Factory or LBS wheels - 32 or 36 spokes?

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chocjohn9
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Factory or LBS wheels - 32 or 36 spokes?

Post by chocjohn9 »

All
I've ridden quite a number of factory made 32 spoke wheels. No issues. Ever. Geared and fixed. They are all still going strong.

Recently, I've had a few 32 spoke wheelsets made for me at a LBS. (Mavic open pro on 105 or Ultegra rear hubs with dynamo at the front. 3 cross) After the first set was made, the spokes kept on breaking at the hub end and unscrewing at the rim end. I changed LBS and had them remade. Now, spokes are breaking less frequently, but they they are still pinging, one say, every 300 kms, but only at the hub end. (The second LBS used DT Swiss "glue" nibbles.) This is starting to drive me nuts. I take part in audaxes and I now start to worry that my wheels will make it...... :(

After my first LBS expereince, I wrote a post here a few months ago, and the general feling was that the shop a disaster. OK. I took this advice and changed.... but the issue has not gone away. I feel slightly embarrassed to say this, but the first and now the second LBS used the excuse that "I am a powerful" rider and that's why they are breaking.

I cycle about 7500 miles per year, in all conditions. The road surfaces are reasonably good. I tend to complete a 200kms audax in 7h45 to 8h all in. I weigh 90kg and I'm 6 foot 1. I use Continental 4 season tyres, 25 or 28mm on either a VN Yukon during the summer, a Charge Juicer Hi during the winter.

Could this is true and should I change to 36 spokes? (My touring bikes have 36 spokes and they too are perfect - but again - they are factory made(Rose bikes))
Is this just an excuse to mask their incompetancy?
Why would factory 32 spoke wheels still be OK and LBS ones not? Bizarre...
Have I found two bad LBS in a row! ?
Where is the tipping point where 36 spokes should be the norm?

Thoughts? I really want this issue to go away. Many thanks.
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TrevA
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by TrevA »

I'm a similar build to you but heavier at 110 kg. I use 32 spoke Open Pros on 105 hubs on my audax bike and have not broken a single spoke in 4 years. Recently had the back one rebuilt as the rim had worn out, but again no issues and probably 2000 miles since the rebuild. I think you've been unlucky in finding 2 incompetent LBSs.

I had a similar problem with a 36 spoke touring wheel (Deore/Sputnik) for my tourer, built by a shop with a good reputation, but I kept breaking spokes. Swapped it for a Deore/Mavic A319 36 spoke built by SJS Cycles and the problem has gone away.
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Keezx
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by Keezx »

Have the tension checked.
A 32 sp. wheel with 90 kg should never have any trouble.
Besides that, a Open Pro is a shallow, not stiff rim which cannot take very hifg tension.
I would never take these for your purposes.
Bowedw
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by Bowedw »

200k Audax including all stops and the hills that such events usually have in under 8 hours is a pretty good indication that you are a powerful rider and asking to much from 32 spokes. The rims as suggested may also not be the best choice under the conditions you use the wheels for.
Many moons ago I had a set of 32 spoke mavic rims built for my son and the same in 36 spoke for myself. After he had the same problems as your self with the 32 spoke wheels I swapped my 36 spoke wheels with him and no more problems for him and the 32 spoke wheels where fine for me being smaller and weaker than him.
I assume its the rear wheel that is giving the problem as the front should be ok with less weight and not being the driving wheel and shorter spokes due to dynamo hub.
I bought a Galaxy about 16 years ago and despite having 36 spokes I would find broken ones at the hub very frequently. The more I had replaced the worse it got until I was never using the bike. A rebuild with a new rim and spokes sorted that problem. I think that once it becomes a frequent problem the strain on the rim and spokes just seems to go around in circles and the unreliability issue curtails your enjoyment.
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by pwa »

I am about 6'1" and weigh about 90kg, and I ride on 32 front and 36 rear for audax, Open Pro / Ultegra. I got my last pair for about £300 from Paul Hewitt and I have not had a broken spoke in about 10 years of using his wheels. If you are tempted, phone the shop rather than using the website and you will get individual advice and a wheel or pair of wheels to meet your needs.
Brucey
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by Brucey »

spokes fail by fatigue which ultimately arises because of the service stresses; they are also sensitive to how they are installed.

So there are very many ways in which a wheel can be built badly including component selection, use of threadlock where necessary, and particularly stress relief of the wheel. If you are breaking front spokes then you have badly built wheels. If you are breaking rear spokes it may not be that simple; a bad build can be part or all the problem but the service stresses may also be too high for your wheels.

The service stresses that the spokes see vary with the wheel design and the conditions of use. Open Pros are very light rims and the reason the first wheel gave problems was almost certainly because the non-drive-side spokes were going slack enough in service that the nipples were able to unscrew. In a wheel with less dish and/or a heavier/stiffer rim, the same variations in spoke tension (during service) do not occur.

If you use threadlock, but build the wheel the same, you 'mask' the first effect of in-service tension variations but if there are other consequences of such tension variations they will soon come.

So when you compare 'factory' wheels with the LBS ones are you really comparing like with like? Or are the factory wheels less dished and/or with heavier rims?

I would note that IIRC Mavic's recommended spoke tensions for Open Pro rims are not high enough to allow a reliable dished rear wheel to be built for a strong rider. You should definitely use DB spokes on the NDS because that will help the spokes not to go slack in service. When you build with a higher tension (which Mavic themselves do when they make factory wheels using similar rims....) you do risk that the rims may crack in service, but with light wheels there is always a compromise, and that is usually the most acceptable. [Open Pros don't last that long anyway (they wear out on the braking surfaces) so you only need to avoid cracking for perhaps half as long vs if the rims were heavier and more durable.]

Spokes can be specified such that they have an almost indefinite fatigue life. But to achieve this;

- the fit in the hub needs to be perfect (and corrected with washers if necessary)
- the angle at the rim cannot be too large
- all the spokes need to be manually set to the correct angle at the hub and rim as necessary
- the spoke tensions need to be set accurately
- the wheel needs to be stress-relieved correctly.

On the last point, to stress relieve a wheel, many builders will simply push on the rim with the wheel on the floor and assume that is 'enough'. Well... sometimes it is, but more usually it isn't. IMHO the correct stress-relief technique is as described in Jobst Brandt's book. The wheel nearly always goes out of true when you do this and the process is only truly complete when the wheel no longer goes out of true when subjected to further stress-relief loads. Obviously the lighter built the wheel is, the more important it is to do this properly. I know of no way of doing this thoroughly in less than about half an hour per wheel (making it the most time-consuming part of any build), and it is hard work too, all of which explains why not that many wheels are built properly in shops.

From an engineering perspective, spokes tend to break at ~250kg. In a well built rear wheel you might have 80kg on the NDS and 120kg on the DS. In service the wheel distributes stresses amongst the spokes so that the stress in any one spoke will not increase much (+20 or 30kg would be quite a lot) but it can decrease a lot more than that. Under ideal conditions a service variation of up to ~80kg in spoke tension should give a very long fatigue life. Failure to build the wheel properly eats into that margin considerably (and so can unusual service conditions if they include a corrosive element).

If nipples unscrew on the NDS without threadlock then it means that the tension wasn't enough and/or that the service loads are very high. If the NDS spokes were at 80kg but routinely go completely slack momentarily in service then it is almost certain that they will break. If spokes actually buckle under a slight compressive load (which can and does happen with the 'leading' NDS spokes in some wheels) then they will fatigue very quickly because they see a bending load at one or both ends. Spokes are not fatigue resistant in bending.

As a further comment I'd also mention that whilst rider weight is a good guide to how strong wheels need to be, it is not an infallible guide. Some people are just very strong, regardless of their weight. Muscling up climbs in high gears, especially out of the saddle, sprinting, etc can destroy wheels that are not quite good enough.

I found out years ago (when I was 2/3 your weight) that if I build a rear wheel with a full dish and a 440g rim, I was strong enough that I can always make the NDS nipples unscrew unless thread locking of some kind is used. I think that threadlock is often a good solution to this, but that it is not infallible; that the nipples unscrew without it (even in a well-built wheel) is nature's way of telling you that you are near (or perhaps already beyond) the limit of that wheel's service envelope. I also found out that if I use;

a) a less dished wheel and/or
b) a heavier/stiffer rim and/or
c) more spokes

then I can make a durable wheel even without threadlock on the NDS nipples. Of the three things above, going to 36 spokes is the easiest thing to do, and has the least effect on the desirable properties of the wheel (i.e. keeping it light and resilient). Unfortunately it is also not that effective at strengthening the wheel; it might make it 10 to 15% stronger, so it is a good solution if that is all you need, and a partial solution otherwise. My preferred route is to reduce the wheel dish; the effect of this can be very powerful indeed; not for me 11s/131mm or 8/9/10s on 130mm... if I'm riding a light wheel for gears then it'll be 132.5mm and slimmer than normal on the gear side too, with fewer sprockets if needs be.

In your case I'd suggest that (especially if you are using a 25-28mm rear tyre anyway) that you use a slightly heavier and stiffer rear rim. If you choose carefully this may 'cost you' 40g (big deal...) and could actually make the wheel faster because the rim is more aerodynamic. I'd also go to 36 spokes (why not?) and at least consider fewer sprockets; I quite like 8 from 9 on a 7s freehub body; there are 9 from 10 options too.

hth

cheers
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interestedcp
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by interestedcp »

The problem is build quality, nothing else. Well built 32H 3X wheels are strong and durable enough even for your use. 36H 3X wheels are however both inherently stronger by design, and have larger build tolerances, leading to statistically more durable wheels.

I think traditionally designed wheels are great, but it has long been a huge problem that there are too many incompetent wheel builders. Basic danger signs are; no idea, or wrong ideas about "stress relieving", claiming that it is natural that wheels "ping" when ridden, and that re-truing is to be expected, and that potholes can cause spokes to break.

Another problem in general with buying bicycle wheels are the instant victim-blaming people often experience when they show up with a problematic wheel at the seller. The blaming may be their honest opinion, but it then show their lack of understanding of the theory of wheel building. It is of course also often suspiciously aligned with their economic interest too.

The major cause for spoke breaking is uneven spoke tension, which causes rapidly accelerated spoke fatigue. That means that when the spokes starts breaking, the still unbroken spokes are often hopelessly compromised. As a general rule then 3 broken spokes means a wheel-rebuild with new spokes, and these days I would generally say only 2.

It is not entirely clear to me whether the second LBS actually disposed of the old spokes, or reused them and just re-tensioned the wheel while using nipple "glue". If they reused the spokes (very bad) it is to be expected that the spoke breaking continue.

As said, I prefer the concept of traditionally designed wheels with 36H X3 spokes; easy and cheap to maintain, and extremely strong and durable. Whether they are factory made or not isn't important, only assembly quality and quality control matters. Even machine build wheels are getting quite acceptable these days.
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NATURAL ANKLING
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by NATURAL ANKLING »

Hi,
Pretty good :!:
I have had a mini depression lately with a wheel I rebuilt (worse ever) :oops: I will apply a lot, all if nothing else said above.

I am not that heavy but I wont go below 30 " on 30+% hills on a all up 100 kgs.
The wheel is already 700 x 36 plain spokes and its NDS nipple breaks.
The original wheel was good for 15 years so my problem exists with reuse of spokes / poor build ?
When I dismantled wheel the spoke nipples shrieked squealed, do you reckon thread lock? as on rebuild I had constant loose spokes :?:
Ended up using threadlock on NDS, but did not cure spoke brakes.
Rim was new double eyelet Mavic (OEM wheels were good for camping off road :) , never broke) T261 x 20, hub deore lx 8 speed, not sure on spokes but plain.

Not using spoke strain gauge.
Probably fluffed on stress relief :oops:
Couldn't get spokes tighter......did I need to :?:
Bad job by me.

So its poor stress relief?
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beardy
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by beardy »

there are too many incompetent wheel builders.


Well the standard of work required to meet the exacting standards of a competent wheelbuilder doesnt seem easy to find, especially at the price which people are willing to pay.

Or we could just accept a combination of components that can be assembled by any reasonably competent person, rather than a master craftsman. This can actually be met by many amateur mechanics for the majority of riders, if not the most powerful.
chocjohn9
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by chocjohn9 »

Thanks to everyone for the replies. Very interesting and helpful.

It's the only the rear spokes that are pinging. I also have a 32 spoke Open Pro, fixed, wheelset, put together by Condor in London, are they have worked brilliantly.....no breaks there. This is what is pushing me to think that I've been unlucky with 2 LBSs. I could give Paul Hewitt a ring. I have one of his tourers :D

A few people mention my wrong choice of rim. I'm a bit lost if I move away from Open Pros. They have served me well, to date. Suggestions then?
DT SWiss? Which model number?
Mavic CXP Pro? (I mention this because Rose do them and I've never had any issues with Rose making wheels)
Exal LX17
Other? .... there must be quite a few....

Many thanks - again!
beardy
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by beardy »

chocjohn9 wrote:Thanks to everyone for the replies. Very interesting and helpful.

It's the only the rear spokes that are pinging. I also have a 32 spoke Open Pro, fixed, wheelset, put together by Condor in London, are they have worked brilliantly.....no breaks there. This is what is pushing me to think that I've been unlucky with 2 LBSs. I could give Paul Hewitt a ring. I have one of his tourers :D

A few people mention my wrong choice of rim. I'm a bit lost if I move away from Open Pros. They have served me well, to date. Suggestions then?
DT SWiss? Which model number?
Mavic CXP Pro? (I mention this because Rose do them and I've never had any issues with Rose making wheels)
Other? .... there must be quite a few....

Many thanks - again!

(Mavic open pro on 105 or Ultegra


All other possibilities exist as to why some wheels failed and others stayed good. The wheels that failed for you are quite dished in comparison to the ones that stayed good. A higher standard of craftsmanship is required for the highly dished and flexible rim combination with a powerful rider to survive than for the less dished wheels.
pwa
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by pwa »

chocjohn9 wrote:Thanks to everyone for the replies. Very interesting and helpful.

It's the only the rear spokes that are pinging. I also have a 32 spoke Open Pro, fixed, wheelset, put together by Condor in London, are they have worked brilliantly.....no breaks there. This is what is pushing me to think that I've been unlucky with 2 LBSs. I could give Paul Hewitt a ring. I have one of his tourers :D

A few people mention my wrong choice of rim. I'm a bit lost if I move away from Open Pros. They have served me well, to date. Suggestions then?
DT SWiss? Which model number?
Mavic CXP Pro? (I mention this because Rose do them and I've never had any issues with Rose making wheels)
Exal LX17
Other? .... there must be quite a few....

Many thanks - again!


That's just the sort of question to ask Hewitt, or any other respected wheel builder.
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by PH »

pwa wrote:I am about 6'1" and weigh about 90kg, and I ride on 32 front and 36 rear for audax, Open Pro / Ultegra. I got my last pair for about £300 from Paul Hewitt and I have not had a broken spoke in about 10 years of using his wheels. If you are tempted, phone the shop rather than using the website and you will get individual advice and a wheel or pair of wheels to meet your needs.


I've had wheels from Paul Hewitt, Spa and SJS, with various rims from Open Pros to Sputniks, none of which has given any trouble until the rims wore out. I've been less lucky with wheels from three LBS, though it's usually been spokes coming lose rather than breaking.
I'm 110kg and it takes me 10+ hours to get round a 200 Audax.
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Mick F
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by Mick F »

In the old days, we British had 40h rear and 32h front.
When I first modernised and build my own bike up in 1986, I tried to buy the same format but was told that the standard was 36h 36h. Some years later, the standard became 32h 32h, and then later they started producing "factory built" wheels with all manner of spoke combinations.

You buy a pair of "handbuilt" wheels these days and they tend to be 32h 32h or even 28h 28h.

I read once, that if you have the same amount of spokes front and rear, you either have too many up front, or not enough at the rear.

I build my own around my Campag Chorus hubs. 36h rear and 32h front. There was nowhere that I could buy a PAIR of hubs that were different holes. I had to buy them separately ............. and luckily found both of them on offer. Had I been able to buy a 40h rear in Campag Chorus - or even Record - I would have done.
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Samuel D
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Re: Factory or LBS wheels - 32 or 36 spokes?

Post by Samuel D »

I think it is simply unrealistic to expect well-built wheels from a randomly chosen local bike shop or even ten of them.

If you read the Jobst Brandt book that Brucey mentions, The Bicycle Wheel (a masterpiece of technical writing), you’ll see that building a good wheel requires a pretty deep understanding of the mechanics of a wire-spoked wheel or having learnt a huge number of things by rote and either way requires a lot of building work.

Anyone who talks down the skill and knowledge of building good wheels probably doesn’t know what a good wheel is.

If you choose a shop known nationally for its good wheels, I am sure you will fare much better.
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