I'd like to replace the anodized Open 4 CD rim on an older wheel set with a set of older Open Pro rims. Both rims are 32 hole. The wheelset with the Open 4 rims is very clean and corrosion free, but I'd like to have a silver alloy rim on this bike and would like to ditch the anodized rim.

Will the spokes be the same length?

Could I use a Sun CR18 rim and reuse the spokes from the Open 4 CD rim on an older wheel set?

Personally, I would never re-use spokes.

I'm not too surprised to hear this statement, how much of no-no is the reuse of spokes when replacing the rim?

Look it up on EDD. I think the Open 4 and Open Pro are very similar and if they are within a couple mm of each other, I think the spokes would work.

As far as reusing spokes, I have no problem reusing spokes if they are in good condition. Some people don't like to reuse spokes, but I'm not one of those people.

Great tool, thanks. As it turns out, the spoke length needed for the Open Pro rim is about about 25mm shorter than Open 4.

Double check that you are using the right size. Most of these rims come in different sizes. 700c, 650b, 26" MTB, etc... I'm willing to bet you might have looked at the wrong size rim.

Yup. According to Spocalc, the Open 4CD is 608mm and the Open Pro is 605mm.

Thanks!

Will that extra 3mm cause the longer spoke to interfere with the tube?

If they're that close, you probably won't have a problem reusing the spokes. That's only 1.5mm per spoke.

I've done a similar rim swap - Open 4CD replacing Campy Omega 19 - used the same DT butted spokes and the resulting wheel is doing fine 18 months later.

I would think you can get away with it. But if you are concerned, screw a nipple onto each spoke end far enough that the spoke sticks out the other end. File end of spoke, and then remove the nipple which will take care of the threads. To answer your query on the CR18, it is 612mm ERD.

There is no reason not to re-use a sound spoke. I have done so repeatedly with great success but you do have to pay attention to where they go. If you look at the bend in the spoke at the head, you will see that some are bent more than 90 degrees and some are bent less. This indicates in which position on the flange the spoke was previously installed, inside or outside. If you are careful to put the spoke back in the same position then there will be no problem. Less bend goes inside the flange, more bend goes outside. It is not that hard to just sort them into two piles before you start to build.

It is also a good idea on the rear wheel to position the pulling spokes on the inside of the flange. They will be under the most tension when riding and less bend is better for that spoke position. You see wheels all the time that are not done that way but it is not proper in my opinion.

How much difference in mm can I go if I use a rim that needs a longer spoke than what I have on hand? For example, I have 32 spokes from the front wheel of the Mavic hub & Mavic Open 4, these are 290.2mm long. If I use the same hub with the Sun CR 18 rim, the calculator specifies a 292.2. So the spokes are 2mm shorter than ideal for the new hub and rim combination. Can I still safely use the existing spokes?

Good advice. I'll be keeping the spokes on the same location on the same hub and with the same 2x pattern with the rebuilt wheel.

If you are swapping out rims on the same hub, no problem re-using the spokes. And when I do it, I tape the new rim along side the old (matching the stem hole and label direction), and swap over the spokes one by one without removing them from the hub. Goes pretty quickly.

I have done it. I am not going to say it is safe but the wheel has not failed.

^This.
I *always* re-use the spokes and have never had a problem.

Be nice if you could also double check the rims yourself... the rim diameter being the most important measurement in calculating spoke length

Check to see how far that the existing spokes come up throughthe nipple's threaded bore.

Depending on how "long" (or short) that the existing spoking looks, will help to judge how much that the 1.5mm difference will make.

Your new rims might even be a better match for the existing spoking than the old ones, but I can't say without looking at the existing wheel and how far that the spokes come up into each nipple.

I've decided to look at other rims that are 22 to 23mm wide (o.d.) that better match the ERD of the Mavic Open 4. The Open 4 has an ERD of 608. The Velo Orange RAID has an ERD of 606 or 607 (the description list both!). I put the RAID 606 ERD data through the EDD, and get a spoke length requirement exactly 1mm shorter than my existing spokes. 1mm of extra spoke length (theoretically) should work well, right?

If it was just 1 mm, I'd give it a shot. I'd prefer not to have too much sticking out of the nipple though.

Looking back at your original post, you mention the spokes are from an older wheelset. I have re-used spokes, but only spokes that didn't have a lot of miles. Considering the effort involved in building a wheel, I like to use new butted spokes. Maybe you could think about getting new spokes. [MENTION=260407]jeirvine[/MENTION] provided a link to some Sapim spokes at $0.40 each with the nipple. https://www.danscomp.com/products/43...ted_Spoke.html That'd put your spoke cost per wheel to about $13.

I haven't purchased from danscomp but this price is exceptional. I'm thinking about a couploe of wheels I want to build this winter.

Yes, the completed wheelset with the Sun CR18 rim and new spokes cost less than the wheelset completed with the reused spokes and a $80 rim. I have the CR18 on two bikes. They're a good match with my 225 weight.

The VO Raid is a very nice rim to use. I have used them twice now with great results! They have a nice classic look and seem very durable (so far)!