krawfo

Newbie here. I just finished truing ther rear wheel of my bike and have it within 2-3/1000" and for my purposes that's just fine. I then switched to the front wheel and it seemed like it was a case of "one step forward and two steps back". There is a visible wobble when I spin it.
Can anyone give me some general guidelines on getting this wheel true again.
A couple of points of reference that I'm using:
- The tire is inflated, on the rim and on a home made truing stand.
- I'm using a dial indicator with a magnetic base to determine which way to move the rim.
- I'm going on the assumption that turning the nipple counter-clockwise will tighten a spoke and pull the rim to that side.
Any help will be most appreciated.

OldBike876

The nipple threads onto the spoke, so be clear in your own head that you are turning the correct way. I tend to consider sets of spokes rather than individuals. If a spoke seems to need adjustment, check the spokes next to it as well. The process takes a long time and involves about a trillion adjustments at 1/8 of a turn each.

Moe Zhoost

Lot of art involved with this, so a short post probably won't provide a lot of savvy. That said, I offer the following:

1) Is the wobble in the wheel the result of damage? If so, it may never be right. You can usually achieve 'good enough' though.
2) Are the spoke tensions pretty much equal? You probably don't have a tension gauge, but if you ping on the spokes with a tool, they should have a similar pitch. If you find a few that are off, address them first.
3) Are you sure that the wobble is in the rim and not the tire? Sometimes you see a tire that is a bit off, either because it's not seated or it's just wonky. I usually like to demount the tire before truing.
4) You didn't say if your wobble is side to side or up and down. Side to side is easier to address. Up and down (for me) is a bit harder.
5) Use small adjustments as @OldBike876 recommends. An eighth turn at a time is what I do.
6) I tighten a spoke by turning the nipple clockwise, but that's related to my frame of reference. I look at the nipple as if it is a nut being screwed onto a long thin bolt.
7) Sometimes it's easier to de-tension all of the spokes and start from scratch.

Good luck and welcome to BikeForums

krawfo

Moe and OldBike, thanks for taking the time to respond.
I believe the rim is in fairly decent physical shape. There's no obvious (to me ) damage.
I've read about the pros and cons of truing a wheel with vs without the tire on. My theory in doing it with the tire on is that putting a tire on a trued rim and then inflating it will induce some stress that could "untrue" the rim.
When I decide to tighten or loosen a given spoke I usually make an 1/8 turn on that spoke and then do ~ 1//16 turn in the opposite direction to the spoke on either side of the one tightened. Not sure if that's good or bad.
Interesting point about pinging spokes before starting. I have noticed that just by feel, some spokes feel a bit tighter or looser than the rest.
All the wobble I was perceiving is side to side and was pretty easy to quantify using the dial indicator. I'm trying to figure out how I would use it to measure radial irregularity.
I've managed to get the wheel within about 7-8/1000". For a casual rider on a hybrid bike just trying to get some exercise I'm hoping this is good enough.
Again, thanks for the help.

Lombard

It hasn't been mentioned, but in case you're not aware, spokes under tension will twist somewhat as you turn the nipples. You need to compensate for this when you turn a nipple. If there is any spoke twist, it will untwist as soon as you stress relieve it or ride on the wheel which will throw the wheel back out of true.

Tires are never true. I prefer to build and adjust without the tire on the wheel as the tire will confuse the eyes.

Spoke tensions need to be relatively equal. If they aren't, it won't be long before the wheel goes back out of true.

If you don't have it already, Roger Musson's e-book "Professional Guide to Wheel Building" is well worth the $12. It comes with lifetime updates:

https://www.wheelpro.co.uk/wheelbuilding/book.php

Follow his directions to the letter and you won't go wrong.

79pmooney

Are you checking for spoke tension? This a re-truing of an older wheel, right? Do you know that it was built well?

If your answers are "no", "yes" and "don't know" then the very first thing you should be doing is looking for spokes that are tighter that the rest or looser than the rest. Easy way to do that (if you can hear pitch; not all can). Pluck the spokes roughly in the middle, either with your finger like a bass player or by tapping with your spoke wrench. Mark the spokes. Now, before you do anything else, see if the rim wobbles correspond to the "bad" spokes. If so, adjust those spokes until they sound like their neighbors. (In back, only compare the pitch to spokes on that side; ie drive side or non-drive side.)

Very often, doing just that will do 90% of the truing needed. (You may have already made a mess of thing and need to address the wheel as a new project. I leave you to the others here if that is the case.)

krawfo

Thanks Mooney and Lombard for the info and suggestions. The rims are Mavic Ksyriums . A friend gave them to me last year. They are older rims but were taken off a practically unused bike and sat in his basement for a number of years. I assume these a relatively decent rims.
I pinged the spokes but to my ear, I can't pick out individual ones that seem especially high pitched or dead. I'll try again later after the coffee kicks in.
I'm using a dial indicator and set the tip on the middle of the rim margin. I've got this wheel within 7-8/1000". I know less is better but practically speaking what is an acceptable amount of runout?

Lombard

Older Mavic Ksyriums were good. Newer ones aren't so good.

8/1000" is 0.2mm which is pretty good. Roger Musson considers these specs good:

Lateral trueness: 0.2mm
Radial trueness: 0.5mm
Dish: 1mm

krawfo

Thanks Lombard. That helps a bunch knowing I’m in the ballpark.

Lombard

More like the strike zone.