Another broken spoke...

[Yellow Saddle]

Its 5kgs it will make sod all difference, I was forever braking spoke on my Weinmann wheels, with or without a rear bag, since then I have had a set of RS10's and 11's and broke one on the front of the RS10's after nearly a year, and one on the rear of the RS11's after hitting a stone pretty hard, though the spoke didn't go till a few weeks later, I carry pretty much the same in the bag sometimes up to 10kg's though usually much less more like the 5kg in total as mentioned., I am about 78-79kgs, but to be fair I ride with just the rack possibly 80-90% of the time, and the bike weighs about 12.5-13kgs with guards and rack, plus lights gps ect......

I think you under estimate the effect of dead weight on a wheel's fatigue life. On a normal bike with no panniers, weight distribution is about 60% 40%, Further, the rear triangle is absolutely rigid whereas the fork flexes a little. Bumps in the road translate to spokes in the load zone becoming slacker but the same bump has a bigger effect on the back than the front. In a shop specializing in wheels, you see that statistically in the number of spokes you have to replace.

Hitting a stone doesn't affect a spoke's life at all. The bump itself momentarily relaxes one or two spokes in the zone and then it is back to normal. Counter-intuitively it doesn't stress the spoke but de-stresses it. People often report that a spoke broke after this or that incident but the nature of cycling is such that we can't say for sure. We look elsewhere at the time of incidents. It is true that the last straw can break the camel's back but then the spoke has to be already fatigued to the point where whatever happens next will be the last straw. But those events are coincidental and not causal.

Weight has a direct effect on spoke life and more weight shortens it. If we have to write a formula for spoke life it would be Tension x E / Payload x Cycles
I've just invented E but it is a variable for how well the wheel was stress relieved.

 

[Yellow Saddle]

I'm no expert but what I have found quite simply is that although true, the spoke tension if not high enough on all the new wheels I've had, whether replacement wheels or on a new bike. I got fed up having to have the wheels trued so got into it myself.

All my stuff is mid to low end and what I do these days is completely relax the tension on all the spokes and then start again, equally tensioning each spoke reasonably tight and then start re-truing. As said I'm no expert but this seems to work for me. It takes ages and ages to do but I find it very theraputic and it really isn't that difficult. I'm sure with a tension gauge and more practice I'd get quicker and even more precise. A truing stand does help though and I was able to knock one up out of bits and bobs.

Oh, also a heavy chap here 110kg.

If you can, my advice is to have a go, get the spoke key out and get stuck in.

Building your own wheels is indeed satisfying. Especially if get it right and you outclass your bike shop by making them last. Don't bother with a spoke tensiometer. It tells you nothing and doesn't help you build a better wheel. Tensiometers are useful when building quantities of the same wheel and you want to homogenize the tension across them or, if a rim manufacturer actually publishes recommended tension. The latter is very rare and you will find ideal tension experimentally. It differs from wheel to wheel.

 

[Yellow Saddle]

Where did you accumulate this knowledge @Yellow Saddle ?

I'm not ignoring you, I just don't know how to answer.

 

[confusedcyclist]

You just seem to know your stuff
A better question would have been, how have you come to know so much!

 

[Yellow Saddle]

You just seem to know your stuff
A better question would have been, how have you come to know so much!

I used to own a training centre where I taught wheelbuilding, general repairs and shock/fork servicing. I've researched this stuff all my life, written many papers in this field, authored courseware, designed curricula and tests and built several thousand wheels. I've made a life-long study of it yet I learn something new almost every day. I've also written a book on wheelbuilding and believe it or not, on the humble bicycle chain. Only the latter is still in print. I'm now updating the wheelbuilding book to deal with carbon and other namby-pamby new-fangled innovations. This will be republished soon. I recently relocated to the UK and will probably end up in the training game somewhere. For now I'm just riding.

 

[PpPete]

Don't bother with a spoke tensiometer. It tells you nothing and doesn't help you build a better wheel.

Well, with your vast experience, it might not help you to build a better wheel, but I find a tensiometer helps me, with only a paltry few dozen wheels experience, to reduce the time necessary to build as good a wheel as I am capable of.

 

[Spoked Wheels]

Well, with your vast experience, it might not help you to build a better wheel, but I find a tensiometer helps me, with only a paltry few dozen wheels experience, to reduce the time necessary to build as good a wheel as I am capable of.

I know where you are coming from but I can also see @Yellow Saddle why he might say that.

As you know you can get the spokes pretty balanced by tone and I find the tensiometer helps as a piece of mind that I don't over tension or under tension but with a bit of experience you kind of develop a feel for it, I don't use the tensiometer until I've completed the final tension and I find that most of the time I'm in the ball part. Now, if somebody took the tool away from me I would probably not feel as confident but that would only be for a little while. the other thing to keep in mind is that tensiometers do loose accuracy with time and use so there is an element there in our heads that translate tension on a spoke to numbers that we can read and makes us feel happy and confident with the level of tension we have in the wheel. I need to build a tensionmeter calibration device to be sure..... for the moment I assume my tensionmeter is as much as 10% off, not just a chosen number but it was what people have been reporting about this particular tension meter.

 

[Yellow Saddle]

Well, with your vast experience, it might not help you to build a better wheel, but I find a tensiometer helps me, with only a paltry few dozen wheels experience, to reduce the time necessary to build as good a wheel as I am capable of.

I humbly disagree. Anyone can build a perfect first wheel without a tensiometer for reasons I've already mentioned. Secondly, a tensiometer cannot tell you whether a wheel is running true or not for one simple reason: If all the spokes on a wheel are exactly the same tension the wheel is not true. Conversely, if the wheel is true, all the spokes will not be at the same tension. This is because a rim is not perfectly homogenous. You can confirm this for yourself by plucking the spokes of a perfectly true wheel. You'll notice the different tones in different areas of the wheel. If this is not obvious at first, include the worst zone in your sample - that around the valve hole. Maximum tension (this is what you want) can only be determined by stress relieving or by experience. A first-time builder would do this by stress relieving or simply compare tone to that of a trusted wheel. Too many people want to build their own wheels but feel that they don't have the right tools. The only tool you really need is an upturned bicycle and a good spoke spanner. Everything else is optional. With the right guidance your first wheel can be perfect. You may take longer to build a perfect wheel and can improve your time with practice, but the end point - perfection - is possible with your first attempt.

 

[PpPete]

I agree with every point of detail you've made there.... but why do you feel the need to preface it by disagreeing with a statement I made that related solely to my own experience?
Humbly ?
I don't think so.

 

[PpPete]

As you know you can get the spokes pretty balanced by tone and I find the tensiometer helps as a piece of mind that I don't over tension or under tension but with a bit of experience you kind of develop a feel for it, I don't use the tensiometer until I've completed the final tension and I find that most of the time I'm in the ball part. Now, if somebody took the tool away from me I would probably not feel as confident but that would only be for a little while. the other thing to keep in mind is that tensiometers do loose accuracy with time and use so there is an element there in our heads that translate tension on a spoke to numbers that we can read and makes us feel happy and confident with the level of tension we have in the wheel. I need to build a tensionmeter calibration device to be sure..... for the moment I assume my tensionmeter is as much as 10% off, not just a chosen number but it was what people have been reporting about this particular tension meter.

Actually I'm not bothered by what the tensiometer says about the final tension. I can do that by ear and by 'feel'. I make no assumptions about the accuracy of the tool whatsoever.
What I use it for is as merely a comparative tool to ensure that I'm keeping tensions reasonably even around the wheel as I proceed though the build process. It just helps ensure I get to a satisfactory end-point reliably and quickly.

 

[Yellow Saddle]

I agree with every point of detail you've made there.... but why do you feel the need to preface it by disagreeing with a statement I made that related solely to my own experience?
Humbly ?
I don't think so.

I'm sorry. I just wanted to encourage people to try now rather than wait for one day when they've saved up for the gadget.

 

[Spoked Wheels]

Anyone can build a perfect first wheel without a tensiometer for reasons I've already mentioned.

I wasn't going to comment on this but on second thoughts I think I have to

I have said before that I don't believe the perfect wheel does exist and I stand by that statement.

With the right guidance your first wheel can be perfect

Now people who read this thread my think "Ahhh, here we have someone that has built thousands of wheels and he can or know how to build perfect wheels," well, I humbly disagree

We agree that spokes, rims and hubs are not perfect so we can't hardly expect to build the perfect wheel that runs 100% true laterally and also is 100% round, close to perfection yes but ZERO errors

You may take longer to build a perfect wheel and can improve your time with practice, but the end point - perfection - is possible with your first attempt.

I learnt to build wheels to a 0.2mm lateral tolerance and 0.5mm radial tolerance which is more than enough. In fact, I can now achieve a little better than that but still, that is not a perfect wheel. It's a fine wheel to ride though.

As for the rest of the statement about the use of a tensiometer all I have to say is this, I'm with you in the general context, however, I think tensiometers are a useful tool that are used by some very reputable professional wheel builders all the time, even the great Harry Rowland. Of course these people can build great wheels without such tools but they still use them . One has to remember is that people building their very first few wheels at home, don't know how little or how far they need to go with their tensioning, they don't have somebody teaching them the skill so it's perfectly understandable to feel more comfortable using a tensionmeter. I went through that phase and I still would buy one if I had to start again I think. Not quite the same but I keep reading from people that don't believe in torque wrenches

Maximum tension (this is what you want) can only be determined by stress relieving or by experience. A first-time builder would do this by stress relieving or simply compare tone to that of a trusted wheel.

Not sure what you mean by this. There is a school of thoughts that believe their target is to achieve maximum tension by tensioning and stress relieving until the wheels is taken beyond the limit and the wheel is distorted, then back off 1/4 of a turn or something like that.... well, I'm not from that school and it doesn't even interest me in all honesty. Jobs Brandts talks about this in his book. There is plenty of room between what is minimum and maximum tension and that is what I aim for. There is plenty of evidence that if the tension is in this zone the wheel will perform very very well and last very long too.

 

[Spoked Wheels]

Actually I'm not bothered by what the tensiometer says about the final tension. I can do that by ear and by 'feel'. I make no assumptions about the accuracy of the tool whatsoever.
What I use it for is as merely a comparative tool to ensure that I'm keeping tensions reasonably even around the wheel as I proceed though the build process. It just helps ensure I get to a satisfactory end-point reliably and quickly.

You just lost me there what you just described is what I use my big ears for

Never mind, as they say, there are many ways to skin a cat and if your way builds good wheels then fine, that is what we are all trying to achieve.

 

[Yellow Saddle]

I wasn't going to comment on this but on second thoughts I think I have to

I have said before that I don't believe the perfect wheel does exist and I stand by that statement.

.

I sincerely doubt that we disagree on this one.Yes, hubs and rims are not perfect in an absolute geometric sense but who cares? Are we riding bikes or entering a tolerance contest? Good enough is good enough. Tyres on MTBs have run-out of up to 5 mm, 10 if it has had a snakebite impact. Why then care if the runout on the rim is 0.2 or 0.5mm? The braking surface is at the disc and a bit of runout at the rim is neither here nor there. As for road bikes with their closely-spaced pads: a 0.5mm or even 1mm runout is of no consequence whatsoever.
Good enough is good enough.

My use of "perfect" is not 100% and I certainly don't include the design errors of the hub manufacturers when I say 100%. Rims have a little radial run-out at the weld - no wheelbuilder can make that go away with a spoke spanner, but why bother?

A perfect wheel by my definition is one that you fit and forget. It gives you close to zero hassles in terms of periodic truing (as rims fatigue they relax around the pull zone and the spokes have to be adjusted to keep the wheel true, but this is after prolonged use only), zero spokes breaking from fatigue, no spokes coming loose by themselves and, gives the user the confidence to ride hard, brake hard and load the bike should it be required. What more could we want from wheels? People obsess too much about wheels and forget that it isn't about the bike.

Now people who read this thread my think "Ahhh, here we have someone that has built thousands of wheels and he can or know how to build perfect wheels," well, I humbly disagree

Hopefully I've now convinced you otherwise.

I learnt to build wheels to a 0.2mm lateral tolerance and 0.5mm radial tolerance which is more than enough. In fact, I can now achieve a little better than that but still, that is not a perfect wheel. It's a fine wheel to ride though.

It is easy to achieve low runout on wheels with plenty of spokes and harder to do so as the spoke count decreases. But the numbers are kinda irrelevant. More important would be the shift in runout after the first 1000kms. That would be a better indication of quality. A wheel is always in transition and a smaller change over time is more important than the initial position of the rim in the truing stand.

As for the rest of the statement about the use of a tensiometer all I have to say is this, I'm with you in the general context, however, I think tensiometers are a useful tool that are used by some very reputable professional wheel builders all the time, even the great Harry Rowland. Of course these people can build great wheels without such tools but they still use them.

I don't know the great Harry Rowland or what makes him great for that matter. The fact that X or Y uses one won't sway me. Of course it is a useful tool and I'll admit that if someone is on their own building their first wheel and they are provided for a set of measures for the particular rim and spoke count they're using, it would be of great help. But that doesn't happen. For instance, let me suck a scenario out of the air. Rear wheel: Hope PROII hub, WTB iFrequency 19mm rim, 29er, SAPIM LASER spokes, 32 of them. What tension would you recommend? The dilemma is this: No (rim or spoke) manufacturer publishes those figures. Rim manufacturers publish vague ranges of tension that are not spoke count specific.

It would be better for our hypothetical student above to simply take a trusted wheel, get the tension tone from plucking and going ahead. Of course he could use the tensiometer to copy the sample wheel but that is more expensive than listening to the tone and where will he/she find the exact same wheel?

I think it has more use in factories where a certain spec is set and has to be adhered to. But, people like buying and owning gadgets. Me too.

You have the Jobst Brand book with you. He describes eloquently how to determine maximum tension. It is in the chapter on Spoke Tension IIRC. I agree that you won't want to do this each time, but it is a great learning experience and teaches you quite a bit about wheel behavior. You may also want to read about the tensiometer that Jobst designed. He designed his own one because ALL other products on the market have a fundamental error. He gave the design to his friends at FSA sometime in the 1990s and they made only 200 of them. I approached Jobs 10 years ago for the design and he sent me the CAD drawings. I then made one for myself. In ten years or more, I can honestly say I only needed it ten times. Each of those occasions was to fight a rep who wouldn't warrantee a customer's wheel because "someone overtensioned the spokes". I used it as a truth machine to cut the BS. It can be viewed on the Wheel Fanatyk website, I think. To most people this great tool would be worthless because it has to be calibrated if you want a reading. Otherwise it simply gives a measurement as deflection, in mm. But it is consistent.

Insert plenty of smileys all over the place. I'm not familiar with this forum program yet.



.

 

[Spoked Wheels]

I sincerely doubt that we disagree on this one.Yes, hubs and rims are not perfect in an absolute geometric sense but who cares? Are we riding bikes or entering a tolerance contest? Good enough is good enough. Tyres on MTBs have run-out of up to 5 mm, 10 if it has had a snakebite impact. Why then care if the runout on the rim is 0.2 or 0.5mm? The braking surface is at the disc and a bit of runout at the rim is neither here nor there. As for road bikes with their closely-spaced pads: a 0.5mm or even 1mm runout is of no consequence whatsoever.
Good enough is good enough.

My use of "perfect" is not 100% and I certainly don't include the design errors of the hub manufacturers when I say 100%. Rims have a little radial run-out at the weld - no wheelbuilder can make that go away with a spoke spanner, but why bother?

OK, I think we are definitely on the same page here and I liked your post .

I understand what you are saying and I agree. I did say that 0.2mm is more than enough but I have to say that I'm a bit of a perfectionists and that plays against me some times. Having said that, I know where to draw the line and it's far more important that the wheel stays within tolerance in service.

A perfect wheel by my definition is one that you fit and forget. It gives you close to zero hassles in terms of periodic truing (as rims fatigue they relax around the pull zone and the spokes have to be adjusted to keep the wheel true, but this is after prolonged use only), zero spokes breaking from fatigue, no spokes coming loose by themselves and, gives the user the confidence to ride hard, brake hard and load the bike should it be required. What more could we want from wheels? People obsess too much about wheels and forget that it isn't about the bike.

I totally share your above definition for a well built wheel.

It is easy to achieve low runout on wheels with plenty of spokes and harder to do so as the spoke count decreases. But the numbers are kinda irrelevant. More important would be the shift in runout after the first 1000kms. That would be a better indication of quality. A wheel is always in transition and a smaller change over time is more important than the initial position of the rim in the truing stand.

Couldn't agree more, still doable with lower spoke count but time consuming. I guess if you work per hour then it's hard to charge the extra £s to achieve lower tolerance when a bit less will work just as well.

I don't know the great Harry Rowland or what makes him great for that matter. The fact that X or Y uses one won't sway me. Of course it is a useful tool and I'll admit that if someone is on their own building their first wheel and they are provided for a set of measures for the particular rim and spoke count they're using, it would be of great help. But that doesn't happen. For instance, let me suck a scenario out of the air. Rear wheel: Hope PROII hub, WTB iFrequency 19mm rim, 29er, SAPIM LASER spokes, 32 of them. What tension would you recommend? The dilemma is this: No (rim or spoke) manufacturer publishes those figures. Rim manufacturers publish vague ranges of tension that are not spoke count specific.

It would be better for our hypothetical student above to simply take a trusted wheel, get the tension tone from plucking and going ahead. Of course he could use the tensiometer to copy the sample wheel but that is more expensive than listening to the tone and where will he/she find the exact same wheel?

I think it has more use in factories where a certain spec is set and has to be adhered to. But, people like buying and owning gadgets. Me too.

The great Harry Rowland is a no nonsense wheel builder, I have even heard people saying that he's rude but his wheels role forever. He is very peculiar about the components he will and wont use to build wheels but he has built himself a good reputation and I know on good authority his method is sound. I've never met the man but I have tried to learn about his wheel building philosophy and I have a lot of respect for him.

I grand you that somebody without a tensiometer might feel a bit lost trying to figure out what tension to achieve and in that case perhaps achieving the limit before backing up a touch is an acceptable solution, at least you have learnt that is as far as you can take the tension before the wheel deforms. But even with a cheap tensiometer like the one made by park tools you can look at the table for steel, round, 1.5mm and find a value that is very acceptable. You can even find smart phone applications that can play the tone that a spoke of a particular material and length can be set. I've not tried that but I know that it does exist. You still have to have a little bit of extra knowledge for particular situations though, say for instance, you are asked to build a wheel that is radially spoked and with 24 spokes then the reading from the park tools table would be excessive tension for this particular application, would it not?

You have the Jobst Brand book with you. He describes eloquently how to determine maximum tension. It is in the chapter on Spoke Tension IIRC. I agree that you won't want to do this each time, but it is a great learning experience and teaches you quite a bit about wheel behavior. You may also want to read about the tensiometer that Jobst designed. He designed his own one because ALL other products on the market have a fundamental error. He gave the design to his friends at FSA sometime in the 1990s and they made only 200 of them. I approached Jobs 10 years ago for the design and he sent me the CAD drawings. I then made one for myself. In ten years or more, I can honestly say I only needed it ten times. Each of those occasions was to fight a rep who wouldn't warrantee a customer's wheel because "someone overtensioned the spokes". I used it as a truth machine to cut the BS. It can be viewed on the Wheel Fanatyk website, I think. To most people this great tool would be worthless because it has to be calibrated if you want a reading. Otherwise it simply gives a measurement as deflection, in mm. But it is consistent.

Yes, I have the book. It was the first book I ever bought on wheel building but I did not like it at the time. I read it after I followed the book of Roger Musson. In my previous post I was actually referring to this particular technique that JB talks about achieving maximum tension. I'm not a fun of it at all but you have introduced a curiosity in me today that the book did not so I will be experimenting with the method and see what I can learn from it. As you said before, there is always something new to be learnt

Yes, I remember reading about the tensiometer. in fact, somebody posted a video on youtube about a tensiometer calibration device he built where he tested it using one of those 200 tensiometers very impressive.

Wheel building for me is a hobby but I'm passionate about it so I spend most of my spare time trying to get better and better. I read anything that can teach me something. I already bought a copy of the art of wheelbuilding by Gerd Schraner which is in the menu for that period between Christmas and New Year .