Nyah

First time building wheels myself. Size 406 rims F and R for a mini-velo. In research of building wheels, I've found some advise that says a spoke is at the correct tension when the plucked sound of it matches middle-C of the musical scale. My problem with that suggestion is that the length of the spoke will theoretically affect the pitch that it makes when plucked at the correct tension. A spoke on a 20" wheel should make a higher tone when plucked at the correct tension than that of a spoke on a correctly tensioned 700c wheel.
I'd appreciate advice, on this or anything else that can help me achieve the correct tension in absence of buying a tension meter.

Calsun

People have been building wheels for over 100 years without need for special devices. Difficult to overtighten a spoke with a small hand tool and a good idea to use a lubricant on the threads. Check out spokes on bikes at a local shop and squeeze adjoining spokes on the rim. You will get a feel for the amount of tension for the spokes of the wheel.

base2 

A tension meter can often be found at a local co-op/bike kitchen type of non-profit. Those types of places usually have some sort of DIY time. I'm sure if you walked in there with a pre-laced wheel & a need to use a truing stand, they'd be more than willing to let you give it a go.

That being said, a tension meter may be difficult to use on a wheel that small. Especially if you are doing 3x & the hub has a high/large flange. The adjoining spokes may simply get in the way. At some point, it may just be up to your best good-sense guess about what is right.

Aluminum rim extrusions are super consistant. A wheel that is axially true will be a good proxy for even-ness.

After that, the actual tension may be best guess "good enough" if the tension meter just won't fit. That's ok.

If you truly are getting zen with your wheel, you'll get a feel for which spokes are doing more than their fair share. Let that one spoke back a bit, then adjust the others accordingly.

Often times a high spot may be caused by a too tight spoke (low spot) near by. By loosening the low spot & retruing the radial run out with any other spokes than the too tight one, the high spot may settle down.

Likewise a high spot may be a spoke that isn't pulling it's weight. Give that one a quarter turn & adjust the radial back to true with the other spokes nearby. Just keep at it, it'll take time. I shoot for an axial deviation less than the thickness of a piece of paper. In reality, anything less than a half-millimeter axial/radial is probably "good enough." When you get that close, the deviation from "round" caused by a single spoke becomes pretty obvious.

The tension meter is only a tool. It's not going to tell you anything that axial run out isn't going to except for a feel good reassuring number. Should you use one? Absolutely. Is it absolutely necessary? The jury is still out on that. It is absolutely 100% possible, 100% likely even, to make a perfectly even tensioned wheel that is shaped like a Pringles potato chip crossed with an egg if the tension meter is improperly used or relied upon with out utilizing good sense about what is actually happening with the wheel.

If the nipple starts wanting to round out, stop. You will not be going any tighter today.

A dab of grease in each spoke hole and on the nipple flange is a good place to start.

Nyah

I'm reading very encouraging words from both of you. Thank you!


Will chain oil be fine for where the nipple meets the rim? The only advice I've read is to not use anything with sulfur in it, as that can degrade the metals (don't know if sulfur typically exists in chain oils). I have Muc-Off Wet and Pedros Dry chain oils.

I plan to use boiled linseed oil on the spoke threads.

base2 

Any local bike shop ought to have a product behind the counter somewhere called "spoke prep." To use it, dip in the thread end of about 2-4 spokes return them to the bunch tip side down & massage/rub the whole bunch together to spread the spoke prep to all the spokes in the bunch. Then let them dry.

I've never used linseed oil. But the bike shop that built all my wheels before I took the big leap used it exclusively. There has never been any issues I have been aware of with it.

Spoke prep acts like a lubricant at build time but is supposed to harden up a bit like a really light loctite type thread locker. A sympathetic shop mechanic may let you use it free of charge. Be sure to explain it is your first wheel build, bring in a plate of something from the local taco truck &/or a six-pack of something delicious, and a promise to bring the wheel back for his professional expertise if you encounter any problems. I can't imagine them turning you away in that scenario. In fact, they may even be enthusiastic & excited you've taken a huge step in being a "real" mechanic yourself. If they do give you any resistance, leave the 6-pack & the tacos for good will; Wheelbuilder has tiny jars good for about a million wheel builds for around $19.

Any basic marine grade axle/bearing grease applied to the spoke hole & nipple with a q-tip will stay put well. I like the red disc brake bearing variety for no reason in particular. I feel chain oil would be runny & do anything other than stay put where you need it, especially long in the future when/if a re-true becomes necessary.

A random tub of axle grease is very common in many peoples garages. You might ask a friend you know has ever worked on cars. He'll probably lend the tub for free if he has one just so that it gets used before it goes bad. Failing that, any autopart store will have a 1 pound tub for ~$10.

ThermionicScott 

Sounds like you've been spending too much time around car guys.

Yeah, in a transmission where brass synchros are meshing under high pressure, sulfur can be a concern, but I wouldn't give it a second thought here. The small amounts of oil used during wheelbuilding or truing don't hang around for long.

And I wouldn't put any stock in the musical notes of spokes. That middle-C only applies to a specific spoke gauge, length, and tension. That goes out the window right away if you change any of the variables. Plucking the spokes is useful, but only to gauge the relative tensions between two spokes. If you can hear that one spoke plays a lower note than another, you can tell it has less tension. Early in a wheel build, some spokes will have enough tension to play a tone while others still go "plunk" so it's a good time to even them out.

Geepig

How many spokes are you using? If you are using 36 and 3x then by the time you have built the wheel you will realize that some of what is applicable for larger wheels is irrelevant for 20" and smaller, as just getting the spokes in can be a challenge. Truing the wheel at the right kind of tension is what you need to focus on as smaller deviations in rim alignment are more important at such small sizes as the percentage effect of 1 mm out on a 700 wheel is much less than for a 20" wheel plus the spokes will be much stiffer on the small wheel and differences would be much more difficult to measure even if you could get the tool in.

After building my first 36 spoke 3x 20" wheel I realized just how easy large wheels are

base2 

For 406/20's I've done 28 & 32's radial, 2x, & 3 cross. I concur with your experience. Even the spoke wrench itself sometimes doesn't want to fit.

One such example of my handi-work:
20210821_090900 by Richard Mozzarella, on Flickr
It looks pretty, but I confess I screwed up with an amateur mistake. The front is half-radial, 2x which I am proud of, but the rear is 2x. It will be rebuilt shortly with the proper 3x pattern when I find some 181/182mm spokes. I'm not exactly looking forward to it.

Dan Burkhart 

Woah, put down that spoke wrench! 2 X is correct for that build. I would NOT do 3 X on that small rim.

pdlamb

Boiled linseed oil has worked well for me on NDS rear spoke threads. Everything else gets Phil's oil; the spokes get enough tension they won't unscrew, but if they need to be tweaked in a few years, the joint can still be moved. Of your two choices, I'd use the wet lube.

I'm guessing you've already located John Allen's page on spoke pitch (Check Spoke Tension by Ear (sheldonbrown.com))

veloz

Boiled linseed is fine. Common 3-in-one is fine. Many of us built wheels long before tensionometers existed. Compare to another 20” wheel if in question. Pitch is good for comparison.

mpetry912 

I'm in agreement, 2x is fine on that size rim. Use some oil on the threads, more important that you use it rather than which brand.

I use loctite PST as my "spoke prep". use your plinking skills to determine when you've arrived at proper spoke tension.

/markp

Andrew R Stewart 

I first came across John Allen's article on spoke tension and pluck tone in the late 1970s when Bike World was still being published. I never tried to match a pluck tone with a specific tension but as an indicator of general tension and spoke to spoke tension consistency.

I will say that 36 spokes in a 20" wheel is a lot of spokes and potential spoke tension stress. I might consider using thinner spokes then usual. Andy

Nyah

I think that I'll be OK with 36 spokes, as that is actually very common on 20" wheels. For another bicycle, I have a 36 spoke, 20" rear wheel built by Bill Mould. He and I decided that 2x was the best, in order to minimize the angles on the nipples. I let him make the decision for spokes and he chose Sapim Race double-butted (14/15/14). So I'm building this pair to those exact specs. Later on, I might even build an additional rear wheel, with Sapim Strong single-butted (13/14), that I'll use for loaded touring.


I have everything that I think I'll need. Boiled linseed oil is known to work similarly to spoke-prep (solidifies after a couple days). Another choice I have in my stock, for where the nipple meets the rim, is Phil's grease.


Thank you, all, for your input on this. I'll probably have time tomorrow to at least do the lacing, maybe even finish a whole wheel.

canopus 

HEHE... If your old you might remember Z-rims... I had a coaster brake setup with .105 guage spokes and I had drilled out the rim for the nipples... I used washers on them of course and I tightened them up to my "usual" back then.. they were gorgeous. I went to put the tire on the rim and it would not seat due to the rim shrinking from the tension. I had the same problem in the front with 14 guage spokes but not as bad. After that I went to aluminum rims on my 20".