperial system was dropped, because one foot isn't one foot.

??

^ Measure your bare foot. How long is it? That's what I think the previous poster was getting at.

But your ?? is fair. In countries that still use the imperial system, a foot is always a foot, defined legally by national bureaus of weights and measures regardless of how long the current king's foot is. So that's not why the imperial system was replaced by the metric system. In Canada, it was a top-down, federal-government-driven decision -- the kind your Second Amendment was written to thwart ;) -- to conform with our major trading partners. (A Japanese power plant buying a "ton" of Alberta coal expects to get 1000 kg, not 908 kg which is what an imperial ton equates to.) At the time we did this (in the 1970s) we thought that our most major trading partner, the U.S.A., was going down the same path but your effort fizzled, leaving Canada (as usual) with one foot in America and the other in the rest of the world.

The best reason for "going metric" was that primary-school math teachers no longer could pretend it was educationally useful to assign homework problems like finding the number of inches in 13 2/3 furlongs. But I miss the sound, the Anglo-Saxon bluntness, of the old one- or two- syllable units resonating with historical tradition back to the Domesday book: ounce, inch, pound, mile, pint, rod, acre, fathom, gallon..... Only the English-speaking countries used them because only to English ears do they sound right.

this is what I mean:
http://en.wikipedia.org/wiki/Comparison_of_the_imperial_and_US_customary_measurement_systems