So I’ve been riding my unicycle for over a year without issue. All of a sudden, a few weeks ago I broke a spoke on my 29er. I broke it at the elbow (where it meets the hub flange) and didn’t even notice until I got home and saw it. Bought some spare spokes, replaced it, life moves on.
Fast forward to today. Went on a ride, whatever. Got home, noticed I have another spoke broken at the elbow (same place as other spoke). It is a different spoke, but it’s only two spokes away from the one I already replaced.
From what I’ve read, this seems to be due to bad spoke tension. I went around flexing my spokes and flicking them. I get around 1/4 to 1/2" flex when I squeeze two spokes together, and they all sound pretty close to the same pitch-wise.
So do I go around my wheel and tighten all my spokes 1/4 or a 1/2 turn? More? Less?
Am I screwed and need to get new spokes and totally relace my wheel?
Should I stop unicycling forever because I didn’t maintain my equipment properly and I’m a bad person? (That’s a joke.)
Spokes usually break because they go totally slack and then tense again too many times. Higher spoke tension can help prevent that, and butted spokes (which are springier and less likely to go slack) can help too. Unicycles seem to have standardized on straight gauge, which makes for a more rigid wheel, and maybe is worth it with all the extra weight and side loading we do, but still.
Anyway, I would try tightening them all up, and then going around and squeezing the parallel spokes together in pairs as hard as you can (wear gloves), to catch any of them that are about to break, and to do some stress relief on the rest. But my experience is that once they start breaking, they keep breaking…
I was thinking about relacing my wheel with sapim force spokes, which are butted and extra thick at the elbows, since my 24" has broken a couple recently.
Perhaps there is too much tension in the area where the two spokes broke,causing those spokes to take more than their fair share of the strain.I wold try loosening some spokes in that area.Loosen by a quarter turn at a time. To check if the wheel is true,you could stand the uni on it’s saddle and spin the wheel. With your hand gripping the frame,extend your thumb until it’s just barely touching the rim. You’ll feel where the rim is uneven. Stop the wheel there and adjust the spokes there. ( mind your fingers when the wheel is turning. OUCH! )
I’ve had my wheel trued/tensioned by an LBS once last summer.
I think unibokk may be on to something. When I broke my first spoke, until I could get some spares, I tightened some of the spokes in that area, trying to bring that section of rim a bit more into true. Perhaps that’s the culprit.
So I’ll replace the spoke, loosen some slightly in that area, and then go around the rest of the wheel and tighten a little bit.
Spokes break for many different reasons. Common reasons on unicycles are (in order of frequency from experience):
Use of small flange hubs (emphasised by loose spokes)
Badly tensioned spokes.
2.1 Over tight spokes on 36" wheels (bike shops do this a lot)
2.2 Loose spokes on trials wheels
2.3 Inconsistently tightened spokes in a wheel
Damaged spokes from grinding.
Bad spoke pattern (single or radial)
Wheels not stress relieved after building the wheel
A well maintained wheel should not have spokes that snap. Although when you do snap the spokes either side of the snapped spoke have additional tension applied to them and they snap. So often you will snap one spoke, fix it only to find that the spokes next to it snap days later. This is often on over tensioned wheels or un-stress relieved wheels.
Replaced the spoke, and went around the wheel tightening 1/4 turn at a time. Ended up at 3/4 turns total I think. (I say I think, because in the beginning, I believe I was loosening them, so had to backtrack and retighten)
Anyway, after every rotation around the wheel, I went around and squeezed two bundles together with my hands as hard as I could to check for spoke head movement, and see if any that were on the verge of breaking, would break. Couldn’t see any moving, and none broke.
I hope this’ll clear the issue up. After I tightened them, I rode around for a minute, and could hear them all popping with the new tension. I had this same experience when my wheel was last trued. After a few minutes, it went away, and now they’re fine.
My rim was very true BTW, much to my surprise. Upon replacing the spoke, I checked for true against my brake pads, and have maybe 1/16 - 1/32" of wobble. Seems acceptable enough? Have one high spot, but it’s no more than a mm or 2 so I’m not worried.
Just broke another and ordered the Sapims. It was a well built wheel, but maybe crappy spokes (Torker DX).
The broken spokes were all in the quarter of the wheel which is on the bottom in my preferred standing/hopping stance, which makes me think it was in fact the usual fatigue failure from losing tension. I’ve rotated the tire a few times to even out the tread wear, but now I’m thinking maybe I should rotate the cranks instead, to even out the tire and spoke life both.
I just broke my fourth spoke on this wheel, this year - I’m out of replacements now, so I’ll rebuild the whole thing when spoke #5 goes. I thought I’d post a pic of the wheel, with the new silver spokes replacing the broken black ones - all four in the same bottom quadrant. Obviously not a coincidence! I really think I will start rotating my cranks.
Funny, I haven’t had any issues since I tightened my wheel up, and I’ve been going a lot bigger lately. Only problem I’ve had so far is a pedal bearing going to hell, but I don’t really care about that.
Reading this thread prompted me to have a quick check of my own spoke tightness as my Uni is a few months old now. I found 3 that were basically slack (all on the same side of the wheel but distributed around its circumference a bit).
I’ve tightened them to ring at the same pitch as the others but it prompted me to ask the questions;
Is this something I need to check regularly with a Uni?
Is it enough to tighten (or, indeed, loosen) the odd spoke that seems to have gone adrift on a monthly basis or should I be zipping the wheel into my LBS to be more professionally ‘trued’ every ‘x’ months.
As a new Uni rider I appreciate your guidance with this.
They’ll creak sometimes from moving against each other where they cross over; I don’t think it’s usually anything to worry about. After a while they’ll actually wear a little bit of a groove into each other at that point, but I’ve never had a spoke break there.
Spokes coming loose is usually from “windup” - when they were tightened, the spoke nipple didn’t spin freely on the threads, so it twisted the spoke with it. Then when you ride, the spoke comes under less tension, and is free to untwist and loosen.
Heavier gauge spokes don’t wind up as much; super light gauge spokes can be horrible and take special building techniques. Unfortunately the heavier gauge spokes also go slack faster when they unwind - a quarter turn makes more tension difference - so it’s still a problem.
It shouldn’t happen in a properly built wheel; one way to avoid it when you are tightening up your own spokes is to over-tighten them a little (say an extra quarter turn) and then back them off to where you want them.
Normally I wouldn’t take the time to pick apart finer points, but in this case it seems important. Spoke failure is almost always due to spokes moving during riding, causing fatigue, and then failure. You are correct that this shouldn’t happen in a properly built wheel.
You shouldn’t hear pinging or creaking noises from the spokes when you ride, ever. If you do that is an indication that the spokes are moving, and that also means they don’t have enough tension. Poorly seated spokes with inadequate stress relief will appear to have “loosened” after riding, but they have just seated themselves resulting in lower tension. This lower tension can lead to spoke failure if it is not remedied.
If the builder was careful to untwist the spokes during the build, and use proper tension the spokes won’t lose tension from windup. If the twist hasn’t been relieved from the spokes it can cause the spoke to loosen as it unwinds, but when nipples loosen to a degree to have a serious effect on wheel tension it is a sign that there was not enough to begin with. Also, if the nipples are lubed, and the nipple seat in the rim is lubed it will reduce windup considerably. I am in the habit of pinching the spoke gently as I turn the nipple to gauge the windup. It also gives me a feel for when I have unwound the spoke without unscrewing the nipple.
Stress relieving and tensioning are the reasons hand built wheels are stronger, and more reliable than machine built wheels. It is a good idea to do this work on any new uni since most are factory built wheels.