Author Topic: Spokes  (Read 3705 times)

Re: Spokes
« Reply #50 on: February 16, 2019, 10:43:07 am »
With sticky tubeless-compatible rim tape that had to come off I couldn't deploy my fibre-fix, so it was ride-ending. One reason I've given up on tubeless - though you could carry spare rim tape I guess.

Hmm, right - so I need add a rim strip to my kit in case this happens (I already carry a clincher tyre and tube). I'm planning to stick with tubeless this year (GP5000 TL seems v. nice so far!) but it has to be said, "extra difficulties in the event of spoke failure" is another strike against tubeless for long-distance cycling.

You have to consider that against the probability of spoke failure.   If spoke failures were common fair enough but they are not.  Based on my own data points I have as much chance of the frame breaking as I do of a spoke failure.  Then you have to consider how many of these rare events will lead to one where fibre fix will not work, and how many of those will be during an important cycling event for you. Even then you could always revert to tube with a bit if gaffa tape over the hole you made in the rim strip.

Re: Spokes
« Reply #51 on: February 16, 2019, 10:45:45 am »
Don't agree there are any.

Wouldn't they'd be:

- sealant everywhere
- tubeless tape that can shred when peeled off (if it's been on for a long time I've had this with Stan's tape)
- having removed the tubeless tyre, even if the tape can be re-fitted then re-seating the tyre roadside is well-nigh impossible - so need to switch to a tubed system

?

Amount of sealant should only be 30-40mL so not a huge volume.

guidon

  • formerly known as cyclone
Re: Spokes
« Reply #52 on: February 16, 2019, 10:50:34 am »
Had an aksium front go on one of Blacksheeps 200 years ago, since then gone for 36 3x and havent had a problem, even with my dodgy wheelbuilding.....So it can happen but I cant see why you would carry so many spokes if you can get a fibrefix, plus as mentioned above the need for a cassette remover, chain whip, adjustable spanner etc

stefan

  • aka martin
Re: Spokes
« Reply #53 on: February 16, 2019, 11:01:30 am »
With sticky tubeless-compatible rim tape that had to come off I couldn't deploy my fibre-fix, so it was ride-ending. One reason I've given up on tubeless - though you could carry spare rim tape I guess.

Couldn't you just put the tape back afterwards and put a tube in?  Doesn't matter if it won't restick, as it's more than strong enough to keep that tube from puncturing on the spoke ends.

yes I tried that - was carrying spare tubes - but the tape wasn't reusable. Might have reflected my inexperience with tubeless in removing it, perhaps with more care it might have been possible...

SPB

Re: Spokes
« Reply #54 on: February 16, 2019, 11:18:52 am »

yes I tried that - was carrying spare tubes - but the tape wasn't reusable. Might have reflected my inexperience with tubeless in removing it, perhaps with more care it might have been possible...

Fair enough.  I've never had a problem with any of the rim tapes I use splitting, but I respect your own experience.

Wouldn't they'd be:

- sealant everywhere
- tubeless tape that can shred when peeled off (if it's been on for a long time I've had this with Stan's tape)
- having removed the tubeless tyre, even if the tape can be re-fitted then re-seating the tyre roadside is well-nigh impossible - so need to switch to a tubed system


- negligible.  And if you take the tyre off vertically and what there is will stay in the tyre.
- fair enough, as reply to Stefan
- you'd have to put the tube in anyway if you had a tubed tyre, so I don't see that as a drawback

wilkyboy

  • "nick" by any other name
    • 16-inch wheels
Re: Spokes
« Reply #55 on: February 16, 2019, 11:45:19 am »
Of course the spokes one can't replace without extra tools on the rear right side are those most likely to go, not because of increased stress: spokes fatigue at the same rate whatever the load (theory, puts head over parapet perhaps, especially in such esteemed company) but because they've more likely to have sustained damage (proximity to RD and chain).

Certainly proximity damage would increase the likelihood of drive-side spokes going.

However, I strongly suspect that the higher static load (tension) that has to be put through DS spokes to dish the wheel to make space for the cassette means that each cyclic loading would contribute more greatly to fatigue on spokes on that side — the difference in tension is significant.  Not a problem for me — I have one gear each side, so the dish is symmetrical   O:-)
RRTY #6 done; #7 aborted and restarted.

SPB

Re: Spokes
« Reply #56 on: February 16, 2019, 11:59:03 am »
With sticky tubeless-compatible rim tape that had to come off I couldn't deploy my fibre-fix, so it was ride-ending. One reason I've given up on tubeless - though you could carry spare rim tape I guess.

I am curious though, why did you need to remove the rim tape?  Was it because the nipple broke?  If it was the spoke, it would in all likelihood have broken at the j-bend and a large part of it would have still been screwed into the nipple, preventing it from falling out.  You would have held the nipple, uncrewed the broken spoke, and screwed in the fibre fix, no?

whosatthewheel

Re: Spokes
« Reply #57 on: February 16, 2019, 12:08:01 pm »
Don't agree there are any.

Wouldn't they'd be:

- sealant everywhere
- tubeless tape that can shred when peeled off (if it's been on for a long time I've had this with Stan's tape)
- having removed the tubeless tyre, even if the tape can be re-fitted then re-seating the tyre roadside is well-nigh impossible - so need to switch to a tubed system

?

Realistically, unless you are really really good, you peel off the tape and you throw it away because it won't stick anymore... then you fix the spoke, then you need to clean the rim throughly to make sure new tape will stick. Then you need to hope that your CO2 canister will sit the tyre without freezing the sealant in a useless lump... a portable pump won't work...
Or, you give up on tubeless, fit an inner tube hoping it does fit and get on with a converted tyre... or you carry a spare clincher tyre + tube

A lot of faff, whichever way you look at it

That said, if you have Mavic rims with FORE drillings, you don't have to do any of that... you just need the correct spokes and bingo!

stefan

  • aka martin
Re: Spokes
« Reply #58 on: February 16, 2019, 12:08:51 pm »
With sticky tubeless-compatible rim tape that had to come off I couldn't deploy my fibre-fix, so it was ride-ending. One reason I've given up on tubeless - though you could carry spare rim tape I guess.

I am curious though, why did you need to remove the rim tape?  Was it because the nipple broke?  If it was the spoke, it would in all likelihood have broken at the j-bend and a large part of it would have still been screwed into the nipple, preventing it from falling out.  You would have held the nipple, uncrewed the broken spoke, and screwed in the fibre fix, no?

good point. Unfortunately the gauge of the fibrefix didn't work with the nipple so the latter had to be replaced. All a bit vexing at the time!!

stefan

  • aka martin
Re: Spokes
« Reply #59 on: February 16, 2019, 12:13:38 pm »
With sticky tubeless-compatible rim tape that had to come off I couldn't deploy my fibre-fix, so it was ride-ending. One reason I've given up on tubeless - though you could carry spare rim tape I guess.

I am curious though, why did you need to remove the rim tape?  Was it because the nipple broke?  If it was the spoke, it would in all likelihood have broken at the j-bend and a large part of it would have still been screwed into the nipple, preventing it from falling out.  You would have held the nipple, uncrewed the broken spoke, and screwed in the fibre fix, no?

good point. Unfortunately the gauge of the fibrefix didn't work with the nipple so the latter had to be replaced. All a bit vexing at the time!!

Anyway since that unfortunate episode I've taken Wilkyboy's advice and learnt to build my own wheels! (And there are other reasons why I've stopped using tubeless, which are probably not for this thread but can be summarised as - great when they work but I didn't find them all that reliable).

SPB

Re: Spokes
« Reply #60 on: February 16, 2019, 12:15:54 pm »

I am curious though, why did you need to remove the rim tape?  Was it because the nipple broke?  If it was the spoke, it would in all likelihood have broken at the j-bend and a large part of it would have still been screwed into the nipple, preventing it from falling out.  You would have held the nipple, uncrewed the broken spoke, and screwed in the fibre fix, no?

good point. Unfortunately the gauge of the fibrefix didn't work with the nipple so the latter had to be replaced. All a bit vexing at the time!!

Got you, sounds like the last thing you need when sleep deprived!  Were they strange, non-standard spokes and nipples you had?  All those I've ever built with have had the same, standard thread.

Re: Spokes
« Reply #61 on: February 16, 2019, 12:31:15 pm »
However, I strongly suspect that the higher static load (tension) that has to be put through DS spokes to dish the wheel to make space for the cassette means that each cyclic loading would contribute more greatly to fatigue on spokes on that side

I believe this is somewhat addressed by newer rims which have asymmetric drillings, like the Pacenti Forza.

Re: Spokes
« Reply #62 on: February 16, 2019, 12:38:05 pm »
You have to consider that against the probability of spoke failure.

Low I think. Yet we know from the LEL mechanics it's not *that* uncommon. Echoing what @vorsprung wrote upthread, from personal observation I think the main risk is from improperly-built wheels. I've even seen some from a prestigious London brand where most of the spokes were just completely loose.

mattc

  • n.b. have grown beard since photo taken
    • Didcot Audaxes
Re: Spokes
« Reply #63 on: February 16, 2019, 12:40:26 pm »
/whitehatthinking

Would a dishless rear wheel be a better all-round package?? It is arguably weaker on the non-DS side, but that side has easier-to-replace spokes, and carrying just the one rear spare would cover the majority of all (still vv rare) failures.

[The non-DS side would still be no weaker than a standard DS - which many here state is invulnerable on a modern wheel anyway :P]
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Re: Spokes
« Reply #64 on: February 16, 2019, 12:59:57 pm »
Of course the spokes one can't replace without extra tools on the rear right side are those most likely to go, not because of increased stress: spokes fatigue at the same rate whatever the load (theory, puts head over parapet perhaps, especially in such esteemed company) but because they've more likely to have sustained damage (proximity to RD and chain).
Certainly proximity damage would increase the likelihood of drive-side spokes going.
However, I strongly suspect that the higher static load (tension) that has to be put through DS spokes to dish the wheel to make space for the cassette means that each cyclic loading would contribute more greatly to fatigue on spokes on that side — the difference in tension is significant.  Not a problem for me — I have one gear each side, so the dish is symmetrical   O:-)
The right hand side ones are at higher tension (dished wheel) - 1400N/1000N say - but the cyclical change in tension is the same eg static (at rest) tension down to static tension minus 300N and back: the amplitude of the cyclic stress and the millions of cycles that cause the (stochastic) fatigue (rather than the normal tension level) a very long way down the road (I think).
I'm expecting my spokes to go though 571,764 stress cycles (approximately  ::-)) during PBP. My front wheel spokes (relaced last year onto a new rim) have done at least 15 million: got me worried now.

Re: Spokes
« Reply #65 on: February 16, 2019, 01:03:12 pm »
You have to consider that against the probability of spoke failure.

Low I think. Yet we know from the LEL mechanics it's not *that* uncommon. Echoing what @vorsprung wrote upthread, from personal observation I think the main risk is from improperly-built wheels. I've even seen some from a prestigious London brand where most of the spokes were just completely loose.

Wo do but what we don't know is whether those riders ride like a sack of spuds, crashing through every pothole imaginable, have low spoke counts, ride on absurdly high pressures, have hand built or machine built wheels, stress relieved the spokes or not, have the wheels been damaged in transit, generally maintain their bike well.  It is uncommon enough in my 50 years of riding that I am happy enough not to worry about an event that has happened to me exactly once on machine built wheels and narrow tyres at high pressure.  Neither of which I ride on these days.

T42

  • Gaulois réfractaire
Re: Spokes
« Reply #66 on: February 16, 2019, 01:11:04 pm »
Maybe I'm a bit happy-go-lucky, but I've done PBP 3 times on 24-spoke rear wheels with no spares.

Quite possible, but you'd probably change something if you did have a problem with that configuration.

It's the same logic as "I've played Russian Roulette four times now and I'm still alive!" or "I've texted whilst driving hundreds of times and haven't killed anyone" although the consequences aren't as extreme.

Yes and no: I always got new wheels a month or two in advance of PBP, so the reasoning was more like "I've done over 1000 km on this wheel, the last one did over ten thou so what's the chance a spoke's going to break in the next thou and a bit?"  I'm not heavy and I don't carry that much kit.
I've dusted all those old bottles and set them up straight.

wilkyboy

  • "nick" by any other name
    • 16-inch wheels
Re: Spokes
« Reply #67 on: February 16, 2019, 02:15:02 pm »
Of course the spokes one can't replace without extra tools on the rear right side are those most likely to go, not because of increased stress: spokes fatigue at the same rate whatever the load (theory, puts head over parapet perhaps, especially in such esteemed company) but because they've more likely to have sustained damage (proximity to RD and chain).
Certainly proximity damage would increase the likelihood of drive-side spokes going.
However, I strongly suspect that the higher static load (tension) that has to be put through DS spokes to dish the wheel to make space for the cassette means that each cyclic loading would contribute more greatly to fatigue on spokes on that side — the difference in tension is significant.  Not a problem for me — I have one gear each side, so the dish is symmetrical   O:-)
The right hand side ones are at higher tension (dished wheel) - 1400N/1000N say - but the cyclical change in tension is the same eg static (at rest) tension down to static tension minus 300N and back: the amplitude of the cyclic stress and the millions of cycles that cause the (stochastic) fatigue (rather than the normal tension level) a very long way down the road (I think).
I'm expecting my spokes to go though 571,764 stress cycles (approximately  ::-)) during PBP. My front wheel spokes (relaced last year onto a new rim) have done at least 15 million: got me worried now.

Yes, I had considered that.  However, the effect of impact loading on the DS spokes is greater than the non-DS spokes, due to the more direct load angle between the application of instant force from the bump and the opposite inertia from one's arse — i.e. DS-spokes will take higher load, and, being already much greater stressed, will suffer greater instant loading, albeit momentary, and these things build up over time on top of cyclic loading.  There won't be that much difference between the two sides, unless built with a radial pattern — multiple-cross lacing patterns create greater angles away from the radius, so impact loads are shared among more spokes, and this offsets most — but not quite all — of the effect of DS spokes being more "vertical".  Specifically, the DS spokes will have a slightly greater cyclic tension amplitude than non-DS, exacerbated over bumps.

Since spoke failures due to fatigue are almost always at the elbow, the ultimate strength of the spoke isn't so important along its length anyway, just where it pokes through the hub.  I would fancy that the higher tension and the higher instantaneous loads (over bumps) on the spoke material just at that bend will cause a significantly greater fatigue rate on DS spokes.  But that's just my fancy. 

Presumably straight-pull spokes will have a different failure mode and possibly no statistically relevant difference between the two sides, although I would still expect the DS spokes to fail more frequently due to the more-vertical angle and greater cyclic stress amplitude, but would take longer to get there — Alex B will let us know in a decade or so  ;)

As always, when building wheels, if you have narrow flanges then spokes should really be washered to bring the elbow as close to the flange-side as possible, to reduce the rate of fatigue on the elbow.  All hubs I've bought in the past five years have NOT needed washers, as the flanges have been thick enough not to need them.
RRTY #6 done; #7 aborted and restarted.

Re: Spokes
« Reply #68 on: February 16, 2019, 03:15:32 pm »
I stopped carrying spare spokes when I stopped carrying cassette removers, chain whips and large adjustable spanners, because the spoke breakages I’d had were all on the drive side rear. I do carry a proper spoke key though in case I need to true the wheel with the remaining spokes following a breakage. I’ve only had maybe 4 spokes break in over 140,000km of Audax rides and all but 1 were on cheap, dodgy 27” wheels in the Dark Ages. These days I typically use Mavic Open Pro rims on Shimano 105 hubs with stainless spokes and use rim brakes and non-tubeless tyres so pretty standard and strong wheels. I have a 32 spoke rear wheel in at the moment and consider that fine as I’ve carried ridiculous amounts of camping gear to the PBP on similar wheels and got away with it. After reading some of the posts above I am slightly worried about my current front wheel as it’s an entry level £50 Shimano road wheel with just 20 radial spokes so I’m no longer sure I dare use that one for the PBP! That said, it’s been great so far getting me round LEL, TINAT 600, Mille Pennines, Mersey 24, Dolomites SR and plenty of shorter rides too. It’s still perfectly true despite hitting some pretty nasty potholes and running 23mm tyres at 100psi.
I might possibly buy myself a fibrax spoke or two, but they seem bit pricey for what they are. Potentially ride ending things I do always guard against are major blowout, snapped derailleur hanger, snapped chain and  freehub failure. I carry a spare tyre, 4 tubes, spare hanger, quick links, mulitool with good chain tool, and about 20 cable ties plus a few other bits and bobs.


whosatthewheel

Re: Spokes
« Reply #69 on: February 16, 2019, 03:27:30 pm »


As always, when building wheels, if you have narrow flanges then spokes should really be washered to bring the elbow as close to the flange-side as possible, to reduce the rate of fatigue on the elbow.  All hubs I've bought in the past five years have NOT needed washers, as the flanges have been thick enough not to need them.

I have built wheels semi-professionally for about 5 years, somewhere north of 500 wheels. I used to washer pretty much everything, with the exception of those spokes too thick to take washers (DT Alpine 3 for instance) , then I stopped when I was no longer able to find DT Swiss washers (the Sapim ones are too thick).
I have no reports of broken spokes in either cases... so I no longer see a reason to use washers, modern hubs are drilled in a more professional way than old 1980s hubs and spokes tend to sit quite flush.

More generally, if a wheel has been built and tensioned properly, the chances of spokes breaking due to fatigue are very low, tending to zero. On the contrary, if the wheels have been poorly tensioned, the chances of fatigue ruptures are very high.
Occasionally some cheap machine built "handbuilt lookalike" wheels flood the market and tend to give all sorts of troubles, but most wheels on the market are solid

Re: Spokes
« Reply #70 on: February 16, 2019, 10:08:57 pm »
I carry an old Pamir Hypercracker so I can easily remove my cassette. There still is 'the next best thing' for those who don't have old stocks. But apparantly this tool may only be used on steel frames since carbon ones may break due to the pressure exerted on a part of the frame not designed for it.

I once had to pack at the Borders of Belgium due to multiple broken spokes. Reason was a rear mech issue a week or so earlier which threw my chain into the spokes, chewing away part of it. I still carry extra spokes.

Re: Spokes
« Reply #71 on: February 16, 2019, 10:20:47 pm »
I have one of the NBT2s and they do work, but make sure you have a strong QR, as I broke a Pitlock skewer while trying to replace my cassette in Varanasi. I couldn't find a replacement QR, and had to swap out the skewer with a solid axle... http://aroundtheworldbyaccident.blogspot.com/2012/03/fixed-and-working-again.html?m=1

Re: Spokes
« Reply #72 on: February 25, 2019, 09:14:05 am »
I've read some people storing spokes in the seat post, with a piece of foam in the frame to stop them slipping down. Might give it a go as I have slightly non-standard spokes

wilkyboy

  • "nick" by any other name
    • 16-inch wheels
Re: Spokes
« Reply #73 on: February 25, 2019, 10:17:06 am »
I've read some people storing spokes in the seat post, with a piece of foam in the frame to stop them slipping down. Might give it a go as I have slightly non-standard spokes

I always thought the standard place to store spokes was taped to the seat stay?  That way you don't have to upset your saddle position to get to them and you can remove them easily enough at the end of the long ride.

That said, last PBP I just chucked a couple into my Carradice, as they weren't that long.  And LEL 2017 I didn't bother, just took a Fiber Fix emergency spoke (I might've taken two, I can't remember).
RRTY #6 done; #7 aborted and restarted.

Re: Spokes
« Reply #74 on: February 25, 2019, 10:26:10 am »
Some framebuilders have a nice solution for this problem: