Tightening Loose Spokes

[ekim]

New bike/rims. About 65 miles ridden so far. I notice the rear wheel was out of true and tightened a few spokes by hand and then added 1/2 turn to put some tension on them.

I can't tighten by sound, but I was able to set up my phone as a sound meter. I was able to go through and get the spokes close by setting the chain side to 440Hz and the opposite side to 360 Hz +/- ~15 Hz. I picked these values simply because that seemed to be the average for each side...

Even with this approach, I don't have a warm fuzzy feeling about everything being even. Would investing in something like the Park TM-1 tool allow me to get things dialed in well?

I'm not looking to use the tool to true the wheel, just to make sure all the spokes are sharing the load evenly. On my last bike, once I started breaking spokes, it seemed like I was replacing them way too often. I'm guessing this was because, although I got the wheel trued I probably didn't have the spokes balanced....

 

[Kaleidopete]

I have that tool and it works great. I too just used it to get my tension right and not to build or true the wheel.
Too bad I'm so far away (by Warwick, NY), you could use mine.

 

[1speed]

If you are going to work on your own bikes, then get the tool. I always go by the mantra "have all the tools". Even if I only use something one time, I'd rather have it.

As for spokes specifically, if you are over- or under-tightening spokes, you would probably be noticing that even before they break - you'd feel it in your balance on the bike. I've built wheels where I screwed up the dish because my truing stand was one of those recreational user ones that only had the dish caliper on one side, so I had to turn the wheel over to check that. It was a PIA and I always thought that after a few tries, I had it "good enough" but that was rarely the case. I'd recommend a pro stand that actually measure it exactly. Tightening to sound is okay as a secondary check, but I'd always use the full truing stand. In the end, this stuff does cost extra money, but take a long view of it: it's still way cheaper than buying new wheels because you made a mistake on less exact measurement and killed them before their time.

 

[mstyer]

Or you could pay your LBS a few bucks to use the tools and knowledge they already have to do it right.

 

[Magic]

Too bad I'm so far away (by Warwick, NY), you could use mine.

Hey neighbor. I thought you were out on Long Island or something. I'm in Monroe.

 

[Kaleidopete]

Hey neighbor. I thought you were out on Long Island or something. I'm in Monroe.

Hey neighbor, I'm about a mile from Wawayanda park and 6 miles from the Warwick drive in.

 

[ekim]

Or you could pay your LBS a few bucks to use the tools and knowledge they already have to do it right.

I prefer to work on my own stuff where possible. I'll usually try to buy parts and tools from my LBS. For example I can probably save $10 on this tool by buying online. If the LBS has it in stock then I'll probably buy it on my way home tonight.

 

[Karate Monkey]

I saw this post this morning, but didn't comment...you can check tension by ear, for sure, but that assumes your ear is fine enough to pick out the fundamental tone, and ignore all the other garbage in the short amount of time the spoke is speaking. It's a neat trick to be sure, and one that even $3-400 tuners have issues with, due to lack of sustain. If you are comfortable doing it, it works just as well as the tensiometer. HOWEVER, people don't expect mumbo-jumbo when you are working professionally, they expect you to use measuring tools. The Park tool is good for taking an average reading, but it isn't an absolute value--that requires two things: a calibrated tool, and the things that it is calibrated to. DT can say that their tool is accurate, since they have tested it on their spokes; I doubt you want to spend $500 on their tool, to be accurate only with their spokes, though (to be fair: their tool is overkill. The Park tool is accurate enough for all but the loonies).

As an aside here (from someone who tunes pianos for $$$), both methods are valid. One uses Hertz as a basis for measurement vis-a-vis pitch--and most spokes of decent quality (Sapim, DT, Wheelsmith) of the same main gauge are within a Hz (less than a semi-tone/half-step) at the same tension--the other method uses deflection, as above.

See this article. It leaves a bit to the imagination, but otherwise has the basis of checking tension by pitch. The downside? Just as with a tensiometer, the readings change depending on the gauge of the spoke, whether it's butted or not, and what material it's made of. They assume 2.0 or 1.8mm round steel spokes.

All that said, even if the tension is perfectly equal, the rim is almost never going to be perfectly true as well. Use the tensiometer/your ear as a jumping off point to true the wheel, and as an ersatz way of telling that your rim is done and needs to be replaced (too much/little tension on any given spoke with a true wheel).

 

[greeek32]

i have literally never checked the tension of my spokes to this level of precision and i never break spokes. it all seems a bit like overkill. the only time i ever broke spokes was on a wheel where i used cheap spokes to build it (having a wheel built improperly can lead to this too). I kinda feel like for this level to be warranted you need to be really heavy, really strong, or really serious; of which i am none of but i'm certainly not nice to my bikes.

I stick the wheel in a truing stand and spin it with a pen bumping against the spokes, this tells me if i have a dead spoke that is way loose; I also like the sound it makes. From there i true the wheel as normal (make sure you know how or you can ovalize the wheel) and pay special attention to the area with the dead sounding spoke as there is probably some sort of damage to the wheel there. before removing it from the stand i make sure all of the spokes are tight, the wheel is true and round, and squeeze the spokes all a couple of times in case they are twisted a bit and need to "pop."

when it comes to working on my bike, i do most of my own maintenance as i worked in a shop back in my 20's and basically know what i'm doing. that being said, Phil and Mike at Town Cycle work on a lot more bikes than me on a daily basis so they are much more well-practiced and therefore do a better job on the tough stuff (I thought that i did a good suspension service until i paid them to do it. the difference is night and day). like with most things, sometimes it's better to let the guys who do it all day every day take care of it.

 

[ekim]

Here are some measurements with the Park tool. I may be up to about 90 miles now.

This is the REAR wheel and each ring represents 25 KGF. I think that all the spokes need to be tightened up. There's no way that this came from the factory sufficiently tight. It's not the tool, since the front measures way tighter - maybe too tight....

I assume that if I bring them all up by the same percentage (but in small steps , going around the then rim multiple times) that I should be able to avoid screwing up the dish. I'll measure the rim/frame distance in multiple spots on both sides before starting and as I go to ensure the pooch isn't getting screwed. It seems like I should be shooting for something closer to 100 (the very outside ring in the chart below) or more.

The average for the left side is 40kgf and the right is 59 kgf. This seems way too low to me. It also explains why things seemed to go out of true so fast and the need to tighten some up on the trail - by hand at first....

This is the FRONT tire. The scale on this is different than the rear. It's 100 kgf per ring. The average for the left is 149KGF and the right is 101KGF. I thing that some of those peaks at near 300 may be a little much.

I know that some are saying to take it to the LBS. I **will** end up taking it to a shop for a 200 mile tune up - in another 100 miles or so.... And I DID buy the tool from a LBS for more than the mail order price, even though it was not in stock.

I'd still prefer to be as self sufficient as possible and am willing to buy the tools and take the time to do it right.

 

[Karate Monkey]

@ekim disc brake wheels, I hope...

100-120ish Kgf on the highest tension side (left front, right rear) is what I usually shoot for, outside of recommendations from the manufacturer of the rim.

*edit* I'm sure you've figured this out, but make sure that you nestle the spoke all the way up to the posts on the tool, and that you apply the correct Kgf conversion based on the type of spoke. If you get a weird reading, take it again.

 

[ekim]

Thanks for the feedback. Wheels are 29" WTB SX19 with disc brakes.

Here's how I'm taking readings:

1) center the tool between the nipple and the first cross
2) squeeze handle, set spoke against two posts
3) gently/slowly release handle
4) measure

As far as I can tell the spokes are steel/1.8 mm and that's what I'm using for the conversion with the tool.

 

[Karate Monkey]

Did they not include a gap gauge with the tool, attached to the card?

Run your fingers from just above the spoke nipple up the spoke, and from the final crossing towards the hub. If you feel an increase in diameter, they are likely butted (2.0/1.8/2.0) and you are right to use the 1.8 reading. Otherwise, I would assume that they are straight gauge 2.0mm spokes. Straight 1.8mm spokes are uncommon, except on road bikes in the past, or a boutique wheelbuild.

 

[jdog]

I have to chime in here.

First off, you must get the roundness, dish and true pretty close before you even consider touching a tension gauge.

All this is worthless if you are working with a wheel that has even a slight bend in the rim. You simply can not get even tension with any kind of bend in the wheel.

As a rule, you won't see a perfectly round, true and evenly tensioned wheel unless you start with a high quality, straight rim.

Wheel building is tough to grasp for those with the right tools in hand.

It is sometimes made a lot harder when you see inconstant tolerances in rims on oem wheels at even thousands of dollars.

Best of luck.

 

[Karate Monkey]

Jdog does make a good point...you are fighting an unknown having not seen the rim in an unbuilt state. Tensiometers are really good when building a new wheel. They are less good when you don't know the state of your parts, and they are not for absolute measurement, but intended to be used as an average reading.

FWIW, a perfect rim/hub would have perfect tension readings--but perfect doesn't exist in this world. The graph is a dangerous thing, because while perfection is a nice goal, you might not be able to reach it with what you have.

 

[ekim]

Did they not include a gap gauge with the tool, attached to the card?

Yes I used the gap tool and got 1.8. I only measured in the middle. You are correct - at the nipple it's 2.0.



First I trued the rim using two pencils secured to the to swing arms. One on each side. This ensured that I didn't **change** the dish. If it was already screwed up then it was that way from the factory. Then I adjusted every 4th spoke 1/4 turn to tighten things. So, 4 passes around the wheel to tighten things up. I also use the pencils to ensure that I didn't make a flat spot in the rim by pointing them at the edge and ensuring there was no bounce. After each 1/4 turn tightening pass I re-trued the rim and then use the gauge to see if I was in a good area as far a tension. All the spokes are still really easy to turn.

I disagree that the tool can only be used for relative measurements. I already proved above that the rear wheel was way too loose and verified that against the front wheel.

So after messing with it for a while here's where I'm at. Now the scale is 50KGF per ring. The average for the left is 65kgf and the right is 108kgf. The factory build was 40kgf on left and 59 kgf on right. I don't know if I'm going to be able to get all the spokes within 20% of each other. I'm sure that the wheel is better now than it was when it left the factory.

Is there a strategy for addressing the one super loose left spoke? Since BOTH the left and the right are a little loose it seems like I should be able to tighten both of them - I just need to watch for creating a flat spot in the rim - and back off it seems as if that's occurring..

OR maybe loosen the two to either side of the loose one - then tighten that some and re-true?

Here's the new chart:

 

[jdog]

This whole thing seems crazy but I will bite

First, is the tire off the rim?? If not, the values will be off as they change wildly when you inflate the tire. Keep in that all the charts are assuming you have not installed a tire.

Second, roundness is SO much more important than trueness.

Third, if it isn't dished right this all is pointless.

 

[ekim]

OK, with a few minor tweaks I got everything to within 20 percent. The new averages are 65 on the left and 110 on the right. I think there's still some room for improvement, but I may put a few trail miles on it to see if things change much after 20 or 30 miles. The rim runout is .015 inches. I'm not sure what a good value to shoot for is on that.

Here's the updated chart:

 

[ekim]

First, is the tire off the rim??

No, but the air is out.

Second, roundness is SO much more important than trueness.

I have to remove the tire to measure roundness. If I use the pencil strapped to the frame I can't see any visible out of round. I also can't see any "bump" when spinning the wheel.

Third, if it isn't dished right this all is pointless.

That measurement may have to wait for a pro. The wheel appears to be evenly spaced in the frame. There's not really a good point to measure from between the frame and the rim. From what measuring I can do the measurement between the frame and rim seems to be within few millimeters, with the margin for error being a few millimeters.

Even if the dish is off a little isn't it better to run a wheel that is round and true with properly tightened spokes vs everything so loose that some nipples can be turned by hand?