What's going in with my wheels (+ I'm an idiot)

Jun 29, 19 15:49

Post #1 of 20 (2141 views)

Let's start by saying I'm an idiot for buying no-name wheels I'd never heard of through a 3rd party which may have not been totally honest and so I'm paying for my greediness by having a set of wheels that are of no use (and now I'm trying to get a refund). I bought the wheels from the main company behind the bike racing team I race for. The wheels are unbranded but were presented to me as being >$2k wheels blablabla for which I had to pay around $700 give or take.

So here is some data and I'm curious as to the technical reasons for what you think is going on so tell me what you think about the reasons for this observation and if there is a way to fix them.

First I received the wheels and I did 2 rides with them - one fast and one easier both adding up to something like 100 miles. When I received them they were straight but after those 2 rides I noticed the tension felt a little low and there was a bit of a wobble in both wheels so I bought a Parktool TM-1 spoke tension meter and started measuring.

- "Initial (2 rides)" is the spoke tension after these two rides. It was all over the place with many spokes having no tension (max deflection).
- "Rebuild, as received" is after I sent them back for repair, received them but did not ride them. I only measured the tension without tires/tubes.
- "Rebuild, as received, 5 weeks later" is the same but I measured them again after sitting in my garage for 5 weeks without tires or any kind of use.
- "Rebuild, 1 ride" is after setting them up and going on a 30 mile flat recovery ride.

Observations:
- After receiving them and measuring them the first time (after 2 rides) the spoke tension was all over the place
- After sending them back the tension was higher but the standard deviation was still high. Supposedly an excellent builder who made them yet I will disagree with that based on my data...
- A little bit of spoke tension loss in the rear wheel just by sitting in my garage (5-7%, could just be measurement error)
- Significant spoke tension loss after one ride (8-16% in the front, 20-25% in rear).

Any ideas what could cause such changes? Charts show averages and error bars are standard deviations. Wheels are disc wheels, 24 spokes, bladed steel,1mm x 2.16mm.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 29, 19 16:44

Post #2 of 20 (2056 views)

I can relate some totally-not-bike-wheels (but on a wheelset with 20+tonnes on it...).

After the initial install / tightening if bolts (spokes in your case) we found that after a week ish, the end load (tension) in bolts actually reduced slightly (5% or so sort of vskue reduction). That's before a wheel had turned. It was from some localised bedding in / yielding of the material (= your rim material in your case under the spoke nipple). Then after they went into service and moved, they lost a few % more in the 1st few days, but then eventually stabilised. Again more localised yielding of the contact area ie between rim and spike nipple in youe case).
In our case the end load in the bolts was super critical - if a bit of end load was reduced (not totally lost ie not loose) it resulted in more movement and a fatigue failure of the bolts (spokes break in your case)

Why variable across spokes? Id guess there are residual stresses in the rim and they are 'coming out' when yoyve ridden.

Re: What's going in with my wheels (+ I'm an idiot) [BobAjobb] [ In reply to ]

Jun 29, 19 18:29

Post #3 of 20 (1948 views)

Yes, I understand that but the level is very different in this wheel set. First time I measured the tension the front wheel had 5 spokes with zero tension while the rear wheel had 8. That's a clear sign of a serious issue with the build, well beyond just some stress relaxation And to see a reduction in tension of 20-25% after a 1.5h easy ride is also totally unacceptable and would never happen with any other wheel.

I've got various other wheels including Hed, Flo, and many made by Wheelbuilder.com and while I don't have any data from what they were first like when I just got them, they have all been very reliable and show excellent spoke tension uniformity when I measure them now after many years of use. They never showed this phenomenon of becoming untrue after 30 miles and having 13 spokes lose ALL tension on them. In fact none of them have ever needed truing at all whereas this set goes well beyond the need for truing (it needs repair) after only one short easy ride.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 29, 19 18:31

Post #4 of 20 (1945 views)

Garbage in Garbage out.

Re: What's going in with my wheels (+ I'm an idiot) [turningscrews] [ In reply to ]

Jun 29, 19 18:32

Post #5 of 20 (1940 views)

turningscrews wrote:

Garbage in Garbage out.

Meaning what, in this case specifically?

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 29, 19 18:56

Post #6 of 20 (1916 views)

Benv wrote:

turningscrews wrote:

Garbage in Garbage out.

Meaning what, in this case specifically?

Means if you have shit quality parts and/or shit quality builder, you end up with shit.

Re: What's going in with my wheels (+ I'm an idiot) [SBRcanuck] [ In reply to ]

Jun 29, 19 19:01

Post #7 of 20 (1909 views)

SBRcanuck wrote:

Benv wrote:

turningscrews wrote:

Garbage in Garbage out.

Meaning what, in this case specifically?

Means if you have shit quality parts and/or shit quality builder, you end up with shit.

I agree with you for sure - but trying to figure out exactly which parts are shitty, based on the experienced behavior and if there is a way to fix it. If I take them to a reputable builder like Rich at Wheelbuilder, could I expect the problem to be gone or is it gonna be one where it will need all new spokes and nipples and a ton of $ and no guarantees?

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 29, 19 19:05

Post #8 of 20 (1901 views)

Well part of the issue with asking that question is that you haven't stated what brand hubs, spokes and rims you have. So its kind of impossible for anyone to give you an accurate answer!

The hubs probably aren't the issue (they could be crap, but likely wouldn't cause the spoke tension issues).
The rims could potentially be causing problems if they aren't true, issues with the spoke drillings, etc.
The spokes might be cheap and possibly damaged or stretched depending on how bad your wheelbuilder was.

So yeah you could send them away to be rebuilt, but at a minimum the builder would probably insist on using fresh spokes of good quality. And could possibly tell you your rim is crap and can't be built properly.

Re: What's going in with my wheels (+ I'm an idiot) [SBRcanuck] [ In reply to ]

Jun 29, 19 19:48

Post #9 of 20 (1857 views)

SBRcanuck wrote:

Well part of the issue with asking that question is that you haven't stated what brand hubs, spokes and rims you have. So its kind of impossible for anyone to give you an accurate answer!

The hubs probably aren't the issue (they could be crap, but likely wouldn't cause the spoke tension issues).
The rims could potentially be causing problems if they aren't true, issues with the spoke drillings, etc.
The spokes might be cheap and possibly damaged or stretched depending on how bad your wheelbuilder was.

So yeah you could send them away to be rebuilt, but at a minimum the builder would probably insist on using fresh spokes of good quality. And could possibly tell you your rim is crap and can't be built properly.

I have no idea what brand of rim, spokes, nipples are used.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 29, 19 20:25

Post #10 of 20 (1814 views)

The spokes should have a maker's mark on them.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 30, 19 2:18

Post #11 of 20 (1687 views)

So that definitely points as poor quality spokes and/or rims. In either terms of just the basic strength being low, or that (almost worse) there is a large variation between each - so for example one spoke stretches more than another for what are supposed to be the same parts.
Or the rim material isnt consistent all the way around the hoop - again just plain poor quality of manufacturing.

Re: What's going in with my wheels (+ I'm an idiot) [BobAjobb] [ In reply to ]

Jun 30, 19 4:45

Post #12 of 20 (1617 views)

1. Take them apart.
2. Post as an unbuilt wheelkit in the classifieds.
3. Buy a set of used Heds or Flos.

***

Re: What's going in with my wheels (+ I'm an idiot) [jimatbeyond] [ In reply to ]

Jun 30, 19 6:21

Post #13 of 20 (1560 views)

jimatbeyond wrote:

The spokes should have a maker's mark on them.

I looked for it but no mark. Guess that means they're unlikely to be Sapim or DT Swiss.

Re: What's going in with my wheels (+ I'm an idiot) [M----n] [ In reply to ]

Jun 30, 19 6:25

Post #14 of 20 (1555 views)

M----n wrote:

1. Take them apart.
2. Post as an unbuilt wheelkit in the classifieds.
3. Buy a set of used Heds or Flos.

I can't do that - I don't want to be selling junk or a potential safety hazard to anyone in good conscience. Worst case scenario I take them apart, buy all new spokes and nipples and use these to learn to build wheels myself.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 30, 19 7:58

Post #15 of 20 (1489 views)

Benv wrote:

Any ideas what could cause such changes? Wheels are disc wheels, 24 spokes, bladed steel,1mm x 2.16mm.

Spokes loose tension because something in the system yields (permanently deforms); the spokes themselves, nipples, rims, or hub. Installing a tire and inflating it also compresses the rim and reduces tension if it's a shallow rim. I built wheels for a living for about 10 years. Once I got wheels up to tension I'd perform at least 3 rounds of stress-relieving (over-stress), and retension, retrue and balancing. On cheap wheels I suspect they just bring them near proper tension and make sure the wheels are true and call it good. These will loose tension and come out of true later.

Since you have Park tool, get the proper spoke wrench and spoke holder and do it yourself.

Also, check the tension a few times so that you don't know which spoke is which until you've finished. That will give an idea of your measurement taking variability.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 30, 19 8:01

Post #16 of 20 (1483 views)

This old saying still holds true: "If you want something done right, do it yourself."

It's not hard to adjust spoke tension for the entire wheel. You already have the Parktool TM-1, so now all you need are a spoke wrench and a dish tool since adjusting spoke tension will likely make your wheel slightly out of true and possibly out of dish. You can use your bike as a truing stand if you don't want to fork out money for one. Just adjust your brake so the brake pads barely clear the brake tracks if you are on rim brake or tape a pencil to your fork pointing at the rim outer edge if you are on disc brake.

You will need to learn how to true a bicycle wheel if you don't already know it. It's fairly easy (and gratifying), and there are tons of references out there. This valuable skill will save you a lot of time and money in the long run. There is no need to waste time and money in shipping the wheels back and forth.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 30, 19 9:56

Post #17 of 20 (1422 views)

Over the last few years, I've built up a lot of wheels using open mold rims (testing for possible OEM use). I've had similar experiences with some of the samples. The last set of rims I tested were the worst I've ever seen, and were very similar to what you described. When brought up to tension evenly, the wheels looked like potato chips. The only way it would have been possible to get the wheels true was to have extremely uneven tension. The spoke bed didn't feel solid (possibly voids, or damaged fibers?) and some spokes would lose tension overnight. The layup appeared to be very inconsistent, the spoke bed depth varied by a couple of mm, which gave the appearance that I had randomly used different length nipples. At the end of testing, we disregarded spoke tension and just got the wheels as true as possible to see what happened, and ended up with spokes that had little or no tension, while others were at the highest recommended tension.

"I'm thinking of a number between 1 and 10, and I don't know why!"

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 30, 19 10:44

Post #18 of 20 (1381 views)

Probably the wheels were built by a robot and had a lot of wind up at the spokes so when you rode it the first time the wheel was stress relieving itself. You can either just re true or loosen up all the spokes and retention and stress relieve the wheel properly. Any competent bike shop should be able to do this. I doubt there's anything awful about the wheel.

Last edited by: jroden: Jun 30, 19 10:46

Re: What's going in with my wheels (+ I'm an idiot) [jroden] [ In reply to ]

Jun 30, 19 12:19

Post #19 of 20 (1325 views)

jroden wrote:

had a lot of wind up at the spokes so when you rode it the first time the wheel was stress relieving itself.

That isn't stress relieving, that's just spokes unwinding.

Since the spokes are bladed, I doubt they had any wind up.

Re: What's going in with my wheels (+ I'm an idiot) [Benv] [ In reply to ]

Jun 30, 19 12:27

Post #20 of 20 (1310 views)

The Park TM-1 isn't exactly the most accurate of measuring devices, even moreso depending on how you use it, so you're on a loser before you start.

My money is on the no-name semi bladed spokes; from experience they're normally as stiff as wet spaghetti, or too long.
Better off starting from scratch with a quality round spoke provided there's no rim damage and rebuilding.

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