I have replaced a knackered hub that had killed 2 axles and and 2 freehubs. Then felt I had to replace the good front hub to match.

I built the wheel by reusing the rim (is an older but straight Raceface ARC 30) with a new Hope Pro 4 hub.

I used an on-line spoke length calculator (Prowheelbuilder) by plugging in the hub make / model and the rim erd (on the rim sticker) but the spokes (269 / 270) look to be at least a mm or two, too short as there is a mm or so of thread showing on the outside.

I used 12 mm nipples, if that is a factor ?

Where have I gone wrong ?

Should I just buy longer spokes or longer nipples ?

Based on the published erd I would have used 271/272 for a 32h hub. 2mm too short sounds about right. You could get some longer nipples but you’ll need to make sure the thread is longer. DT for example are not, it’s just the wrench faces are longer. Or new spokes of course.

Also worth… Checking the lacing pattern, easy to mess it up a little and it looks ok but spokes seem short

Measuring the ERd yourself.

Based on a few assumptions I get similar lengths to you with the DT Swiss calculator.
I think ERD may be the culprit here. I’ve found over the years that manufacturers published numbers can be quite a bit out.
I’d be surprised if it’s your lacing pattern as you’re pretty close and pattern errors tend to produce greater discrepancies in my experience.

As Ben suggested, longer nipples are really meant to allow easier access to get a key on them but in your case would at least make the wheel look nicer but you’re effectively just covering the problem.

Personally if I was going to go to the hassle of changing the nipples I’d just strip the wheel and start again with the correct length spokes. Depending on your actual numbers you could likely reuse your drive side spokes in the non-drive side and you’d only need to buy 16 x longer ones.

If you don’t want to buy anything new you could always go to 2 cross rather than 3.

Cheers Ben,

I have only done a couple of wheels before, so anything could be wrong. It was a bit messy.

I did check the ERD with Raceface Rim, the rim is marked marked 558++ (not sure what ++ means) but I guess I could only measure it with it stripped down ?

Is there any clue to whether I had laced it wrong eg  spoke cross overs distance from the hub ?

https://photos.app.goo.gl/u2Esr4bzCfRyUwRR7

Cheers,

Paul

Thanks Ansdy !

New spokes then .

I believe RaceFace ++ is code for add the height of the nipple head, twice. This is probably where you have gone wrong.

Lacing looks good. One thing I didn’t consider – is this an offset rim? If it is did you account for the offset on the calc? And dumb question of the day, have you got the offset on the right side?

Having looked into it Ive found 3 different ERDs for the ‘same’ rim listed. So god knows which is the right one 😉 This is why its often easier just to measure it yourself.

Ben,

<span style=”font-size: 0.8rem;”>It is a pre-offset rim ( I find them much easier to mount tyres tubeless 😁). Many thanks for checking. </span>

Thanks GeForce..

Probably explains it ! I am always going to believe that ++ means add 2 mm !!

I will strip down, measure and order the correct spokes !

<span style=”font-size: 0.8rem;”>Thanks all. </span>

Have you stressed the spokes by standing on them to allow them to need into the alloy hub? That’ll probably give you a few extra turns on each nipple to get back to the correct tension.

1mm of thread showing outside the nipple is fine – with aluminium you need to have ~2x the diameter of a thread engaged before its not the weak point (ie the spoke will snap before the thread strips). with 2mm showing you’ll still have something massive like 8mm engaged, which is plenty to not cause any issues.

Thread showing outside of the nipple shouldn’t be an issue, it depends how much of the spoke is actually threaded into the nipple.

1mm of thread showing outside the nipple is fine

I wouldn’t agree here – you’re aiming to have some head engagement so that the nipple head will not break at the seat.

Some good diagrams to explain it here:

https://kstoerz.com/freespoke/tech-threadengagement.php

The ++ thing is an annoying variation on the ERD measurement and just reinforces what Ben says about measuring it for yourself.

Copy and paste from Spank on the subject

ERD and “++” – In the past ERD was usually communicated as a calculation including a standard nipple head height, (ERD = Inner Diameter of the Rim + 2x Spoke Bed Wall thickness + 2x Nipple Head Height). However, in recent years many new standards of nipples have been introduced, and nipple head heights vary. For example a standard external nipple has a 2mm head, while a DSN type nipple has a 4mm head.

For this reason, Spank communicates ERD without including nipple head height, so the user can add the exact height of the nipples they have chosen for their build, (Inner Diameter of the Rim + 2X Spoke Bed Wall Thickness = ERD ++).

If you are using an online spoke calculator, and the ERD value is expected to include nipple head height, then you may need to add the head height of the nipples you have chosen to the spoke length offered.

I wouldn’t agree here – you’re aiming to have some head engagement so that the nipple head will not break at the seat.

whilst I agree you’re aiming for that, I’ve never actually seen (brass) nipples break in that way, and I’ve busted a whole load of wheels in my life. the weak point, in my experience is always the spoke (or the nipple falling apart if alloy is used). given the cost of the nipples starting to snap is rebuilding the wheel with new, longer nipples, which is what the OP is thinking about doing anyway, I can’t see any harm in just carrying on for now

built my first wheels 10 years ago, I’ve built/rebuilt a dozen or so since. I always measured ERD, as per Wheelpro book and all the reasons he states. Chatting to a bike-shop-running mate on a ride about the Easton (as was) Arcs that I’d got silly cheap from CRC a coupe of years ago. Said I was in a hurry to get them built up, but that I’d have to wait for them to land before I could measure ERD, calculate and order spokes. He said he’d always gone by manufacturer’s ERD and never had an issue.

I went off Easton’s ERD and ordered spokes. They were too short.

@binman ,

I’ve got spokes and nipples in front of me. DT comp and DT 12mm brass. I’ve got 11 full rotations of the spoke into the nipple to the point where there’s 1mm of thread out of the nipple on the hub side.

Might not be tidy, might look like you’ve messed up a bit if anyone ever looks that closely, but there’s plenty of thread engaged.

I’d ride them.

It’s a gamble, reality is if they start pinging and breaking you know it’s not right, i’ve had this on a previous build, it ended up with me having to rebuild it, but that’s probably due to me not being that gentle on landings or jumps 😂

The issue of having threads showing is always down to the probability that the nipple head has no thread engagement with the spoke, so it’s a stress point that can fatigue and fail a lot more than if there’s some engagement at the head.

it’s a gamble, but without much of a downside either way. As above, You rebuild the wheel now, or ride it. If you ride it and a nipple or two goes, you rebuild the wheel then.

And you never know, you might trash them rim before you ever have any issues with the spokes, then you’d have wasted you’re timing rebuilding now. Could be more of a downside in rebuilding now than riding and keeping an eye. Depends how much you like building wheels vs riding!

Agreed, completely depends on the use-case. If never going too far from home or always have a spare wheel close to hand then fine to just risk it and see if it fails – if it does it will probably after several thousand kms.

If I’m building a wheel I want it to be as good as I can make it so that I don’t get left stranded a hundred km from the nearest shop with barely any food or water.

Thanks all.

I bought some 14mm nipples, but thought again and bought 16 new longer spokes.

Will swap the longest of the existing ones to the disk side and put the new ones on the non-disc side.

I think I would like to do it properly if I can.

Good choice – like a lot of folk have said, it would probably be fine but if you have the time then get it right now and you’ll never look back

I made the same mistake in the past. I don’t like having any thread showing and I like to have a consistent nipple length throughout all my rims. 12mm for me is the default even though with the deep blacktek rims that Lightbicycle produce 14mm apparently is the recommended. I coughed up the extra expense and bought longer spokes. The exposed thread would piss me off forever and you don’t want that with wheel builds that you really don’t want to have to return to if necessary. To me a wheel build is a one off event. Get it done right the first time and never look back.
Also, what weighs more…two extra mm on 16 spokes or having to replace all 32 nipples with nipples that are 2mm longer. Additionally what about your other wheel? You’re going to have a different set of nipples unless you replace those too. Spokes every time.

I’m with 5lab and the guy that said run it.

The chances of a catastrophic failure are soooo small.

The bike world is so full of overthinking perfectionists! 😉