Advice on Spoke Count

grahamcp

I've been running a set of Easton EA90SLXs on my best bike for a few years. Last night I had a broken spoke on the front which resulted in the rim going so far out of true the wheel would not turn due to rubbing against the inside of the fork.

I have actually had 2 sets of these wheels and had an identical issue with the the other one on a different bike. I've had a few other niggles with them as well and think the time has come to replace with something new.

It may be obvious but I'm guessing that the low spoke count (18 I think, not at home at the moment) was likely the main factor in scale of the problem?

I realise that spokes may go pop from time to time but it would be nice to have the ability to limp home rather than in this case where I had to call for a lift to avoid damage to the fork/tyre. Fortunately I wasn't too far from home but could easily have been in the middle of nowhere.

Is there an optimal number of spokes that I should consider in future? I had a quick look online and came across some Shimano wheels that had even less (16!) which seems a bit crazy... also are there any benefits of going handbuilt vs factory ready, and anything I should look for in terms of spoke/nipple types and materials?

Thankyou :-)

keef66

I too discovered this downside of low spoke count wheels. Took the day off work to watch the TDF go past south of Cambridge with my wife, spot of pub lunch, then out for a nice ride in the summer sunshine. 5 miles later and bang! Rear drive side spoke snapped. Wheel pringled and the tyre jamming so hard against the chainstay I couldn't even push the thing along. This on a Shimano wheelset with as you say 16 front and 20 rear spokes.

Once rescued, the next problem was obtaining a replacement spoke. In the end I settled for a silver spoke in an otherwise black wheel. (The alternative was buying a black one from Germany). I did manage to fit it and true the wheel satisfactorily which was quite pleasing.

Dunno what the minimum number of spokes would be F/R to ensure you can still ride after losing one. Must depend also on rider weight, rim, spokes and lacing...

36F / 36R laced 3 cross is obviously the gold standard; I'm guessing that for most riders 24F / 36R would be pretty robust?

wishitwasallflat

If your tired of spokes breaking contact Malcolm ( cycleclinic)* tell him what you weigh, where and how much your ride and he will build you a set of wheels to fit your needs.

* Or another reputable wheel builder, I reccomend Malcolm because I've had a few sets from him, quality and service are superb, but I'm sure there are others who are good as well.

Bobbinogs

I have ridden with someone on those wheels who suffered the same issue after popping a spoke on the front, I was amazed at just how much the wheel deformed and he was very lucky to be able to get home (he ended up with the brakes completely disconnected and the wheel missed the forks by about 1mm). I figured that tension must play a part; I suspect someone who knows what they are on about can explain just why some wheels are toast after a single spoke going, perhaps it is not as simple as spoke count?

cycleclinic

36F/36R is not a gold standard. It was used on old wheels back in day when narrow shallow flexible rims where used under the mistaken belief they where more comfortable but that meant lots of spoke were needed so the wheel holds together. I have a set of 32F/32R Mavic GEL280's (280g tubular rims and yes they are not stiff) laced to some silver novatec hubs and the cornering requires shall we say balls of steel if you go turn in at speed. My balls are not made of steel I nearly crapped myself.

Spoke life is not a function of spoke count it is determined by radial. lateral and torsion stiffness of the wheel and how big the tension changes are each cycle on the spokes. The stiffer the wheel the smaller the tension changes on the spokes when loaded and the long the wheel lives. the smaller the tension changes relative to the original tension of the spokes the longer the spoke last, simple as that. Spoke count does increase stiffness but the rim and bracing angles from the hubs are important too. Also tension balance has an effect (offset rims for the rear wheel are helpful) as does how much spoke tension there. There is no secret to any of this it is simple physics.

This why your eastons have failed it is not because they are low spoke count (that does not help) but they are not stiff enough. Of course I am assuming the spokes were tensioned to about 1000N on the front and tension varied by no more than +/-5% of the mean. this of course is the other reason why spoke fail. tension variance leads to some spokes fatiguing faster than others. Low tension means early spoke failure too.

Sorry to get technical with you all but the same myths just keep circulating.

keef66

I don't think anyone is suggesting low spoke count means they are more likely to fatigue /break.

More that if you lose a spoke in a 16 or 20 spoke wheel it is more likely to go so far out of true as to be unrideable.

How many spokes and what lacing would give a wheel that stays fairly true despite a broken spoke?

(My only ever spoke breakage was almost certainly because of an earlier fall / bent mech hanger / chain off the back of the cassette incident. I should really replace another DS spoke that looks a bit chewed too...)

ugo.santalucia

Rule of thumb... 24 spokes or less will most likely foul the brake pads/fork, the difference between 20 and 16 is very little, they are both useless if a spoke snaps. You should get away with 28, 32 is pretty safe, 36 you hardly notice.

This is a rule of thumb, great big motherfuxxing carbon rims might stay true-ish even with low spoke counts.

They sell an emergency spoke, which is basically a kevlar rope to be tensioned between the hub and the rim, but I have never used it, so no idea how good it is