LeeG

YooHoo Shotland!

32 spokes, 425gram, 20mm wide rim, killer racing/ training wheels with heavy hubs! Obviously you need butted 13g spokes.

cyccommute 

I have read the links and I'm not impressed. As George E. P. Box said "all models are wrong, but some are useful." In this case the models are both wrong and not terrible useful. The "compression" that Jonathandavid and others have been going on about isn't really "compression" but is a mathematical fiction. In the pretensioned state, the spokes at the bottom have a negative tension compared to the other spokes but the spokes are still under tension. They aren't "compressed" but they are at a lower state of tension. They are still being pulled up by the hub. They aren't being pushed on by the rim or any other force. If they are still in tension, they can't be in compression. If you look at the link that nickw provided, you'll find "Ian" even admits this:

The problem is that he never added the results of the analysis to the initial state and he, along with Brandt and Jonathandavid, are guilty of misusing terms and ideas. "Less tension" should not be read as compression. It should be read as "less tension" only. If you can see that the spokes are only under less tension and realize that there is nothing to actually compress the spokes in real life (not a mathematical fiction), then you are left with the only possible conclusion of the hub hanging from the spokes.

To be useful, models have to fit the observations. The model you and others have linked to don't fit the observations. I've offered numerous examples where the bottom spokes cannot be described as being under compression. The picture in my post above, BobG's picture, removing the bottom half of the spoke and then rotating the wheel 180 degrees, even simply lacing a wheel, etc. You, nor anyone else, can show where a spoke that is only attached to the rim through tension on the spoke can have a vector that causes compression...not mathematical (and incorrect) compression but real pushing on both ends of the spoke compression.

The models that have been cited aren't intuitive because they aren't correct. The way that a wheel actually works is what is not intuitive. We aren't used to seeing, or thinking about, spokes of a wheel that aren't in compression. These wheels are definitely in compression to hold up the vehicle. The weight of the vehicle stands on these wheels




But these wheels are very, very different from the tensioned wire spoke wheel. They are intuitive and you can easily see the forces at work. A wire spoke wheel isn't intuitive at all. I've even made the argument that both of you have been making until I really looked at a bicycle wheel and came to understand that there is nothing pressing upwards on a bicycle spoke. The spoke is only being pulled.

vik 

No I linked to one failure. I have come across many. Enough that I have no interst in spending a lot of money on a heavy hub that doesn't live up to its reputation.

I haven't regretted the choice.

LeeG

When I first got into cycling big time I kind of developed a limit on component purchases, if it was over $50 it was too much. Which locked out a lot of Campy stuff. Later as I building bikes and had a shop that limit still stuck. While it was neat to see high quality boutique components pass through my hands what mattered the most was the ride and that mechanically everything was sound. I'll go the same speed with a $15 Exage hub or a $350 Phil Wood hub. But I did buy the grease.

cyccommute 

I have several Phil Wood hubs. Each and every one of them lives up to the reputation and I haven't regretted the choice either.

As to the failure rate, I've not seen anything on the Bike Forums about massive numbers of Phil Wood hubs failing. I've not seen anything on Phil Wood hubs failing. We discuss all kinds of things ad infinitum...see current thread...and if Phil Wood hubs failed with any kind of regularity, it would show up here.

Null66

I hate walking. I got fed up with breaking spokes.

I'm heavy, rather strong.

Figured nothing succeeds like excess...

48 sp pw disc tandem hub, velocity chukker rims.

Nearly silent and silky... They just spin and spin. They are really nice.

Expensive? Yes...
Overkill? Yes...

But I never question they'll get me home, and they make me smile every time I ride.

MassiveD

What are you talking about? If parts break, and they are replaced, how does that prove they were not necessary to the strength of the wheel? If they weren't they wouldn't break. Any of the parts mentioned can be replaced and you will have a fine wheel. You can and should replace spokes and drive on. There is something seriously wrong if too many spokes break because on a properly built and structured touring wheel, the spokes shouldn't break. But if you got the one Peter White wheel where there were 6 bad spokes from the factory, or whatever, just replace them, and all that, and drive on.

AS far as which part is more important to be carefully sourced, obviously it isn't the spokes, despite your endless (if here restrained through the four pages of the thread) pumping of Alpine III spokes. Commercially most cyclist have no idea what spokes they are riding, compared to what rims or hubs. There are many good makes of spokes, and you can be pretty safe getting no name spokes on a touring bike from a reputable source. No way on earth I would get no name rims or hubs, though partly as a mater of value.

But more seriously, you need to choose a proper rim because it is more likely to break or let down your wheel than the spokes. When this happens it sometimes shows as a broken spoke, and at other times shows as a broken rim. When the rim needs to be replaced, to conserve the spokes one has to replace the rim with a similar size and geometry rim, so you need to choose your rim carefully, but your spokes, meh.

MassiveD

As you say, that is all very simplistic, or sophomoric stuff. You aren't arguing with Jobst, if you make those points. You are bouncing between your understanding of his work, and your simplistic models. Better you than me since I don't get his work either. But then over the decade or so you have been on Bikeforums, Jobst (did I miss the funeral?) hasn't exactly been a ghost. He always returned my emails and used to hang out a lot on other forums. If you had something to say you didn't have to wait till now.

Jobst's model is as follows (I hope). He, who designed the spoke tensionmeter that is the benchmark of the industry (if little used), measured spoke tension of loaded and unloaded wheels. His observation, which is presumably repeatable, or disprovable, is that the only change in tension occurs in a few spokes under the hub where tension decreases. That is not consistent with the as often as you like to repeat it "fact" that the hub hangs from the rim. If so where are the loads.

The contention is that in a pre-stressed structure, this change in spoke tensions is what one would expect if the wheel was supported by the ground through the spokes that are between the ground and the hub. One can say the spokes are compressed, or that the wheel stands on the spokes or whatever is in fact the correct terminology when dealing with pre-stressed load paths.

Disproving Jobst is basically a two step thing, make credible observations that reveal different results; or describe what is going on in the affected spokes by some other explanation than the one he gave. Saying stuff like that you can't push on a spoke just shows you are arguing with yourself.

vik 

There is a life beyond bike forums. If anyone actually wants to look into problems with Phil hubs just Google the subject.

MassiveD

Except in that case there would be changes in the tension of every spoke in the wheel, not just the ones directly between the hub and the earth. If you have carefully measured data that shows changes in spokes other than those the wheel is standing on, you have an easy win.

alan s 

Easy win. The wheel is standing on the rim, not the spokes. The slight detensioning of the lower spokes is due to rim compression and deformation.

Edit: Looking at the front end of a bike, the load of the rider, gear and bike compresses the fork and axle/hub, tensions the upper spokes, and compresses the rim all the way around to the ground. The lower spokes are detensioned slightly, and mainly serve to keep the wheel as round as possible and resist lateral forces. The rim compression and slight deformation is concentrated at the point where the wheel meets the ground, which accounts for the noticeable spoke detensioning there.

Jonathandavid

That doesn't really invalidate Brandt's point, just looks at it from a different perspective. He doesn't say that nothing happens to the rim or that it remains rigid.

chriskmurray

I wonder how often these incessant rants about how there is only one way to make something work in the bike world completely turn newbies off of cycling for good?

I have built thousands of wheels, many of which have went to some extremely remote places and I can assure anyone here who questions it, a weak link is a weak link. A poor quality rim can be just as bad for wheel durability as using generic poor quality spokes or nipples. A poor quality hub can also ruin a ride and put a rider in just as dangerous of a position as a rim or spokes failing if they are 400 miles from the nearest town.

One other crazy thing you will see in the bike world. Parts fail, cheap ones, expensive ones, properly maintained ones, if it is mechanical it can break. Saying Phil hubs are of bad quality and almost promised to fail is simply not true, as is saying there is no way a Phil hub can fail, same goes for the "bombproof" Rohloff, some of them have made it to 100,000 miles with little to no problems, others have only made it to 1,000. Sometimes this is simply operator error from silly things like installation errors, other times it is genuine manufacturer defects.

The really crazy thing about all of this, you can take the "best" parts in the world and still have a wheel that will not last if it is not properly built. Building a good wheel is not rocket surgery but you have to pay attention to the little details to do it right.

To answer the OP's original question, it is hard to know if that will be a good set up for your tour. It depends on a few things like your weight, the amount of gear you are carrying, the road conditions etc. It should be more than sufficient for any road tour as long as you are not an extremely heavy rider. Especially if you are hoping to make this set of wheels do double duty on a fun and quick bike for when you are not touring. If this will only be used for touring or heavy duty use there are probably better rims out there for you than this that would be a little tougher like the Velocity Dyad or Deep V or even their NoBS/Atlas rims depending on how wide of tires you want to run.

cyccommute 

I did. I didn't find much.

Miles2go

I did too, then did the same search substituting "Phil Wood hub failed" for name any brand, and got roughly the same or more results, except when I searched for failures of Campagnolo hub failures.

Also of note, many hub failures occur on mountain bikes, under much, much harder use than most touring bikes will ever see.

cyccommute 

You completely missed the point. If a rim wears out or a rim cracks, I doubt that you would find a competent wheelbuilder anywhere who would have a problem with just replacing the rim. Break another rim and a competent wheelbuilder will just replace it. Break a dozen rims and the same thing will happen.

But, break one spoke and a competent wheelbuilder will tell you to watch the wheel. Break two and they will tell you to watch the wheel closely. Break three and any competent wheelbuilder will tell you that the wheel should be replaced. If you break 6 spokes, a competent wheelbuilder will tell you that you can replace the spokes yourself and you can live with the consequences.

Even properly built and tensioned wheels can break spokes. Stuff happens. We ask a lot more of our wheels when we tour than just about bicyclist except downhill mountain bikers.

Therein lies the problem. People are very, very careful about choosing the rim and the hub and then pick just any old spoke because they don't understand the dynamics of the bicycle wheel. Spoke breakage is something that comes up over and over again on the Bike Forums while rim failure and hub failure don't. Choosing a spoke that is up to the job instead of concentrating on just the rim and hub would go a long way towards solving that problem.

When was the last time you broke a rim? When was the last time you talked to someone who had broken a rim? I see hundreds of wheels per year at the co-op where I volunteer. The ages range from brand new to some that are dragging 40 years. They are old generic wheels, new name brand and everything in between. With the exception of rims ruined by impact, the number of broken spokes vs broken rims runs about 1000 to 1. I can't recall actually seeing any broken rims.

I, on the other hand, have broken some rims. I've had several that cracked, a few that have worn out the brake track and a few that have pull a spoke though the rim. It's no big deal to replace the rim and I don't give it a second thought. Broken spokes, on the other hand, are something I give second thoughts to...I even give them 3rd or 4th thoughts.

I have not said that this is very simplistic nor sophomoric stuff. You are just saying that as an ad hominem in an attempt to discredit me without actually addressing what I have said. It's extremely complicated and difficult to understand. You don't even seem to understand what I said. Go do the experiment that I suggested or even just look at a wheel. You can't "compress" a wire spoke because there is nothing to compress it against nor is would the spoke stand up to any compression without buckling. See BobG's picture.

Where's Brandt's model? All I see is an appeal to authority. Yes, the tension only changes in a small number of spokes where the rim is deformed upwards. It changes in some of the spokes before the contact patch and after the contact patch. It's a stressed structure that spreads the load around the wheel. By the time the load has spread around to the spokes on the top of the wheel, the amount of load that is shared is minuscule and probably unmeasurable. Anyone who builds wheels should know that there is a lot of elasticity in a wheel and what you do in one area doesn't necessarily have a reaction on the opposite side of the wheel.

The wheel stands on the ground. The rim, as alan s has said, stands on the ground. But the spokes are not in contact with the ground nor is there any mechanism by which you can put pressure from the ground on the spokes. Brandt calls the spoke a "column" that supports the hub but you have to have a base for a column to work. There is no base on a spoke in a wheel. The end is free to move.

Brandt and others use the idea of "compressing the spokes" too loosely and incorrectly. As I've said above many times, compression is a force that works in an opposite direction than tension but it is not necessarily the opposite of tension. You can compress something or you can put it under tension but if you remove the compression, you aren't placing tension on the object and vice versa. Further, no matter what Jonathandavid says, Brandt's "compressed" spoke is still under tension and you can't have something that is simultaneously being compressed and being tensioned. They are in fact opposite forces and mutually exclusive. Tension or compression, take your pick but you can't have both.

More ad hominems. I don't care if you like me or not. Address the question and leave the personality out of it. If you have a better explanation or you can show me how a spoke that is floating free of the hub can be pushed on so that it compresses, do so.

I have made observations and have given a different explanation of the one he gave. You can do it too. Go get a wheel or even just a spoke. Try to put it under tension and compression at the same time. Better yet do it with a piece of string. The results are easier to see with the string. Pull it tight between your hands, then try to push your hands back together while keeping tension on the string. The results will be clear very quickly.

alan s has already answered this one.

Well said.

Yes, it does invalidate Brandt's point. If you look at "Ian's" analysis, you can see that there is a large decrease in the tension when the rim is at the bottom. Nothing surprising about that. Where they both go wrong (and you along with them) is considering that decrease in tension to be an increase in compression. Once you make that mistake, you can say that the wheel stands on the spokes. The problem is that Brandt and "Ian" didn't check the model against the observation. I see it happen all the time where people trust their model and say that the world is wrong. The opposite is always true.

alan s 

Here is another experiment you can try at home. Roll up a mouse pad, which represents a rim, hold it in your hand, and looking at it end on, press your finger into the side at one point. Your finger represents the ground. You will notice the mouse pad flattens inward where you press your finger, and bulges outward beyond that point. The outward bulging decreases to zero opposite of where you press your finger.

The imaginary spokes on either side of where you press with your finger would counteract the bulging, keeping the mouse pad round, and the tension on those spokes would increase slightly as a result. The only spokes that would show noticeable detensioning are those at the contact patch, due to deformation of the rim inward.

Of course, a wheel rim is made of metal or carbon and is held in place by spokes, so the deformation is very small. In addition, the tire and air inside help spread the compression load over the couple inches (the contact patch).

cyccommute 

The only thing I would add is "of the rim" so that the statement reads "... the tire and air help spread the compression load of the rim over a couple of inches."

nickw

Alan S / Cyccommute - you guys should take the time to read the articles cited, mathematical calcs showing the stresses. One of the articles even points to the semantics regarding compression vs tension. You are getting into a dew loop over compressive load vs stress.

You are really underestimating us if you think we need to push on a string....or spoke....to understand what would happen.

mev

Ok, I'll bite. I like Phil Woods hubs and service I've gotten from Phil Woods company. However, I have had three failures:

1. First time, January 2002 in New Zealand: January 1-10 Hub started freewheeling both directions until finally spun both ways. I had ridden just over 26,000km in preceding year (across USA, one time around Australia) and at some point hub just started failing. Wasn't easy to find a 48-spoke wheel, so got a ride to Napier and local bike shop built up a 36-spoke wheel for further travels. When I arrived back in USA two months later, Phil Woods did replace the hub.
2. Second time. December 2007 in Thailand. Similar symptoms where new hub started freewheeling both directions. I had ridden at least 18,000 kilometers in preceding 10 months (12768km from Amsterdam to Vladivostok, ~4000 km from Urumchi to Beijing, down to southern parts of Thailand, as well as ~1600km in Texas before departure).
2. Third time. April 2013 in Maun Botswanna: Maun rest day | A bicycle ride across Africa The spring had broken and hub was starting to skip. TDA mechanic on our tour replaced the innards of my hub with a spare I had brought along, but most importantly getting a fixed spring.

So overall, I do have personal experience with Phil Woods hubs failing. Company has been reasonable on replacing broken hubs and failure points included points after extended riding (around Australia, across Russia and across much of Africa respectively). Also learned that PW aren't too hard to service and also that it is useful to have spare paws and a spare spring. So I don't necessarily knock PW from that point and still ride them. However, now you have heard of a few failures

cyccommute 

Perhaps you should go back and read my post 77. I have read the articles cited and looked at the calculations for the stresses, along with seeing...and even quoting...the semantics. All I can say at this point is that you need to look at a wheel and see where you can "compress" a spoke. There simply is no "compressive" load on a spoke.

By the way, I think the term you are looking for is a "DO loop". And you seem to have fallen into your own DO loop.

Let's try it this way. Say you start with each spoke at a tensive force of 500 N (newtons) pulling from the rim towards the hub. As the spoke passes through the bottom of the stroke, according to "Ian", the force on the bottom spokes reduces until the one at the bottom is reduced by 325 N (or there about). It is still under 175 N tensive force. The tensive force has been reduced but that doesn't the spoke itself has been compressed. The rim has been compressed and the tension on the spoke has been reduced but the spoke hasn't been compressed. You can even apply enough force to permanently deform the rim (hit a curb sometime) and the tensive force can completely to zero but the spoke hasn't been compressed. If you attempt to compress the spoke, it will buckle like those shown by BobG...or like a string that you try to compress.

Let's further reduce the problem to a simple one spoke/one rim/one hub problem. Connect a spoke to a rim. Hold the rim up so that the hub is hanging from the rim by the spoke. Now grab the hub and let the rim hang from the hub. If there is any compressional load on the spoke, you should be able to release the hub and the hub will "stand" on that spoke. I've built far too many wheels to know that the hub will stand on the rim. On the other hand, the hub will hang from the rim for (nearly) an eternity as long as you hold up the rim.

The problem is, indeed, semantics. If you assume that compression is the opposite of tension and proceed accordingly, you reach the wrong conclusion...no matter who you are. If you understand that compression and tension are, indeed, forces in opposite direction but that the lack of one does not necessarily mean the presence of the other, you reach a very different conclusion. It also helps to look at real world examples rather than mathematical models.

nickw

It is what it is....if you feel the need to argue the point about Comp vs Tens, AGAIN and how a spoke can't be in compression, after the article clearly hints at the semantics behind it...you just don't get it. Your examples, like other have stated, are worthless in the context of the 'discussion'.

Apologies for derailing the thread, I should have known better...

Phil Wood Hubs rock...no question there!

cyccommute 

You say my examples are worthless in the context of the discussion but I haven't seen any "discussion" from you or others giving counter explanations. I don't "get it" because you haven't provided any discussion to help me get it. Simply saying "go read the links" endlessly when it is quite clear that I have read the links and disagree with them, isn't discussion. It's parroting.

Take that extra step. Explain where the compression comes from and what the mechanism for compressing the spoke is. I've given you a simple example of the single spoke. It should be easy to explain how a spoke will hold up the hub if compression is really present.

There should be no need to "hint" at semantics. You shouldn't have to read between the lines to get the point. Even "Ian" seems to understand where he (and others) have gone wrong. This quote bears repeating

The problem, as I've elucidated several times, is in referring to a spoke as being a "compressive" spoke instead of a "less tensile" one.

B. Carfree

After over 250,000 miles on a Phil Wood hub I own, the flange finally started to give way about 25 years after I bought it. Lots of hard miles on that hub (I'm 6'2" around 190 lbs and a great many of those miles were loaded off-road touring) Phil wood would have probably replaced it if I gave them a chance, but I felt obliged to acknowledge that I had gotten more than my money's worth. They make reliable gear that I'm willing to pay the price for because of their unparalleled track record.