Spoke count for touring

danny1c
danny1c Posts: 38
edited June 2012 in Tour & expedition
Hi

I've just returned from a trip which in the end I had to cut short due to continual spoke failure in the rear wheel. total bike weight (inc bike) was 26.5 kgs. I had 14kgs was over the back wheel in panniers. I weigh 75kgs. The rear wheel is a Royce hub with a mavic open pro rim with 32 spokes. The first 2 spokes to break were non drive side the next 2 were drive side. Each time a spoke broke I had to ride on until I got to a bike shop. The furtherest I rode with a broken spoke was about 15 miles.
The first spoke broke after I'd only covered 35 miles, I rode on for about 8 miles to get it fixed. After a further 50 miles the second spoke broke, I went on for 15 miles to get it fixed. I then managed 192 miles before the next breakage this time driveside, I rode 13 miles to get it fixed. The wheel went on for another 120 miles when another spoke broke, I rode 3 miles to get it fixed. 50 miles later another driveside spoke went, rode on for 3 miles to get it fixed. At this point the shop said it couldn't sbe fixed as they could no longer true the wheel. Eventually they did fix it as best they could (although the wheel was nowhere near true) and another spoke went whilst they were trying to true the wheel. At this point I got on a train.
The wheel is about 2 years old and only covered about 4000 miles
I was riding on well surfaced roads in England, spain and France

I supose my questions are
Is that to much weight for a 32 spoke wheel so was it always going to fail?
Is there a rule of thumb about spoke numbers for certain weights?
Was I unlucky in breaking the first one but then damaged the wheel by riding on which led to further failures?

Comments

  • andymiller
    andymiller Posts: 2,856
    The OpenPros are a good quality rim and with that sort of weight and on normal roads 32 spokes should have been perfectly fine.
    Italy Cycling Guide
  • Hoopdriver
    Hoopdriver Posts: 2,023
    Open Pros are a fine rim, but not for touring in my opinion. And 32 spokes are too few, again in m opinion. I would definitely go with 36 for touring and more for expedition touring in rough and remote places.

    With 32 spokes if you do break one and continue to ride another broken spoke is almost a certainty. You can get away with that kind of thing if you have 36.

    At for rims, I'd leave the Open Pros alone for tourin. Nice rim, I've go a set on m road bike, but on m ligh tourer I have Ambrosio Excellence - a nice compromise between sportiness and durability.
    http://www.My-Bicycle-and-I.com
  • Hoopdriver
    Hoopdriver Posts: 2,023
    andymiller wrote:
    The OpenPros are a good quality rim and with that sort of weight and on normal roads 32 spokes should have been perfectly fine.
    Although I disagree with the idea of Open Pros for touring, he is quite right in saying that your set up should have been usuable on normal roads. You were either very unlucky or you need a better wheelbuilder
    http://www.My-Bicycle-and-I.com
  • MichaelW
    MichaelW Posts: 2,164
    As you have found out, it's a bit marginal for medium-weight Euro-touring. That wheel may have worked with a thicker 13/14g butted spoke rather than a racing style 14/15g.
    My old wheel used Campy Mirage, 36x 13/14 spokes and a heavy duty rim and never gave me any problem, on or off road. A de-chaining incident can gauge the driveside spokes and set you up for a series of spoke failures. My new wheel uses 14/14g spokes and has proven much more vulnerable than the old one.
  • andymiller
    andymiller Posts: 2,856
    Hoopdriver wrote:
    Open Pros are a fine rim, but not for touring in my opinion. And 32 spokes are too few, again in m opinion. I would definitely go with 36 for touring and more for expedition touring in rough and remote places.

    Erm he was in road touring in France - not exactly expedition touring in rough terrain. I probably wouldn't choose OpenPros for touring but for road touring in Western Europe they really should be up to the job.

    I think that what matters first and foremost is the quality of the build, then the right choice of rims and spokes, and only then the number of spokes. After all mountainbikers can ride with 28-spoked wheels without problems.
    Italy Cycling Guide
  • Hoopdriver
    Hoopdriver Posts: 2,023
    andymiller wrote:
    Hoopdriver wrote:
    Open Pros are a fine rim, but not for touring in my opinion. And 32 spokes are too few, again in m opinion. I would definitely go with 36 for touring and more for expedition touring in rough and remote places.

    Erm he was in road touring in France - not exactly expedition touring in rough terrain. I probably wouldn't choose OpenPros for touring but for road touring in Western Europe they really should be up to the job.

    I think that what matters first and foremost is the quality of the build, then the right choice of rims and spokes, and only then the number of spokes. After all mountainbikers can ride with 28-spoked wheels without problems.
    I know he said he was road touring in France. I read the post. I said I would have 36 for touring, and more for an expedition bike. For exampe, I have 48 on my expedition bike. I have 36 on my light tourer - Phil Woods hubs on an Ambrosio rim.

    People have toured on al kinds of things and managed. I would not, if I had a choice, tour with less than 36 spokes. Really, until not so many years ago 36 was the normal number of spokes on a bicycle wheel. It was manufacturers that convinced the world that less was more in this regard.
    http://www.My-Bicycle-and-I.com
  • andymiller
    andymiller Posts: 2,856
    Hoopdriver wrote:
    I know he said he was road touring in France. I read the post. I said I would have 36 for touring, and more for an expedition bike. For exampe, I have 48 on my expedition bike. I have 36 on my light tourer - Phil Woods hubs on an Ambrosio rim.

    Whoops you did indeed. Sorry.

    I still think that the wheel should not have failed that soon under those conditions and fairly lightly-loaded. I suspect the main culprit was the wheel build.

    I've done lots of fully-loaded touring with 28 spokes up front and 36 on the back. 48 spokes seems like massive overkill to me.
    Italy Cycling Guide
  • Hoopdriver
    Hoopdriver Posts: 2,023
    andymiller wrote:
    Hoopdriver wrote:
    I know he said he was road touring in France. I read the post. I said I would have 36 for touring, and more for an expedition bike. For exampe, I have 48 on my expedition bike. I have 36 on my light tourer - Phil Woods hubs on an Ambrosio rim.

    Whoops you did indeed. Sorry.

    I still think that the wheel should not have failed that soon under those conditions and fairly lightly-loaded. I suspect the main culprit was the wheel build.

    I've done lots of fully-loaded touring with 28 spokes up front and 36 on the back. 48 spokes seems like massive overkill to me.
    I agree with you that they should have lasted. He clearly had a lousy build on those wheels.

    48 spokes is a lot but then I was doing some very strenuous and remote desert crossings in high temperatures and had to carry as much as 23 litres of water along with my other gear on some of the longer and lonelier stretches. It didn't seem like overkill at the time.
    http://www.My-Bicycle-and-I.com
  • nicktheluddite
    nicktheluddite Posts: 221
    what someone said earlier about de-chaining (chain falls off cassette and jams between cassette and spokes of rear wheel). I had couple of spokes fail while touring in France - when I got a bike shop they pointed out the small gouge in every drive-side spoke and explained that this was my problem. They then did a fast job replacing all the spokes. Maybe this is what happened to you. (Deore hub with Mavic A319 36 spokes - fully loaded - picture on my signature if you want).
  • danny1c
    danny1c Posts: 38
    Thanks for all the replies and information. I can say the chain has never gone over the largest sprocket and into the spokes.
    The wheel has been taken to my LBS and they have said "the bearing behind the freehub has gone causing play in the axel" so I supose this must be the cause. I assume the bearing was suspect when I set off and the distance with the weight caused it to give up.
  • andrew_s
    andrew_s Posts: 2,511
    It's unlikely that the state of the hub had anything to do with the spoke breakages.
    It will be that the wheel wasn't well built in the first place, and that the spokes were fatigued before you set off. With fatigued spokes, once one goes, you can bet that others will follow soon. It's likely that the spokes weren't tight enough.
    All you can do is get the wheel rebuilt with a complete fresh set of spokes, preferably by someone other than whoever built the wheel in the first place.

    32 spokes on Open Pro should be OK for touring, though I'd go for 36 by preference.
    40 or 48 are stronger, but have the drawback that finding a replacement rim when on tour would not be easy. You'd probably end up having to get a new wheel.
  • Hoopdriver
    Hoopdriver Posts: 2,023
    andrew_s wrote:
    It's unlikely that the state of the hub had anything to do with the spoke breakages.
    It will be that the wheel wasn't well built in the first place, and that the spokes were fatigued before you set off. With fatigued spokes, once one goes, you can bet that others will follow soon. It's likely that the spokes weren't tight enough.
    All you can do is get the wheel rebuilt with a complete fresh set of spokes, preferably by someone other than whoever built the wheel in the first place.

    32 spokes on Open Pro should be OK for touring, though I'd go for 36 by preference.
    40 or 48 are stronger, but have the drawback that finding a replacement rim when on tour would not be easy. You'd probably end up having to get a new wheel.
    Yup. That just about sums it up. You need a better builder. And good point about the 40and 48 spoke hubs.
    http://www.My-Bicycle-and-I.com

Categories