Spoke Count

[hubgearfreak]

Subject diversion: anyone seen the new Crank Brothers wheels? An interesting design.

these?

i would have thought that straightening the bend out of spokes would weaken them

 

[simonali]

That is they. The "nipples" are in the middle of the spoke and the rim has a raised flange instead of holes in it. Quite a major re-invention.

 

[hubgearfreak]

i doubt that there's any real benefits

 

[andrew_s]

I would disagree with that. Try leaning on a spoke and it will bend in half, I can't see how it supports any compression load at all.

if you imagine a wheel with just a few spokes at the top, and a few at the bottom, ....

Neither of you are talking about a normal wheel. That's why I said this:

provided we are talking about a normal wheel under normal loads.

In the case of the compressed spoke, you've taken a spoke, applied a force to its ends, and it has become a modicum shorter as a result. That's what compression means.
It hasn't buckled because of the pretension that's on it as a result of being part of a wheel.

My post was a (failed?) attempt to point out that there is more than one way of describing a situation, and that Jobst isn't a numpty because he uses a different way to you.
FWIW my personal view is that "hangs" is a better description in normal, non-specialised English than "stands".

 

[andrew_s]

i doubt that there's any real benefits

I'm not so sure. The spoke/rim joint is a definite weak point in standard wheels. In the past I've had eyelets pull through the rim, and nipples snap (under provocation).

For me, I doubt that any benefits would be sufficient to override the flexibility and repairability that a standard wheel gives, however.

 

[hubgearfreak]

FWIW my personal view is that "hangs" is a better description in normal, non-specialised English than "stands".

it's neither, as i pointed out earlier, and that you have chosen to part quote me on.

a bicycle wheel is a collection of parts, all of them under some loading before they carry a load.
any missing part will mean the wheel is far from complete, so it's a nonsense to say that it's either the top or the bottom spoke, as it's the dozen or 3 dozen others aswell

 

[simonali]

For me, I doubt that any benefits would be sufficient to override the flexibility and repairability that a standard wheel gives, however.

That and the fact that they'll cost around £650!!

 

[simonali]

i would have thought that straightening the bend out of spokes would weaken them

That statement makes it look like you think they take bent spokes and straighten them?!!

Many manufacturers have been using straight pull spokes for years and they've not gone back to the old type, have they? Plus, whenever I've had a spoke break it's been at the hub end where said bend is!

 

[hubgearfreak]

That statement makes it look like you think they take bent spokes and straighten them?!!

i was being facetious, sorry

 

[simon l& and a half]

that's the same system as my Dura-Ace wheels. And the 105s. Too many spokes, though

 

[mondobongo]

Thanks for your replies everyone decided to err on the cautious side and have some 105's built up 36/32. Don't have the luxury of a second bike at the moment so need the reliability for my commute plus as posted by Kyuss don't fancy walking a mile in cleated shoes never mind 3 should a spoke fail whilst out on a bigger ride.

 

[NickM]

If the weight of bike and rider hangs from the top spoke, what is the top spoke hanging from? The rim? What is keeping that part of the rim which is bearing the weight in place? The other spokes, or at least those which are not in compression?

When wheels are robust with low spoke counts, surely it can only be because mass has been redistributed in favour of the rims, which are therefore stiffer. If you have aluminium spokes, you don't want them flexing much, do you? Have they discovered aluminium alloys that are no more susceptible to fatigue than steel? Or is the "magic ingredient" the removal of the bend at the hub end of the spoke?

 

[rich p]

Great stuff you lot. Very informative and also entertaining.
These threads are a bit like 3 card brag it's only fun when when there are more than one protagonist.

 

[hubgearfreak]

Plus, whenever I've had a spoke break it's been at the hub end where said bend is!

i'll bet that when it happens, it's not to a hand built 32, 36 or 40 spoker

 

[MartinC]

Points of information:

This thread got bad tempered when people started dissing other's motives for their choices.

There is no way that a normal spoke can ever do anything but tension 'cos the nipple will just push through the hole in the rim in compression.

Materials, especially aluminium, are way better than they were 30 years ago when 36 spoke wheels became the norm. Aluminium was much softer then and you wouldn't have dreamed of buying a rim without double eyelets.

Factory built (low spoke count) wheels have much stronger rims 'cos they can now.

Factory wheels often have straight spokes. By and large spokes only ever break on the bend on the drive side of rear wheels.

Straight pull spokes and stronger rims allow bigger tensions in spokes.

Low spoke count wheels will be unusable if a spoke breaks. STI/Ergos aren't repairable on the road either but this doesn't stop us using them (or indexed gears even).

Opinion.

I used to be really sceptical about low spoke count wheels but the experience is different. I've just bought some for my touring bike. Seems to me that a lot of my initial objections were just old fashioned begrudgery.