Weight Weenies

I've emailed the same question to P-x, but haven't heard back, so I thought I'd ask you guys for your opinion:
I picked up a set of Planet X 50mm's on sale a few weeks back. They were delivered this week, look very nice and fairly light, but I was a little dissapointed with their trueness. There's a small but noticeable wobble (particularly in the front wheel), and running them in the trueing stand they are out of true by a couple mm's.

Is this normal for cheaper carbon wheels, as in you get what you pay for, or is this not acceptable? Or could this have happened during transport?

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It sounds like there could be a few things going on. First, the wheels were not properly stress relieved. After sitting in a box for a bit, the spokes may have settled causing the hoop to go out of true. The other possibility is that the builder who did it simply thinks that a few mm's is an acceptable tolerance. Either way it sounds like a lack of effort on the builders part.
Regardless of whether its an Enve or a cheapo carbon rim, you should be able to get your tolerances well under a mm with not too much struggling.

Mhmh ok, what would you advise? Try to true them myself, or return them? I have no problems trueing 32spoke handbuilds, but have no experience with working on low spoke count carbon wheels..

thanks

Couple mm's? That sounds like a lot. Some carbon hoops tend to be a tiny bit out of true, but not that much.

I would wait for a response from the seller before having them trued of truing them yourself.

Maybe a couple of mm's is a little overstated, but they're definately visibly out of true, at least by 1 or 2mm.
I'll wait to hear what the seller says, even though I'm eager to try to sort it out myself, glue a pair of tubs and ride 'em

Grimpeur wrote:Maybe a couple of mm's is a little overstated, but they're definately visibly out of true, at least by 1 or 2mm.

1/2 mm is easily visible.

If you know how to true wheels, you can stress relieve them and true them yourself... if that is less hassle than sending them back. If they can be made true with even tension, then they are likely fine. If not, then send them back.

Even 0.4mm out is visible. The carbon rims I have seen have been ~0.7mm out of the box. Take them to a shop that has dial guages on there jig and get the roundness and lateral runout you may find ity is less than you think. If you are near Glemsford Suffolk I will do it for you.

If it is out of round you need to re centre the hub by adjustiong spokes causing the hop and opoosite the hop so you re- centre the hub. Carbon rims are so stiff that this need to be done. Truing laterally is just the same as any other wheel but each spoke will have more of an effect. Getting carbon rims as straight as alloy rims is hard as you can get to the point of chasing a wobble around the rim. Carbon rims especially the cheaper ones are not as straight as a good quality alloy rim.

Does this make sense?

0.7mm lateral/radial should be doable.

Also this is why many shops see Planet X wheels for repairs becuase of there poor build.

As a reference point for roundness & side to side, you could do worse than referring to http://lightweight.info/gb/en/service & clicking on the roundness & side to side headline on Q&A. Basically under .5mm (but they do not say +/- which could mean they are saying 1mm overall).

If you read thru the wheelbuilding thread the consensus on tolerance was around .5mm on side to side and 1mm in round (albeit most people reckoned it would be impossible to notice 1mm in the round if it was there).

Make sure you get PX to confirm they will cover the cost of insured postage there & back if there is proven defect. Make sure you have photos of the box that got delivered to you to prove no damage in delivery (if that is the case). It would be sensible to make a video of the problems before you send them off - otherwise you no longer have any info to prove the defect was there in the first place & then you will get hit for the courier costs if they get argumentative.

If you can get the tensions looked at (& the deviations between tensions on each side of the build) you should do - there may be an underlying problem.

Grimpeur wrote:Mhmh ok, what would you advise? Try to true them myself, or return them? I have no problems trueing 32spoke handbuilds, but have no experience with working on low spoke count carbon wheels..

thanks

It sounds like you are quite capable of truing your own wheels. In that case, I say dive right in.
I don't want to generalize here, but I have heard quite a few horror stories about these chinese carbon hoops and warranties. I guess that would be worth a shot too though.

Thanks for the confidence, I need to buy a hex wrench for internal nipples at some point anyways, so might as well put it to use right away .

You may be right about the warranty part though, I got a reply saying "they can be 1-2mm out, but generally we don't have any problems with them".

Maybe I'm just being picky, it's not as if the wheels aren't rideable with this deviation. It just feels better to have them as straight as possible before tubs over the spoke holes .

The rims look real nice though, even when looking inside the spoke holes, so I don't suspect a problem with the rim itself..

You pretty much get what you pay for when it comes to generic carbon wheels. I have heard that the wheel manufacturers shoot for up to 1 mm lateral runout. I have several wheelsets from Campy, Mavic, Easton, Hed, Ligero, and Shimano and you can see a slight runout which looks to be maybe 0.5 mm. One wheelset I have looks to be close to 1 mm. You shouldn't accept >1.0 mm runout for road wheels, as it's shoddy workmanship.

To their credit, I've measured 4-5 Shimano wheelsets with dual dial indicators and they all look to be <0.3 mm lateral and <0.3 radial runout. Pretty impressive for factory wheelsets. Or more correctly, handbuilt wheelsets from their factory in Malaysia. One wheelset is the WH-R560, an Ultegra wheelset which I bought for $165, and those tolerances are after four years of use!

Some noobs on RBR say the wheelset should have 0.1 mm runout but come on. Maybe if you are a pro wheelbuilder and you dedicate enough time to build your own private wheelset to those tolerances for you or a friend. But not if you are in a factory and have to build so many wheelsets in a day.

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How appropriate that this is my first post here then

I work wheel assembly, and our maximum tolerance going out the door is 0.5mm radial, 0.3 lateral. Most wheels I build come out to 0.3mm radial and 0.1mm lateral. Given good rims, it's not that tough to get the lateral to at least 0.2mm.

Then again, my supervisor is constantly pushing me to get faster. So there definitely is a push-pull with quality vs. efficiency.