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Burn baby, burn.
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Discussion Starter · #1 · (Edited)
Just thought some of the wheel-builders here might be interested in my recent experience with Pacenti.
In mid-September, 2018 I purchased a wheel-build kit from Brandon at Bikehubstore which included their SL hubs, Sapim CX-Ray spokes and the Pacenti Forza rims.
I built these up according to the tensions listed on the Pacenti website, and with even tension according to my Park tension meter (yep, I know all tension meters can have some variances).

Wind forward 9 months and 4,000km, and I find my Forza rear rim has multiple cracks around the spoke holes so I reach out to Brandon who advises me that based on past experiences with Kirk he will send me a replacement rear rim. Soon after I got another email from Brandon saying that the new owners of Pacenti had advised that they would manage the warranty replacement from their end.

After some questions about my spoke tensions and requests for pics and additional information it was agreed that they would send me a replacement rim (which is great), but here is the reason for my post. Luke from Pacenti provided the following reason for the rim breakage, which I believe may impact many wheelbulders who use the Forza rim (or are considering it).

Stephen

Brandon confirms the kit was sold with CX-Ray spokes. We and our best wheel builders disagree with Brandon on this subject. We find that the CX-Ray spoke is not compatible with this rim and hub combination. We build all our wheels with D-Light spokes. Both our independent whee building contractors agree that the d-light spike builds the best rear wheel. I would like to replace you rim and have asked Brandon to supply d-light spokes for your rebuild.

This should give you a long lasting wheel that will ride much better.

Kind regards

Luke
So be aware that if you intend to use Sapim CX-Ray spokes, your wheels may not be covered by Pacenti's warranty.

Just FYI. Brandon has been awesome to deal with and has done everything he could to assist me.
I would 100% recommend buying from Brandon and will do so in the future should the opportunity arise.
 

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'brifter' is f'ing stupid
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Great customer service...

But it's complete BS that the type/brand of spoke used would cause this. Same w/ a wheel having a 'much better ride' because it's built w/ one brand/type of spoke instead of another. Tension is tension. The spoke never touches the rim, the nipple does. I'd love to see the data behind this claim.
 

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I would think elasticity of the spoke would impact spoke hole cracks so it doesn't sound like BS to me.

But I could swear I've read CX Rays are one of the more elastic spoke out there.

Either way, that's absurd.
 

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'brifter' is f'ing stupid
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Elasticity? There's over 100kg of tension on a finished wheel, you don't want any elasticity. You want the spokes and thus the tension to be as stable as possible. That's what keeps a wheel round and straight. Complete BS.
 

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First of all, the tension is exactly the same for CX-Ray or the biggest spoke that will fit through the hole.
And if the elasticity of the spoke makes any difference, a more elastic spoke will absorb shock.

And here is the word from the man, Kirk Pacenti, himself.

Mon, Aug 27, 2018 at 1:21 PM, xxxxxxxx wrote:

Hi Kirk,
I am curious, what is the reason for D-Light spokes on the rear? Stiffness? Cost?


On Mon, Aug 27, 2018 at 1:24 PM, Kirk Pacenti wrote:

Stiffness.

Or, at least balancing weight and stiffness. Lighter than Race spokes, stiffer than CX-Ray / Laser spokes


Best regards,

Kirk A. Pacenti
And for the record, thousands of Forza wheels have been built with CX-Ray spokes. This is the only reported failure that I know of.
 

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First of all, the tension is exactly the same for CX-Ray or the biggest spoke that will fit through the hole.
And if the elasticity of the spoke makes any difference, a more elastic spoke will absorb shock.

And here is the word from the man, Kirk Pacenti, himself.
yeah, that was my point. Or more specifically be a bit more forgiving on pulling on the spoke hole and nip interface.

A spoke that results in a stiffer wheel (less elastic) would do the opposite I think.

So from what I can gather D-lights are suggested for wheel stiffness (per Kirk) and the dude in the OP BS'd him by saying not using them is the cause of rim cracks. When in reality CX-Rays, if anything, would be BETTER at preventing rim cracks.
 

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No idea, but I'm glad I never bought any Pacenti Rims. Bike Hub Store is my "go to" for all Wheel components and Brandon has never steered me wrong in all the years I've known him.
If I were him.....I'd drop Pacenti products immediately.
 

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Burn baby, burn.
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Discussion Starter · #11 ·
Curious then as to why BHS site shows this for the Forza Rim: https://www.bikehubstore.com/product-p/forza.htm . If so great, why discontinued and offering prior purchasers a 15% discount on a substitute rim?
I will hazard a guess it is due to my experience and Pacenti's blame game outlined above.
Brandon is not impressed with what has occurred and has stated this very clearly in a number of emails that he has sent to me.
 

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The main reason I have heard is that sales have been too slow lately, and not just for BHS. Which is a shame because it is one of the best alloy rims out there. I consider it in second place behind HED, with HED mainly winning on style. I prefer the asymmetrical design because spoke tension really is better.
 

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. I have never had a failure and this is the only problem with nipple cracks Brandon has seen, and Pacenti has sold thousands. The Forza quality, durability, and weight is on par with HED. Which is the best alloy rim there is.
You might be right. But after hearing the same thing about the SL23 over and over, until the reports became to frequent to ignore, and now to see the problem was 'fixed' by making a design that apparently can not be used with the most common and popular spoke on the market I'd think it pretty easy to understand why Chbrad is just glad he never bought any of their rims.
 

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Burn baby, burn.
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Discussion Starter · #14 ·
You might be right. But after hearing the same thing about the SL23 over and over, until the reports became to frequent to ignore, and now to see the problem was 'fixed' by making a design that apparently can not be used with the most common and popular spoke on the market I'd think it pretty easy to understand why Chbrad is just glad he never bought any of their rims.
TBH I have had the "we have never seen any failures of this type before" from many bike manufacturers. The best example of this was my experience from Niner bikes. I had 2 breakages of their Jet9 before they suddenly and without warning made a global recall of the model.
 

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So I figured I would though my two cents into the mix to try and bring as much objectivity to this discussion as possible. First off, I do not agree with the notion that the CX Ray spoke choice had anything to do with the rim failure. The rim failed most likely do to either metal fatigue or simply porosity within the extrusion. The later does happen from time to time and is not caught as it requires qc to x ray of the product.

Now onto the spokes:

Regarding the pulling force transmitted to the rim through the nipple. There is a miss understanding that the vertical force applied to the rim will transmit directly through the spokes and therefore back into the rim with no loss of energy however this is not the case (unless the lacing pattern in radial in nature). By introducing a crossed lacing pattern the force is dissipated due to the cantilevered angles and therefore removing some of the energy passed through the wheel.
Next, tensile strength. The CX Ray spokes have one of the highest tensile strengths available in this gauge. That means the notion of elasticity being one of the reasons the CX Ray would have caused this rim to fail is silly.
When not to use CX Ray spokes. despite having one of the highest tensile strengths out there, they do not resist lateral forces well due to there narrow cross section. Therefore, if the rim you are using lacks structure i.e. width or depth and/or running a low spoke count and finally you are a heavier rider then these spokes are probably not for you. The other reson to not purchase them is for durability. The way one of the smallest / lightest spokes is able to achieve such a high tensile strength is due to the hardness of the alloy and the work hardening the alloy goes through to achieve its shape. So hard and lots of movement equals failure. So if you want a super durable build steer clear of these types of spokes.
Lastly, what type of spoke can lead to a rim failure? The shorter the spoke the steeper the angle of attack is between the rim and the hub i.e. supper deep carbon rims. Given that the nipples do not articulate enough to compensate for this extreme angle (do to the need for the nipple to be accessed for the back end) this causes allot of stress at the rim. That being said, any super stiff spoke such as Sapim Strongs of DT Alpines which are both made from the same higher grade stainless alloy as the upper end spokes such as CX Ray's but are larger in diameter over there entire length. This is a where a softer alloyed Sapim Leader or smaller diametered Race, Laser, CX Ray or yes even D Lite's would work better.

To conclude, I believe the Pacenti Forza rim is one of the better ones given its dimensions and should still be considered for your builds however not with CX Rays. I know it flies in the face of all that I have said but when a manufacture states something like this and you have an issue not related to the spokes then you have no legal standing in case of injury. Please note, If in the future Pacenti rims are removed from our site it is not due to there quality but simply do to a lack of ability on our part to exclude builds with CX Rays.
 

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!! I'm coming out of Forum retirement for this one. I got tipped off that a load of bullshit was being spread at RBR and that the new Pacenti people had thrown good ol' Brandon at BikeHubStore under the bus. The Pacenti people claim that it was Brandon's fault for specing CX-Rays for a Forza rim build that led to the cracked nipple holes. And they did this without any reasoning, let alone any proof.

I'm no engineer but if they can have an unproven opinion then so can I. I would think that the "elasticity" of thinner gauge spokes like CX-Ray and Laser would lead to LESS spoke hole cracking, not MORE. It's been long opinionated that straight gauge spokes would tend to absorb less shock and therefore transfer it to the rim and hub flanges.

I see that Brandon made the wise move of cessation of dealings with Pacenti -
https://www.bikehubstore.com/product-p/forza.htm

What the hell else is he going to do? You don't throw a good customer like Brandon under the bus when he's sold thousands of their product. And if he thought for one second that a certain spoke was contributing to rim cracks, I'm damn sure he would stop specing that spoke and offer compensation in a heartbeat to anyone affected.

That frikkin does it. I've been running v2 of the P-word rim for the last 3-4 years even though the rear rim's plug has rattled since Day 1. I'm just too lazy to fix it. But I'm gonna support the most honest retailer I've ever dealt with and get a set of rims & spokes that he recommends for my beautiful DuraAce hubs. Harrummpphh. That'll lern 'em eh? Ok, back to retirement................
 
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