Bicycle Mechanics - breaking spokes

I am a novice cross country rider. I don't do any real hard riding, ie: drops, etc., but I keep breaking the spokes on the back wheel of my bike. I am 260 pounds, is this a possible reason. Any advice please.

There are two possible reasons for your broken spokes. One is the 260lbs. The other may be the fact that you are a novice. Learning the nuances of weighting yourself properly on the bike in rough terrain, combined with your weight may be the source of your problem. My advice is to hang in there and don't get frustrated. Just keep riding. You will break less spokes eventually. But as long as your weight is at 260, broken spokes will most likely be a fact of life.

I have a customer who fluctuates between 375 and 450. He has eaten many wheels in his day. And he does not ride in the woods. But just watch him settle down on his Rocky "Grind" and you know those wheels are taking it hard. Jason doesn't just break spokes, he annihilates them. I have had to fetch him on more than one occaision after he flattened a rear wheel after contacting a pothole or some other unforgiving object.

Depending on how far you want to go to alleviate this problem, a stronger, albeit, more expensive wheel could be built up. The least expensive build I could find to hold him and give a reasonable return on his investment was a Sun Rhyno, 36', 2.0 DT spokes, high flange hub, and built with a 3x patern. The last one I built is still cruising after a year. But I also have to true it regularly and replace a couple of spokes every other week or so. But Jason is the exception. For your size, I would expect better durability out of this build.

I have also had to build "tough" wheels for my bigger customers. Using 14g (and sometimes heavier) spokes, downhill/freeride rims and beefy hubs, once we even built a singlespeed hub to get a wider flange spacing and even tension.

If this wheel is older or from a bike under $500 you might want to just go with a beefy rim like the Ryno CRUM mentioned or a Mavic F519 and straight 14g spokes built up by a good wheel guy.

I would suggest using a wheel design for tandem or heavy touring with 40 spokes on the front and 48 on the rear. Sun makes a rim called the CR18 that has both of these spoke counts and is a very heavy duty rim and only cost $35 for just the rim. I would also get it laced in a 4x pattern for a bit more strength. Use brass nipples for greater reliablity. With this higher spoke count use DT Alpine III, these are butted for max strenght for heavy loads. This is just my opinion anyway and a friends who weighs 240 pounds and tours with an additional 80 pounds of stuff on a Rivendell and his wheels after 4800 miles are still going strong.

When it comes to breaking spokes a lot of it seems to come from riding "style". I weigh 275 and have broken 2 spokes in over 15000 miles of riding. I had Race Lites on my road bike and could not even knock them out of true. On my current mtb I have never broken a spoke (36 hole 3X) The only time I broke a spoke was on huge potholes and this was on my entry level Trek. "Ride Light" and get a decent set of wheels and I think your problems will disappear.

If it is a good wheel build you should not have broken spokes often.
I am 295lbs and have never had a spoke brake unless I run into something. All my bikes get abused on the DH/freeride trails. I also build all my own wheels so I know they are good.

One set of wheels I use has Mavic 317, 32h laced with 14/15g spokes to CK hubs on my XC bike. Never had a problem even when hitting 5'-6' drops to flat with them. My frames usually brake before the rims. :D

Because of our weight however, it is a good idea to learn how to true your wheels and keep the spokes properly tightened. I check mine twice weekly or after every DH run depending on the terrain.

Also, what type of wheel set is it? Do you ride a box store bike(Wallmart and such) or a bike with decent parts from a bike store? Is it a HT or a squishy?

:beer:

My last two 32 spoke wheelsets have come with very low tension on the spokes and I suspect companies don't build wheels with heavy people in mind anymore. I used to break spokes all the time until I retensioned my wheels with a bit more tension and haven't had a problem since. The caveat here is to not go too far or you can ruin the rim. So far my mavic open pros have held up for 3000 miles without a broken spoke and even took a pannier into the spokes going 20 and locked the wheel. Not even a bent rim on that one (I thought for sure I had broken a spoke or bent the wheel). Must say I think the drivers around me were impressed when I went skidding by and managed to stay up. Anyway, I weigh in at 200 pds and my pannier usually weighs in between 20 and 30 pds., not super heavy but not the 170 most wheelsets are designed for these days either.

I would suggest using a wheel design for tandem or heavy touring with 40 spokes on the front and 48 on the rear. Sun makes a rim called the CR18 that has both of these spoke counts and is a very heavy duty rim and only cost $35 for just the rim. I would also get it laced in a 4x pattern for a bit more strength. Use brass nipples for greater reliablity. With this higher spoke count use DT Alpine III, these are butted for max strenght for heavy loads. This is just my opinion anyway and a friends who weighs 240 pounds and tours with an additional 80 pounds of stuff on a Rivendell and his wheels after 4800 miles are still going strong.

One word - Bulletproof!

Those tips about maintaining proper tension are golden. 260 pounds isn't to much for a quality wheel that is properly tensioned.

Fatigue happens to all metal components, and it usually occurs pretty equally on all the spokes in a wheel. Once I break my second or third spoke on a wheel, I relace it. Breakage is going to continue until all the fatigued spokes have been replaced, so you can do them one at a time or all at once. I find all at once less frustrating.