New wheel build, spoke seating question

[Steve O'C]

So what with the enforced lockdown I finally got round to building up my Shimano DH-3N73 dynamo wheel. Using Sapim race spokes in an Exal LX17 rim.

2 questions. Spoke tension is 100kgf using my lifeline tension meter (cheap version of the parktools one). Is this Ok?

Should I have used washers to support the spoke elbows?

Steve

[Brucey]

Should I have used washers to support the spoke elbows?

yes.

BTW I'm not sure there is any such thing as a DH-3N73

cheers

[Steve O'C]

Thanks Brucey. Had a feeling you would say that ☹️. Pity as it is the best wheel in terms of trueness and even tension that I have built so far (although that is not saying much).

Sorry made a typo on the hub, it is a DH-3N72

Steve

[Steve O'C]

Deleted

[Sweep]

2 questions. Spoke tension is 100kgf using my lifeline tension meter (cheap version of the parktools one).

Steve

Can I ask how you found that x tools meter to use?

Have you used any others before?
ie - can you compare it?

[Steve O'C]

I am a novice wheelbuilder and this is the only spoke tension meter I have used. You just place it on the spoke and release the spring tension to take a reading.

Seems to give the same reading each time. However to translate that in to spoke tension relies on this spring at the back being set correctly at the factory.

And then using this table (The column on the left is the reading and the other columns give spoke tension for different spoke diameters)

As Brucey has mentioned elsewhere a small difference in spoke diameter and a small error in reading the scale can translate in to quite a large difference in the final value.

[Sweep]

Thanks for reply steve.
Still weighing up whether to get that or the Park.
Pretty sure I will just use whatever I get to check consistency of spoke tension, not absolute value - will just rely on feel for things being tight enough.
So I suppose I don't need to worry about the fraught issue of calibration.

[Brucey]

So what with the enforced lockdown I finally got round to building up my Shimano DH-3N73 dynamo wheel. Using Sapim race spokes in an Exal LX17 rim.

2 questions. Spoke tension is 100kgf using my lifeline tension meter (cheap version of the parktools one). Is this Ok?

Should I have used washers to support the spoke elbows?IMG_20200404_174148591.jpg

Steve

this spoke fit is worse than I'd have expected to see; Sapim spokes don't usually have very long elbow bends, and shimano hubs don't usually have skimpy flanges either.

I didn't have a DH-3N72 to hand but I did have a DH-3N71.

Comparing with a shimano MTB rear hub;

Spoke drilling; 2.5mm dia in both
Flange thickness; 3.4mm (MTB) vs 3.1mm (DH)
Counterbores in spoke holes; small (MTB) vs large (DH)

All of which means that if the spoke heads will fit into the counterbores (which is almost invariably the case), the DH will build up a lot like a hub with a ~2mm thickness flange, without counterbores. It also explains why, having tested the fit between sport series shimano dynohubs and the various spokes I have ever built them with, I have always decided to use spoke washers.

cheers

[Steve O'C]

Thanks, I tried to measure the flange thickness but with the spokes still in situ I could not get my calipers on straight.

FWIW the hub is much smoother than the Nexus dynamo hub that was in the Decathlon wheel it replaced.

I see that you can now get clones of the DT Swiss spoke tension meter on eBay for about £40. Anyone have any experience with them?

https://tinyurl.com/yd4lz3w2

[Jamesh]

Thanks, I tried to measure the flange thickness but with the spokes still in situ I could not get my calipers on straight.

FWIW the hub is much smoother than the Nexus dynamo hub that was in the Decathlon wheel it replaced.

I see that you can now get clones of the DT Swiss spoke tension meter on eBay for about £40. Anyone have any experience with them?

https://tinyurl.com/yd4lz3w2

Fine bit of Chinese knock offs.

We're even dependant upon them for Ppe!!!

Cheers James