I'm building my 4th ever wheel, the first 3 went really well, but I've just had a nightmare with this last one.
It's a Suntour track hub and Mavic CX18. DT Comps 36x3. This is the rear wheel (the front built fine).
I noticed that the rim is not laterally perfect - but I held it against other wheels and it's not way out (maybe 1cm here and there). In other words it's a bit wavey !
I didn't think this would cause a problem, but I could not get the wheel built with anything resembling even spoke tension: one spoje would be loose and rattling and the next 160kgf just to get it laterally true (I was aiming for 100kgf even).
I did all the same steps in the same order as my first 3 wheels so I don't think I did anything incorrect (although I'm new to this ..) so I can only assume the wobbles in the rims are the cause of my problems.
I also believe that not all rims are made perfect and so it must be possible to build a perfectly good wheel with such a rim - it just takes some skills and knowledge I currently don't possess.
FYI: Tools employed - TM-1, TS-2, Spokey, Spoke Prep
Wester-Ross wrote:I noticed that the rim is not laterally perfect - but I held it against other wheels and it's not way out (maybe 1cm here and there). In other words it's a bit wavey !
"Lack of perfection" means it could deviate from round and straight by a mm or so before it is built... a cm is way too much.
If you've done everything correctly it sounds like a duff rim, however you need to check that your spoke lengths are correct, you might have some odd ones in there bottoming out maybe? And check your crossings are correct, one wrong and it has a knock-on effect.
If all else fails, strip it down and start again making sure you measure each spoke length and keep the right and left spokes separate, check the rim on a flat surface and bin it if its well warped.
You could try to strip it and start again I suppose, as when you get too high on tension you're just making things worse rather than better and 160kgf is way too high for an alloy rim like that.
As Leloby has already pointed out I've had a few OP rims that have been awful from a quality point of veiw, anyone else had any?
I'm talking about thin patches in the extrusion, extremely flexy rims and dodgy joints leading to the joint spoke being loose even at lowish tensions.
All were recent newish stock rims, I built a couple of pairs of older ones last week and they were perfect?
I'm starting to think either the extrusion is being done by another firm or the rims are being built without any quality control at all?
I've started using Ambrosios and DT rims for a while instead.
legs 11 wrote:As Leloby has already pointed out I've had a few OP rims that have been awful from a quality point of veiw, anyone else had any?
In the US at least, these rims are ubiquitous on low priced mail-order wheels... like $250 or less for a set with Ultegra hubs and butted spokes. So Mavic is churning these out by the boatload and practically giving them away in bulk sales. That is a good enough reason IMO not to use them for customs, because the brand has been cheapened... and there are other options.
I can see Mavic's angle... the big money is in the fancy factory wheels. They just don't care about selling loose rims anymore.
The DT tying wire is Copper coated in silver zinc, but you can use plain copper wire too as it's cheaper and easier to get hold of.
You'll need to practice getting the solder on there a bit before attacking your best wheels as it's a bit on a knack getting just the right temperature and amount of solder on there.
I normally use enough turns to make the copper thick enough to take the solder easily (7-8 turns plus a little Knot) but it depends on the application I suppose as this many turns may not look right on a DT rev or a very thin spoke like that.
I've found that the lowest temperature grade of solder works best as you can put it on with a hot air gun instead of a bare flame.
Or, try one of them small pencil gas torches as they give a nice heat that stays very local to where you need to get the solder on.
And don't forget to touch the solder and wire up after you've finished with a bit of nail varnish or a permanent marker pen as they corrode if not.
I have found though that if you get the solder on there really nice it corrodes into a nice dark grey colour and looks ok in the longer term, it's just any bare copper that will look nasty with corrosion.
Plenty of flux helps the solder run nicely and makes a neat job.
Keep the wire perfectly clean and grease free too.
legs 11 wrote:Hi Weenie, yes I have done some spoke tying in the past but not for some time as I think the benefits are very small if any.
I think the only benefits are:
a) A broken spoke will not fling around
rruff wrote:....a) A broken spoke will not fling around
I've seen a nice carbon track frame ruined because of this, if the spoke had somewhere to go it might have saved it. The spoke broke at the nipple.
If the spoke breaks at the flange then I could see it all holding together OK. Maybe?
I reckon the Cr used in spokes, even the ones manufactured today, will use the highly toxic hexavalent Cr(VI) and this is the one which can get through your skin. Its use is restricted in Europe but not banned.
After reading through Wikipedia, its still not clear what the pragmatic effects would be from handling these things up to 8hrs a day! Is it possible that this could be harmful?
I think most wheelbuilders would appreciate some guidance on this before snapping into surgical gloves of a day.....
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