Spoke length, is this ok?
 

I looked up the spokes for a Deep V, Ultegra 6700 hub, 32 hole 3x and came up with these numbers.

A buddy says I can round off both to 284 using on both left and right and it wouldn't a make a difference.

True or.........?



Left spoke length: 284.9

Right spoke length: 283.2

Maybe. I rounded up once on the DS spokes and ran out of thread on more than a couple nipples, but the wheel ended up OK, but zero margin for error. So personally I'll never round up again. YMMV.

I can't tell you which way to round because I don't know whether your methodology would give an answer to the long or short side. However, since a rear wheel typically has a difference of 2mm between right and left spokes, I'd round correctly to 285 and 283.

There's latitude in spoke length, so if your calculation is spot on, you can split the difference and use one length. But you have to be spot on because the right will be about 1mm long, and the left 1mm short. Since the total working margin of error is only 3-4mm max. using one length cuts it pretty close to one side or another.

If you're worried about too long, then you might consider adding a brass washer underneath each spoke-head (Gerd Schraner recommends their use on all builds).

HTH -

- Wil

Thanks for the replies. Seems ok then as he got the same calculations as prowheelbuilderdotcom's calculator.

Not worried about too long. Deep V's are deep rims so they have lots of play on the inside as the spoke seats far from the inside wall (where the tape sets).

Be aware that the latest DeepV's made in USA now have the joint sleeve holes counter-sunk - instead of raw as was previously the case for Australian versions. Thus the ERD when aiming for the screwdriver flat of a 12mm nipple has dropped down to 581 as opposed to the old 582.

New ERD of 581

284.25 and 282.42

Old ERD of 582

284.75 and 282.92

Using the specs for Ultegra 6600...

...assuming not much has changed.

=8-)

Why not use 283 for both sides?

Why not accept that the calculator might be right, and round each side to the closest length?

The OP might get by with 283 on the left. OTOH, if the calculator had a bias to the short side, then he'll come up short. Of course poor engagement to the head of the nipple is less critical on the left since they spokes have 40% less tension, but why start out looking for problems.

Plus I have received spokes that were > 1mm wrong from vendors. By the time you add up the margins for errors in ERD, rounding, vendor measurement, etc, you might already be past the 3-4mm that could leave you with not enough thread in either direction. I worry about it on every order. I've complained about 1mm errors from vendors before. It seems a little anal but when the other margins of error all go wrong, that 1mm can make a difference.

In fact I no longer blindly accept ERD from other sources when using rims I have not seen before.. I prefer to order rim and hub first, measure them myself, then calculate and order spokes.

This statement confuses me. Too long spokes = run out of thread. I don't see where rim depth comes into play (well I do see your point, but it's answering the wrong question)

OH, I didn't think of it that way. I've never had spokes that were too long so I've never run out of threads. In other words, never had that experience to know the threads would run out on the inner side of the wheel.

I was thinking more having the end of the spoke poke through the rim hole causing punctures in the tube.

What I don't get is that having gone to the effort to make the various measurements and use a spoke calculating program, why you'd look to worsen your odds by fudging the data.

I can understanding fudging when you're 100% familiar with the process and calculator, and can base adjustments on experience, but doing so blind simply increases the odds of spokes too short or long.

You'll be fine at 284 all around. I've built a bizzilion thousand wheels and have been down this road a mizzilion thousand times.

So has my buddy, built a bazillion wheels. He owns a shop and he's the guy that provided the spokes for me. I was just checking to see if what he told me was true. I just always thought you had to use the exact numbers a I have in the past. Of course he provided the spokes back then too but they were different lengths. ;)

As a "rule-of-thumb" round down on the drive side rear.