For the tandem. Its got a rohloff and has been breaking spokes so its off to the LBS for a rebuild as once spokes start breaking I guess they will carry on doing so.

It needs to be as strong a build as possible – usually tandem wheels are build with high tension IIRC but my wheelbuilder said this could be leading to the spoke breakages.

so plain or butted spokes? washers on the spoke heads or not? Max tension or not?

The bike gets ridden offroad and we are not the most smooth of teams and often have a heavily laden trailer on the bike

thoughts?

I prefer double butted and loose as it will flex more rather than break – i guess the risk you have is buckling it when out heavily laden

A previous incarnation had the spokes not to max tension – in a 30 mile unladen ride they all worked loose to the point I had to retrue and tighten trailside as it virtually disassembled its self

threadlock?

Not a fan but perhaps worth a try in this case?

A previous incarnation had the spokes not to max tension – in a 30 mile unladen ride they all worked loose to the point I had to retrue and tighten trailside

I always saw that as a symptom of under tensioning.

Double butted, spokes don’t break in the middle unless they’ve been damaged. And “there’s only one way to build a wheel and that’s tight” as Roger Musson says.

double butted, high tension, washers not needed if the rim is eyeleted.

where along the spokes are they breaking?

Spokes break at the elbow. Rim is eyeleted and remains pretty straight

I’d expect you to have most experience of this tj!

dB are meant not to break by stretching in the middle. What spoke did you have and where are they breaking? This should answer some of your Q’s.

Building tight is what I’d do. Strong rim and high spoke count (latter already chosen I know).

Tandem fora?

Edit – elbow – what brand?

I thought it was the cyclical loading/unloading of the spokes that caused this type of failure due to fatigue (although 30miles is a pretty low number of cycles).This would be worse with less tension (as the difference between max and min tension will be higher).Certainly double butted will lessen this as they elongate more under tension.Washers may help if the spoke holes in the flange are a little oversize.

I don’t know the brand of spokes thats in the wheel – done by a chap with good reputation tho. Stainless and butted. breaking at the elbow just riding along!

If he is saying the wheel should be built not tight, I’d question that.

Also if his build isn’t lasting.

Rohloff’s have a huge flange {fnarr fnarr}.

My 32 spoke Rohloff wheel has not broken in 6 odd years of touring and load carrying, infact IIRC the official Rohloff tandem build is still 32 spokes. The flange leads to differing spoke angle at the rim, so that could be a weak point in many cases. SJS/Thorn use specifically drilled Ridiga Andrea 30s with a hole pattern designed to suit the Rohloff. I wonder in your case if the spoke angle is causing some rubbing or kinking where the spokes cross.

Summit’s up.

I think SJS build the Thorn rims with Linseed oil as a lube, it’s certainly sticky stuff. They don’t use washers and I don’t even think the Andrea is eyeletted.

DB spokes should be a strong as plain gauge, however the drawing process will work-harden the spoke in the centre, this also makes me think there is fatigue possible.

Al – different builder this time. In the chat I had with him I suggested that a tandem wheel should be built right to max tension – he questioned this and said it could be the cause of the spoke breakage

spokes are breaking at the elbow / bend

Building a wheel deliberately slacker won’t make it stronger, more compliant or help avoid spoke breakages. It’ll just make it more likely to go out of true.

I don’t think he was maning build it slack – just in the middle of the range of tension not right at max as I suggested and I ave seen elsewhere that this would tend to a more compliant wheel therefore less likely to break – but wheelbuilding seems to be one of those things where there are a lot of myths

Sorry, didn’t see that (breakage point) Would be the angle then, I think that’s where the problem usually occurs. What rim is it? Maybe you should check with Rohloff/specs for the best rim?

Also, MTB+tandem+trailer is nonetheless brutal! Surely you need whatever spokes are the strongest, DB may not be weaker while still being light, but others might be stronger still? Downhill/tandem oriented?

Certainly brutal usage. I intend to reuse the rim – its a rigida sputnik and has remained straight despite the beating and spoke breakages. We did once go off a dropoff the best part of two feet with the trailer.

Big flanges? I know that Alfine hubs are often built 2x for this reason. Is your wheel 3x?

Nope – 2x as per rohloffs instructions

Dt Swiss alpine 3 spokes , they are over built at the elbow but still double butted.

That and some Dt pro lock nipples.

What wheel size is it ? Might be hard to get alpine 3s in the right length for 2x if it’s a small wheel

26″ if that counts as small these days

Spokes should be tight, no reason not to be. Comfort should be in the tyres, not in the wheel IMHO.

sure – but there is a range of tensions given for spokes is there not? Go to the top of the range its a more rigid wheel but is it more likely to break spokes? Bottom of the range more compliant and thus spreads the stress over more spokes?

I don’t know really – just asking questions on how to get the strongest wheel build given we absolutely hammer the rear wheel.

I’m sure you should ask Rohloff for advice.

Off-road tandem is one place where I’d expect significant side loads causing increase in spoke tension. I wouldn’t build it loose but a bit below max would be worth trying. And TBH max tension jobst brandt style must be f-ing high on a rohloff with beefy rim, maybe more than the spokes are really designed to handle. The tight spoke theory is based on solo road bikes with puny rims, an MTB tandem (with trailer!) is really pushing the boundaries of normal.

We also break a few spokes on the MTB tandems, including a rohloff rear. And we are a fairly light/gentle team (light stoker anyway, and I have a sus fork to cushion the loads).

When we went on tour to the western isles, for a laugh we went on the weighbridge at Oban – well over 200kg! (including us) Add to that low gearing and the grace of a dancing heffalump and I do feel sorry for the poor rear wheel

considering freeriders land from stupid heights on standard 3X 32 spoke wheels and they survive lots of this abuse if correctly built I would guess the problem lies with the way the elbows are leaving the hub flange.

is large flange diameter why rohloff spec 2X lacing? to avoid a sharp bend ath the j or have the nipples at an acute angle in the rim?

I think you can also use washers on the spoke/flange area, no idea if that will help or make things worse..

I’d check for any sharp edges in that area as well that could cause a stress riser to form, and gently round off any sharp contact points.