Help - which spokes do I need for my Rohloff wheel build?

[AlexRa]

I知 building my hub into a new rim. Wish me luck!. On the advice of lots of people I知 using a Ryde Andra 30 rim - 700c / 622. I知 also going to use the Rohloff spokes that are sold by SJS cycles. So far so good.

But which length do I need? There are options ranging from 232 to 297. I致e drawn a blank Googling for the answer. Any help very welcome.

[RonS]

There are several online calculators for spoke length. You would need to input certain measurements. I think, however, that SJS have built up so many wheels with Andra 30 rims that an email to them will answer your question, especially if you are buying the spokes from them.
Good luck

[JohnR]

Note the Rohloff advice at https://www.rohloff.de/en/service/handbook/speedhub/assembly/wheel and https://www.rohloff.de/en/service/handbook/speedhub/assembly/wheel/wheel-lacing, in particular that the spoke lacing should note be more than 2 cross and flange support rings should be fitted to the hub (I think recent hubs have these fitted in the factory). The hub dimensions are here https://www.rohloff.de/en/service/handbook/speedhub/technical-data.

[mickeg]

SJS has built up lots of Rohloff wheels with Andra 30 rims, ask them.  It is my recollection that they deviated slightly from the Rohloff suggestion for spoke length.  I do not recall what nipple lengths they use, but it might be an extra long one.  I used normal Sapim nipples, and they do not stick out of the rim very far.

I used the table provided by Rohloff for spoke length using the ERD from SJS website for the Andra 30 rims when I built my wheels.

When I bought my Andra 30 rims from SJS a decade ago, I wanted one rim with normal drilling (front wheel) and one with Rohloff drilling.  When I received the rims, one rim had a tag on it with a hand written "Rohloff".

[PH]

I知 building my hub into a new rim. Wish me luck!. On the advice of lots of people I知 using a Ryde Andra 30 rim - 700c / 622.

Whose recommendation?  It is the go to for rim braked heavy duty touring use, or in 26" where Rohloff specific drilling is available. But it looked from your other posts that that wasn't the sort of bike you are building. For lighter touring use (But still touring) SJS/Thorn usually use the DT Swiss TK 540, which would probably be my choice. It's not a huge deal, the 700c Rohloff on my Mercury is on a heavy Sputnik rim, because the wheel pre-dates the bike, and though it wouldn't be my choice for this bike I'd rather put up with it than disturb the wheel. 
For spoke length, there's no substitute  for measuring the ERD of the rim yourself, even SJS's website has got it wrong in the past, I know that adds a second postage fee, but it's a lot cheaper than getting it wrong.
I built one of my Rohloff wheels myself, but only because the wheelbuilders I'd trust were closed for Covid.  I've built a few other wheels but the value of a Rohloff I'd rather leave to an expert.  I was lucky as I already had an SJS wheel and simply copied that. There's a thread somewhere on here explaining why SJS choose to build 1X, rather than the handbook recommended 2X, though of course deviation from the Rohloff instructions on your own build may impact the warranty.

[AlexRa]

Thanks everyone.
All super useful advice. I'm still getting some conflicting answers.
Online spoke calculators are telling me 266mm (for a 32h hub, 700c wheel, 2 cross lacing).
SJS suggested I buy the 270mm spokes.

Just wondering about this difference. Is that the kind of difference that doen't make much difference? or is there some reason why slightly longer spokes are going to work better, in spite of what SJS says?

[mickeg]

Did SJS say what length nipples they use with those spokes?

I am not sure why there would be a difference, but I remembered hearing in the past that SJS used a different length.

I built up my wheel with 36 spokes and I think SJS only does 32, so I never asked them what to use, I used the table from Rohloff.  This table is dated 2019, I built my wheel in 2014, so I do not know if there is a difference.
https://www.rohloff.de/fileadmin/user_upload/erd_32_36_Speichenlaenge_03_2019_de_en.pdf

Different topic, if your hub is an old one that did not come with the flange reinforcing rings, you might consider adding those at the time you build your new wheel.
https://www.rohloff.de/en/company/news/news/flange-support-rings

I added the rings to my hub, even though I was not rebuilding the wheel at that time. I have ridden into remote areas where I did not want a wheel failure.  The rings do not make the hub flange stronger, but if a spoke pulls out a piece of the flange, the ring will hold it in place so you can keep riding, then fix it later.

[PH]

Online spoke calculators are telling me 266mm (for a 32h hub, 700c wheel, 2 cross lacing).
SJS suggested I buy the 270mm spokes.

Based on what ERD? If you're using a calculator where you can pick the rim rather than enter the ERD, they may be using manufacturers information and Rigida are notoriously bad, I think they measure to the face of the rim rather than where you want the spoke to end*.  I've already said what I'd do, measure a rim myself.  If you're not going to do that, I'd suggest buying rims and spokes from the same supplier, on their recommendation, at least if they get it wrong you have an argument for returning them (Something unlikely to happen if you specified them and had a go building with the wrong length!)

*Opinions vary, but the correct answer is flush with the bottom of the slot 

[Danneaux]

The Andra 40s I bought for my tandem were way off from Ryde's listed specs of 534mm and also off substantially from the information SJS Cycles provided me in good faith (534, with 536 as closer based n personal measurements). In the end, I had to get my wheelbuilding supplies in two stages -- first the rims so I could measure actual wheel diameter at the spoke seat faces to determine ERD in my spoke calculator and then the spokes.

I found mine had an actual ERD of 540mm as measured by myself, verified when several spoke calculators agreed and my tensioned spokes ended even with the bottom of the nipple slots, as Phil correctly advised...

*Opinions vary, but the correct answer is flush with the bottom of the slot 

Right. My standards are spokes ending at the bottom of the nipple slot as well. This ensures maximum thread engagement without the spoke protruding past the end of the nipple. Get the spokes too long and you can run a bit short on threads depending on nipple length used and you've got to deal with protrusion. Too short and the brass or alloy nipple supports the load on the hub side of the rim with the spoke end in the exposed end of the nipple column. The nipple is soft and includes lots of internal threads as stress risers. You might get away with it but a wheel with uniform high even tension will sometimes result in nipple fractures if the spokes are too short. What you want is full engagement with the nipple collar serving as the terminus for the spoke end.

Best, Dan.

[martinf]

For spoke length, there's no substitute for measuring the ERD of the rim yourself, I know that adds a second postage fee, but it's a lot cheaper than getting it wrong.

It's what I usually do nowadays.

It was easier up to about 20 years ago because I could source rims and spokes locally from a bike shop about 2kms from home.

More recently, I would order rims that the local shop couldn't get via Internet, then get the spokes locally, they had a good stock and would order odd lengths if necessary. But that shop closed a few years ago when the owner retiired.