CJ Str3tch

Okay, apologizing for a newbie stupid question.

I have an old Trek 720 I use for commuting back and forth to work 15 miles roundtrip. Had the bike for years, didn't ride as much as I do now but never had any problems with broken spokes. Now, in two months, have taken the back wheel in twice to the LBS for spoke repairs (three the first time and two / three the second) and just notice again today the the wheel isn't true any more and - you guessed it! - more spokes are broke.

Is this crazy or normal? never replaced the rims - they're originals. I'm spending too much every time to fix the dang spokes! Is this normal?

Help!

jimc101

More than 3 broken spokes, would be looking are re-lacing with all new spokes. As you have had some replaced, you now have a wheel with some spokes with zero fatigue life, some with a lot of fatigue.

Sure others will give more technical reasons, for this, but would expect that that you will be replacing more or the older spokes over the next few weeks / months.

ratdog

Your spokes broke due to fatigue at the head/hub from being too loose. Once you get multiple breakages like this you should replace all the spokes. You may also have to replace the rim if it is too out of round which may give too much variation in spoke tension. Do a search on "broken spokes" and you will find lots of old post covering this.

Kimmo

You can prolly get away with just replacing all the non drive side spokes; they're the loose ones. Make that wheel tight.

mrrabbit 

1. New spokes.
2. Wheel rebuilt by a wheelbuilder who trues, tensions, and properly stress relieves the wheel.

So long as the rim sidewalls aren't worn too much, and the extrusion looks consistent all the way around, and the joint is straight, and no flat spots, rim re-use is okay.

=8-)

CJ Str3tch

So, an update: Went back to the LBS and asked about the tire. They suggested that I replace the tire with a new one - double lined rim and possibly more spokes (sorry, don't know the techie jargon for it so hopefully you know what I'm talking about). I explained that I do have a rack on the back and usually carry 10 - 15 lbs of weight on it at the most. They want me to bring the bike in and they will take a look and recommend something. BTW, the new rim they recommend initially would be about $100 - $120, which is somewhat hard to swallow.

Thoughts? Looking for advice...

Drew Eckhardt 

Read _The Bicycle Wheel_ by Jobst Brandt so you under stand what's going on.

Remove tension.

Replace all of the spokes in the failing group(s) (drive-side or non-drive side). Use DT Competition 2.0/1.8 butted spokes. Replace the nipples which go with them if they were unusually tight.

If you've had failures in both wheel halves take the opportunity to lubricate both threads and sockets with anti-seize applied with an acid brush that's had half its bristles cut off. You may also consider rim replacement (where the rim is _not_ the wheel - just the outer part) if spokes failed in both sides since the whole thing will be apart. Definitely replace it if the brake tracks are visibly concave. Otherwise put a drop of oil in each rim socket when it's at the top and a drop in each nipple at the bottom before you tension.

Form outbound spokes to match the hub flanges better, correct spoke line at the rim if necessary, tension taking care of windup (tape flags on the one (front) or two (rear) holes following the valve hole, sharpie dots on each one), and stress relieve. You can use the Jobst Brandt method of achieving correct tension in a box section wheel by alternately tightening and stress relieving until the wheel goes out of true in waves at which point you back off half a turn, true, and be happy.

This may cost as little as $0.69 per spoke which is $11 + shipping for a 32 spoke wheel. You can use your bike frame as a truing stand if you really need to although the real thing can be more pleasant (you may have a not-for-profit bike cooperative near you).

zacster

I would recommend a complete rebuild of the rear with new spokes and rim. As an alternative, you may just find a new pre-built wheel is cheaper than rebuilding. You don't need a high-end lightweight wheel, just something functional and I'll bet the store will have one of decent quality.

Drew Eckhardt 

In the non-drive side.

In the drive side they fail due to residual stress in the elbow from its forming operation with the number of cycles reduced by heavy riders and cargo.

Drew Eckhardt 

Once you're building your own wheels rim replacement with nice double-walled rims can run $50-$70 a pop regardless of how nice and expensive the hubs and spokes are (both of which can last 300,000 miles in a properly built wheel)

Kimmo

They're milking you.

What's meant to be wrong with your old tyre and rim?

The broken spokes are down to a poor build. If the rim's straight, round, and has braking metal left, there's no reason to change it (aside from seeing if it builds perfectly, you can't be sure it's good until the wheel's apart though).

There's no reason to spend that much on a rim for commuting. Hell, I can buy a nice racing/training rim for $70. BTW, I have no idea what kind of wheels we're talking about cause 'Trek 720' means nothing next to '90s hybrid' for example.

dramiscram

I have the same problem :https://www.bikeforums.net/showthread...think-I-can-go

I changed (not me, my LBS) 9 spokes in 3 different occasion. My LBS suggested that I buy a new, stronger wheel but as it's been okay for the previous 5-6000 kms I asked him the rebuild the wheel. I'll pick it up tomorow.
I've been commuting the whole week with a borrowed identical wheel and for the first time since the beginning of the summer I didn't broke a single spoke this week. So clearly not the fault of the wheel design or strengt.

I think that my low quality wheel just needed new spokes, the metal looked flaky and I'm sure I'll be okay as time will tell.

davidad

Big factor. How much do you weigh? A 36 spoke wheel properly tensioned and stress relieved should last thousands of miles.
A friend bought a Windsor from Bikes Direct and the spokes on the rear began to break. We replaced them with DT double butted spokes and the wheel held up for 40,000 miles until the rim gave out.

Lexi01

Sorry to say I agree with Kimmo...

I'm over 100kgs and I rode a set of RS10's (very cheap Shimano) for 12 months without any truing needed or spokes breaking. I did ask the LBS to make sure the wheels were properly set-up out of the box before I rode it though - cos I was a little concerned about the quality of the wheels at my weight.

I'd find a new LBS and explain your situation to them. You don't need new wheels (unless of course they're now damaged as a result of your experience).

Retro Grouch 

How old is the rim? What does the brake track look like? If the brake track feels noticeably concave, it's time for a new rim.

DannoXYZ 

Are you talking about lacing a new rim onto your wheel with replacement spokes? Or buying a completely new wheel? The cost of labour to rebuild a wheel with new spokes is simply not worth it and you're sure to get sub-par expertise in wheel-building. For that price, you're better off just buying a complete wheel. You'd guaranteed zero-mileage hub, zero-mileage spokes and zero-mileage rim.

CJ Str3tch

Guys,
Thanks for the opinions.

Kimmo - that's what I thought. I don't want to spend that kind of money. The bike is a late 90's model (a tank is how I describe it) and at the time it was labelled as a 'hybrid'. It's nothing fancy, but in the past it's hauled me and the kids (when they were younger) around the city.

Drew - thanks for the advice and the read. I will take a look, although I gotta say, your explanation took a couple of times to read and I think I might get most of it now.

Davidad - I'm around 215 lbs. and the panniers I carry general don't weigh more than 10 or 12 lbs.

Retro - the bike (and rims) are about 15 to 20 years old, but as for mileage I'd say relatively low - like less than 750 miles.

So let me ask a different question based on your responses: It sounds like rebuild the tire is an option, so can anyone recommend a guide to help me do that? I'll have plenty of time during the winter, and if it solves my problem, I'll give it a shot. Thoughts?

Kimmo

First you have to call it a wheel.

I'm sure there are a few good pages you could google up, but Jobst Brandt's The Bicycle Wheel is generally regarded as the wheelbuilding bible.

If you're too skint or stingy to buy a copy, CBD9A113B67582BFA8598C0B30139F0D66C53C54

davidad

At 215 36 spokes are a better bet. You can find Gerd Schraner's book The Art of Wheelbuilding on-line. Ignore the tired spokes part and you will be ok.