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-   -   Used hub relacing--when the gouges don't line up . . . (https://www.bikeforums.net/bicycle-mechanics/995349-used-hub-relacing-when-gouges-dont-line-up.html)

ClarkinHawaii 02-23-15 02:08 PM

Used hub relacing--when the gouges don't line up . . .
 
Seems like I read that when you're relacing a used hub that has gouges from the previous spokes, you should line up the new spokes so they fit into the old gouges.

Unfortunately I only know one way to lace wheels--I go to Sheldon and follow him very carefully step by step:
Wheelbuilding

What if following Sheldon step by step results in not using the old gouges? I can see where it would be cosmetically undesirable, but might actually prolong the life of the hub, no?

If it is definitely better to stick with the old gouges, is there a quick tip how to orient the hub/rim so as to follow Sheldon's steps?

I know I could figure this out for myself if I had leisure time, but this stuff always comes along when I have work backed up and they need it yesterday and my brain is befuddled and I can't even hardly think straight!

Thanks for your help.

dabac 02-23-15 02:39 PM

Thing is, the old furrows work as something called stress risers, a point from where cracks are more prone to start. So while giving the spokes a new resting place with new material to wear at might certainly seem like a good idea, it actually isn't. You're just creating a double set of stress risers. And since the first ones aren't getting bigger any longer, you're not improving things by starting a new set.

With that said, I have relaced in another pattern and not had any trouble from it.

ClarkinHawaii 02-23-15 02:44 PM


Originally Posted by dabac (Post 17578853)
And since the first ones aren't getting bigger any longer,

This is interesting and counterintuitive.

79pmooney 02-23-15 02:52 PM

But by not using the existing gouges in your hub you are violating some cardinal laws, enforced by both engineers and purists. Your flanges may break. The certainty is that you will carry this bad karma into your next life.

I've transgressed in this lifetime. I have learned not to mention it or show that detail of my wheelbuilding to anyone. Since I no longer own any of those wheels, I will just deny, deny, deny till I die. Maybe that will work.

Ben

BCRider 02-23-15 02:55 PM

What's wrong with following the original lacing method and re-using the existing marks? It may require a bit of trial and error to mate the existing marks to a spoke pattern but it doesn't take all that long before it makes sense.

It also fits in nicely with a commonly used method of taping a new rim to the old rim and just moving the spokes over to the new rim. If the spokes are not damaged and if care is taken to match the old and new rim's ERD this method works very nicely. I've done this in the past on commuter wheels. And a local bike shop used this method frequently back when dirt bikes used rim brakes and wore out rims in muddy areas so often that it was almost the norm to replace the rims about the same time the tires wore out.

If working with a hub only with no rim it can begin to get more interesting. But since 3 cross patterns are the most common found it shouldn't take a whole lot of trial and error to figure out how to match up the marks to produce a 3 cross that matches the existing marks. The worst that will occur is that you end up with the outer spokes and inner spokes not matching the trailing and leading pattern suggested by Sheldon. While not perfect I'd suggest it's better to "go with the flow" and use the hub the way it was originally used instead of trying to be perfect and ending up with more pressure marks in the hub. It's the lesser of two evils.

79pmooney 02-23-15 03:01 PM


Originally Posted by BCRider (Post 17578904)
What's wrong with following the original lacing method and re-using the existing marks? It may require a bit of trial and error to mate the existing marks to a spoke pattern but it doesn't take all that long before it makes sense.

It also fits in nicely with a commonly used method of taping a new rim to the old rim and just moving the spokes over to the new rim. If the spokes are not damaged and if care is taken to match the old and new rim's ERD this method works very nicely. I've done this in the past on commuter wheels. And a local bike shop used this method frequently back when dirt bikes used rim brakes and wore out rims in muddy areas so often that it was almost the norm to replace the rims about the same time the tires wore out.

There are certain things I always do on wheels I build. Right hand pulling threads head out is one. My experience is that considerably less damage happens when a chain goes between the cogs and spokes, especially to the frame. If I pick up a used hub and those were run the other way; well frames come before hub beauty, or even next life karma.

Edit: Taping rims? I do that all the time. But not until I like the spokes used and the pattern.

Ben

BCRider 02-23-15 03:15 PM

The one time I had a chain fall into a wheel like that it resulted in a ruined wheel with lots of broken spokes. The frame survived with no issues. So did the rider that was test riding the bike towards possible purchase. Fortunately no injury occurred. Just a few anxious moments. We both apologized to each other. Me for not checking the bike over a bit more thoroughly and putting him at risk and he to me for breaking my bike.

Since thenI've been a staunch and eager user or the classic "dork disc" as cheap insurance against damage or injury in a chain fall off situation.

Of course using a disc means I can lace the hub as it was originally without an issue.

Bill Kapaun 02-23-15 04:12 PM

The word "gouge" makes me shudder.
How about "witness marks"?

Maybe the hub was laced to a rim with eyelets pointing the opposite direction, where you start on the 2nd hole from the valve instead of the 1st???

ClarkinHawaii 02-23-15 11:14 PM

Thanks, everybody--

New and different model rims together with new spokes and old hubs in this case.

What I'm gonna do is take a series of close-up pictures of the old setups before I cut the spokes and then just rebuild both new wheels exactly like the old ones. Should work. I mean . . . should . . . I mean . . . right?

dabac 02-24-15 04:11 AM


Originally Posted by ClarkinHawaii (Post 17578866)
This is interesting and counterintuitive.

Think of it like this:
You have the pristine hub with all its original metal still left in its rightful place.
Whichever way you pull/push/twist it, it's at its strongest.

Now you add the spokes, put tension to them.
Like a dog getting ready to sleep, they bed down, pushing some metal out of the way as they do so.
Now you're once removed from optimal strength.
In a little way through material removed. In a slightly bigger way by providing a point where cracks might start.
Pretty much like frame tubing beginning to crack around water bottle mounts or small dings.
Or the little nip where you start to tear a snacks bag open.
But once bedded in, the damage is done. There isn't any more material removed. The hub isn't getting any weaker.
Add mileage, see if the hub survives.
If it does, apparently once removed from optimal strength is still strong enough.

Now, relace in another pattern.
The first damage is still there. The hub doesn't heal.
The process starts over, but this time you already have one set of stress risers and gets another one. And another direction for the spokes to pull at the hub
Now you're twice removed from optimal strength. And at another pull angle.

Maybe the hub is still strong enough, maybe it isn't.

It'd be different if the spokes kept fretting at the hub, then it'd be growing damage. And eventually a swap might make sense. Like early sprockets could be flipped over and act like new.

dabac 02-24-15 04:28 AM


Originally Posted by ClarkinHawaii (Post 17578743)
Unfortunately I only know one way to lace wheels--I go to Sheldon and follow him very carefully step by step:
Wheelbuilding

Among all the good stuff at SB, I didn't find that one particularly useful.

if you look at a cross laced wheel, you'll see that spokes come in pairs, one heads-in one heads-out, that run almost parallell.
And as you want the valve to end up between such a pair, it seems like a good place to start.
For a 36H, 3X, these spokes will be six holes apart at the hub, and have one empty hole in the rim(and the valve hole!) between them.
So I pop these in, and they become my reference spokes.

Then it's easy to add the rest, starting with the heads-out spokes. Where they go in the hub is (close to) self-evident, and where they hook up to the rim isn't much more difficult.
But I'd need a moment with a wheel in front of me to tell you the number of holes in the rim between each heads-in/out spokes from the same hub flange. My eyes know the pattern so the brain doesn't have to remember - five, maybe.

For a 2x pattern, the parallell spokes start out with a 4 hole separation.

Trakhak 02-24-15 06:08 AM

Back when Campagnolo offered lifetime warranties on their products, the list of exceptions included flange failures in hubs that showed multiple sets of gouges of the kind described in this thread.

ClarkinHawaii 02-24-15 07:09 AM


Originally Posted by dabac (Post 17580425)
Among all the good stuff at SB, I didn't find that one particularly useful.

if you look at a cross laced wheel, you'll see that spokes come in pairs, one heads-in one heads-out, that run almost parallell.
And as you want the valve to end up between such a pair, it seems like a good place to start.
For a 36H, 3X, these spokes will be six holes apart at the hub, and have one empty hole in the rim(and the valve hole!) between them.
So I pop these in, and they become my reference spokes.

Then it's easy to add the rest, starting with the heads-out spokes. Where they go in the hub is (close to) self-evident, and where they hook up to the rim isn't much more difficult.
But I'd need a moment with a wheel in front of me to tell you the number of holes in the rim between each heads-in/out spokes from the same hub flange. My eyes know the pattern so the brain doesn't have to remember - five, maybe.

For a 2x pattern, the parallell spokes start out with a 4 hole separation.

Thank you for taking the time and trouble to write all this out . . . I'm bookmarking it for further study when time allows!

Bill Kapaun 02-24-15 07:23 AM


Originally Posted by ClarkinHawaii (Post 17580232)
Thanks, everybody--

New and different model rims together with new spokes and old hubs in this case.

What I'm gonna do is take a series of close-up pictures of the old setups before I cut the spokes and then just rebuild both new wheels exactly like the old ones. Should work. I mean . . . should . . . I mean . . . right?

What if the old rim is RH and the new LH (or opposite)/
To quote Sheldon-
"As viewed from the right (sprocket) side of the hub, the key spoke will run counterclockwise, and it will go to either the hole just to the right of the valve hole (as illustrated) or the second hole to the right, depending on how the rim is drilled."

dsbrantjr 02-24-15 07:29 AM


Originally Posted by BCRider (Post 17578960)
The one time I had a chain fall into a wheel like that it resulted in a ruined wheel with lots of broken spokes. The frame survived with no issues. So did the rider that was test riding the bike towards possible purchase. Fortunately no injury occurred. Just a few anxious moments. We both apologized to each other. Me for not checking the bike over a bit more thoroughly and putting him at risk and he to me for breaking my bike.

Since thenI've been a staunch and eager user or the classic "dork disc" as cheap insurance against damage or injury in a chain fall off situation.

Of course using a disc means I can lace the hub as it was originally without an issue.

My name is Don, and I am a dork disc user...

ClarkinHawaii 02-24-15 07:49 AM


Originally Posted by Bill Kapaun (Post 17580606)
What if the old rim is RH and the new LH (or opposite)/
To quote Sheldon-
"As viewed from the right (sprocket) side of the hub, the key spoke will run counterclockwise, and it will go to either the hole just to the right of the valve hole (as illustrated) or the second hole to the right, depending on how the rim is drilled."

Oh, God, I don't know--wouldn't work, huh?

Bill Kapaun 02-24-15 08:16 AM


Originally Posted by ClarkinHawaii (Post 17580651)
Oh, God, I don't know--wouldn't work, huh?

I haven't built a wheel for a bunch of months.
Not going to go out to the cold garage and do the mental gymnastics trying to figure it out.
You're the one in Hawaii-

That might be the cause of your initial problem that i tried to point out earlier.

reddog3 02-24-15 09:05 AM

Lacing a new rim to a used hub, and following the existing wear pattern is elementary, and "stuff" a wheelbuilder just knows.

By selling your services building wheels and such, you are labeling yourself as a wheelbuilder. If you need to follow a tutorial to lace wheels maybe you are not ready to do business.

There's nothing wrong with asking questions of this forum, but hopefully you take some time and learn the basics before charging for your work, Just sayin'...

melloveloyellow 02-24-15 11:06 AM

I've laced several used hubs, using Musson's book/technique. When a hub's old wear marks from previous spokes don't match the placement of the new spokes, start over and work from the opposite side. This applies to rear hubs, too. If your instructions state to begin with the right side facing you, just begin with the left, and follow the instructions, switching the words "right side" and "left side". DO NOT forget to place the correct spokes into the correct flange if they are of different lengths.

Clearly, I am not a bike mechanic by trade. This was not intuitive to me until I did it. If I've somehow missed the OP's point, my apologies.

PS: I looked at Sheldon's instructions. If you want to match up the old "gouges" in the hub, put a piece of tape on the left (non drive) side of the hub, label it "right", and follow his instructions while pretending that the tape marks the drive side. This may avoid confusion.

Retro Grouch 02-24-15 12:23 PM

What kind of hub?

If I was working with a run-of-the-mill Shimano hub or something like that, I'd just clean up the divots a bit with a fine tooth file and lace them up however I like. I've done it several times and had no failures that I'm aware of.

FBinNY 02-24-15 01:04 PM

I've seen flanges crack when laced in new patterns, but most of the time they don't. So I rank following the old pattern as preferable, but not critical. It's just a good thing to do, unless it's impossible.

One reason I won't or can't follow the old pattern is when the right/left sequence on the new rim is reversed from the old. That mean I can't follow the old pattern at the hub and have the valve hole where I want it. In those cases I'll follow the pattern on the right (tighter) flange, and reverse it on the left.

Also, there's the qustion of whether "pulling" spokes are inside or out. I prefer building pulling elbows out, but many of the hubs I'm given were last laced elbows in. For these, I'll make a judgement call based on cosmetics and other factors, but usually follow the old pattern since it's not critical to me anyway.


BTW- the OP itself raises another question. I've often referenced my dislike (nearest word) for paint by numbers mechanical teaching or work. While this may serve a purpose, at some point mechanics have to develop an understanding of their work, and be able to work freehand. Put another way, someone who navigates by GPS never learns about the area he's operating in and can remain dependent on GPS forever. But if someone makes the effort to learn the area, including landmarks, and other navigation clues, he'll never be lost.

My advice, follow the old marks in the hub and force yourself to wean away from the one single method you know so far. It'll do both you and the wheel some good.


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