triathloner

So I have a new bike that came with some lower quality 32 spoke wheels. I weigh 225 and after about 100 miles some of the spokes are loosening up quite a bit and have re trued the wheel 3 times already. I bought some wheelsmith spoke prep and am going to install tonight. think this will help? Also I'd swear that the tiny bottle of spoke prep I bought for $15 bucks is just latex paint? What are your thoughts. Thanks. AL.

rpenmanparker 

Spoke prep is an aqueous suspension of solid particles that dries to a slightly gritty film. No it really doesn't resemble paint all that much other than solids in water. How are you going to install the prep without taking the whole wheel apart and rebuilding it? The prep goes on the spoke threads and is left to dry prior to the wheel assembly. You can't put it on afterwards successfully without rebuilding the wheel.

More to the point I have never encountered a wheel on which the spokes loosened on their own UNLESS THEY WERE TOO LOOSE TO BEGIN WITH. Properly tensioned spokes will not commonly loosen even without any spoke thread treatment if all the spokes in the wheel are properly tensioned. But it sounds like your wheels were poorly built and really require a rebuild. At least a completely loosening and retensioning to even, high tension and nearly perfect wheel true. Who does that is up to you.

Shimagnolo

My guess is the wheels were built with insufficient tension.
I had the same thing happen with the last store-bought bike I owned.
After taking it back the the shop, and figuring out their "top mechanic" didn't know squat about wheels,
I bought the Jobst Brandt book, and learned to build my own, and never had another wheel problem, (except when I hit road damage).

FBinNY 

As said above, a properly tensioned wheel doesn't need anything to keep from unwinding. Tension holds the nipple tight against the rim, and friction keeps it from turning.

So the key is to get the tension high enough so the spokes are always under tension, even when on the bottom. That said, a typical high dish rear wheel is hard to tension enough to ensure that the left spokes won't loosen. I don't like to do anything that binds the nipples to the spokes because it causes twist and makes it harder to tighten and true, and much harder to true later on.

I prefer to increase the friction between the nipple and rim. Loctite makes a wickable grade, which you can apply into the gap between the nipple and rim, and spin the wheel to drive it deeper. You can also use a spray rubber cement the same way and it usually works very effectively. If you don't want to do the whole wheel, treating the left side spokes this way is all that's needed, since the right ones will be tight enough to stay true on their own.

Retro Grouch 

If you think that you're up to it, you might try this:

1. Loosen every single spoke until you have about 5 mm of threads showing.
2. Paint the exposed threads with your newly purchased spoke prep and wait overnight.
3. Stick your thumbnail into the last spoke thread and use a screwdriver to tighten the spoke that much. They'll still be pretty loose.
4. Starting at the valve hole, tighten each spoke 1/2 turn, no more, with your spoke wrench.
5. Repeat step #4 until you very gradually build even tension into the wheel.
6. True, stress relieve, and dish as needed.

Drew Eckhardt 

Wheelsmith invented Spokeprep so they could sell under-tensioned wheels cranked out by machines without dealing with warranty returns by heavier riders because the low tension allowed their nipples to unscrew, buying more expensive machines and/or running them slower, or paying for expensive human labor to finish wheels.

That's arguably fine when you're trying to maximize profits as a wheel making business, although as an individual rider you're much better off putting enough tension in the wheels so the spokes don't unload completely on a hard bump which leaves the rim unsupported horizontally and allows it to move off center where it collapses as the bump passes and tension returns.

100-110kgf front and 110kgf rear drive side is a good starting point for most wheels with traditional spoke counts. Deeper rims can usually handle 120kgf and that's a good idea so that the rear non-drive side tension can be higher (it's a fixed percentage of the drive side tension as dictated by the bracing angles on both sides).

Stretchier spokes (notably 2.0/1.5mm) tolerate lower tensions before they become slack enough the nipples unscrew and are an especially good idea on the rear non-drive side.

JohnDThompson 

The traditional spoke prep is boiled linseed oil; you can buy a lifetime supply for only a few bucks at any hardware store. The oil lubricates as you're building the wheel, and over the course of a day or two hardens into a varnish that locks the nipples in place.

triathloner

I took the wheel all the way apart and put the spoke prep on last night. I've built and trued many wheels. I had even tensoin on the spokes around 25kfb on the drive side and around 18-20 on the NDF and they still unwound , It seems to be just two spokes next to eachother every time. so I thought I'd try the spoke prep, Ive never used it before so I thought I'd try it.

davidad

The DS spokes should be at least 100Kg of tension. For your weight on a 32 hole wheel I would go to 120Kg. You can get by with 100 on the fronts.

triathloner

Yeah I misspoke/typed. It was 25 on my park tension meter, which I think is around 115 if I remember correctly.

jyl

Is spoke prep really necessary?

So far all I've built all my wheels with simply grease on the spoke threads and also a little grease in the eyelets. I use brass nipples, stress relieve, remove windup by turning the spoke backwards a bit, and work up to adequate tension. I've not had any problems with unwinding, and I'm not lightweight at 185 lb plus clothes and backpack.

triathloner

Usually spoke prep is not necessary, I've built many wheels for myself and had many trouble free miles. This wheel came on a new bike I bought and it's been trouble for some reason. So I laced the wheel last night and got it trued and is all set, now it will just take some rides to see if it worked or not. thanks for all the replies.