Spoke count for a commuter wheel build

[Spoked Wheels]

A higher spoke count wheel easier to build? Mmmm I think I know what you mean but other people might not understand it so well. A higher spoke count has a bigger number of spokes to lace, tension, fine tune, stress, prepared. The difficult part with lower count is that it takes more fine tuning to get it spot on and most importantly, needs to be very well balanced as fewer spokes are sharing the punishment. I think it's fair to say it's harder to build a good low spoke count wheel.

I've seen quite a number of issues on the NDS when the spokes are not well balanced on such wheels.

 

[Smokin Joe]

Thirty six in each wheel, it's a commuter not a TT machine!

Never, ever, ever, seen the sense of that combination which was introduced in the late sixties to replace the then standard 32/40 in order to make the manufacturers job easier and cheaper. The front wheel is subject to only a fraction of the stress going through the rear and having the same spoke count on each wheel means you either have more than you need on the front or not enough on the back.

 

[Smurfy]

Never, ever, ever, seen the sense of that combination which was introduced in the late sixties to replace the then standard 32/40 in order to make the manufacturers job easier and cheaper. The front wheel is subject to only a fraction of the stress going through the rear and having the same spoke count on each wheel means you either have more than you need on the front or not enough on the back.

Totally agree, but last time I discussed this with a bike shop proprietor he said something about bike manufacturers preferring equal numbers of spokes. Makes their supply line easier or something like that.

 

[Spoked Wheels]

Never, ever, ever, seen the sense of that combination which was introduced in the late sixties to replace the then standard 32/40 in order to make the manufacturers job easier and cheaper. The front wheel is subject to only a fraction of the stress going through the rear and having the same spoke count on each wheel means you either have more than you need on the front or not enough on the back.

Yes, I'd agree with that. Unless you are carrying front panniers you don't need as many spokes as the rear wheel.
Some hubs come in a set or they are cheaper to buy in a set. Shimano does 32 and 36 drilling mainly, unless you go for Dura-Ace. Is it worth paying substantially more to save a few spokes when you need at least a good quality 32 spokes hub at the back? For a heavy rider it does not make sense I think.

 

[John the Monkey]

I'll try and find some references, in any case, so my assertions are a bit less hand wavey.

Well, @RRSODL that was interesting - Gerd Schraner (The Art of Wheelbuilding, p55);

"The more spokes used, the more stable the wheel.

...

Fewer spokes reduce weight and improve the aerodynamic qualities, but need to be given a higher tension, which, on the other hand, require more stable, and thus heavier rims. The weight advantage of fewer spokes is therefore lost on the rims. Fewer spokes improve the aerodynamics ... only from speeds of 50kph (30mph) upwards.

More spokes mean that the wheel is more stable, not only radially, but also laterally ...

In case of doubt, always use a higher spoke count.

(The book then recommends the following counts - for road front 24 - 32, rear 28 - 32, trekking, touring, city - front 36, rear 36) "

But he then relates (p56) an anecdote about building a 24 spoked downhill wheelset which survived "very tough" off road and trekking!

"Thousands of miles offroad and downhill, as well as a 1,000 mile bike tour (with a lot of luggage) down the Californian coast presented no problem at all. The wheels needed no adjusting afterwards and they're still 'standing'."

Jobst Brandt's book has this (p39 in my edition of "The Bicycle Wheel");

"The strength of a wheel is measured by the greatest load it can carry. This is the load that will cause one or more spokes in the load affected zone to become loose.

...

A rigid rim combined with thin spokes gives the longest load-affected zone. The resistance to bending of a strong rim distributes the load over more spokes than one of lower strength. ... The more spokes that carry the load, the stronger the wheel."

If I read him correctly, the key is the number of spokes that the rim is relying on, which is a function of the stiffness of the rim. So - for a "strong" rim, few spokes (but at high tension) = a strong wheel. For a "weak" rim, more spokes (possibly at lower tensions) = a strong wheel.

EDIT: Reading that through again, the theoretically strongest wheel you could build would be a stiff rim with lots of spokes. Whether it'd be nice to ride or not is another matter The other thing Brandt mentions in that section is that as wheel size increases, so does the need for more spokes, (or, I guess, more strength in the rim). So again, theoretically, for a given rim stiffness, you can use fewer spokes for the same "strength" the smaller the wheel gets (as the area over which the load is being spread is becoming smaller).

Roger Musson's book doesn't talk about strength as a function of spoke count, so far as I can tell.

 

[John the Monkey]

Schraner's 24 spoke per wheel wheelset, incidentally;

DT Swiss Revolution (2.0 / 1.5 / 2.0) spokes for the front. DT Swiss Competition (2.0 / 1.8 / 2.0) for the rear. Rigida DP22 "high v profile rims". He doesn't mention the hubs, and says that the weight "compared favourably with robustly built 32 spoke wheels."

 

[Spoked Wheels]

Well, @RRSODL that was interesting - Gerd Schraner (The Art of Wheelbuilding, p55);



But he then relates (p56) an anecdote about building a 24 spoked downhill wheelset which survived "very tough" off road and trekking!


Jobst Brandt's book has this (p39 in my edition of "The Bicycle Wheel");


If I read him correctly, the key is the number of spokes that the rim is relying on, which is a function of the stiffness of the rim. So - for a "strong" rim, few spokes (but at high tension) = a strong wheel. For a "weak" rim, more spokes (possibly at lower tensions) = a strong wheel.

Roger Musson's book doesn't talk about strength as a function of spoke count, so far as I can tell.

Interesting. I'm sure most wheelbuilders are rather careful when it comes to specifying a set of wheels. On the other hand I cannot blame them. Their businesses depend on building not only good wheels but also wheels that will last long and will not cause any injuries to the rider. It would take very little for people start talking in a negative way about a particular builder and we can imagine where that can lead.
I don't remember whether Roger Musson talks about spoke count being a factor in wheel strength or not, maybe that is because he concentrated in downhill racing wheels, road wheels wasn't a big thing for him. His emphasis is in the building technique and quality which I found so good and inspired me so much.
As I see more and more wheels from the wheelbuilder point of view I learn that some configurations of rims, spoke type, spoke count, rider style and rider weight are possible even though most wheelbuilders aren't happy building. I can experiment with my own wheels but sometimes I'm still reluctant to accommodate some people's ideas for a set of wheels.

I've seen strong rims and few spokes, not so strong rims and few but very strong spokes and not so strong rims with plenty of spokes. The spokes that one can easily get off the shelf limits what a wheelbuilder can build but companies like Mavic can build their own spokes, etc.

I guess this is a never ending topic for discussion. I read everything and I try to see what fits and make sense with my own experience.

 

[John the Monkey]

I guess this is a never ending topic for discussion. I read everything and I try to see what fits and make sense with my own experience.

Definitely - it was an interesting exercise to go back through the books looking at what these far more knowledgable (than I) builders had to say about it.

I think, for most cases, the skill of the builder is the key - personally, I'd not feel up to a build with fewer than 32 spokes, but luckily, I only build for myself I can think of several I'd trust with more complex/technically difficult builds though, and I'd feel better riding their 24s than I would riding one of my earlier 36s

 

[Spoked Wheels]

Definitely - it was an interesting exercise to go back through the books looking at what these far more knowledgable (than I) builders had to say about it.

I think, for most cases, the skill of the builder is the key

Yes, I would agree with that.

I have to say that the rest of your post makes wheelbuiling sound like a difficult skill. I don't forget that my experience is small in comparison with professional wheelbuilders that make a living out of that but I have to say that I don't find wheelbuilding difficult. Drawing, plastering, woodwork, etc are tasks that I strugle with but not with wheelbuilding. I guess my biggest advantage is that I never let the building process frustrate me and that must be the reason why I don't end up in trouble. Time, patient, the will for doing the best I can and the skills I learnt from Musson are still making the process of wheelbuilding enjoyable.

I now need to satisfy my own appetite for a challenge. If anybody here rides over 8k miles per year then please let me build you a set of wheels.

 

[John the Monkey]

I have to say that the rest of your post makes wheelbuiling sound like a difficult skill.

I view it as a process, really - I think that's the beauty of Musson's book, the demystification of it. Having said that, I've built wheels that have just come together easily, and others that have taken more effort by far - I don't think I build enough to be really confident, personally, and I suspect my problem wheels are the result of unnoticed bad starts. They're always recoverable though.

My personal view is that most people could build a rideable 36, or a 32 (standard 3x) if they have the patience - it's probable that an experienced, skilled builder could make a wheel that was objectively better, but it won't matter unless the wheel is taken to the limits of its strength.

I hope I've not put anyone off having a go - it's a very satisfying process, and my first set of homebuilts (Deore, A319, 36 x3) carried me and luggage through Belgium and France, with a few kilometres of cobbles for a proper test

I guess my biggest advantage is that I never let the building process frustrate me and that must be the reason why I don't end up in trouble. Time, patient, the will for doing the best I can and the skills I learnt from Musson are still making the process of wheelbuilding enjoyable.

Yes - for me, having the strength of mind to walk away when it just isn't going well, or to start again if necessary (back the spokes off, and start from the nipple driver stage) are the two things I try to keep in mind

 

[Spoked Wheels]

I view it as a process, really - I think that's the beauty of Musson's book, the demystification of it. Having said that, I've built wheels that have just come together easily, and others that have taken more effort by far - I don't think I build enough to be really confident, personally, and I suspect my problem wheels are the result of unnoticed bad starts. They're always recoverable though.

That is to be expected, components are not perfect and sometimes it takes longer to complete the wheel.

My personal view is that most people could build a rideable 36, or a 32 (standard 3x) if they have the patience - it's probable that an experienced, skilled builder could make a wheel that was objectively better, but it won't matter unless the wheel is taken to the limits of its strength.

Although I accept the fine tuning is more time consuming on a 20 spokes wheel than on a 36 spokes, I fail to see such a big difference in degree of difficulty TBHWY. I've built 20, 24, and 28 spokes wheels and radial, 2x and 3x.

Yes - for me, having the strength of mind to walk away when it just isn't going well, or to start again if necessary (back the spokes off, and start from the nipple driver stage) are the two things I try to keep in mind

I do the same and I think that makes a big difference in my head, knowing that I can go back, and prepare a platform from where I can start making controlled progress again. I've had to go back only once so far and that was because I lost concentration while listening to a radio programme.

 

[Spoked Wheels]

Well, @RRSODL that was interesting - Gerd Schraner (The Art of Wheelbuilding, p55);



But he then relates (p56) an anecdote about building a 24 spoked downhill wheelset which survived "very tough" off road and trekking!


Jobst Brandt's book has this (p39 in my edition of "The Bicycle Wheel");


If I read him correctly, the key is the number of spokes that the rim is relying on, which is a function of the stiffness of the rim. So - for a "strong" rim, few spokes (but at high tension) = a strong wheel. For a "weak" rim, more spokes (possibly at lower tensions) = a strong wheel.

EDIT: Reading that through again, the theoretically strongest wheel you could build would be a stiff rim with lots of spokes. Whether it'd be nice to ride or not is another matter The other thing Brandt mentions in that section is that as wheel size increases, so does the need for more spokes, (or, I guess, more strength in the rim). So again, theoretically, for a given rim stiffness, you can use fewer spokes for the same "strength" the smaller the wheel gets (as the area over which the load is being spread is becoming smaller).

Roger Musson's book doesn't talk about strength as a function of spoke count, so far as I can tell.

While we are on the subject, I really have to post a quote by the great Harry Rowland, It doesn't come from a book where a little bit of background information is expected but from talking to a journalist about his job, pretty informal talk.

"If a 100kg guy comes in and wants 28 spokes, he’s not having it from me. I’d rather lose the sale because I’m going to expect problems. A spoke’s a spoke, and the more you have, the more are sharing the load, it’s as simple as that."

Of course this re-opens the debate, so and so builds wheels with 3 spokes but if we consider only spokes available to wheelbuilders then what HR is saying, makes sense to me. The other argument is to use a very strong rim, something like a touring rim then it wouldn't make sense to use less spokes, the weight of such wheel would be greater than a standard rim with 36 spokes.

So for a reliable wheel a heavy rider, I'm afraid, has to have lots of spokes and that is assuming the wheel is correctly built.

 

[John the Monkey]

Of course this re-opens the debate, so and so builds wheels with 3 spokes but if we consider only spokes available to wheelbuilders then what HR is saying, makes sense to me. The other argument is to use a very strong rim, something like a touring rim then it wouldn't make sense to use less spokes, the weight of such wheel would be greater than a standard rim with 36 spokes.

So for a reliable wheel a heavy rider, I'm afraid, has to have lots of spokes and that is assuming the wheel is correctly built.

...although Schraner's 24 spoke touring wheel used spokes from the commercially available DT Swiss range (but, as you allude to, the stronger rim put the weight on par (or "comparing favourably"!) with a 32 spoked wheel). I think, if I remember Schraner's book correctly, he favours a deep section rim to provide the extra strength, rather than an overbuilt box section.

The part about "sharing the load" is essentially what Brandt says (I think) - but the stiffer the rim, the wider the area that's loaded - so for differing rim stiffnesses, you could load, say, four spokes at a particular point in the rotation (but with the spokes further apart). Returning to Brandt (p39) he says "for a common 36 spoke wheel, the load affected zone spans about four spokes. If the spokes are tensioned to 100Kg, the wheel could support a 400kg load". If we trust that calculation, Schraner talks of deep profile rims being able to take higher spoke tensions ("up to 337lbs" (152kg) p32) - even assuming fewer spokes means, say, only two spokes form the load affected zone, that's still a load of slightly more than 300Kg. If the rim is stiff enough that the load affected zone spans more than two spokes, that goes up, of course (I can't say how likely that is).

 

[Shut Up Legs]

I'd be thinking 32 or 36 myself, tbh - not for strength per se, so much as for limpability should a spoke break. I reckon spoke counts in the 20s mean an unrideable wheel should a spoke break.

If the wheel is well built to start with, and looked after, that may be something you don't feel is enough of a possibility to merit consideration. Talk to your builder about it, and see what they reckon.

Agreed, I use 36 rear and 32 front on my carbon road bike, because I planned right from the start to use it on very long rides, but it's also handy to withstand the bumps of commuting when I use it for this. The weight difference compared to, say, 28/24, is paltry***.

*** and I'd be a real chicken if I let it make a difference .

 

[Spoked Wheels]

I think we are on the same page basically. There are times when people get confuse with different types of rim and spokes. A touring wheel with 24 spokes must have pretty strong rim otherwise I don't see how such wheel could handle the weight.

I think RM talks about narrow rims with a wide diameter (700c) can take substantially less tension than 26" wheels or wheels with a deep section.
He says that it's impossible to buckle a 26" wheel by applying tension to spokes by hand. I imagine he means using standard type of spoke keys. I've seen some spoke keys that would probably let you do some damage if you wanted to.