Solo_rider

Hi.

Never done this before but I need to replace a broken spoke on the rear wheel (with disc brakes) and I'm wondering if I have to remove both the cassette and the disc rotor. I got the cassette off already.

Another question if someone wants to answer, is a spoke tension gauge something necessary (not for this job but I mean in general) ?

Thanks.

alo

It depends on where the broken spoke is. With some spokes on some wheels, you should be able to go through a gap in the disc rotor. You should be able to see for yourself.

If you are only replacing one spoke, I would not be concerned about a spoke tension gauge. You can gently squeeze the spokes together to get a rough idea of the tension.

Iride01 

Some hubs and/or spoke lacings you might be able to get the spoke in the hole in the hub, others you'll have to take stuff off. When you start taking stuff off, think to yourself if you know how to adjust it when you put it back together.

One spoke itself isn't usually and issue to tension somewhat adequately as someone else previously answered. However if your wheel is out of true by any amount, then take it to a wheel builder and get it all trued up. It's usually not much cost in my area. And wheels that aren't true usually have more problems than just one spoke.

Solo_rider

Thanks for the reply, alo. I appreciate it. I'm just having a hard time getting the spoke more than a couple of inches through its whole (in the rim) without bending it. From watching a couple videos it seems like I have to bend the spoke a little to get it in place but I just don't see it in my case -looks like it will take more than just a little bending. It looks like the disc rotor needs a star head screw driver which I don't think I have.

My question about the spoke tension tool wasn't about this job but like I said as a tool to have to check the tension in the spokes once in a while. It's easy to tell if a spoke is loose but it's kind of hard to tell if it's the right tension once it's tightened up.

Bigbus

Sometimes you do and sometimes you get lucky and the spoke slides by everything. My luck is usually that I have to pull off the disk or the cassette, usually not both for one spoke. And if you're serious about truing up wheels, the spoke tensioner tool is a nicety, but not a necessity. A truing stand, home-built like mine or store bought is much more necessary, but even that can be worked around by flipping the bike upside down and using wire or zip ties off the frame components for gauges. Lots of ways to skin this cat if you don't want to go to the LBS. But at least if you do decide to take it to the shop, it should be right the first time, if you get my meaning...

Bill Kapaun

Are these J bend or straight pull spokes?
I'll assume J bend.
You start the spoke through the hub FIRST.
You'll likely have to remove the "device" on that side of the hub.
When building a wheel, the last spoke takes the most bending to get in place. Ditto re the first spoke removed.

JohnDThompson 

Bending doesn't hurt the spoke unless you bend it so much, and so acutely, that it leaves a permanent kink in the spoke. Bend it just enough to get it in place; tensioning the spoke will pull it straight again.

cxwrench

Why would you say this? If you have a 32 spoke wheel, for instance, the last 8 will be exactly the same.

Solo_rider

Thank you all for the replies and the help. Much appreciated. I had no luck getting the spoke through with the rotor on. It was impossible. Luckily, I found a star head bit for my screwdriver and took the rotor off. It was a simple thing to do. I then was able to get the spoke through but it did take a little bit of bending but once it was in place and with some tension it was straight again.

The wheel didn't wobble much after I put the spoke in. It still needed just a little bit of truing, which I did as it's something I've done before. No truing stand but used a pen and the bike's frame to hold the pen against it. But thanks for the zip tie tip. I usually use the brake calipers as a guide but this is a bike I just bought and it's my first one with disc brakes. I also did a brake adjustment on it. Both brake levers were touching the handle grips when pulled. A couple of YT videos and i think I got it right. I like tinkering with stuff, which I think helps.

Again, the question about the spoke tension meter wasn't for this job since it's only one spoke but I am a perfectionist and I always try to get things as close to perfect as possible and try to keep them that way. I know spokes tension changes with time and was wondering if that tool is really necessary to avoid problems. The few times I did my truing was just by feel and sight but is that good enough ? Obviously if the wheel is reasonably true that should be a good indication but is it possible to overtighten one side of the spokes to where the rim pulls more to one side? Is that even possible ? I'm thinking it should be easy to see that if it happens but I don't know.

Thanks again for the replies.

Geepig

Well if you have progressed this far then you may be ready for a spoke tension meter. It will, of course, unleash a whole new set of issues in interpreting the results, but nothing a good tinkerer cannot handle.

cyccommute 

It depends on how much you want to fight with the wheel. Bending the spoke probably won’t hurt it but the bending process is long and tedious. Why make the job harder than it needs to be? If you don’t have a T25 Torx wrench, they are readily available at your local hardware store. It is a lot less frustrating to go to the hardware store, get the tool, take off the rotor, and install the spoke than it will struggling with bending the spoke into place. You’ll have the tool for future use as well.

pdlamb

A tensiometer helps build (or rebuild) wheels in a couple ways:

1. It'll make sure you are tensioning the wheel enough, but not too much. It's possible to build a wheel that's perfectly true, but the spokes will unscrew within a few hundred miles -- and start breaking, if you don't catch it in time. It's also possible to overtension the wheel, which can result in the spoke pulling through the rim. Expert wheelbuilders with lots of experience can get it right without this tool, but dabblers like me using a tensiometer can build a wheel better than some of the best LBS mechanics in my town without using one.

2. Especially on an older wheel, it's possible to get a wheel true in the stand while having widely varying spoke tension. The tensiometer will let you identify and correct an undertensioned spoke with two overtensioned spokes on either side of it (or vice versa). That'll save you finding out the undertensioned spoke unscrewing on the road, throwing the wheel out of true and, again, the unscrewed spoke may experience enough detension cycles to fracture.

You may be able to tune the spokes by ear if you're musical, or use a tuning meter, in place of a tensiometer. But that's another post.

ARider2

To answer a couple of your questions:

The few times I did my truing was just by feel and sight but is that good enough ?
YES it is fine but since your bike has disc brakes it is a good idea to check it every now and then because unlike a rim brake your disc brakes won't rub and tell you the wheel is out of true.

Obviously if the wheel is reasonably true that should be a good indication but is it possible to overtighten one side of the spokes to where the rim pulls more to one side?
YES reasonably true is good enough and over tight is easy to do and can be avoided by making a series of small adjustments, turning the spokes minimally each time, and rechecking rather than over tightening and overshooting the mark.

davidad

Spokes can be bent quite a bit when building or repairing a wheel as long as you don't kink it.
I use a tensiometer when I build or repair a wheel. It takes the guess work out of the equation.

Solo_rider

OK. Thanks again for the feedback. I gather a tensionmeter isn't really necessary then but a good tool to have for more accuracy and obviously to save time. I do have a musical ear and I know you can tell the difference between a loose spoke and an overtightened one by pulling on them. I don't think I'll ever need to rebuild a wheel since I ride my bike very gently on paved roads and I mostly ride during the summer months. I still haven't got a chance to ride this bike because of the cold wave we've been having here.