Wheel Truing How-To
Written by: Greg Kopecky
Added: Fri Apr 05 2013
Truing a wheel can seem daunting for those who have never done it. I’ve been there. I remember buying my first set of “nice” wheels and immediately bringing them to my local mechanic just to have him check the spoke tension. I had no clue how to even approach the topic. Are the wheels okay? Did I get my money’s worth?
Alas, wheel truing is rather simple when you break it down. The key – as with most things – is practice. It really does make perfect.
This guide is not necessarily all-encompassing. There are just too many different types of proprietary spokes, spoke nipples, rims, wheel designs, and tools to cover everything. I will attempt to cover the basics that apply to ALL wheels, and note important exceptions when necessary.
The photos in this article were taken while I was building up a new pair of wheels. However – it is NOT a guide to building wheels. For that, I recommend you purchase The Art of Wheelbuilding by Gerd Schraner. It’s a classic, and still very relevant today. Our article intends to cover what you should do for simply wheel truing (i.e. you spin your wheel at home, notice it’s wobbly side-to-side, and want to fix it).
You will also need a spoke wrench. Be prepared, because there are at least a couple dozen different types out there. Here are a few of mine:
So your wheel is in the truing stand. Must you always remove the tire beforehand? If you can access the spoke nipples from the inside diameter of the wheel, you do not need to remove the tire (provided the tire fits in the truing stand – some large mountain bike tires do not fit). If your wheel has internal nipples or those that are otherwise accessed from the outside of the rim, you must remove the tire and rim tape. If you have a tubular tire, yes, that means it must come off (which is the number one reason mechanics hate tubular wheels with internal nipples).
What now? Just pull the rim left or right as needed? Is it that simple?
First, always use a lubricant before you start adjusting spokes. This goes double for old wheels. Where do you apply it?
Whether or not you apply lubricant at the location of the red arrow (between the spoke and nipple) is a little bit more open to debate. Some manufacturers use various thread locking compounds after wheel assembly. Some do not. What I usually do is try to adjust a spoke nipple without lube; if it is easy to turn, I roll with it. If it’s difficult to turn, I add lube. If the manufacturer did something stupid like use a high strength Loctite on the spoke threads, I drench everything in lube; at that point, I’m just hoping to avoid breaking alloy nipples and getting myself in to a lot more work than I bargained for.
So we’re ready to start pulling the rim left and right? You may have honed in on that ‘high spot’ in the rim, and are ready to pull it back in line. Before you do, you may want to consider a few things:
Yes, it tightening that one spoke will absolutely bring the rim back in the proper direction, but that does not mean it is the best decision. Another option might be to loosen the two neighboring spokes (with blue dots). Or – what if we actually want to tighten the spokes with orange dots? Or a combination of everything?!
The best way to find out the answer is to use a tension meter. There are several different types out there; I have the simple blue model from Park.
Looking down on the chart, the left column (in bold) shows the arbitrary units that show up on the tension meter itself. If you go over to your appropriate column, you see another number. That is the actual tension, in kilograms force (Kgf). If you prefer to talk in Newtons, one Kgf equals ten Newtons.
For my wheel today, I’m looking at the fourth column from the left on the chart above. The closest number to 120 Kgf is ‘122’. This is 15 units on the Park tension meter, so that is my target for the drive side of the wheel. If I was using a 2.0mm round spoke, the same 120 Kgf would net a meter reading of 25 (due to the much thicker spoke).
The point of the tension meter is this: Even if you know nothing about what tension your wheel is supposed to be at, the tension meter will at least give you an objective comparison between the spokes that are actually on your wheel. If you’re measuring the drive side and two neighboring spokes read ‘10’ and ‘20’ – you know that there’s a big problem. The spoke tension is very uneven. When adjusting your rim left or right, it is always best to evaluate an area of spokes to see what the best decision is. In my experience, adjusting a single spoke by a large amount is the correct decision about 10% of the time. In the other 90% of cases, you’re usually adjusting more than one spoke a smaller amount. The end goal is both a straight wheel AND a wheel with even tension.
When it comes to actually turning wrenches, there are a couple things to keep in mind. If you’re using bladed spokes, it is in your best interest to buy a bladed spoke tool, such as mine from DT Swiss:
The other widely-accepted method of reducing spoke wind-up is to “de-stress” the spokes. That’s a nice way of saying “smash the heck out of the spokes”.
It is also worth noting which direction you should turn those spoke nipples. Most spokes have standard right hand threads (righty-tighty). Note, however, that you must approach this in your head knowing that it's righty-tighty from THIS direction:
When the wheel is getting close to straight, I pull out the heavy artillery – the Morningstar R.O.C2-TECH dial gauges.
While we’ve only dealt with lateral (side-to-side) truing up to this point, you should also consider the radial true of your wheels. Put simply, your wheels might not be as round as you think. If you want to look at radial true, you MUST remove the tire from your wheel.
The Park TS-2 stand has an easy method for looking at the radial true of your wheel – bring the calipers together, and adjust them like this:
This is also the point where carbon and aluminum wheels differ. Carbon rims are much stiffer than aluminum. Put simply, the amount that you can radially manipulate a carbon rim is MUCH less than aluminum. As such, when adjusting radial trueness, you need to adjust many more spokes. Think of it as shifting the entire rim up or down – rather than bending a part of that rim to be more straight. Instead of adjusting 4 spokes, I might adjust 8 or 10. This also brings up the point that carbon wheels rely much more on roundness of the rim itself for a straight wheel; an imperfect rim cannot be manipulated very much (unlike aluminum).
Morningstar Tools also makes a radial-truing version of their R.O.C2-TECH dials, seen here:
In addition to lateral and radial true, you may also want to check the dish of your wheel. What is dish? This term refers to how centered the rim is relative to the hub. If the rim is offset to the left or right, you’d say that the wheel is “out of dish”.
To check dish, you will need a dishing gauge. The idea is to lay the flat part over your rim, and adjust a piece in the center to meet your hub. Before you go doing so, make note of this:
Lay the dishing gauge on one side of the wheel. You want to adjust the center piece so it just barely clears the lock nut. Note – the lock nut is NOT the end of the axle. You want the dishing gauge on the surface that actually touches inside face of your frame or fork (NOT the axle end – which rests inside of your frame/fork dropouts).
The process of truing wheels just takes time and experience. Even if I made a perfect guide on how to do it, you will still screw it up. I’ve certainly screwed up a lot. It is best to start practicing on cheap wheels; you’ll eventually figure it out. The most important thing is to consider ALL adjustments at the same time. If you adjust lateral trueness, it will also affect radial trueness and dish – there’s no way around it. Because that is the case, always evaluate a large area of spokes (on both sides of the wheel) before making a decision on what to adjust. More often than not, your best course of action is to adjust three or four spokes by a quarter or eighth turn, rather than one or two spokes by a half turn.
Miscellaneous Notes and Considerations:
1. Truing ‘race’ wheels. As noted above, carbon rims behave differently than aluminum rims, especially when it comes to radial truing. The other thing to consider is that most ‘race’ wheels usually have fewer spokes than training wheels. Fewer spokes means that your adjustment points are fewer and further between. Translation: It’s harder to make them as true as training wheels. That’s life. You must be more precise with your adjustments and live with the fact that a 16 spoke wheel might never be as true as one with 36 spokes.
2. When replacing a broken spoke, you should always reduce the spoke tension of the entire wheel. If you simply replace the one spoke and bring it back up to tension, your chance for problems later on goes up. I reduce the entire wheel’s tension by about 50%, replace the spoke, and bring everything back up to tension together. If you’re using alloy nipples – yes, the chance for breaking one goes up compared to brass.
3. Retaining compounds. Should you use one on the spoke threads? I’ve tried everything under the sun – linseed oil, Spoke Prep, regular oil, Loctite, etc. When building new wheels, I’ve taken to using a tiny amount of oil on the end of the spoke threads before beginning assembly, and then using a little bit of low strength Loctite when the build is complete.
If I am truing a wheel (not building from scratch), I normally do NOT use a retaining compound. Often times the manufacturer used one of their own during building, and I don’t know whether it will mix well with mine. The exception to this is the case of a particularly problematic wheel. If spokes keep loosening over and over, I Loctite them (but it’s rare).
All images © Greg Kopecky / slowtwitch.com
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