Need a new rear wheel for a bike which will be used by a slightly ham-fisted individual……

Deore disc hub with a Mavic EN 521 rim…..assuming it is slightly stronger than the EN321 being welded rather than pinned.

However, should I go with ACI db spokes or DT plain gauge?

Obviously a Merlin build too.

One theory is that all stress and stretching in db spokes is contained in the thin section so they don’t break at the elbow. A bit of flex in the wheel is not a bad thing. When I wrenched, the view was there was no benefit in straight guage.

Agreed strength is down to manufacture consistency not single or DB.

Planty of consistent manufacturers around, not sure what your point is

2.0/1.8/2.0 double butted spokes are designed to be as strong as plain gauge but with reduced weight. 2.0/1.6/2.0 are reduced in both weight and strength. I would get 2.0/1.8/2.0, and if you are worried about strength then use 36 spokes.

No need to beat yourself about being a little slow, if you think about it for long enough I’m sure you’ll get there in the end.

My point is that a well manufactured spoke regardless of being SG or 2/1.8/2 Db will beat some no brand piece of shit.

ah. That’s so obvious I assumed it was a given. Can you even buy crap spokes?

Most spokes are stainless steel are they not? Despite mild steel being better?????

Id imagine corroded spokes dont perform too well.

You can get galvanised ones on eBay I notice. Would they be mild steel underneath?

Stoner – yes – galvanised mild steel. more ultimate tensile strength assuming decent quality of manufacture

lighter?

Lighter for the same strength or stronger for the same weight. Pretty marginal tho

It depends if you’re worried about breaking spokes, or about ultimate wheel strength when putting big side loads on it. If the latter then PG are actually better as they make the wheel stiffer, thus less likely to pringle.

galvanised mild steel. more ultimate tensile strength assuming decent quality of manufacture

But UTS isn’t particularly important with spokes, and your assumption is quite a big one.

Cynic and myself disagree about this !

However the perception of distributing forces/stresses is pretty well established. Also, DB spokes are[/i] stronger when [/i]considered as a strength to weight ratio.

But my own experience is pretty simple as where I ride, rock strikes onto rims and spokes is common (how do they roll and flip into your wheel so neatly). With DB spokes they bend and stretch under such impacts and wheel goes out of true – often requiring a spoke relacement. With plain gauge the damage is rarely like this and the spokes seem to withstand the scaping etc. better, wheels don’t go out of true.

So on my XC bike – DB spokes and faffing around truing them.

For the play and ‘big’ bike PG and rarely if ever touch them (including several alpine trips and whistler bike park).

You certainly can get crap spokes, usually OE only though. DT swiss are by far the best.

Ultimately the sum of the parts is only as good as the wheelbuilder who is putting the parts together.

Does mild steel not have a better fatigue life than stainless?

See, i’d take Sapim over DT.

Yep, Sapim spokes, most definitely.

I agree with steel4real regarding type of spokes. For general use, 2.0/1.8/2.0 will do the job nicely. If you’re really trying to build a light wheelset and don’t mind a bit of flex then something like 1.8/1.6/1.8 will suit you. For a burly wheelset where weight is not the primary concern and you want them to stand up to a bit more abuse from impact as well as riding I think there’s a definitely place for plain gauge spokes.

Ah, the usual confusion present on every wheelbuilding thread!!

Cheapo spokes are made of either chrome or zinc plated (aka galvinised) carbon steel which is heavy and prone to rust. Stainless steel is the most common material for spokes and by far the best: it’s strong, has good fatigue life and doesn’t rust. So ignore what TJ has written, he’s wrong… 😉
You can also get Ti spokes but they’re very expensive and difficult to get for very little advantage.

Double butted spokes (2 common diamaters 2.0/1.8/2.0 (aka 14/15 gauge) and 1.8/1.6/1.8 (aka 15/16 gauge)) not only save weight over plain-gauge, they add strength because the thick ends make them as strong in the highly-stressed areas as straight-gauge spokes of the same thickness, but the thinner middle sections make the spokes effectively more elastic. This allows them to stretch (temporarily) more than thicker spokes thus transferring force onto adjoining spokes. 14/15 for normal trail wheels, 15/16 for XC race wheels basically.

You can also get triple butted spokes which are even stronger, they add weight at the head and reduce weight at the thread and (apparently) they are the choice of spoke for heavily laden touring bikes.

Bottom line is that whenever I’ve built wheels for customers, double butted spokes were offered as standard, we’d only ever build plain gauge on request (and no-one ever requested them!) as the extra price of DB was well worth it.

I’m having a wheel built by Freeborn in Esher at the moment. BigUn 12mm bolt-thru and the new Mavic 521 rim. Spokes? DT Competition. It’s about 100gms of the wieght difference and a tiny amount of flex. I had wheels built with PG spokes anf they felt wooden compared to the same but DB spokes. Never again.

Can’t be bothered arguing with you al – once more you miss my point. Galvanised steel made to the correct specs will have a longer fatigue life and greater strength. this is really only theoretical as no one wants galvanised on high end bikes for cosmetic reasons. So no one makes good quality ones.

Double butted spokes … not only save weight over plain-gauge, they add strength because the thick ends make them as strong in the highly-stressed areas as straight-gauge spokes of the same thickness, but the thinner middle sections make the spokes effectively more elastic.

Strength to the spokes, not to the wheels – where strength is closely related to stiffness, which stiffer (ie PG) spokes improve.

James stainless spokes may not ‘rust’ but they still prone to corrosion when subject to salt.

Google ‘crevice corrosion’ one of the common causes of stress cracks.

Stainless is also very brittle when compared with what used to be called rustless spokes.

Chrome plated spokes are just sh1t – period.

Aero spokes offer a couple of advantages over round spokes also, so worth considering.

Double butted spokes are, for a given weight, stronger.

Also, as they are a higher grade product, they may be made from stronger materials.

Traditionally, the problem with stainless spokes is that they’re a bit more brittle, however this is no longer a problem with the grades of stainless now available.

You’d have a problem with corrosion on even a rustless spoke before you had a fatigue problem on a well built wheel in any case (fatigue only comes into play if the spokes are too loose, never quite got my head around why a spoke going in and out of tension is worse than one having a varying amount of tension above zero, but have proved it to myself through lazyness on hack bikes…)

Anyway, for the ultimate in strength, as someone has already said, go for triple butted.

Lacing, wheel build, spoke count and the rim strength will make far more difference though in any case. Plus you can always end up dinging the rim on a rock etc.

In the OP’s situation, I’d go for it using DT competitions. Have found Sapim’s not as good, and some other brands way inferior.

fatigue only comes into play if the spokes are too loose

Not true. You can definitely fatigue well tensioned spokes – it’s just that too loose means they’re likely to go sooner. I think it’s because the spoke will bend when the tension is low, as classic metal fatigue is accelerated by a static force superposed on the varying one.