Hitchcocks Forum

Just been fitting a stainless 21" rim to my half-width front hub. Got it from central wheel because our hosts don't do one (they list stainless for full width hubs and alloy for half width but not stainless for half width).

Two of the nipples stripped on assembly. I'd have said they were not really up to full tension at the point they went rather than over-tightened, I was using a spoke-key but not at the "creaking" stage, I could have still been on a screwdriver at that point in the process. Oddly they were both on "long" spokes (the non drum side) adjacent to a drilling in the rim (one for the valve, the other for the rimlock).

Happily they provided two spares in the kit but it struck me as odd I should get two nipples failing like that, or is this a common thing with motorbike spokes and nipples? I've only laced up a couple of motorbike wheels before, I never seem to get this issue with bicycle wheels. The finish of the threads and nipples on motorcycle wheels does seem quite shonky compared to what I'm used to working with on pushbikes.

I’ve built four wheels and I recall a couple of nipples like that, not the spokes.

Can’t recall whether that was the new spokes and nipples or existing though...... actually whilst typing that, I recall it was the new spoke and nipple set for a Yamaha wheel.

That does not sound good. I have only had that happen on one wheel, with two spokes, out of probably a couple of hundred wheels I have built. It was with a rim and spokes a customer obtained from another UK supplier, rather than CWC, who have supplied the majority of my rims and spokes, either directly or indirectly. I told my customer I wasn't happy with the wheel, after this happened during final truing, as all the nipples had seemed a bit sloppy on the spokes, but he took it away anyway, undeterred.

Now I think back, there were a couple of those nipples with ropy threads, two wouldn't screw onto the spoke properly by hand as I was lacing it and had to be wound on with the spoke key. Once they'd been wound down until the spoke came out of the top and back up again (not under tension, off the wheel), they screwed on as normal. I put it down to a slightly galled thread that straightened up when it was screwed all the way home.

Now I'm wondering if it was those two that have failed. Maybe a good thing if it was, or at least that I found it now.

The rim has a bit of a pinch in it too, right where the valve hole is. I do wonder if it was clamped into something as the hole was punched (I think they punch holes in motorcycle rims rather than drill them?). It's not massive but enough to deflect the DGI about 0.5mm. I've had to allow for both that and the weld seam, it's made trueing a bit of a PITA. I've got it to under 1mm both ways with the exception of those two points.

Wouldn't surprise me if it was pinched, that stainless rim is hard as nails so it must take a lot of force to pop a hole in it. I really struggled to drill it for the rim lock. Had to break out the good 4mm cobalt drill bit I keep in case I ever snap an exhaust stud on one of my Jap bikes. A brand new HSS wouldn't even mark it.

All rims, be they chromed steel, stainless, or alloy, will have what I call a 'blip' where the weld runs across and this can often result in a step of a millimetre or so in the radial and / or lateral plains and nothing much can be done about it. I usually try to keep all other areas in both plains within 0.5 mm overall run out, which is usually quite possible, without getting too bogged down.
Here is the most recent wheel build I worked on, from a Triumph T140.
https://youtu.be/M3THtOrHWLY