Story goes.
Bough a pair of bargaintastic arch ex on sram hubs from P/X for £68 the pair and doing a hub swap for evo’s
calc for Hopes is 260/262.
Carefully de-laced the wheels and have 262/264 with 12mm nipples.
Is this doable or will they bottom out.
Cheers all.

If the spoke calc is right then you’ll probably end up with soggy wheels. If time is on your side you could just run up a rough build to see how far out the length is. Costs you nowt.

We can all guess with varying degrees of success but there’s only really one way to be sure.

The brand of nipple can make a difference to this as well as the depth of thread will influence how far down it goes.

Just spin a nipple down the spoke thread now and see how much protrudes. Nipple washers may also help.

Having built a lot of wheels, often with the ‘wrong’ length spokes, if be very surprised if it didn’t work but as above there’s only one way to confirm it.

The precise calculation length is important. Because if 260/262 is already rounded up then going up another 2mm is going to be more of a problem than if the 260/262 length is rounded down.

There is a bit of flexibility as you can have the spoke threads extending a couple of mm above the top of the nipple, although you need to think about how much thread remains engaged inside the nips, it depends on how much of the spoke is threaded etc. NOTE: This is assuming you have non crap spokes where the thread is rolled in rather than cut in so the nip won’t bottom out at the bottom of the thread.

Another thing you could do is use nipple washers, not a bad idea on stans rims anyway as they tend to be lightweight and without eyelets.

Something else to consider is if the spokes are worth the effort, are they nice double butted Sapim/DT or something of lower quality?

EDIT: poosticks, I’m mostly repeating what others said – I was on the phone for half an hour before I got to press send.

Mechanically, threads only engage over 6 turns – the rest is redundant so theoretically you only need to engage with half the nipple threads, so if they are protruding a couple of mm of the 10mm then you’re pretty safe.

Nipples come to a stop when you screw them too far into rolled threads IME. At least it does with spokes with 2mm dia. ends. According to Park Tool a standard spoke thread is 2.2mm x 56TPI. So the diameter at the bottom of the threads is going to be way more than .2mm lower then the max diameter – approx 1/56″ which is ~0.45mm. Even allowing for a flatter thread profile, it won’t go.

Fair enough, so the thing to do is test twiddle a nipple onto one of the spokes and see how far it can be turned on.

Don’t reuse the old spokes.

Cyclebasket sell ACI DB spokes for 21p each:
http://www.cyclebasket.com/m9b0s454p0/Components_/Spokes_-_Stainless_Steel_Double_Butted_-_Silver_

The difficulty is knowing how much spoke stretch and other deformations are going to take place by the time you get to full spoke tension. I’ve never used washers, but if they came in decent thickness that would be useful.

personally I wouldn’t re-use old spokes, but building it is really the only sure way of telling

Thanks very much all for the words of wisdom.Think i,ll just bin the spokes and go for dt comp from rose to save any major cock ups.
Cheers..

I always round down, and wouldn’t fancy using 2mm too long. Those ACI spokes linked to by emyr have never given me any grief.

I have reused spokes- some of them have been on at least three rims and are still fine- I bet the oldest are nearing a decade old now
depends as for would i sue them waht was the exact spoke lenthy calculation? the difference range is 1-3 mm. the former fine the later unlikely to try but i would still give it a go

I have definitely built a wheel with the wrong spokes but i forget how wrong they were

Sod it.I’ll take the lot to my wheel builder tomorrow and see what he says.
The stripped wheel set was brand new and there only spokes after all and no damage on them. 😀

By all means get new spokes if you need to but as above, spokes will last years and multiple rims /wheels if properly built so there’s no need to bin them on principle.

I’ve built a wheel with spokes 6mm out… Worked fine though there was a lot of thread out of the nipple. Not an issue for the deep rims I was using though

Threads bottoming is the biggest issue you’ll face, if anything.
I’ve built with +2mm, wheel is still running fine.

Built some wheels a few months ago using dt swiss rims. They were supplied with squorx nipples, they seem to sit deeper into the rim, so my spokes were too short. I used a spoke calculator. When I started to get the spokes tight the there was still a few threads of the spoke showing. decided it would be better to use 14mm standard brass ones as my wheels were 28 spoke and the squorx nips were aluminium.

You could always use nipple washers to gain crucial ERD.

I cocked up the ERD on my carbon rims by about 2mm. The spokes just worked but I opted for fitting some matching polyax nipples to go with the polyax (sapim) nipples. They are like mini versions of the cupped washers you get on brake caliper bolts and should spread the load quite well. I did notice just how much the carbon rims had damaged the black nipples on tightening and rebuilding was definitely easier to get the spokes up to tension.