Question for the wheel builders

[Tony T]

Is this rear hub laced correctly?
Took the wheel to a LBS to have it trued (after the 2nd popped spoke), and I was told that the rear drive side is laced backwards.

Here's a pic:

[zacstanley]

Sort hard to tell from the pic. But the alternating head up/head down configuration looks correct. From what I can tell the lacing looks correct as well.

Did they suggest another lacing pattern?

Zac

[Marburg]

Definitely wrong. Send it to me and I'll ensure it's properly destroyed ...

Sorry. Looks right to me unless there is literally a mistake in the lacing pattern. I _believe_ that having the "pulling" spokes (the ones that point backwards) head-in (as you have) is a better configuration due to the slightly wider bracing angle, but I also suspect anyone who tells you it _must_ be that way or else is trying to sell you something.

[ultraman6970]

You need to put a picture of the whole wheel to start with, then the driver side but from the side.

Laced backwards?? how you can lace backwards? when the spoke is heads in, then the guy put it heads out?

What is the wheel for? how much do you weight? and how many spokes are we talking about?

Where did the spoke snapped? head or nipple?

[Tony T]

Sort hard to tell from the pic. But the alternating head up/head down configuration looks correct. From what I can tell the lacing looks correct as well.

Did they suggest another lacing pattern?

Zac

The LBS was not suggesting another lacing pattern. Said that it was laced 'backward', his meaning that the trailing spoke (the pulling spoke) should be "head out" and the leading spoke (the pushing spoke) should be "head in".
He said this could be the cause of my popped spokes. I don't see how this could be the cause (and one popped at the head, while the other popped at the nipple).

[Tony T]

You need to put a picture of the whole wheel to start with, then the driver side but from the side.

Laced backwards?? how you can lace backwards? when the spoke is heads in, then the guy put it heads out?

What is the wheel for? how much do you weight? and how many spokes are we talking about?

Where did the spoke snapped? head or nipple?

Wheel is being trued, so I can't post another pic for a few days (I never could learn the art of wheel truing :()

Spoke count is 28, rider weight 160.

Two week ago popped at the head (was out of town, LBS repaired), and yesterday popped at the nipple.

[oldpotatoe]

The LBS was not suggesting another lacing pattern. Said that it was laced 'backward', his meaning that the trailing spoke (the pulling spoke) should be "head out" and the leading spoke (the pushing spoke) should be "head in".
He said this could be the cause of my popped spokes. I don't see how this could be the cause (and one popped at the head, while the other popped at the nipple).

Balderdash. 'Most' lace head in or 'outside pulling' but either works.

Not the 'cause' of broken spokes. Broken spokes due to too low tension either from a warped(bent) rim either from an impact or poor build to start with.

Alloy nipples?

[dvancleve]

There are (very) minor pros and cons to each of the options, but it really comes down to preference. There's no right and wrong. Me personally, I lace my wheels the way yours are laced, but I understand the reason someone would do it the other way. I don't believe it has any bearing on any forces on the spokes...

Doug

The LBS was not suggesting another lacing pattern. Said that it was laced 'backward', his meaning that the trailing spoke (the pulling spoke) should be "head out" and the leading spoke (the pushing spoke) should be "head in".

[thirdgenbird]

I had someone tell me my wheel was "backwards" too. In reality, Campagnolo laces their OEM wheels in the same manor. The wheels I had built from a trusted builder are also laced that way.

I would find a different mechanic to true it...

[Tony T]

Balderdash. 'Most' lace head in or 'outside pulling' but either works.

Not the 'cause' of broken spokes. Broken spokes due to too low tension either from a warped(bent) rim either from an impact or poor build to start with.


Thanks. That's what I thought, as I couldn't see how it would have any effect, but while I can handle just about any wrenching on a bike, wheel building is still a mystery to me.


Alloy nipples?

Yes

[Tony T]

I had someone tell me my wheel was "backwards" too. In reality, Campagnolo laces their OEM wheels in the same manor. The wheels I had built from a trusted builder are also laced that way.

I would find a different mechanic to true it...

Getting harder to do these days….

Thanks guys for the info. I'll comfortable now that the lacing, as is, is ok.

[ultraman6970]

I dont lace wheels profesionally ok? just for me and probably like 1 set each two years and honestly dont see why the cross in that picture can be wrong, worse case scenario the valve hole is in the wrong cross but is not like... "yeah must be done such and such way or wont work".

The main problem when you have low count spoke wheels (your wheel is 28 spokes right?) is that once one spoke snaps, the other ones will start failing afterwards, so probably that's why the other spoke died afterwards. IMO soon you will have another spoke gone.

This is what I would do... since apparently you can true wheels ok? Swap all the spokes at the side that failed for straight gauge spokes (hope you arent picky because you have no matching spokes) and retrue that thing yourself. Why? well... looks like you can do it, second you will have more control of what had been done to the wheel, LBS guy can tell you whatever but one thing is for sure, the 50 or 60 bucks to replace the spoke won't include a 3 hour truing session, but maybe a 10 mins "ok its like round now" truing session, thing that is logical IMO.

[Tony T]

This is what I would do... since apparently you can true wheels ok?

I can handle just about any wrenching job, but I could never master the art of truing a wheel (I have the cheaper Park stand), so this is one of the few jobs I leave to a LBS. I could send back to the builder to true, but with shipping costs and turn-around time, easier to take local.


The main problem when you have low count spoke wheels (your wheel is 28 spokes right?) is that once one spoke snaps, the other ones will start failing afterwards, so probably that's why the other spoke died afterwards. IMO soon you will have another spoke gone.


Well, it that does happen, I might just send the hub to the builder and get a new build with a new rim.

[ultraman6970]

Tony, honestly, true wheels isnt that hard as you think it is. Use the oldest wheels you have to practice... you get bored, try again till you figure it out.

:)

[jhat]

Just a note that breaking at the nipple or spoke head will not de corrected by straight gauge spokes. You are not breaking the spokes in the thinner middle section of a butted spoke. As was mentioned the other spokes have probably been stressed by the original break and you might have had insufficient tension to begin with.

Truing a wheel is not that hard, just take your time and see if you can get someone to help you with the first one.

[bikinchris]

Is this rear hub laced correctly?
Took the wheel to a LBS to have it trued (after the 2nd popped spoke), and I was told that the rear drive side is laced backwards.

Here's a pic:

Honestly, it doesn't make an enormous durability difference whether the pulling spoke is inboard or outboard of the hub flange. Certainly not enough to re-lace the wheel. Don't lose sleep over it, but have the spoke tension rechecked to help prevent spoke breakage. Of course, if you break many more, you will need to rebuild the whole wheel anyway.
If I had built that wheel, I would have put the pulling spokes inboard, but that only makes a few percent difference over the life of the wheel.

Campagnolo has their own reasons for lacing their wheels the way they do.

[thirdgenbird]

Campagnolo has their own reasons for lacing their wheels the way they do.

Do you know what they are?

[marciero]

Just a note that breaking at the nipple or spoke head will not de corrected by straight gauge spokes. You are not breaking the spokes in the thinner middle section of a butted spoke.

Indeed-straight-guage spokes could have the opposite effect. Since they are stiffer, there will be even greater stress on the part of the spoke that breaks.

[marciero]

There are (very) minor pros and cons to each of the options, but it really comes down to preference. There's no right and wrong. Me personally, I lace my wheels the way yours are laced, but I understand the reason someone would do it the other way. I don't believe it has any bearing on any forces on the spokes...

Doug

Am curious-I can see the logic in lacing pulling/trailing spokes head-in for greater bracing angle. As for the benefits of doing it the other way, the Sheldon Brown article only lists precautionary benefits (eg, in case the chain comes off, misadjusted derauler hitting the spokes under load). Are there functional, performance, or durability benefits of doing it the other way?

[oldpotatoe]

Am curious-I can see the logic in lacing pulling/trailing spokes head-in for greater bracing angle. As for the benefits of doing it the other way, the Sheldon Brown article only lists precautionary benefits (eg, in case the chain comes off, misadjusted derauler hitting the spokes under load). Are there functional, performance, or durability benefits of doing it the other way?

I lace inside pulling for 28 3 cross or large flange hubs, where the pulling spoke may overlap a big portion of the hub flange so I put the pulling spoke on the inside of the flange so that angle or overlap, is minimized.

There is no performance or durability differences on say a 32, 3 cross, small flange, hub.I've done it both ways, I prefer outside pulling. Bracing angle and the guy that taught me wheelbuilding 29 years ago said wheels are a series of triangles, wider base tri angles are stronger, make the 'base' of the triangle formed by rim and pulling spokes to hub wider...stronger but I don't think it really makes any difference.

[fuzzalow]

I prefer inside pulling spokes. This discussion has been had here before where I have stood on the opposing side from the deluge. It boils down to no one patently correct answer but I also choose to build grounded on sound construction theories because I like to know why I am doing something. For example the fact the Campagnolo laces outside pulling is irrelevant to me because I am not privvy to the reasons why they chose this method.

The design of a wheel always involves compromises between bracing angle versus spoke tension in a heavily dished modern wheel. The dish required of Campagnolo hubs makes the DS spokes nearly vertical/flat so I prefer to try for greater clearance tolerance to the rear derailleur.

Ultimately, the quality of the build trumps most all other considerations. Riding wheels of your own design, preferences and construction is gratifying. It is also a confident statement to personal responsibility but, in fairness, it is not rocket science either.

[oldpotatoe]

I prefer inside pulling spokes. This discussion has been had here before where I have stood on the opposing side from the deluge. It boils down to no one patently correct answer but I also choose to build grounded on sound construction theories because I like to know why I am doing something. For example the fact the Campagnolo laces outside pulling is irrelevant to me because I am not privvy to the reasons why they chose this method.

The design of a wheel always involves compromises between bracing angle versus spoke tension in a heavily dished modern wheel. The dish required of Campagnolo hubs makes the DS spokes nearly vertical/flat so I prefer to try for greater clearance tolerance to the rear derailleur.

Ultimately, the quality of the build trumps most all other considerations. Riding wheels of your own design, preferences and construction is gratifying. It is also a confident statement to personal responsibility but, in fairness, it is not rocket science either.

AND shimano 11s rear hubs..almost the same dimensions.

Most, but not all, IMHO..a poor choice of components for the rider and it's use=problems. Like 3 strikes you are out..too light rim, too few spokes, too thin spokes.....

But I'm outta this one..I really like building wheels, my favorite 'bike thing' to do, so I like to talk about them as well(along with the "rim for 205 pound guy" thread), but it often becomes evangelical, when there are really few 'truisms' in wheel design and building.

[dvancleve]

Am curious-I can see the logic in lacing pulling/trailing spokes head-in for greater bracing angle. As for the benefits of doing it the other way, the Sheldon Brown article only lists precautionary benefits (eg, in case the chain comes off, misadjusted derauler hitting the spokes under load). Are there functional, performance, or durability benefits of doing it the other way?

That's the stuff I was referring to, less likely to jam an inside derailed chain into the spokes. Some good ideas here, I never thought about the way inside pulling wouldn't overlap the flanges or touch the other spoke heads as much under certain circumstances. Something I think I've read about outside pulling spokes is that any trivial flex in the hub flanges will be pulling away from the cassette. I can't imagine this is of much consequence, but there it is. On bracing angle, with laced spokes it seems to me that the bracing angle is the average of the inside and outside spokes rather than based only on the outside spokes. Is that wrong?

I've done quite a few wheels where I'm only redoing one of the wheels, or I'm building a wheel to match an existing wheel. I always lace so that it matches the existing wheel, or so that the spokes are in the same orientation in the flange on a used hub. I think either of those reasons probably matter more than whether you go with inside or outside pulling spokes as a general rule.

Doug

[Tony T]

Tony, honestly, true wheels isnt that hard as you think it is. Use the oldest wheels you have to practice... you get bored, try again till you figure it out.:)

I may have to give it a try again. Maybe I have more patience in my old age.

I have an old Park "Home Mechanic" truing stand (the cheap one) that I got back in the 80's (then after frustration, stored away in the basement :))

Is this old truing stand good enough? If not what stands do you guys use? I only know of the Park stands.

[ultraman6970]

I have the spin doctor one... works fine, not to get super professional work done but does the work fine. I have used the pro line of park and is way better than the Spin Doctor i have, pretty much as heavier it is the better because is more stable, but for home regular joe guy probably what you have is more than enough.

Remember a guy from england diving away his secrets truing, thats a good web page to read.

What is a must is the dishing tool tho, if you are good with wood work you can even make your own (google)

[rockdoc]

..I really like building wheels, my favorite 'bike thing' to do, so I like to talk about them as well............ there are really few 'truisms' in wheel design and building.

Probably my favorite bike thing too. I love building wheels. I bought a couple sets of Ksyrium wheels a few years back; one road, one 29er mountain, and they are great. But I might sell them just because I like and appreciate my own wheels so much more.

Steve

[marciero]

On bracing angle, with laced spokes it seems to me that the bracing angle is the average of the inside and outside spokes rather than based only on the outside spokes. Is that wrong?

Doug

I think there might be something to this. I think the bracing angle comes into play only for side loads rather than torsional, so that drive vs non-drive would be a wash.

[Mark McM]

I think there might be something to this. I think the bracing angle comes into play only for side loads rather than torsional, so that drive vs non-drive would be a wash.

An interesting side affect of increasing the number of spoke crossings is that it slightly decreases bracing angle. Which is why, on front wheels (which aren't subject to torque loads if rim brakes are used) I frequently use fewer spoke crossings than I might on a rear wheel.

[ceolwulf]

I may have to give it a try again. Maybe I have more patience in my old age.

I have an old Park "Home Mechanic" truing stand (the cheap one) that I got back in the 80's (then after frustration, stored away in the basement :))

Is this old truing stand good enough? If not what stands do you guys use? I only know of the Park stands.


I have a flimsy-ish Minoura stand and it gets the job done. Pretty sure yours will be fine.

[bikinchris]

Do you know what they are?

Mostly to effectively widen the hub flanges for a wider angle.

I used to buy wheels from a company called Winkel Wheel. They used to build an option where ALL of the spokes would exit the flange with the heads inboard. The spokes would overlap each other and crawl over each other in an odd way, but that would really bring the spoke angle out wider and it built stronger wheels. It was mostly used for Campagnolo hubs, but any hub could be built that way.

[marciero]

I think there might be something to this. I think the bracing angle comes into play only for side loads rather than torsional, so that drive vs non-drive would be a wash.

... meant to say pulling vs non-pulling.

[Mark McM]

Mostly to effectively widen the hub flanges for a wider angle.

Huh? When spokes are laced half heads-in and half heads-out, the effective bracing angle is the same regardless of which spokes are leading or trailing.

[krismac23]

Laced backwards for road application IMHO. Traditionally you want the spokes with the head's out the pulling spokes. so as you drive the wheel it increase's tension on the wheel. Disc, MTB's have the reverse pattern generally, because the disc brake applies more force on the wheel then you driving the wheel. Shimano Actually reccomend a half hybrid, so the disc side is reverse and the drive side is "normal." That being said it shouldn't be popping spoke's if the wheel was built evenly. I know a lot of reputable builder's that build this way, the have their reasons. :P

Wheel is being trued, so I can't post another pic for a few days (I never could learn the art of wheel truing :()

Spoke count is 28, rider weight 160.

Two week ago popped at the head (was out of town, LBS repaired), and yesterday popped at the nipple.

[Mark McM]

Laced backwards for road application IMHO. Traditionally you want the spokes with the head's out the pulling spokes. so as you drive the wheel it increase's tension on the wheel. Disc, MTB's have the reverse pattern generally, because the disc brake applies more force on the wheel then you driving the wheel. Shimano Actually reccomend a half hybrid, so the disc side is reverse and the drive side is "normal." That being said it shouldn't be popping spoke's if the wheel was built evenly. I know a lot of reputable builder's that build this way, the have their reasons. :P

That logic doesn't really work. you can easily apply more torque to the rear wheel from pedaling than you can from a disc brake. With low MTB gearing, it is not difficult to pedal hard enough to lift the rear wheel (which requires an acceleration of about 1/2 g). Even on exceptionally grippy surfaces you can only apply about half that much torque from braking with the rear wheel before reaching the traction limit, due to the forward weight shift unweighting the rear wheel. On the more typically soft and loose surfaces off-road the braking torque limit is even less.

Since most disc brake rear hubs have large diameter 'spools' (the portion of the hub between the flanges), hub torques are shared nearly equally between the flanges. But even if only 1/3 of the torque from pedaling or braking was transmitted to the opposite flange, there would still be more torque transmitted to the opposite flange from pedaling than from braking.

[fuzzalow]

Disc, MTB's have the reverse pattern generally, because the disc brake applies more force on the wheel then you driving the wheel.

That logic doesn't really work. you can easily apply more torque to the rear wheel from pedaling than you can from a disc brake.

Agree with the first and incorrect about the second. Easy to validate using simple common sense:
Threshold braking stop using just the rear brake v.s. maximum acceleration from a standstill

Compare acceleration 0MPH to 20MPH against a stop from 20 MPH to Zero. Whichever is done at a shorter distance has had the greater torque applied through the structure of the wheel. For anything short of a cat shot off the bow of the Nimitz, braking G loads almost always exceed acceleration G loads.

[Mark McM]

oops, double post.

[Mark McM]

Agree with the first and incorrect about the second. Easy to validate using simple common sense:
Threshold braking stop using just the rear brake v.s. maximum acceleration from a standstill

Compare acceleration 0MPH to 20MPH against a stop from 20 MPH to Zero. Whichever is done at a shorter distance has had the greater torque applied through the structure of the wheel. For anything short of a cat shot off the bow of the Nimitz, braking G loads almost always exceed acceleration G loads.

Your application of physics is too simplistic with this example. There are at least 3 different ways your conclusion falls down:

Firstly, acceleration in a shorter distance requires the highest average torque, but it doesn't necessarily have the highest peak torque. Since the fatigue of wheel components is due to repeated peak torques, we're more interested in the peak torques. An example of taking this concept to the extreme, what if we accelerated a bike by slamming the forward pedal down with a sledge hammer everytime they came around the circle (assume a fixed gear where the pedals keep rotating)? If you timed it right and hit the pedals hard enough, you could accelerate the bike in the same distance as you could during the braking example, so it would be same average torque - but it would also put much higher peak torques on the wheel.

Secondly, we don't have to go all the way up to 20 mph to find the highest peak torque. For drive torque, we know the maximum torque that can be applied is the point at which the front wheel lifts off the ground. The front wheel lift off point occurs with an acceleration of about 0.5g, and increasing the torque beyond this won't increase the acceleration, it will cause the bike to wheelie and start to flip over backwards. Since we know that with very low gears we can lift the front wheel off the ground with hard pedal strokes, then it is clear that pedaling can produce the maximum acceleration torque on the wheel.

Thirdly, the maximum braking torque on the rear wheel is limited by rear wheel traction - once the wheel starts skidding, we can't increase braking torque. Traction on the rear wheel is dependent on the normal force (i.e. force holding the tire to the road) - the less weight on the wheel, the less traction. But as the bike decelerates, there is a forward weight shift, decreasing the weight on the rear wheel, and therefore decreasing traction. When braking with just the rear wheel under perfect traction conditions, the braking force will equal the traction force at an decceleration of about 1/4 g. Beyond this, the rear wheel becomes so un-weighted that it's traction can't support the braking force.

Since the maximum rear wheel acceleration torque from pedaling (1/2 g acceleration) exceeds the maximum deceleration torque (1/4 g deceleration) from braking, it is clear that pedaling can produce higher peak torques on the rear wheel.

Couple that in with the fact that we spend far more time (and therefore rear wheel load cycles) while pedaling than we do braking, pedaling contributes more to wheel fatigue than braking.

Now, braking torques with front disc brakes may exceed rear wheel pedaling torques, so lacing orientation might be a consideration in disc brake front wheels - but not so much for rear wheels.

[fuzzalow]

Your application of physics is too simplistic with this example. There are at least 3 different ways your conclusion falls down:


Hello Mark McM and thanks for an interesting response. I edited your quoted post for brevity as I won't go into a point-by-point of it in this reply.

I think the difference between our replies & positions boils down to your theoretical based reply versus my practical-use based reply about the wheels. As such, I don't willfully choose to be simplistic about the underlying physics but that the theoretical limits are not part of normal use. The typical use of any structure in a bicycle should be well below its theoretical failure point so this line of reasoning, for me, did not enter into the discussion as relevant.

I agree that most of the underlying physics you posted is probably correct although I have no way of vouching for the numbers you propose. Correct from a SAE (Society of Automotive Engineers) perspective but IMO not completely applicable to a bicycle. Only because there is weight shift and rider skill implicit to riding a bike that changes the weight balance and therefore the performance envelope of the vehicle. For example: any rider anticipating braking on a downhill pushes weight back over the rear wheel. Same thing in effect in riding a Superbike as far as weight shift versus the technique in being harnessed into a race car.

As stated earlier this thread: quality of build trumps most all other considerations in constructing a wheel. But certainly knowing theory is preferable to being ignorant of any knowledge as to what makes a wheel a wheel.

[Mark McM]

Hello Mark McM and thanks for an interesting response. I edited your quoted post for brevity as I won't go into a point-by-point of it in this reply.

I think the difference between our replies & positions boils down to your theoretical based reply versus my practical-use based reply about the wheels.

I think it's all theoretical. I don't think there has been much rigorous testing of heads inside vs. outside spoke lacing for disc brake wheels (or any other wheels, for that matter). As I've indicated, my position is that it makes little difference - if there is a real difference, its in the noise. If there really was a big difference, you'd think more people would have noticed by now.