Spokes Breaking Repeatedly - MTB
#1
Addicted to Dirt
Thread Starter
Join Date: Oct 2007
Location: Socal
Posts: 227
Bikes: Stumpjumper Comp 09, Nishiki Prestige (1990)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Spokes Breaking Repeatedly - MTB
So a while back I broke a spoke on my mtb, I replaced it and it seemed like no big deal. However, since then every 3 or four rides I get a broken spoke. I initially thought that maybe I didn't know what I was doing and took it to a shop and had them replace the spoke and true the wheel. The result is the same (broken spokes).
The spokes are breaking right at the nipple which means I've been having to junk them. I've also that they seem to be on the non-drive side with the disc brake. Finally, the rim has faint, small lines (possibly stress lines?) that run perpendicular to the edge of the rim. I showed these to a mechanic and he said to monitor them but not to worry too much.
I've heard some people suggest that when this happens you should think about rebuilding the wheel? Is this just a tensioning issue or is this something that I'm going to have to replace? It's putting a real hamper on my ability to go ride.
The spokes are breaking right at the nipple which means I've been having to junk them. I've also that they seem to be on the non-drive side with the disc brake. Finally, the rim has faint, small lines (possibly stress lines?) that run perpendicular to the edge of the rim. I showed these to a mechanic and he said to monitor them but not to worry too much.
I've heard some people suggest that when this happens you should think about rebuilding the wheel? Is this just a tensioning issue or is this something that I'm going to have to replace? It's putting a real hamper on my ability to go ride.
#2
Senior Member
Join Date: Sep 2007
Location: Gaseous Cloud around Uranus
Posts: 3,741
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Likes: 0
Liked 11 Times
in
7 Posts
If it was mine,I would rebuild the wheel with new spokes.As far as the rim goes,depends on where the little lines are and if it's the front or back.If the lines are around the spoke hole,I'd put a new rim on also.If they are where the braking surface would be,I might run it if I was broke and it was the back wheel.I don't second guess with the front wheel,you could have a real bad day if it fails.Normally,I would put a rim and spokes on and call it a day.
Last edited by Booger1; 09-02-10 at 12:06 PM.
#3
Senior Member
Join Date: Oct 2007
Location: Riverdale, NY
Posts: 761
Bikes: 2002 Seven Axiom
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Some times when you break a spoke others will follow unless the entire wheel is re-tensioned. Most shops will not spend the time needed.
HOWEVER, Faint hairline cracks at the spoke hole are IMHO cracks. Wheels and cracks do not go well. I bet it's where the spokes were replaced.
I think the rim is on it's way out and time for a new wheel.
Have another shop check the wheel and if I am correct then lose the other shop.
HOWEVER, Faint hairline cracks at the spoke hole are IMHO cracks. Wheels and cracks do not go well. I bet it's where the spokes were replaced.
I think the rim is on it's way out and time for a new wheel.
Have another shop check the wheel and if I am correct then lose the other shop.
#5
Senior Member
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225
Bikes: Catrike 559 I own some others but they don't get ridden very much.
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 643 Times
in
364 Posts
Some times when you break a spoke others will follow unless the entire wheel is re-tensioned. Most shops will not spend the time needed.
HOWEVER, Faint hairline cracks at the spoke hole are IMHO cracks. Wheels and cracks do not go well. I bet it's where the spokes were replaced.
I think the rim is on it's way out and time for a new wheel.
HOWEVER, Faint hairline cracks at the spoke hole are IMHO cracks. Wheels and cracks do not go well. I bet it's where the spokes were replaced.
I think the rim is on it's way out and time for a new wheel.
1. I suspect that the spokes breaking at the nipple is the result of inadequate tension allowing the spokes to move back and forth as you go from powering the bike to brakeing.
2. A hairline crack is still a crack. Rims never heal themselves. The cracks can only get bigger.
#6
Senior Member
Join Date: Dec 2005
Location: Boulder, Colorado
Posts: 1,383
Bikes: Cinelli Supercoursa 69, Ritchey Breakaway Cross, Mondonico Diamond Extra 05, Coors Light Greg Lemond (built by Scapin) 88, Scapin MTB, Stumpjumper 83, Specialized Stumpjumper M4, Lemond Poprad 2001
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked 2 Times
in
1 Post
If the wheel has a lot of miles and breaks a spoke then you will probably see an increasing number of broken spokes occur with some regularity. Best to relace the wheel with all new spokes and nipples. If you are seeing cracks check closely with a magnifying glass. Sometimes you can get a crazing of the anodization which may not be a problem. BUT if the cracks are around the spoke hole then go for a new rim...insurance. Medical bills from a crash are very costly. If you have gotten a lot of miles of hard riding with those wheels then retire the rims, spokes, and nipples...rebuild the hubs...check the cones for pitting and build up new wheels. I would go for a wheel with a stamped eyelet. This will takeup and distribute the spoke stress over a larger area and prevent stress risers and cracking.
#7
Addicted to Dirt
Thread Starter
Join Date: Oct 2007
Location: Socal
Posts: 227
Bikes: Stumpjumper Comp 09, Nishiki Prestige (1990)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I will check it out tomorrow morning and report back to you. Hopefully I'll be able to take some pictures of the lines that I'm reporting that will show them. They're not really around the nipple.
Having to replace the rim makes me cringe. Poor student and all. I actually haven't gotten what I think are decent number of miles out of the rims but the bike was crashed which I suspect is contributing to my problems.
Having to replace the rim makes me cringe. Poor student and all. I actually haven't gotten what I think are decent number of miles out of the rims but the bike was crashed which I suspect is contributing to my problems.
#8
Oldtimer
Join Date: Mar 2008
Location: Foothills of the Catskills in New York
Posts: 221
Bikes: 1972 Raleigh LTD, 1985 Cannondale SR300 (2), 1986 ROSS Eurotour, 1991 Giant Sedona MTB, 1992 Trek Antelope MTB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Your breakage problem sounds like something I went through recently:
https://www.bikeforums.net/showthread...or-Explainable
Replacing the spokes, because I could do it myself, was the way to go in this case.
In your case, if the rim is even questionable, consider buying a new factory wheel. It'll be as cost effective or cheaper than building a wheel on an old hub and you'll have little reason to worry about future failure, especially if there's a chance that the hub design was contributing to the breakage.
https://www.bikeforums.net/showthread...or-Explainable
Replacing the spokes, because I could do it myself, was the way to go in this case.
In your case, if the rim is even questionable, consider buying a new factory wheel. It'll be as cost effective or cheaper than building a wheel on an old hub and you'll have little reason to worry about future failure, especially if there's a chance that the hub design was contributing to the breakage.
#9
aka Tom Reingold
Join Date: Jan 2009
Location: New York, NY, and High Falls, NY, USA
Posts: 40,498
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
Mentioned: 511 Post(s)
Tagged: 0 Thread(s)
Quoted: 7346 Post(s)
Liked 2,452 Times
in
1,430 Posts
One broken spoke could be a fluke.
Two broken spokes is marginal.
Three or more means it's time to replace all the spokes or the entire wheel, whichever makes more sense for your situation.
Riding stresses the spokes but not to the point where they break. But the greater the stress, the more you weaken a spoke. You increase stress if your spokes aren't adequately tight to begin with.
So this happens: you ride, thereby weakening your spokes. Then you ride again, with weaker spokes. At this point, the stress is too great for the newly weakened (fatigued) spokes.
Once your spokes are fatigued, replacing them one by one does no good.
Two broken spokes is marginal.
Three or more means it's time to replace all the spokes or the entire wheel, whichever makes more sense for your situation.
Riding stresses the spokes but not to the point where they break. But the greater the stress, the more you weaken a spoke. You increase stress if your spokes aren't adequately tight to begin with.
So this happens: you ride, thereby weakening your spokes. Then you ride again, with weaker spokes. At this point, the stress is too great for the newly weakened (fatigued) spokes.
Once your spokes are fatigued, replacing them one by one does no good.
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.