Got a 2009 Marin Mount Vision 5.8 – very nice bike and I like the way it rides…but the rear wheel seems to be shearing nipples like they are going out of fashion – last 3 rides I've managed to shear 3 nipples. They appear to be rather cheese like.

Standard wheels that came with the bike – Hope Pro 2, black spokes and Mavic XM317 rims – but whilst replacing the nipples I noticed that there seems to be uneven thread spacing between nipples – not just laterally i.e. drive-side and non-drive side (I'd expect a slight variance between the 2 due to dish and spoke length) but either side of the wheel – the valve 'half' of the wheel has a lot of spoke in the nipple but the opposite side of the wheel there is very little spoke in the nipple.

I'm guessing the wheel was machine built as the spoke tension on either side of the wheel is uneven – driveside tight like a drum and the non-driveside rather loose (as well as the wheel needing to be redished) but has anyone else found the nipples on the stock wheels to be utter rubbish and keep shearing them?

Just annoying as I end up getting the nipple replaced and then start getting all anoraky over whether or not the wheel is true – a 5 minute job turns into 2 hours and even then I'm not happy with my work! (my work being replacing these sheared nipples with brass nipples and then trying to get the spoke tension right).

Actually it doesn't really matter what bike I've got, has anyone experienced a similar issue with their wheels? I'm guessing it's either a fault with the nipples or they are alloy and just not intended for MTB use (I'm 6'1", weigh 11.5 stone and struggling with riding over a kerb so I'm not a heavy rider by any stretch of the imagination so it's not down to my 'extreme' riding style).

I had a OE rear wheel on a Kona that kept breaking spokes right at the nipple (not the nipple itself), I persevered with replacing spokes and retensioning as you described, but it was never cured until I got the whole wheel relaced with new spokes. I put it down to a Friday afternoon job.

I've had it on cheap factory wheels before but your wheels don't sound particularly cheap if they have hope hubs. For me it was on a commuting bike so Mtb wheels used solely on the road.

Not that it helps but with my various handbuilt (merlin) wheels have only ever broken a spoke twice in 5 years. I've broken some hubs and a rim in that time 🙁

Have a pro wheelbuilder look it over. For peace of mind get him to rebuild it with good quality spokes and nipples. When I sold Marins I had a few problems with the wheelbuild quality, but ATB were good about warranty.

Bought some discounted OE wheels for my road bike a few years ago for winter training. The front wheel developed the same problem you describe. Nipples shearing in line with the rim. I guessed that some of the spokes were not screwed in to the nipples below the level of the rim. Maching build probably. As riding on the road there would have been no issue re riding heavily or big impacts.

Replaced the spokes and nipples as they went with new ones of the right length. I think 1 or 2 nipples snapped. Replaced them and the wheel was fine.

Not sure if using discs or rim brakes would make any difference?

Had similar problem with Pro 3s .Hope had them back and rebuilt them .Been fine so far .Apparently nipples were 1.8mm now been changed to 2 mm .

Hmmm, hadn't really thought of a warranty and bike is a year in May, so might give the shop a call and see what they think…just annoying.

Currently having exactly the same problem except I built the wheels! Used DT Swiss spokes and brass nipples, the spokes are the correct length and the spoke tensions are even/wheel is true. Still not sure what is wrong.

I'd go for warranty – all that's neeeded is a rebuild and new nipples. Looseness is likely to have occurred over time.

Well the wheel is meant to be built with DT Swiss Competition spokes – how would I identify these? I'd expect to see a DT stamp on the end of the spoke that sits in the hub (checked all 32 and none of them have that), they are also meant to be double butted – how do I check that on the Competition spoke? From what I can tell from the DT Swiss website, the butting is meant to be quite obvious and could easily be felt – all 32 spokes appear to be plain gauge with no tapering on them at all.

Shop has been in touch with ATB Sales and they confirmed that the wheels are hand built using DT Swiss Competition spokes and I was to report back on what I found…now reported back so hopefully there has been some error made and I can get the wheel sorted out.

So how do I identify a DT Swiss Competition spoke?

Thanks.

DT spokes have the initials stamped on the head of the spoke(where it goes through the hub flange), looks a little like a diamond shape.As for the butting, look for it a couple of cm from the ends, it's only a small difference, nowhere near as pronounced as on Revolutions or Sapims.

Can you feel it if you run your finger and thumb up and down the spoke?

Checked head of spoke and nothing is stamped there…nothing on the spoke head at all, I even wiped it clean in case it was covered in dirt…

DT Competition spokes are double butted. They are 2mm thick at each end and 1.8mm in the middle.
Also check if the spokes used are the right length.
If you take your tyre and rim tape off, the spoke thread should come flush to the top of the spoke nipple.

Alloy nipples can cause this too, especially if they corrode, they turn into cheese.

It happens because the spoke is too short and especially with alloy nipples.

I had a plague of this in one wheel and replacing the spokes with a proper length and the nipples with brass solved the problem. Some spokes were about 2mm too short and were not engaging in the whole length of the nipple – looks like the wheelbuilder ran out of the proper length because it was only about 6 spokes 🙁

Some find it easier to feel butting rather than see it. What they said about the DT stamp in the end of the spoke.

Can't see or feel the butting, which is why I'm asking how to detect it…might see it I can borrow some verneier calipers to see if the spoke thickness does vary…admittedly it is only 0.2mm of a difference but I'm sure I would feel that as previous wheels that have been built using butted spokes have been feelable…

Sounds like you've been done!

You can easily feel the 'butting' and they are stamped – doesn't sound too good but a new wheel should help!

Scratch the surface of one of the broken nipples.
Silver grey = ally and they will always break if the spoke is too short.
brassy coloured is what you want to see. They will be more tolerant of short spokes. They usually won't snap, but the thread will pull out.
If you're breaking either then it's time for a respoke anyway.

[Edit] Black DT comps come with alloy nipples. All the others come with brass. Only the Swiss know why!

DB – go back to the shop and look at it on warranty – good rims and hubs but looks like dodgy nipples. If no go on the warranty get it re-built anyway, it'll be a lot easier for you in the long run!

Aye, that is the plan…