mysterious case of the loosening spokes

I was out last week and after a rocky descent i noticed the tyre was rubbing on the frame, on closer inspection all the spokes had come loose to the extent that the wheel had lost all tension and i had to walk home. So i tightened them all up again but last night the same thing happened, not as bad as i was checking them regularly and i’d remembered my spoke key but they seemed to undo themsleves.

The thing thats most puzzling is that it isn’t a new build, i did it a few months ago and it’s had plenty of previous outings so why should it start doing it now?

It’s an 819 on a hope xc hub with the correct length spokes, i’ve checked the hub, rim and eyelets for damage but there doesn’t seem to be any.

Any advice before i rebuild the whole thing with new spokes and nipples??

ta

although the wheel may be “true” when you’ve tightened them, this is a classic cass of uneven spoke tension. I little time spent evening out the tensions will sort this problem.

Like Onzadog says – I’ve had exactly the same problem recently, and when I fixed it the first time I guess I’d trued the wheel ok but not sorted out the tension. So I was out the next ride and the wheel reverted to banana shape.

I was on a long ride in the Lakes last a coupld of years ago (sam houghton challenge), with wheels that I’d been using for a few months. I had a flat half way down a massive descent, and after I’d fixed it I noticed that it was rubbing. When I got to the bottom all the spokes were totally loose, like they’d come unscrewed. I never worked out why it happened, it’s never done it since. Bizarre.

thanks all, that’s reassuring, back on the gig tonight then

cheers

I’d de-tension the rim, check all the nipples and threads, check that the rim doesn’t go a horrible shape with no tension. Then zip it all back together again. Should be fine.

819s- check the UST nipple/eyelets things are all tight, I had to tighten a few of mine up, it has same effect on spokes as loose nipples.

I hadto have one 819 rebuilt with new rim as I had flatspotted the rim and the buggerign spokes wouldnt stay tight. I think 819s may be a bugger to get spokes correct once a bit of damage has knocked the rim about a bit.

yeh i’ll check the nipple holder things, i did threadlock them when i built it uo but i suppose they could have worked loose, i don’t think the rim is knackered in fact i was very supprised how true it was whan i retensioned it.