The wheelbuilding thread

[battler]

ok i think i will go with 3x on DS and NDS and 2x on the front both sides. i dont know anything about tension difference and imagine it will be a problem i will encounter (or not), but i'm still constantly learning from forums/documentation so as problems arise i'll always be searching and learning to work it out.

bracing angles (if i'm using spocalc correctly) are giving 5.2deg for radial (both sides) and 6.8 for 2x (both sides)
rear NDS is 7.1deg and DS is 4deg, tension difference of 56%

not sure if that sounds right. i have to order soon so i can get the spokes in time to build them up.

thx!

[bm0p700f]

I work with hubs that give worse tension balance than that and I get no problems. Get the tensions even and you will be fine.

[pam]

I built my first wheel today. American Classic 2218 to Novatec A291SB-SL front hub with 24 radial Sapim Lasers is 558 grams. I also played around with my new Park TM-1 and as far as I can tell it reads around 20 Kgf high, leading to under tensioning. I purchased it in March 2014 from Amazon and have only read other accounts of it reading high, never low. Makes sense because it gives Park a bit of insurance that people won't overtension using their meter. I set up an experiment involving standing on a board being supported by a Laser spoke hanging from a weighing scale and then measuring deflection with the TM-1. For this test the TM-1 was used vertically with the lever downward which leads to readings about 0.5 units lower than with the tool horizontal. You guys can draw conclusions:

TM-1 calibration test

Code: Select all

Reading    Kgf
12         51
14         60
15.5       70

Current table from Park for 1.5 mm spokes:

Code: Select all

Reading    Kgf
12         66 
13         73
14         80
15         88
16         97
17         107
18         119

I also tried out the iOS app “Spoke Tension Gauge” and it seems to agree with my experiment, reading 100 Kgf when the Park reads 119 Kgf. The app seems pretty great for radial spokes, more accurate than the Park and only $5. Probably not as good for cross patterns but might still beat the park meter.

[pam]

Went to the LBS for a fourth data point and their Wheelsmith gauge said 97 Kgf on a 2.0 spoke that the Park gauge said was 120 Kgf. The Park TM-1 can be adjusted with a set screw that changes the spring preload but if it isn't accurate from the factory that really decreases it's value. The meter also isn't very repeatable with quite a bit of friction in the lever arm even after oiling it. Readings are different each time you measure by at least 5 Kgf. The TM-1 is cheap but it isn't really a better deal than using a mobile app to tune by sound or getting a better quality gauge.

[bm0p700f]

I have calibration jig with a load cell. The park guage I have reads 15% high. The DT Swiss guage on laser and race spokes is spot on. The sapim guage oddly enough is not spot on. go figure hey!

The TM-1 is good for getting even relative tensions well evenish. The sound methods works for those that are not deaf. I have real trouble with descerning small changes in pitch for some reason.

[pam]

Here is the "Spoke Tension Gauge" app's readings of the spokes based on the sound when plucked. The big number is the middle is where it shows the current tensions reading if it hears a spoke. This is with a tire mounted after riding around a bit.
Steps:
Thread all nipples an even distance with screwdriver
Go around wheel doing a full spoke wrench turn at a time until the whole wheel is up to tension
Relieve stress with pinching and pressure on the rim
Go around wheel getting each spoke at exactly 99 Kgf
Mount it in a fork and get rim running true
Map out spoke tensions in the app
Narrow tensions range by bringing the loosest and tightest few spokes in line
Mount up a tire and ride around
Adjust until less than 0.5 mm out of round


The wrench at the LBS, King Street Cycles in Waterloo, Ontario, also said there is a guy locally that calibrates meters with a tensions jig he had made up. I'm not going to bother because it's not worth it on this meter, I can just turn the screw myself to match the other data points I have.

[Calnago]

Agreed on the TM-1 reading high. I have a TM-1 and a digital DT Swiss Tensiometer. Sent them both back to the factory for calibration. Best to find the max tension on the rim itself by trial and error (easier on box section alloy rims than carbon). Then go from there. But when using DT Swiss spokes I feel that using the DT Swiss charts for the specific spoke you're using is in line with what their tensiometer reads. Frustrating though if you're going off a published spec for a carbon rim, say, and you're not even sure your meter is reading correctly. I had to redo a wheel that was tensioned with the TM-1 due to spokes going slack and coming loose. Even though the TM-1 would indicate the wheel was tensioned properly, the DT Swiss gauge said it was low, which was confirmed when the non-drive side spokes started coming loose. After a nice even retension with the DT Swiss guage all has been fine. Should add that now that I know the TM-1 was reading low for a specific spoke (DT Comps) it's easy to compensate so no big deal.

[bm0p700f]

The Pacenti SL23 rim has angled spoke holes at least on entry I am wondering though given the exit spoke hole is centred is there any angle at the nipple bed that would rule out using this rim with a 2:1 lacing pattern. I may have to use the Kinlin XC-279 instead. Thoughts please.

[shimmeD]

BHS sells centre-drilled SL23 for 2:1 lacing.

Which hub are you using? I'm still thinking about 32-hole Record hub skipping holes & radially on the NDS.

[bm0p700f]

Custom Royce hubs with a 43mm NDS to centre flange spacing and 19.5mm DS to centre spacing. 2:1 lacing patterns need high NDS bracing angles I think higher than normal hubs give or the wheel will less stiff than a 24 spokes 2x wheelset with the same rim making the excerise pointless.

As I am in the U.K getting rims from the U.S is expensive but I have ordered one of those centre drilled SL23's from BHS so thanks for that. Noticed they do a 27H centre drilled as well which is interesting if you had a campagnolo hub and I did have one once but I sold it as I though I would never find a rim for it.

[shimmeD]

Are you saying that the Record hub will not be that good for 2:1? With 35.16/15.2 flange spacings, 44/46 dia flange the calculator says approx 7 and 3 deg angles - I have no idea if that's good or bad. Will having heads in on the NDS make much difference?

[bm0p700f]

I am not saying it is bad but with 16 spoke on the DS with a low bracing angle and only 8 spokes on the NDS with a moderate bracing angle it is far from optimal. 2:1 lacing works best with purpose made hubs that push the NDS flange far out board. This increase in NDS bracing angle compensates for the fewer NDS spokes. Personally I would not bother with this combo personally as even with the Kinlin XC-279 there might be a bot of flex unless stiff spokes are used.

With my hubs I will have 3.9/9.1 degree bracing angles that is good for 2:1 lacing.

[shimmeD]

Thanks bm0p700f

Decided to go with BHS special SL23 20 radial/24 2x, and Schwalbe One tubeless 25mm; hoping to do more unsealed roads.

Anyone has recommendation(s) for wheelbuilding in Christchurch NZ? I'd love to start building my own but would rather have more experience & precision as well as supporting local craftsmanship.

TB25 BHS wheelset are crash damaged but rideable, but I have Bora One to fly the tubular flag. We'll see how the tubeless experiment goes, even though I do like tubulars full-time.

[Asymptotic]

Quick question about vertical truing - couldn't find an exact answer. Am just finishing up building a rear Pacenti sl23 and BHS SL211, and there is a distinct (0.6-0.8mm) hop around the rim weld that I cannot seem to improve by increasing spoke tension around this point. People have said previously that you can expect some hop around the joint - so what kind of hop have other people experienced around rim joints? And what do people consider an acceptable tolerance vertically?

I should mention that I did not experience this much hop around the joint when building the front with the same rim.

[istigatrice]

@Asymptotic, try losening some spokes as well - no good just tightening if you don't losen a bit on the other side as well. I'm guessing 1/4 turn should do the trick