bikerbobbbb

I haven't done anything with truing on this yet. Something is still confusing me I think.

The last time I touched this wheel for truing was late at night. I probably adjusted things backwards and the wheel now pulls to the left, enough so to rub on the brake. (I've got all new spokes on the way. I'm waiting for those to come in before I mess with truing this for now, esp considering what might be confusing me.)

So wheel pulls to the left a lot. To far to the non-drive side.

My inner tube popped today, so I took some pics of the dish tool while the wheel was off.

I lined up with the drive side/cassette/right side since that's shorter than the non-drive side. Then on the non-drive side, the difference is about a 2cm gap.

I pulled the skewer out and measured on the end of where the skewer goes in.

None of the spokes are too loose now. By that I mean they don't wiggle. Judging by hand, they have some tension on them.(I did take measurements on the spoke tension. That's in another thread.)

Something is confusing me about the general process though. If I wanted to adjust this, I would want the hub to move closer to the non-drive side, right? To close that 2cm gap. I could do that by increasing tensions all around on the non-drive spokes or by loosening tension on the drive side spokes. But if the wheel itself is already pulling to the left... I'm wondering if that's the solution. It probably still is. I've never messed with dishing before. I don't want to do anything until I've got all the new spokes in. Then I'll experiment with this current set up. If it messes up, they're old/used spokes.

Or is that correct...? If I pull the hub close to the non-drive side to close that gap, then when the wheel sits in the frame, it will be more centered, not so far off to the left that it rubs on the brake? I could see that but my brain is also saying it's moving the hub and everything closer to the left too.

When I do mess with this, I'm thinking I'll loosen all the spokes up around the wheel, then focus on getting the dish right, gradually tightening them. Then focus on truing. Check dish, check truing, back and forth, narrowing in on being more precise. I'm concerned I'll go through that process though, stick the wheel back on the bike, and then discover it's really off and rubs on the brakes even more or something, something potentially where I couldn't use the bike then at that point.

What do you think? I'm sure these pics are freakish for some. And yes, I'm planning on fixing this. It's going to be waaaay less effort to pedal once the wheel is true again (with correct dish though too).


These pics and spoke tensions numbers in the other thread will be my "before" pics/specs.

techsensei

The rim is definitely not centered over the locknuts, but that has nothing to do with the wheel pulling to one side(?!) during pedaling. The rim needs to move half the measured distance to the left. In other words, you need to tighten the non-drive side spokes and/or lossen the drive side spokes.

BTW, your cassette cogs look really worn out

fietsbob

yea remove the cassette , its way out of dish 3 and 5 should have the gage on the dish stick touching..

I use the face of the lock nuts rather than the end of the axle

You have to dish a Hub a Lot for all those 'speeds', on the drive side , Or as done on tandems,

in a much wider frame there is a longer axle and a left side spacer added ...

then a Less Dished wheel is centered..

Kopsis

1. Normally you measure dish to the outer face of the locknut, not the end of the axle. This is because the locknut faces are what meet up with the dropout to determine the hub location in the frame. The bits of axle sticking out past the locknuts may be the same on left and right sides, but no guarantee.
2. Learning the names of the parts would allow you to explain things more clearly.
3. It's best to think of the hub as "fixed" (since it can't move within the frame) and make adjustments to move the *rim* the direction it needs to go relative to the hub. You have a big gap on the NDS, so the rim needs to move toward the NDS. You do that by shortening the NDS spokes and lengthening the DS spokes.
4. You can't tension/true piecemeal. You need to keep some semblance of lateral and radial true as you gradually bring up spoke tension. You also need to maintain dish. Some expert builders will say you can tension DS to about 80% of target then use just the NDS to set dish. That doesn't apply to you.

You really need to understand the relationship between spoke length, tension, and wheel geometry. You also need to be doing things incrementally. When there's very little tension in the wheel, you should never be doing more than one turn on a spoke at a time. As you near full tension, 1/8 turn is a typical adjustment, 1/4 turn is a big adjustment. Each time you go around the wheel adding tension, check lateral true, radial true, and dish and adjust as necessary. You should be getting the idea that this is a very slow, methodical process. Experts can describe all kinds of shortcuts to do it more quickly -- you're not an expert. Wax on, wax off.

jyl

Clean that wheel. Dish soap, warm water, and a rag. Working on dirty parts is unpleasant, your hands and tools get filthy.

Put two drops of oil on each nipple, where the spoke enters the nipple and where the nipple exits from the rim. This helps avoid nipples sticking on the spokes, which causes each turn of the nipple to simply twist (wind-up) the spoke instead of moving the nipple on the spoke threads.

Remeasure dish, using the locknuts instead of the axle end.

To move the rim toward the DS (if that is what the measurement shows) you need to tighten the DS spoke nipples and loosen the NDS spoke nipples. You have a truing stand, right? Put the wheel in the stand, DS facing to the right. Assess the radial and lateral true of the rim.

Fix the radial true first. That always comes first. Get it as close to perfect as you want the finished wheel to be.

If the wheel is laterally very untrue, fix that next. Don't need to get it all the way laterally true, but get it roughly trued, like to 3 or 4 mm. If the wheel is very laterally untrue, it is hard to accurately measure dish.

Fix the dish next. Get it close, like to 2 mm.

Then get the wheel all the way laterally true. You need to keep rechecking dish, spoke tension, and radial true as you do the lateral true. It is possible to pull a rim to be laterally true by only tightening some of the spokes, leaving other spokes much too loose, you want to avoid that.

Small turns, 1/4 and 1/8. It is a iterative process.

You want lateral true to within 1 mm. Dish should also end up to within 1 mm or less. Same with radial true. Less is better, but 1 mm is the minimum tolerable standard you should aim for.

That's my process, anyway. I don't know if it is the best process, but it works.

dsaul

You are thinking of this wrong. Tightening spokes pulls the rim toward the hub flange that the spoke is attached to. You can't think about it as moving the hub. You have to think about it as moving the rim. In your case, you have the non-drive spokes too tight. To correct that, you need to loosen the non-drive side and tighten the drive side.

The spokes on the non-drive side will always have less tension than the drive side, due to the offset of the hub flanges for the cassette. If you try to make them all even tension, you end up with an off center rim like you have now.

FBinNY 

I like to build mechanical knowledge the same way as a house by starting with a good foundation. So let's start by understanding what dish is about.

1- Wheels need to be symmetrical between the faces of the locknuts so the rim is centered in the frame or fork.
2- If a wheel is built with equal tension on both sides the rim will end up centered between the flanges.

In front wheels both conditions work together, because the hub is symmetrical. So centering the rim between the flanges automatically centers it between the locknut faces and by extension the fork.

In rear wheels both conditions can't be met at the same time because the hub isn't symmetrical. Because centering in the frame is paramount, we need to compensate for the hub's asymmetry by moving the rim off center between the flanges. Since the flanges are offset to the left, we move the rim closer to the right flange by having more tension on that side. This moving of the rim away from it's position centered between the flanges is what we call dishing.

So understanding the basics, we apply that to using the dishing tool. First and foremost, measurements are taken of the rim's distance from the locknut face since that's what determines the position in the frame. The wheel in the photo has the rim closer to the left, so it needs to be moved right by loosening left spokes and tightening right spokes. As a matter of good practice, you want to do this by degrees rather than trying to guess what it will take to move it far enough. Also, so as to work with looser rather than tighter spokes always loosen the spokes on the too close side (left for this wheel) before tightening the other side. If the rim was basically true before, preserve that by being careful to move each nipple the same distance, ie. 1/2 turn. Retrue roughly before checking the dish because you can't get meaningful readings if the wheel isn't true.

jyl

What's the spoke tension? I can't find the other thread.

Edit: I found it. https://www.bikeforums.net/bicycle-me...l#post18699544

Your DS and NDS spokes are the same tension overall, which is why your wheel is so badly out of dish.

Get the spoke tensions to be roughly consistent on the DS, and roughly consistent but lower on the NDS. When the wheel is properly dished, the NDS spokes will be something like 2/3 the tension of the DS spokes, assuming overall tension is reasonably close to final. Then when you are doing the final truing, if you have a choice between loosening a spoke or tightening the adjacent spoke, make the choice that increases the consistency of tension and brings overall tension up to final desired level.

When deciding on desired tension level, figure on around 110-120 kgf average for DS. Don't know what rim you have but this should be okay for most sturdy modern rims. Translate that to the numbers on the Park tool based on spoke gauge. Final tension should be consistent to within about 2 points on the tool scale (e.g. all DS spokes in the range of 21 to 23). More consistent is better but 2 points is good enough.

When doing the final adjustments, turn the nipple a little farther than needed, then turn it back. E.g for a 1/8 turn adjustment, turn 1/4 turn then back it off 1/8 turn. This helps reduce spoke windup. May not be an issue if you are using thicker gauge spokes.