Bicycle Mechanics - Spokes Loosening

I tried to search for this one, but did not find it....

anyhow I have noticed that in about the past 3 months of riding my road bike (100 miles per week) I will get a loose spoke every 3 to 4 weeks, loose enough that I can tighten it by hand. (it's not a big deal I just re true the wheel) but it makes me wonder if something may not be right with my wheel. I'm using Mavic MA3 rims, with DT (maybe swiss? I don't remember) double butted 14 gague spokes, Shimano Ultergra hubs. Mind you I built these wheels myself so it is entirely possible that I did something wrong (if so what is it :p) Anyhow has anyone has this problem before or has a solution?

thanks in advance :)

It sounds like maybe the spokes are no longer equally tensioned. Is your wheel still true? Is it still round? Try plucking the spokes to see if they all vibrate at the same frequency. On the back wheel, the driving spokes will have a higher pitch but they should all have the same degree of tension.

just this last week, somewhere on the web, I saw a product intended for locking the nipples from turning, a la locktite. It was on a bike site, so it is application specific, and its availability would indicate you are not the only one with this problem.

Did you put oil (other than linseed oil) on the threads of the spokes? If you did, that's probably your problem.

BTW, don't get mixed up about which type of loctite to use! If you do, you'll need a torch to loosen nipples!

When you built the wheel, did you settle the spokes against the hub shell? My usual method is to insert a 10mm nut driver with a smooth shank between the spokes, inboard of their outermost cross, and lever them gently so their elbows settle against the hub flange. If this isn't done, the spokes "bow" outwards from the flange for quite a while, and have a little more spring in them as a result, potentially causing them to loosen.

And I agree with the others, it would be good to treat the threads with an anti-loosening agent, whether it's DT SpokeFreeze (made by Loctite), linseed oil, or Wheelsmith SpokePrep. Having adequate spoke tension also helps prevent the problem, of course.

The only time I have seen spokes loosen (actually I could hear then relaxing as the wheel rotated) was when my wife borrowed her sister's bike, years ago. It was a factory built wheel and was not sufficiently tensioned.

My experience is road riding, so things may work out differently on trails, but it sound like the spokes were not sufficiently tensioned when the wheel was built.

In all the wheels I have built or relaced (just for my own bikes, I'm not a pro), I have never had a loose spoke problem, or even any problem with the wheel going out of true.

My preference is for double butted spoked, which make the wheel more resilient and are as strong as single gauge spokes with the same end gauge.

I use Wheelsmith spoke thread prep, and a bit of oil in the spoke hole grommets.

After lacing the wheel, most of my time is spent bring the wheel up to tension AND stress relieving (the rear wheel, of course adds dishing). After final trueing, the wheels all been have been good for thousands and thousands of miles, a lot of that fully loaded touring.

The reference book I have used is The Bicycle Wheel by Jobst Brandt, though it looks like there are a couple other good wheel building books out there, now. Check the instructions about tensioning and stress relieving. You may have to go back and do those again. Jobst Brandt gives a simple and reliable method of deciding when you have tensioned the wheel enough.

From my experience, if the wheel is properly tensioned and stress relieved (trueing is assumed), you should have lots of trouble free riding ahead.

Mike Sakarias
Juneau Alaska

Spokes can be considered simply as fasteners (nuts and bolts). Like any nut and bolt system, spokes tend to loosen because they were not tight to begin with. This same is true with crankarm bolts that loosen.

It likely you will need more overall tension. However, too much tension will also cause problems, specifically in the rim. If possible use a spoke tension meter.

See also http://www.parktool.com/repair_help/howfix_truing.shtml

now that I think about it, it is more then likely I never had the wheels tensioned correctly (this was the first wheelset I ever built or trued.) I'm going to see if my lbs can help me a bit on the issue.