How to reliably tell if the rim is correctly drilled?

Question

The typical advice is to put down the rim, find the hole for valve and compare two adjacent holes which one is "higher" and which one is "lower" one (the counterclockwise hole should be higher).

The problem is with my new purchase I cannot tell the difference (maybe it is due to the fact so far I used 26" rims, now I have 28" and the distances are tad bigger between holes). I look once and I see pattern, I take a look again with different angle and I see the opposite pattern.

So, is there some reliable way to measure the difference and tell which hole is higher/lower? I would need this for my purpose but also to convince the shop they sent me incorrectly drilled rim (in correct one you have almost parallel spokes over the valve, in incorrect one the spokes are more angled making less space when using the pump over the valve).

Important note: Here and in general I am interested of testing new rims, so I cannot in any way change them or even fully unpack (i.e. remove the thin protective wrap which manufacturer glued to the rim), so if the rim is incorrect I could send it back and the return will be accepted.

The rim is DT-Swiss 535 28" and all I did so far is I took it out from the package. I looked it from the inside and from the outside as well -- but after first "reading" I also rotated rim by one hole and the previous reading was contradicted by the new one (the holes should be in high-low-high-low-... pattern) because I saw the same pattern. In short, I cannot rely on my eyes.

This is just an example of spoke crossing. The perfect rim would have valve at (for example) 12 o'clock, between parallel spokes.

Answer 1

It looks like the holes are quite close to centerline of the rim, but the rim profile has an angle that can be used as reference. So, here are my suggestions:

• Use a vernier caliper to measure the distance from eyelet to the angle. Measure both to both sides, and several eyelets.

• Arrange lights so that the flat center part is highlighted, like in the photo but so that the highlight covers several eyelets. Take a photo, zoom in and count the pixels to both edges of the highlighted area.

Finally, when you know how the spoke holes are arranged, you can always build the wheel so that the spokes are not crossed over the valve. Just start at the valve and choose the side for first leading spoke so that they match the rim, or choose the side first and spoke hole that matches the side second. Note that spokes from the same side are two holes apart, and you need to have spokes from both sides not cross at the valve.

Answer 2

I remember well the mental confusion of re-lacing my first and second wheels. If you step back and take a deep breath and look at an already laced wheel, it will help. It can be a 26 27.5 or 29 inch wheel. It can be a 28, 32, or 36 spoke wheel. Lay it beside your new Swiss rim. I am right now looking at a rim I re-laced. It is a DT Swiss 520 SL from my 29er and looks just like your 525 picture. You can trust your eyeballs. Just look at the radius on the rim closest to the spoke hole. On my 32 spoke rim there are 16 holes crowding the radius on each side of the rim. All holes are equally spaced. The valve hole is drilled exactly between the two spoke holes opposite of the rim weld or splice by convention. (However, it can be drilled exactly between any 2 spoke holes - I ruined a valve hole on my good old Giant AC 1 by using a Stan's valve in a genuine tubeless rim and pulled it through. Couldn't get it to seal. I closed the damaged hole with a strip of Stan's yellow tape and re-drilled the hole 4 holes away between parallel spokes and used a Mavic tubeless valve, and it works perfectly). My point is only that a valve hole can't be mis-located (except on an asymmetric rim side to side. All spoke holes are identical. This is just a lacing issue. I can't explain the lacing process better than the printed materials you have. I can say erase your preconceived ideas and look at a completed wheel. Visually move the valve 4 holes away to the next set of parallel holes and it will suddenly be clear. Your first few wheels will be a struggle, but then, you will be able to replace hubs, retension spokes, and be in control with huge cost savings. It is worth it. Have fun. Take your time and visualize the steps you are taking and mentally record why you are doing them. Quick things on that rim - note that it is symmetrical side to side. First- Because it is symmetrical, the spokes are different lengths by 2 to 3 mm?? Don't mix them up or you will run out of spoke threads in tensioning. I did and had to re-lace some. Second - MY DC SWISS WHEELS ARE ALL LACED DRIVE SIDE TRAILING THE VALVE FOR 1st SPOKE TO END UP PARALLEL SPOKES TO THE VALVE. (So are my Bontrager and Ryde wheels) I have only done 5 complete wheels. I am hoping my beginner's thought processes may help. What is automatic to experts is not automatic to us. My greatest problem was my unwillingness to back up when I thought I had learned something and it didn't work. Remember, If you lace it up and have angled spokes over the valve, it is still easy to add air and it will work just fine. Parallel spokes at the valve is just cosmetic and convention. Keep your wheel and dig in.