|Broken Spoke||John Evans|
Oct 11, 2001 5:07 AM
|Went out for a ride last night and heard something flopping around in my rear wheel, broken spoke. It might have happened on the last ride I don?t know. It was broken in the nipple. What causes this? Could I have removed the spoke and continued the ride?|
|re: Broken Spoke||MrCelloBoy|
Oct 11, 2001 6:26 AM
|Often the cause is fatigue, caused by repeated tension changes. You can bend the spoke arou\nd the adjacent one, adjust nearby spokes to true the wheel, and continue on. With radial lacing this may not work.
Pre-stressing the spokes will help. Look this up on Sheldon Brown's website.
|re: Broken Spoke||badabill|
Oct 11, 2001 6:33 AM
|A lot depends on the spoke count of your wheels. Newer wheels with 24 or fewer spokes I would not trust very far with a spoke removed. I broke 2 spokes last week, 1 on my road bike and 1 on my cross bike. Both wheels are 32 spoke built 3x. so finishing a ride with 1 less spoke is no problem as long as the wheel stays true. I have never broke a spoke at the nipple, only at the hub. Usually on the rear non drive side. 2 in 1 week was a record for me :-)|
|re: Broken Spoke||Rusty McNasty|
Oct 11, 2001 7:59 AM
|Take a look at the surface of the break. If it is smooth and flat across most of the break (except for a bit on one edge), then it is probably fatigue. Evidence of oxidation in the break would tend to confirm this. If there is either a pronounced edge or bevel around most of the break edge, then tensile failure (that is, your spoke was too damn tight!) is likely the cause. Fatigue usually happens at the bend, unless the spoke is some single or triple butted design. Was it by any chance an aero (bladed) spoke??|
|New spoke||John Evans|
Oct 11, 2001 9:34 AM
|It was fairly new. Maybe 500mi, stock wheels, 2001 Trek 1000, rider wt 240lbs. Does this happen more on low end bikes, poor wheel building?|
|yes (nm)||Rusty McNasty|
Oct 11, 2001 9:48 AM
Oct 11, 2001 10:11 AM
|Are the stock wheels really suitable for a 240lb rider?|
|You may need stronger wheels||Rich Clark|
Oct 11, 2001 11:14 AM
|Machine-built wheels are less likely to have had the spokes stress-relieved prior to installation on the bike. If the spokes weren't sufficiently tensioned also, then early stress failure, especially with a heavier rider, wouldn't be surprising.
One broken spoke may be a fluke, but the wheelbuilder at your bike shop should check the tension on all spokes when he replaces the broken one and re-trues the wheel. Then, if you continue to break spokes, you'll know that the wheel's original build quality is at fault.
IMO, properly built wheels (including stress relief, tensioning with a tensionometer, and truing) are a basic warranty item: if you keep breaking spokes, the bike shop should rebuild the wheel with new spokes and certify that these steps were taken.
However, in the long run, a 240-pound rider needs strong rims with a high spoke-count, using name-brand double-butted spokes -- at least for routine use on public roads. Since wheels can be moved from one bike to another, this is one upgrade that makes sense on a Trek 1000 after these current ones get to be too much of a headache.
|re: Broken Spoke on older bike||jagiger|
Oct 11, 2001 8:00 AM
|I started breaking them on an old Peuget. They were steel & started to rust. I'm going to have to replace them all eventually.|
|If they are rusting||Rusty McNasty|
Oct 11, 2001 11:45 AM
|Then you don't have stainless steel spokes, but el-cheapo plain steel spokes. Either this wheel is as old as the hills (and not a very good one at that), or it is a cheap chinese piece of $hit. I'd replace the whole damn wheel, and soon!|
|A fluke||Kerry Irons|
Oct 11, 2001 5:03 PM
|A spoke breaking at the nipple is relatively unusual - 99% break at the head. On such a new wheel and with this kind of break, you can safely assume that there was one defective spoke - perhaps the threads were cut too deep. If you have another, then I would assume you got poor wheels built with defective spokes - two failures like this would be way past coincidence.|
|actually||alex the engineer|
Oct 12, 2001 4:47 AM
|The threads are ROLLED on a spoke, not cut.|
|I'm not so sure||nee Spoke Wrench|
Oct 12, 2001 4:12 PM
|I had never seen a spoke break at the nipple until recently. During the past month, I've seen such failures on three different bikes.
The first was a Green Gear triple with 20" wheels and a Sachs 3X7 rear hub. It had a bunch of spokes broken at the nipple and had already been completely rebuilt twice by two different wheelbuilders. I attributed these failures to the large flange hub and 20" wheel. The spokes entered the rim at quite an angle. I rebuilt the wheel cross 2 rather than cross 3 to lessen the angle. I know the bike has been ridden at least once since my rebuild, so far so good.
One of the others was a Santana tandem wheel with 48 13/14 ga. Wheelsmith swedged spokes - pretty heavy duty stuff. Both the owner and I felt the spoke tension was a little wimpy when the wheel came from Santana. He replaced the spoke himself and retensioned both wheels.
The third was a relatively normal mountain bike wheel.
Three in one month seems a little many to be just a coincidence. Then again, two of the bikes are pretty unusual. I have to think that maybe something new is going on with spoke makers, maybe they all buy nipples from the same source. Maybe greazy or one of the engineering guys will have some enlightenment for us.
|re: Broken Spoke||Club|
Oct 12, 2001 6:22 AM
|test, couldn't post yesterday, sorry in invade yer thread|| |