elderJoined: 10 Feb 2006Posts: 594Location: The Bucket
my friend kevin is going to teach me to build a new set of wheels but i'm having trouble finding a decent variety of spokes; i haven't seen double-butted spokes anywhere.
whatcha got?
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Aaron
Posted: Tue Feb 28, 2006 10:35 pm
Joined: 25 Jul 2005Posts: 4645
leah wrote:
my friend kevin is going to teach me to build a new set of wheels but i'm having trouble finding a decent variety of spokes; i haven't seen double-butted spokes anywhere.
whatcha got?
Racing spokes? Why? I can cut you some aero spokes.
leah
Posted: Tue Feb 28, 2006 10:40 pm
elderJoined: 10 Feb 2006Posts: 594Location: The Bucket
racing spokes? never heard 'em described that way. i just know that they build stronger wheels and that i'm rough on everything i come in contact with.
but if we're talking about the same thing, though (thicker at the ends) then i'd like to know what you're selling. i was surprised to not see any on the phil wood site.
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Aaron
Posted: Tue Feb 28, 2006 10:48 pm
Joined: 25 Jul 2005Posts: 4645
leah wrote:
racing spokes? never heard 'em described that way. i just know that they build stronger wheels and that i'm rough on everything i come in contact with.
but if we're talking about the same thing, though (thicker at the ends) then i'd like to know what you're selling. i was surprised to not see any on the phil wood site.
Who says they are stronger? That is such a bunch of nonesense! They are equally as strong, just lighter. Hence, racing. The weight you save is about a spoke or two. Not much! I am talking from the experience of building over 5000 wheels. I use straight 14 gauge Phil Wood spokes in my custom wheels. They do not break prematurely like DT and I guarantee a wheel I build forever. I do have a stock of older DT and Alpina Aero spokes. They are OK of a front wheel. For a rear, stick with straight 14g. DT changed their design in 2000 and conciquently their spokes started to break after just a few months riding so I stopped using them.
Also Phil spokes measure exactly 2.0mm (14g). DT and others are slightly undersized. Phil spokes are by far the best I have ever used.
I also used to love Mavic rims but they started making the walls too thin and now they crack at the eyelets.
leah
Posted: Tue Feb 28, 2006 10:57 pm
elderJoined: 10 Feb 2006Posts: 594Location: The Bucket
kevin's giving me his rims and hubs (which are, like everything else, much newer than mine) on top of teaching me i new fancy art. i'm keeping a long baking list of things i will owe him for this. machines are so rad.
i'll be by later in the week to pick up spokes. maybe thursday.
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dennyt
Posted: Tue Feb 28, 2006 11:15 pm
rocket mechanicJoined: 02 Aug 2005Posts: 2708
The main effect of double-butted (14/15/14) spokes is that they are less stiff than straight gage spokes. But not by much. But this is a bigger effect than the weight difference.
You should be able to get away with double-butted, but there's not really a reason to use them. I'd just go with whatever's available and not worry about it.
My front wheel is ancient and 15g straight gage. It's still true after my dock incident, which bent my frame and fork. D'oh.
The rear wheel didn't last a month under my ass, though.
joby
Posted: Tue Feb 28, 2006 11:28 pm
goes to elevenJoined: 25 Jul 2005Posts: 3899Location: The Cloud
Isn't the point of double-butted "Make the spokes thicker where they tend to break"?
Isn't that sound?
If spokes usually break at the ends, then either the ends are too thin or the middle is too thick, right?
Couldn't you get double-butted spokes that weighed the same as regular spokes, but were stronger, since the material was put where it's most needed?
I don't have any experience with this and I'm not an Mechanical Engineer, but the concept sure seems right.
dennyt
Posted: Tue Feb 28, 2006 11:51 pm
rocket mechanicJoined: 02 Aug 2005Posts: 2708
Yeah, that's the point. But they don't make them any BIGGER than 14g at the ends. So they end up being basically as strong as straight 14g, but marginally lighter and less stiff (less cross sectional area).
I haven't seen any double butted spokes bigger than 14g at the ends. Aaron, do they exist? You'd also need to drill your hubs out bigger, to fit them...
Aaron
Posted: Tue Feb 28, 2006 11:56 pm
Joined: 25 Jul 2005Posts: 4645
dennyt wrote:
I haven't seen any double butted spokes bigger than 14g at the ends. Aaron, do they exist? You'd also need to drill your hubs out bigger, to fit them...
DT makes spokes called Alpine that are 13g at the elbow and 14g at the threads. They are 15g in the middle. These are probably the very smartest spokes ever designed but nobody uses them. I can order them but they cost some bank and yes, you will have to drill out most hubs just a little.
DT, however, changed their elbow design in 2000. Peter White has a complete explanation.
zuvembi
Posted: Wed Mar 01, 2006 9:33 am
Joined: 24 Jul 2005Posts: 942Location: Little Addis Ababa
joby wrote:
Isn't the point of double-butted "Make the spokes thicker where they tend to break"?
The big advantage IMO to DB 14/15/14 spokes is they are more elastic than a straight 14 gauge spoke. This means you can run a good high tension without making it more likely to have spoke pull-throughs on the rim. Additionally the fatigue life of the spoke is greater (i.e. you can get more miles out of them).
Yes, they are a touch lighter, but that's not really a great reason to use them.
The alpines, which are 13/15/14, are supposed to provide a little better seat in the hub, which I guess would make it a little less likely to break spokes near the head. I've never felt it necessary to use them myself.
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lieutenantsean
Posted: Wed Mar 01, 2006 9:35 am
Joined: 10 Oct 2005Posts: 1255
Or, you could just use the phil spokes, take good care of your wheels and use the extra money to buy more beer.
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zuvembi
Posted: Wed Mar 01, 2006 9:43 am
Joined: 24 Jul 2005Posts: 942Location: Little Addis Ababa
lieutenantsean wrote:
Or, you could just use the phil spokes, take good care of your wheels and use the extra money to buy more beer.
How much are the Phils? I haven't priced them from anyone previously. I doubt they're that much cheaper that they are worth it (to me) to make a weaker wheel.
Another caveat is that people who are <= 175 lbs or so riding 32 or 36 spoke wheels probably don't need DB spokes. And of course it matters how rough you are on your wheels also (bunny hopping, curb hopping, etc.)
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lieutenantsean
Posted: Wed Mar 01, 2006 9:53 am
Joined: 10 Oct 2005Posts: 1255
I'd have to dig up the reciept from the wheels aaron built me.
Or you could just ask him.
I suggest you review basic physics, specifically:
Quote:
The big advantage IMO to DB 14/15/14 spokes is they are more elastic than a straight 14 gauge spoke. This means you can run a good high tension without making it more likely to have spoke pull-throughs on the rim. Additionally the fatigue life of the spoke is greater (i.e. you can get more miles out of them).
1) If you are running a higher tension in your spokes, the higher tension will still be felt at both the rim and the hub. The spokes still have to pull against something.
2) Spokes tend to fail in torsion (twisting) not laterally or longitudinally. This is easy to prevent.
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zuvembi
Posted: Wed Mar 01, 2006 10:22 am
Joined: 24 Jul 2005Posts: 942Location: Little Addis Ababa
lieutenantsean wrote:
I'd have to dig up the reciept from the wheels aaron built me.
Or you could just ask him.
Fair enough.
Quote:
I suggest you review basic physics, specifically:
Quote:
The big advantage IMO to DB 14/15/14 spokes is they are more elastic than a straight 14 gauge spoke. This means you can run a good high tension without making it more likely to have spoke pull-throughs on the rim. Additionally the fatigue life of the spoke is greater (i.e. you can get more miles out of them).
1) If you are running a higher tension in your spokes, the higher tension will still be felt at both the rim and the hub. The spokes still have to pull against something.
You are assuming I'm talking about static load, which I am not. The greater elasticity helps with peak load, which is what is most likely to cause pull-through. Additionally the increased elasticity reduces the occurrence of slack spokes on wheel impacts.
I don't know if you count Sheldon Brown as an authority or not, but his wheelbuilding article mentions this exact topic (specifically the couple paragraphs about double-butted spokes). It's also the prevailing opinion on rb.tech (assuming you don't think they are a bunch of chuckleheads).
Quote:
2) Spokes tend to fail in torsion (twisting) not laterally or longitudinally. This is easy to prevent.
I'm not quite sure what you're saying here...
Last edited by zuvembi on Wed Mar 01, 2006 10:31 am; edited 1 time in total _________________ When the revolution comes, we're going to need a longer wall
dennyt
Posted: Wed Mar 01, 2006 10:30 am
rocket mechanicJoined: 02 Aug 2005Posts: 2708
I don't think they fail due to torsion. The highest torque they will ever see is when you build the wheel and tension it, before you put any load on it. Once the wheel is loaded, the low-tension spokes on the bottom of the wheel will be more free to twist to their neutral position and release that windup. Hence, the pinging noise when you first ride recently trued wheels (if the mechanic didn't releive the windup in the shop by loading the wheel).
There may still be some torsional stress in the spokes during their life, as they should never go completely slack (so some windup may remain). But the stress due to a spoke being, say, 90 degrees twisted, is much less than the stress due to axial loading.
I guess I could do a quick calculation...
2.0mm diameter, 300mm length. 90 deg twist = 211mpa torsional stress. This is about 1/3 of what it takes to yield the spoke. For axial loading, it would take 960lbs to yield the center section of a spoke (assuming a straight spoke with no elbow or threading on the ends...)
There may be some residual torque in the spoke that contributes to fatigue failure, but my money is on bending at the elbow and the stress riser of the first thread at the nipple as the main causes of failure.
Add cyclic loading to taste, and repeat until failure.
I think we are arguing terminology here. It's true that, all other things being equal, the more elastic spoke will reduce the rate at which the rim is shock loaded.
Mathematically, when the rate at which the rim is loaded, dF/dt, exceeds some critical value, the spoke will fail. In elastic spokes, dF is the same, but dt is longer so dF/dt is smaller.
However, think about the system as a whole. You have loads in two directions plus rotational tension (torsion) on the spokes. In an earlier thread, Aaron pointed out that when spokes (vice rims) fail, they tend to fail due to excessive torsion rather than excessive loading in the other two directions.
Experience has proven to me that if you take a fundamentally strong wheel with straight guage spokes (such as the ones Aaron builds), and take the time to do proper maintenance, spoke breakage is a non-issue. I have broken 1 spoke in 25 years of cycling and that was when I didn't know what the hell I was doing.
Learn how to properly true a wheel and do it regularly. A little oil in the spoke nipples will help them dissipate the torsional loads.
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langston
Posted: Wed Mar 01, 2006 10:46 am
Joined: 25 Jul 2005Posts: 5547Location: Columbia City
Hey Aaron-
I want to rebuild my back wheel this weekend. Can I meet up with you Saturday to buy some spokes, rent/borrow your FSA spoke wrench and pick your brain?
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dennyt
Posted: Wed Mar 01, 2006 10:50 am
rocket mechanicJoined: 02 Aug 2005Posts: 2708
lieutenantsean wrote:
Right on most counts.
You must have the solution manual. Care to share?
lieutenantsean
Posted: Wed Mar 01, 2006 10:51 am
Joined: 10 Oct 2005Posts: 1255
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lieutenantsean
Posted: Wed Mar 01, 2006 10:52 am
Joined: 10 Oct 2005Posts: 1255
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zuvembi
Posted: Wed Mar 01, 2006 11:12 am
Joined: 24 Jul 2005Posts: 942Location: Little Addis Ababa
Torsion: Why are you having a lot of torsion problems? Granted smaller gauge spokes do have more twist, but if you're oiling the nipples, doing the overshoot and come-back method and properly stress relieving the wheel, that really shouldn't be an issue.
Spoke breakage: I've broken quite a few straight 14g spokes and few to none of the double butted. I've done in a few rims by spoke pullthrough, all but one with straight gauge.
I've had much less issue with rim and spoke breakage since I started building up my own wheels with DB spokes to a nice high tension. That is where I am coming from; i.e. it works for me. I've had a lot of trouble with breaking rear wheels since I've started cycling, so I'm very interested in anything that makes a stronger wheel. Additionally the higher tension wheel (with even tension of course) holds it's true *much* better.
I find it curious that you bring up Jobst Brandt, because he does not agree with your opinion of double butted spokes (he's a prolific poster on rb.tech).
edit: I'm trying (and probably failing) not to sound like a dick, sorry if I come across that way.
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lieutenantsean
Posted: Wed Mar 01, 2006 11:27 am
Joined: 10 Oct 2005Posts: 1255
eh, no worries.
I threw Jobst in there because I wanted to be a smart-ass about having the answer book. Usually I can manage smartass pretty well.
Most of my prejudices are based on what I know of physics and bicycles. Most of my knowledge on the latter is gained by doing everything wrong in a creative manner until I figure out what right looks like. Just found out how to get a front derailleur dialed in perfectly last weekend.
My last wheel was a 32 spoke wheel built on a monster mavic rim. It may have had db spokes, don't rightly remember. Never had a damn problem with that wheel. Guy who built it was an artist.
My current wheels are 36 front (with a high-flange hub) and 40 rear, built with 14 guage spokes on Velocity Dyads. Before then, it was whatever I could afford.
I did run into problems with spoke pull through but assumed it was due to me over-tightening the spokes (you mean you can loosen them too?). Once I started doing both, the problems went away.
Beyond that, I've never had a problem with spokes. Presently, I can attest this to my massively overbuilt wheels. Also, taking good care of my bike is my religion.
And, I've been starting to think lately that I must lead a charmed life vis a vis bicycles. I don't have a quarter of the problems most people seem to. Luck doesn't last that long so apparently at some point in the past I must have done something to please the cyclings gods.
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zuvembi
Posted: Wed Mar 01, 2006 1:04 pm
Joined: 24 Jul 2005Posts: 942Location: Little Addis Ababa
lieutenantsean wrote:
I did run into problems with spoke pull through but assumed it was due to me over-tightening the spokes (you mean you can loosen them too?). Once I started doing both, the problems went away.
Yeah, that's how I killed one rim. I do know better... now.
Quote:
Beyond that, I've never had a problem with spokes. Presently, I can attest this to my massively overbuilt wheels. Also, taking good care of my bike is my religion.
Part of it was I started off riding at my heaviest (240lbs) on stock 32 spoke factory wheels. After they went wildly out of true a couple times, I had them rebuilt by the fellow up at 'Perfect Wheels'. Those lasted about 8000 miles until the rim had pull throughs. I bought a quick crap replacement to get me back on the road, and then Sammamish Cycle build me up a MA-3/105 wheel (which after a couple trys on their part) lasted less than 3000 miles. Not learning my lesson, I replaced the rim with another MA3 that died in less than 2000 miles. I've switched to using Alex rims and have been much happier since.
I'm working on the massively overbuilt wheels concept for myself. 36 spokes seems to be plenty for me for a front wheel, and the 36 spoke Alex/105 rear I have is holding up well. But I'm building a 48 spoke wheel so I have something totally bombproof for my commute.
Quote:
And, I've been starting to think lately that I must lead a charmed life vis a vis bicycles. I don't have a quarter of the problems most people seem to. Luck doesn't last that long so apparently at some point in the past I must have done something to please the cyclings gods.
/sigh
In just under four years of cycling I've broken: [2]
6 rims (I think that's the right number)
3 frames
2 forks
2 handlebars
1 saddle
1 chain
1 sprocket (right in the middle of the cluster too)
1 pedal
2 rear derailleurs
1 rack [1]
some spokes
No stems or cranks yet, thankfully. And of couse the list doesn't count consumables (tires, tubes, cables, etc.) or things that died from corrosion/weather (lights, blinkies).
[1] When doing an endo, even if you do a nice roll and come out pretty much unscathed, it will most likely turn your rear rack into a pretzel.
[2] Keep in mind these are all road miles, the vast majority just going back and forth to work.
This is the other thing killed in the endo. Hitting cars with your rear wheel at speed is bad.
edit: forgot about the derailleur taken out by the broken chain.
Last edited by zuvembi on Wed Mar 01, 2006 1:45 pm; edited 2 times in total _________________ When the revolution comes, we're going to need a longer wall
lieutenantsean
Posted: Wed Mar 01, 2006 1:27 pm
Joined: 10 Oct 2005Posts: 1255
In 24 years of cycling:
Things I've broken in crashes:
1) Rear derailleur
2) Possibly a frame (aluminum).
My own mechanical ineptness:
1) 5 wheels (one time I decided it would be a good idea to tighten EVERY spoke on my rear wheel.)
2) A rear derailleur
3) Headset (over tightened it)
4) 2 hubs. I am the reason cartridge bearings were invented.
5) I've stripped or broken more fasteners than I care to remember.
6) Numerous tubes
stupid bad luck:
1) 1 blown out side wall.
That's pretty much it. Everything else I've replaced was either an upgrade or replacing worn gear.
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Aaron
Posted: Wed Mar 01, 2006 2:46 pm
Joined: 25 Jul 2005Posts: 4645
langston wrote:
Hey Aaron-
I want to rebuild my back wheel this weekend. Can I meet up with you Saturday to buy some spokes, rent/borrow your FSA spoke wrench and pick your brain?
Sure. I like Organic IPA. Don't show up with anything less, mother bitch!
Aaron
Posted: Wed Mar 01, 2006 2:58 pm
Joined: 25 Jul 2005Posts: 4645
zuvembi wrote:
I had them rebuilt by the fellow <Larry> up at 'Perfect Wheels'. Those lasted about 8000 miles until the rim had pull throughs.
I hope you were not complaining about 8000 miles! Jesus, man, that is plenty of miles. The average rear wheel will last 5000-10000 miles depending on many factors.
It is a bunch of bull-shit about double butted spokes being stronger or "elastic" (whatever that means). I have built well over 5000 wheels. I guarantee my wheels forever. Double Butted wheels do not last longer in my experience building for the general public. Rims pull thru because they are shitty rims. Mavic are especially bad.
dennyt
Posted: Wed Mar 01, 2006 3:09 pm
rocket mechanicJoined: 02 Aug 2005Posts: 2708
Aaron, do you guarantee your wheels forever, or 8000 miles or 10000 miles?
You know I've got your back, but you seem to be talking in circles...
And 'modulus of elasticity' is the material property related to stiffness. The 'elasticity' zuvembi is talking about is 1/stiffness (of a certain material in a certain shape).
More elastic spokes = less stiff spokes = more of the spokes share the load, especially with an uber-stiff rim like a Deep V.
lieutenantsean
Posted: Wed Mar 01, 2006 3:13 pm
Joined: 10 Oct 2005Posts: 1255
Quote:
Aaron, do you guarantee your wheels forever, or 8000 miles or 10000 miles?
Yeah, I was sort of wondering about that. 10000 miles is about two years of normal riding for me.
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Aaron
Posted: Wed Mar 01, 2006 3:17 pm
Joined: 25 Jul 2005Posts: 4645
dennyt wrote:
Aaron, do you guarantee your wheels forever, or 8000 miles or 10000 miles?
You know I've got your back, but you seem to be talking in circles...
And 'modulus of elasticity' is the material property related to stiffness. The 'elasticity' zuvembi is talking about is 1/stiffness (of a certain material in a certain shape).
More elastic spokes = less stiff spokes = more of the spokes share the load, especially with an uber-stiff rim like a Deep V.
Foroever. I guarantee that they will stay true forever. To that end, I also replace spokes for free, up to 3. After that it is time to rebuild the wheel. In ANY wheel, it is the spokes that will eventually break first if the rim lasts that long. A rim, technially does not wear out from rolling. Rims usually get damgaged or worn thru from the brake pads. I do not guarantee that won't happen! I also don't guarantee rim pull thru. That usually happens when the rim gets pushed in. Or it was a Mavic rim.
Stiffness/Elasticity, Rim, Hub, Spokes. All that matters less than how the wheel was built and the care and precision of the tensioning and stress releaving. All I am saying, is that if you have a master wheel builder, like Larry, Dobie, or I build you a wheel, you ain't gonna have problems!
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elder
Joined: 10 Feb 2006
Posts: 594
Location: The Bucket
rocket mechanic
Joined: 02 Aug 2005
Posts: 2708
goes to eleven
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Posts: 3899
Location: The Cloud
Joined: 24 Jul 2005
Posts: 942
Location: Little Addis Ababa
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