Bicycle Mechanics - 600 miles and a broken spoke, already?

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jpatkinson
05-26-08, 05:01 PM
My Bontrager Race rear wheel lost a spoke today, after only about 600 miles on the wheel. No trauma to the wheel before the break, BTW. Bontrager web site indicates 5 year warranty on their new bike parts, so I am hoping the dealer or manufacturer will take care of replacing the spoke and then truing the wheel [VERY out-of-true after the break, unridable].
My brother mentioned last year that these wheels may not be strong enough for me, @ 180#, and I recall asking the dealer about this when I bought the bike. Is there any way of finding out if I should be getting more "substantial" wheels? Do wheels have rider weight limits? The spokes are the 'bladed' type, which seem like they would be more likely to break.
http://www.pbase.com/atkinson/image/97685604.jpg
randomgear
05-26-08, 10:25 PM
Did that spoke break in the middle?
Very strange.
mostlybent
05-26-08, 10:42 PM
Did that spoke break in the middle?
Very strange.
Maybe a flaw in the metal, or something hit/cut and weaked the spoke to break where it did.
I think the wheel is plenty strong to hold your weight (180) and then some. Make darn sure you tighten the pokes after first few hundred miles, especially for the lesser spoke count wheels.
mark9950
05-26-08, 11:49 PM
As the trek dealer told me time to buy a new wheel.
I was looking at a pair of Forte Titans this weekend, 16 front, 20 rear. At 6'1"/205, I didn't think they'd hold me. The tech who was there said they would, but they'd need constant care. Just didn't think it was worth the extra effort, and God forbid I bust a spoke doing 40 downhill.
Sixty Fiver
05-27-08, 12:19 AM
And the point of running so few spokes is ?
Exactly. I've always run 32 spoke at least. Fewer spokes look neat, but aren't wroth the headache to me.
The spokes are the 'bladed' type, which seem like they would be more likely to break.
No immediate reason for that. A spoke pretty much only sees loads in tension, and for tensional loads the cross-sectional area is far more important than the cross-sectional shape.
The advantage of bladed spokes are areodynamic, which sort of implies that there's probably an interest in getting away with as few spokes as possible at the same time. Fewer spokes equals higher loads on each spoke - which may lead to more breakage.
jpatkinson
05-27-08, 07:30 AM
And the point of running so few spokes is ?
I suspect for the 'look' and the aerodynamics. These wheels came on my bike, so I was either going to have to go with them, or pay to change out to something with more spokes. I am new to cycling, not very strong, and certainly not racing. Give me something strong, reliable, and low maintenance, any day!
I await a reply from the shop owner where I bought the bike [small, nice shop: selling Felt, Niner, Litespeed, LeMond, Maverick, Titus, and Fisher].
Sixty Fiver
05-27-08, 11:47 AM
jp - My comment was somewhat sarcastic... I've been riding and working on bikes for a long time and don't subscribe to the less is better philosophy in wheel building as it isn't practical for most people.
Most of us aren't professional racers who are trying to eke out every advantage we can and need components that are a little stronger and more spokes in a wheel does not mean that the wheel is going to be any heavier. 32 in the rear is a good minimum but that all depends on what you are doing with your bike.
I built up a rear wheel for my 235 pound friend (for his SS road bike) and he has not been able to do anything bad to a Sansin hub laced to a Ukai single walled rim (36 spoke) because the wheel was built right... and he is evil fast.
I think spokes are pretty... of course you probably don't need 40 of them as there are in this wheel I built for my 1948 Rudge roadster. :D
http://www.ravingbikefiend.com/bikepics/rudgewheel.jpg
nonotatall
05-27-08, 12:17 PM
My bike bought in 2003 came with minimally spoked wheels (24 spokes grouped in sets of three with big gaps between). I was suspicious that they wouldn't manage well for my 190 Lb weight and asked the shop to change them but they wouldn't play ball and I couldn't go elsewhere as it was an insurance replacement.
They ran fine for a year (about 1500 miles for me) but then a spoke went on the rear. I diligently replaced it and then 3 weeks later another went which I replaced. A third went after another two weeks and then I decided to replace the set with 'proper' 32 spoke handbuilt wheels (they were exactly the same weight BTW AND they have a normal depth rim so I don't need 'special' long-valve tubes).
I've now been riding on that wheelset since late 2004 and it has been completely trouble-free, only requiring minimal re-truing (rear mainly).
My advice to you is to ask the shop to replace them with proper wheels or get them to buy the (fixed) ones from you so you can get some decent wheels made up.
This fashion for minimal spoking is loony in my opinion – especially for those of us carrying substantial bulk.
Oldpeddaller
05-27-08, 01:30 PM
Just got me a pair of used Bontrager Racelites 30/24 bladed spokes and worried because I am a bit of a salad-dodger nowadays. Sure enough, after 2 miles I'd got loose spokes! I found the alloy nipples had split on a lot of spokes. Spent the weekend rebuilding them with brass nipples and eventually got'em true. They seem to ride OK now but I'll be using my good "'Ol' Faithful" 32/36's until I lose a bit of bulk.
Oldpeddaller
05-27-08, 01:32 PM
Oops! The Bontragers are 20 spoke front, not 30! If they'd had more spokes they might have held together longer!!!
jpatkinson
05-27-08, 08:52 PM
UPDATE:
Shop owner will have a replacement spoke under warranty, by THU end of the day, and will replace the entire wheel under warranty, if this happens, again. I only hope that if it does happen, again, it won't be catastrophic! He noted this is 'very rare.' I can only hope so!!
Thanks for all the comments!
jpatkinson
05-28-08, 08:32 PM
FINAL UPDATE:
On the way into the bike shop to have my spoke replaced and the wheel trued, I was looking at the adjacent spokes: a few of them were bent!
The shop owner suggested something must have gotten caught between the smallest cog and the spokes, weakening the spokes, one of which finally failed [at the rounded/blade juncture].
So, my riding partner later reminded me of an episode during our Wine Country Century on May 3rd, when I dropped my chain into the space next to the spokes [where the plastic ring is supposed to be!]. I think this must have been the event that damaged the spokes, with that one taking the greatest force. It must have been weakened enough to finally break last Sunday, when I was doing hill repeats, with lots of out-of-the-saddle time!
This is GREAT news to me, since I don't have to wonder how a spoke just spontaneously BROKE!
darksiderising
05-28-08, 08:49 PM
So it sounds like the moral of the story is to have properly set limit screws.
Exactly. I've always run 32 spoke at least. Fewer spokes look neat, but aren't wroth the headache to me.
+1
I understand the desire for fewer spokes. Less air turbulence, weight, and you can sell a set of wheels for more money.
Be aware of other problems related to wheels with very few spokes providing lots of open space in the wheel. I was riding an MUP and came upon a roadie sprawled out on the pavement. She had taken a nasty dive over the handlebars. I helped her up and checked for serious injuries and asked what happened. She said the front wheel locked up as she was dodging a squirrel. I go over to the bike and find a mangled squirrel jammed in the fork and what's left of the wheel! In the process of running across the MUP in front of the bicycle (as they all seam to do) it ran through the wheel between the spokes. Needless to say it never quite got all the way through before a spoke grabbed it and took it up to the fork bridge where it jammed up locking the wheel, throwing the rider over the handlebar, and destroying the wheel in the process.
jpatkinson
05-28-08, 10:37 PM
So it sounds like the moral of the story is to have properly set limit screws.
Nice. Actually the limit screws are set perfectly, and work flawlessly. I think there are certain situations when you can shift too quickly while putting too much force on the drive train, and cause the chain to jump.
I think the moral of the story is to leave on the unattractive plastic protector shield, placed by the manufacturer! It is there for a reason!
- JP
jpatkinson
05-28-08, 10:39 PM
In the process of running across the MUP in front of the bicycle (as they all seam to do) it ran through the wheel between the spokes.
Something tells me this is possible with ANY wheel, not just those with fewer spokes!
Joshua A.C. New
05-29-08, 01:09 PM
I blew a bunch of spokes on a 36-spoke mountain wheel, just because a stick popped up and knocked the chain into the wheel. This was on a paved path. Sometimes, stupid just happens.
jpatkinson
05-31-08, 05:10 PM
So, my spokes won't be in until next week, but the LBS just earned a customer for LIFE: the shop owner loaned me his personal road bike for the weekend [frame alone retails for over $4k]. No collateral, no fee, nothing. I will never shop anywhere else. BTW: I don't 'know' this guy, I just bought my bike from him!
King of Kadence
05-31-08, 07:48 PM
Lemme guess, Was the shop on Irving in sf?
jpatkinson
06-01-08, 12:17 AM
Lemme guess, Was the shop on Irving in sf?
It's all a ploy to get me to spend the big bucks, I know...
mechBgon
06-01-08, 01:04 AM
UPDATE:
Shop owner will have a replacement spoke under warranty, by THU end of the day, and will replace the entire wheel under warranty, if this happens, again. I only hope that if it does happen, again, it won't be catastrophic! He noted this is 'very rare.' I can only hope so!!
Yep, it's very rare... because usually the hub's driveside flange just breaks instead. We've got a couple Bontrager rear wheels in the shop right now that met their doom that way. And if that doesn't happen, the rim develops cracks around the spoke nipple holes. Inspect the rear rim closely whenever you're cleaning your bike or doing maintenance. One of my co-workers makes Bontrager rim inspection the first step in working on any bike that has Bontrager paired-spoke wheels, it's that predictable. Being a Trek dealership, we get to see plenty of them.
Personally, "normal" wheels are fine with me. I've had >$1400 Zipp carbon superwheels... never again. Sign me up for some Open Pros on Ultegra hubs, thanks.
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