Carbon Frames

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Ivanerrol
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Carbon Frames

Postby Ivanerrol » Fri Aug 31, 2018 9:16 pm

Checking the end of year bike sales, I saw some opportunities to pounce.

Cannondale Synapse at my size at bargain price.

Put down my money, went to pick up the bike but did a few rounds around the block to make sure things were right.
Strange noises from the bottom bracket area. Workshop boys made some adjustment and out for another ride. Same noises.
These noises weren't really apparent during the test ride.

Shop manager came out and we had a round table discussion.
Did I mention I'm 189cm and 105 kilos?
Consensus was : My riding style put too much pressure on the bottom bracket. This bike was not for me.
I volunteered to try a different bike - it might have been that particular one I picked up.
The shop manager stated that other models of the Synapse were likely to have the same problem

Changed tack: Plan B which was my preferred route in the first place. Very good price on a Wilier GTR Team Disc.
Sized that up, set it up. Took it for a test ride and all was well.

Put some more money down and took the bike home.

Book of instructions.

Image

My weight - 105 kg, Bike weight with wheels - 10 kg, load 2 - 3 kilos.
Total hovering around 117 - 118 kilos. :roll:

Interesting discussion I will have at the LBS tomorrow. :?

According to the Specialized site the Roubaix's overall weight limit is 109 kilo's.

Obviously you need to be very careful when making the decision to buy a carbon frame. Warranty's may not be honoured in the event of frame damage.
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Duck!
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Re: Carbon Frames

Postby Duck! » Fri Aug 31, 2018 9:28 pm

The Cannondale's noise is more likely due to its BB30 bottom bracket format, which is known to be noisy, but not an indication of any stuctural flaw in the bike or anything you're doing.

The Wilier note says "built and tested based on...." That does not say "thou shalt not weigh more than...." There will be a considerable margin of safety engineered in; it's not going to spontaneously splinter under you (carbon doesn't do that anyway).
I had a thought, but it got run over as it crossed my mind.

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Ivanerrol
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Re: Carbon Frames

Postby Ivanerrol » Fri Aug 31, 2018 10:22 pm

The BB30's shortcomings were discussed. It was reasoned the noises would only get worse as the bike gets used.
The Manager was not convinced that I wouldn't be back in a shortish period with a creaking BB.

I have checked Wilier's site. There is nowhere on that site any information on over loading their tested weights except to say that doing this will shorten the life of the frame. Whether or not some warranty claim arises for some spurious reason later is rejected or not is interesting.
There is a consumer technical support section at Wilier. But, at the moment it's down. :roll:
If and when it rejuvenates itself I'll send them a request for information on warranty and over loading their testing criteria.

Here is the disclaimer from the Specialized site: FRAME STRUCTURAL WEIGHT LIMITS

WARNING! Failure to follow these instructions and exceeding the specified Structural Weight and Cargo Limits may impair the structural integrity of the bicycle and may cause serious personal injury or death. For riders at the Rider Weight Limit, you may not be able to carry cargo if the Structural Weight Limit is exceeded


That seems to be pretty clear to me. Even though it's a Cover thy A*se statement
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Ivanerrol
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Re: Carbon Frames

Postby Ivanerrol » Sat Sep 01, 2018 9:18 pm

So, I went down to the LBS and spoke to one of the store managers.
I showed him the User manual and the above statement.
He had to admit that he didn't understand what the statement was trying to say.
I don't know what that means! :?


To us engineers it's a simple statement - a product has been designed with a specific design tolerance.
If you exceed the design spec there could be consequences.

Specialized and Cannondale prophesies death or destruction if you exceed their stated weight design limits :shock: :roll:

The manager made the point that replacement frames have never been knocked back by manufacturers in the event of structural failure and a warranty claim. Most rejections are due to accident damage or misuse.
As also noted by others - it's the wheels to be more concerned about.
More spinning - less grinding.

Meanwhile, a carbon frame bicycle of any type needs to adhere to the manufacturers recommendations to achieve a tolerable lifetime.

Have a read through this PDF from Specialized. https://media.specialized.com/support/0000057489/0000057489.pdf.

If you are to buying a carbon frame bike there's much interesting information there. Cannondale has a similar publication.
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Re: Carbon Frames

Postby trailgumby » Sat Sep 01, 2018 9:46 pm

Motivation to shed some weight? ;)

I had a similar issue a few years back with some lightweight Mavic XLR cross country mountain bike wheels. I discovered I was more than 15kg over the combined weight limit. Like you, it pissed me off that this weight limit "detail" was buried in a technical document on the dealer website that I stumbled across in a google search, but was otherwise unavailable to consumers prior to purchase.

Long story short, I took the wheels off and used them as "Race Day Only" wheels, and went back to a heavier set for general riding and training.

The consequence of exceeding the weight limit was they needed continual attention to re-truing after use, pretty much after each race.

I am no longer a Mavic customer.

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Re: Carbon Frames

Postby Duck! » Sun Sep 02, 2018 6:41 pm

Ivanerrol wrote:The BB30's shortcomings were discussed. It was reasoned the noises would only get worse as the bike gets used.
The Manager was not convinced that I wouldn't be back in a shortish period with a creaking BB.

No more likely than if it was an aluminium frame with BB30 bottom bracket; the BB30 system has a machined groove around the inside of the bottom bracket shell near each end, into which a circlip is fitted, which the bearings are then pressed against. This system by its design dictates that carbon BB30 frames have an aluminium liner sleeve bonded into the frame. BB30s well-documented flaws are utterly due to the system design, and absolutely not related to the frame material. It is possible that over time the liner sleeve can debond from the carbon frame, but this is very, very rare.
I had a thought, but it got run over as it crossed my mind.

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Ivanerrol
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Re: Carbon Frames

Postby Ivanerrol » Mon Sep 03, 2018 8:03 pm

It was a carbon frame but it's all moot now as I whipped away the Wilier.
The Wilier with a BB7421B bottom bracket which I assume is probably made from unobtanium.

The point here is that the bike shops have a great array of frames on display. The vast majority of road bikes and a good many other types are carbon. There are the odd few alloy frames which are usually hidden away in the rear. One shop I went into only had one alloy frame in stock.

The sales guys should be making prospective purchases aware of the limitations of carbon and for what it matters light weight aluminum frame bikes.
As described in detail in the user manual appendices of many manufacturers.
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Mububban
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Re: Carbon Frames

Postby Mububban » Mon Sep 03, 2018 11:55 pm

Ivanerrol wrote:It was a carbon frame but it's all moot now as I whipped away the Wilier.
The Wilier with a BB7421B bottom bracket which I assume is probably made from unobtanium.

The point here is that the bike shops have a great array of frames on display. The vast majority of road bikes and a good many other types are carbon. There are the odd few alloy frames which are usually hidden away in the rear. One shop I went into only had one alloy frame in stock.

The sales guys should be making prospective purchases aware of the limitations of carbon and for what it matters light weight aluminum frame bikes.
As described in detail in the user manual appendices of many manufacturers.


I would have thought any knowledgeable and ethical LBS sales person would know of a rider weight limit and could discretely ask a potential buyer what their weight is. Did they really not know or just not care and want to make a sale regardless?
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Ivanerrol
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Re: Carbon Frames

Postby Ivanerrol » Wed Sep 05, 2018 10:25 am

Mububban wrote:
I would have thought any knowledgeable and ethical LBS sales person would know of a rider weight limit and could discretely ask a potential buyer what their weight is. Did they really not know or just not care and want to make a sale regardless?


Not this place. Get stock off the floor and out of the warehouse. Those in Melbourne are probably aware of this very large LBS
Having said that price was at a serious discount. So Caveat Emptor :roll:

I was discussing this issue at another LBS.
Owner did say that he is very wary of selling inappropriate bikes to those "Gravitationally challenged).
He might lose a $200.00 commission on a sale but the warranty grief later on more than overcomes the initial profit. He does make up his own bikes. He did say that casually mentioning the need for a custom bike to some prospective customers is hit and miss
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Re: Carbon Frames

Postby g-boaf » Wed Sep 05, 2018 11:52 am

Ivanerrol wrote:The BB30's shortcomings were discussed. It was reasoned the noises would only get worse as the bike gets used.
The Manager was not convinced that I wouldn't be back in a shortish period with a creaking BB.



There are alternatives to that bottom bracket that can be installed, and those should eliminate the creaking. I have a bike with your noted style bottom bracket and it never creaks.

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Ivanerrol
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Re: Carbon Frames

Postby Ivanerrol » Wed Sep 05, 2018 3:43 pm

g-boaf wrote:There are alternatives to that bottom bracket that can be installed, and those should eliminate the creaking. I have a bike with your noted style bottom bracket and it never creaks.


True if you don't worry about the warranty.
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Re: Carbon Frames

Postby Duck! » Wed Sep 05, 2018 3:52 pm

Nothing to do with warranty, they don't modify the frame.
I had a thought, but it got run over as it crossed my mind.

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