Repairing a $20 Schwinn Ranger
 

I'm trying my hand at wheel truing. I bought a $20 Schwinn Ranger off craigslist - and now I'm attempting to true the wheel. Looked at a few videos online before I tried this. The wheel in the video below was fairly out of true. If you look at the video now, would you say the wheel is still badly out of true? There seem to be some scraping sounds that the camera picked up, but I'm not able to detect myself so far.

https://picasaweb.google.com/113076625055999932909/Bike?authkey=Gv1sRgCJDjn63zv7iNuwE#5820473833358084690 Edited to add:
This thread will now be used not just for the wheel truing, but to ask any other questions related to the same bike as I work on it to learn wrenching, and hopefully improve the bike! I don't want to create a new thread each time. I can't update the title of the thread to reflect this though.

The bare minimum standard for a passably true wheel, is that it can clear reasonably adjusted brakes without ever rubbing. Better yet, pass closely adjusted brakes with room to spare on both sides.

On new wheels, I shot for 1/2mm TIR (total wobble), but for repairs 1-2mm is passable, if the wheel started in bad shape.

More important is radial alignment since you can feel high and low spots as you ride. Here I try for well better than 1/2mm, or to where the joint distortion is the worst spot. This applies to both new wheels and repairs.

Looks ok to me. All depends on how anal you are about it but is not that bad to me, seen worse.

Looks fine.

All the spokes on the same side of the hub should feel about the same tension.

In a perfect world,both sides of the wheel should have the same tension,but it doesn't always work that way,especially on the rear wheel or with disk brakes.

Looks fine. Give it a ride. Listen for pings. Then check the true/round again. Is it holding? If so, then you've done good.

+1.

.5mm is also always my goal on lateral true. I get better than that most of the time, but that is where I consider a wheel "good enough".

This thread will now be used not just for the wheel truing, but to ask any other questions related to the same bike as I work on it to learn wrenching, and hopefully improve the bike! I don't want to create a new thread each time. I can't update the title of the thread to reflect this though.

I took it for a short ride - seems to have held up. Need a longer ride though, which will be challenging since the bike isn't my size - its too small. It was bought just for my wife to figure out if she can still bike :) We will probably get her a new bike now, so this one is mine to mess around with.

The brakes seem to have improved a lot. I had ridden it before, but the stopping power of the brakes seemed so much better now.

Next: change the rear shifter - the current one is broken. I'd like to change the rear cassette/freewheel too (not sure what it is at the moment) - so I'm going to be looking at ebay lots I think. 7 speed parts are really hard to find though, how do I figure out whether I can move the bike up to an 8 speed in the rear?

Is the shifting indexed? If so then for most reliable shifting the shifter (lever or grip), cog set, likely rear deraillure will all have to be replaced to keep within the family of index compatibility. If the bike is friction shifted then just the cog set. Either way the chain might not mesh well with the new cog teeth and might also need replacement. In the shop I work at and out suppliers 7 speed parts are readily available. Maybe not in the nicer grades but still easily gotten. Andy.

Shifting is indexed on the rear, friction on the front. 8 speed used parts are pretty cheap on ebay, even if means more changes. There seems to be plenty of space between the rear dropouts, so that may not be an issue. I'll go around to the LBS or Performance and have a chat, see what I can find.

I kinda messed up the rear wheel. I did (what I felt) was a better job on the front, so I went to do some minor tweaks to the rear and messed it up quite badly - it is now worse than it was before. Grr. Took a break - been a long day and I'm clearly not thinking right. So two steps behind on that one. And I think I also rounded off one of the nipples while turning - didn't really apply too much strength. Does this mean I have to change it? Can I just remove that one spoke and change the nipple? Assuming I can just buy that one ..

I wish there was a co-op close by. The closest is San Francisco - I tend to have free time in max 2 hour chunks (have a busy, busy toddler) so going to SF for a co-op isn't really possible.

Truing a wheel is comparable to medicine via the adage "first, do no harm". If you do not know what you are doing, things can go south in a hurry. If I were you, I won't touch that wheelset with a spoke wrench until I have a general idea what is wrong and how I can fix it. There are many tutorials on YouTube about wheel truing. I think you should start there.

You can get replacement nipples, no worries.

If you've screwed it up, often the best idea is to back off all the tension until the threads all just start to show, and add even amounts of tension. Start at the valve, maybe two or three turns to start with, and tighten the drive side until it just begins to firm up with the beginnings of some tension (as opposed to being a floppy mess). Add tension to the NDS and it should be somewhere near the correct dish. Flip the wheel in the frame to figure out which side you need to add tension to. By the time you have it dished it should be pretty tight (it's hard to get much tension into the NDS spokes, you should be able to get more of a ping than a plunk). If the rim isn't damaged the wheel should only need minor truing at this point.

FB-
do you mean total summed runout (deviation from true) of the left AND the right side of wheel, or just the runout on a side?

The acronym TIR means total indicator readout, so is the measure from low to high. It could be double the runout of either side from center if the deflection is symmetrical, but remember that one side may be where it belongs and all the error on the other.

One way to look at this is to imagine spinning earth. The highest mountain is 29,000' above sea level, but if you were to run an indicator on Earth it would bottom at Challenger deep at 36,000' so the total TIR would be 65,000', and the sea level not the mid point. TIR is useful as a measure of error, but if you were truing Earth, you'd do more correction on the depth side, than at the mtn side.

BTW- question, if, with global warming polar ice raises sea level, does that mean that all the mountains just got shorter?

You can look at ParkTool's website. They have a good repair section, then come here if your stuck.

http://www.parktool.com/blog/repair-help

The physical measurements of the mountains won't change. Having said that, sea level is always the reference point, which means the reported height above sea level will change. I am not a geologist, just thinking out loud here.

Ground elevations and sea floor depths are measured from mean sea level, half way between high and low tide. Mean sea level is not a constant around the earth, so any "official" elevation must be relative to some standard. Standards vary from country to country, how the measurements are made and various corrections are applied. Here is some interesting information on the subject.
http://en.wikipedia.org/wiki/Sea_level
When sea level changes significantly it will be necessary for all sea-level elevations and depths to be changed accordingly. As sea-level rises mountains will become lower and ocean depths will become deeper even if the land masses don't change. To complicate things more we know that continents and sea floors do change.
You don't need to trade you bike for a boat, just keep riding.

I know that may be convenient for you, but both those who wish to learn and those who provide help may have particular specialties or interests that determine which threads they read. Your approach makes it impossible to filter accordingly, which may deprive you of the best help, as well as being a less constructive use of time for others.

Also something not mentioned above is that a proper true job consists of not only true, round and dish, but also a sufficient and consistent tention level so as to keep the wheel in that condition. If one gets a wheel very true but with insufficient or uneven tension it will not stay that way for long.

Finally, when learning any new procedure you are ill-served merely following directions. You need to think as you are doing things about the why, not just the how of what you are doing, or do enough studying that you find sources that explain the why. For example:

If you tighten a spoke it moves the rim toward the side the spoke is on - but why? The answer of course is that it effectively shortens the spoke, and because the other end of the spoke is offset to one side from the rim the rim moves in that direction. But because it shortens the spoke, and the spoke is effectively inside the rim, it also moves the rim toward the center. That is why you tighten and loosen in pairs, and that knowledge is much more helpful than "always tighten and loosen in pairs."

The same thought process applies to your problem getting the rear wheel true and rounding off of the spoke. The fact that you rounded off a spoke trying to get a spot true indicates the rim may be physically bent, and you may well have uneven tension because you used the spokes to try to pull it into shape. If you have to crank down on one spoke there has to be something resisting movement. If the spokes on the other side are looser then the rim must be bent away from the spoke. The spokes are there to align the rim to the bike, rather than to align the rim itself. If the rim itself is not true (flat) and round then it either needs to be replaced or physically bent back.

Thanks. I'll start a separate thread for other queries - I thought that would be more inconvenient to others, though convenient to me :)

I am reading more theory before trying again, thats one of the reasons I took a break. It is possible that the rim is bent, but in that case I probably will not buy a new one - this bike is more for experimentation and I doubt I'll spend much more money on it. W.r.t rounding off the spoke - it is possible that I cranked down too hard, but it didn't feel like it.

Is there any way to tell if the rim is bent (at home) without unlacing the hub and laying the rim flat on a table? Again, I'm happy if its a reasonable test - I'm not flush at the moment, so buying new tools is out for now. Also, I may never become any good at wrenching - this bike is a kind of testing ground - if I enjoy it and don't suck at it too much, I will start investing in better tools.

It's very easy to crank down too hard. You're dealing with a 2mm fine pitched screw, so unless there's a sticky thread the spoke wrench torques are pretty low. Rounding is common when turning right side rear spokes since the combination of high tension and nipple friction can make nipples hard to turn. Many builders switch to a 4 corner spoke wrench for right rear spokes, especially when working on an older wheel. After a while you develop feel and sort of know what the nipple can take without rounding, but even the most experienced wheel builders round off nipples once in a while.

Sometimes based on the extent and nature of the wheels problems you can predict that the rim is bent, but when there's no local distortion, and the wobble is gentle over large sections, the rim is likely OK or reasonably so. You find out the condition of the rim as you work by having a sense of what it takes in spoke tension to compensate. A straight rim will align with fairly even tension. A bent rim requires uneven tension to compensate for the rims resistance to straightening.

IMO- it takes far less skill to build decent wheels than it does to align wheels, especially those which are older or in worse condition.

FB-
Too complicated for me...Suppose left side is out of true(relative to wheel centerline) by 0.020" and the right side is also out of true by
0.020", then TIR is 0.040"? Or, is TIR just for one side, only? Just want to be sure...

TIR is the TOTAL difference high to low, or left to right, so in your case it's 0.040. Note that TIR doesn't tell you where the average or center is, so a TIR of 0.040 could be 0.010 in one direction and 0.030 in the other.

No need to unlace - logic will tell you the story. Again, if on a particular section of the rim you have to tighten spoke(s) on one side more than on the rest of the wheel there has to be something resisting movement to that side. If the spokes on the other side are loose then the rim must be bent in that area. Same thing applies if there's a flat/low spot on the wheel. If the spokes are loose then the rim has been pushed in at that point.