Carbon Ti dissapointment

Back by popular demand, the general all-things Road forum!

Moderator: robbosmans

Post Reply
User avatar
wheelsONfire
Posts: 6280
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

You guys with this "issue", are all of you on Farsport rims and disc brake setup?
Bikes:

Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)


Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



Pugrot
Posts: 74
Joined: Wed May 12, 2010 11:52 am

by Pugrot

cberg wrote:
Fri Oct 15, 2021 10:21 pm
Saw this thread and didnt think anything of it, about 15000 km with no problems. Then out of nowhere while standing in my living room my bike made a loud noise like when a tire sets into the rim and this was the result:
billede_2021-10-15_231610.png

Back to DT Swiss for my next wheels I guess :|
These were also with Farsports rims
Looking at your spoke head....it seems to have 'pillars'? Like it is not a smooth conical surface? That would definitely make for a stress concentrator. Can you confirm?

Look at straight pull spokes online and they are usually smooth cone heads...

Pugrot
Posts: 74
Joined: Wed May 12, 2010 11:52 am

by Pugrot

Delete double post

cberg
Posts: 318
Joined: Wed Jan 13, 2021 11:30 am

by cberg

Pugrot wrote:
Sat Oct 16, 2021 11:37 am
cberg wrote:
Fri Oct 15, 2021 10:21 pm
Saw this thread and didnt think anything of it, about 15000 km with no problems. Then out of nowhere while standing in my living room my bike made a loud noise like when a tire sets into the rim and this was the result:
billede_2021-10-15_231610.png

Back to DT Swiss for my next wheels I guess :|
These were also with Farsports rims
Looking at your spoke head....it seems to have 'pillars'? Like it is not a smooth conical surface? That would definitely make for a stress concentrator. Can you confirm?

Look at straight pull spokes online and they are usually smooth cone heads...
The shape of the head is definatly conical :) The spokes are CX-Rays, so I highly doubt those are the issue

cberg
Posts: 318
Joined: Wed Jan 13, 2021 11:30 am

by cberg

Some iPhone close ups of the part that broke off. Seems to have some wear marks around where the head sits imo
BC6539E0-B89E-438A-B3A3-28D37CE19566.jpeg
2B6138C7-4F4F-4232-B74A-9FF6F070E098.jpeg

Kingstonian
Posts: 38
Joined: Sat Jun 27, 2020 11:59 am

by Kingstonian

Damn, that's not good

User avatar
Mr.Gib
Posts: 5548
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

The finish and countersink of the hole seems very rough. That could be the issue right there. I've got two wheelsets on Carbon Ti, both rim brake. Neither have very many miles. One Farsports, one LB, (and a second LB disc set on the way). Fingers crossed.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

cberg
Posts: 318
Joined: Wed Jan 13, 2021 11:30 am

by cberg

Mr.Gib wrote:
Sun Oct 17, 2021 6:44 am
The finish and countersink of the hole seems very rough. That could be the issue right there. I've got two wheelsets on Carbon Ti, both rim brake. Neither have very many miles. One Farsports, one LB, (and a second LB disc set on the way). Fingers crossed.
Tbf some of it is just dirt from riding in all weather :!:

romanmoser
Posts: 573
Joined: Sun May 06, 2018 8:30 pm

by romanmoser

Have the same issue exactly on the rear ( drive side flange broke ) .
And it's beginning to crack in a longitudinal way next to a spoke for the front hub.

No farsports rims but boyd altamont lite rim brake rims. Bought nearly new second hands for cheap ( the price of the hubs new ) so 1/3 of what the first owner paid. Wheels were build by wheeltec nl, a quality wheelbuilder quite renowned in nederlands.
I put 5 to 6000Km before it broke; the first owner 1500 2000km I think

20 spokes front sapim cx super ray
24 rear mix of cx super ray , and cx ray '' classic "
wheels were really nice

been in contact with carbon ti
and they have been very responsive , I should finish the procedure and get replacement hubs from carbon ti it seems
don't think the wheels were badly buid , or overtensionned, i am 65 to 68kg 1m88 height , rode them in belgium and portugal.
me think it's a corrosion issue al7075 or lack of material .

will update you

jff
Posts: 22
Joined: Sun Aug 08, 2010 10:33 am

by jff

romanmoser wrote:
Mon Oct 18, 2021 11:09 am
been in contact with carbon ti
and they have been very responsive , I should finish the procedure and get replacement hubs from carbon ti it seems
don't think the wheels were badly buid , or overtensionned, i am 65 to 68kg 1m88 height , rode them in belgium and portugal.
me think it's a corrosion issue al7075 or lack of material .

will update you
Did they mention if it is a fabrication/material issue or is it a design flaw of the hubs? If you get replacement hubs and the same design as the original, it is likely to occur again, no?

User avatar
nickf
Posts: 1427
Joined: Sat Mar 06, 2010 10:34 pm

by nickf

Here are some pictures of my two rear hubs. First hub 3 flanges went. This latest hub was one flange and I just noticed a crack on another. Like I said carbon ti sent a replacement quickly. Carbon Ti stands by over tensioning being the cause when I was communicating with them

The latest warranty replacement.
Image

Image

The original hub built by farsports.
Image

RDY
Posts: 2327
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

If it's so sensitive to tension, then it's still a design / production problem which they're responsible for. 99% of other hub designs do not exhibit this problem.

User avatar
Mr.Gib
Posts: 5548
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

I was thinking about too high tension as a cause of these failures and I am doubtful. If too high tension was the cause, wouldn't the failure occure pretty much immediately? OTOH If this is a case of metal fatigue than wouldn't a lower tension increase the amount of loading and unloading and the likelihood of failure? Just speculating. Either way Carbon Ti has a big problem (and so do I with three sets). Really hoping that there was some bad aluminum and failures will be limited to affected hubs. If it is a design issue the failure rate will be 100% (ultimately). A bit tired of getting cornholed by this industry.

@nickf, how the f*** do three flanges go at the same time. That's a wheel explosion. If that happens at the wrong moment on the road really bad things could happen. I think the US federal consumer affairs should be informed. They could force a recall.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

User avatar
nickf
Posts: 1427
Joined: Sat Mar 06, 2010 10:34 pm

by nickf

Mr.Gib wrote:
Tue Oct 19, 2021 3:12 am
@nickf, how the f*** do three flanges go at the same time. That's a wheel explosion. If that happens at the wrong moment on the road really bad things could happen. I think the US federal consumer affairs should be informed. They could force a recall.
Lucky I was just out the front door when it happened. Literally all I did was clip in my left foot, heard a loud pop.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



tjvirden
Posts: 540
Joined: Sun Nov 22, 2020 9:21 pm

by tjvirden

Mr.Gib wrote:
Tue Oct 19, 2021 3:12 am
I was thinking about too high tension as a cause of these failures and I am doubtful. If too high tension was the cause, wouldn't the failure occure pretty much immediately? OTOH If this is a case of metal fatigue than wouldn't a lower tension increase the amount of loading and unloading and the likelihood of failure? Just speculating. Either way Carbon Ti has a big problem (and so do I with three sets). Really hoping that there was some bad aluminum and failures will be limited to affected hubs. If it is a design issue the failure rate will be 100% (ultimately). A bit tired of getting cornholed by this industry.

@nickf, how the f*** do three flanges go at the same time. That's a wheel explosion. If that happens at the wrong moment on the road really bad things could happen. I think the US federal consumer affairs should be informed. They could force a recall.
Broadly, fatigue is a combination of the inital stress, the amplitude of the cyclic loading and the number of cycles.So in general, higher spoke tension exposes flaws in design or materials more quickly; it's classic "fatigue failure" here. Parts of the metal (where the spokes attach of course) are at a high % of the yield stress of the alloy once the wheel is built. As an example, perhaps 60% of yield stress; cyclic loading of aluminum alloys in this condition results in crack formation almost immediately. As soon as you use the wheels the crack starts and grows as you continue using them.

Those three 'flanges' started cracking at about the same time and so when the first one let go, the stress on the others increased and so they failed immediately.

It could be that the alloy wasn't heat-treated properly (an impact test usually reveals that), or perhaps the design of the hub simply results in the stress in the alloy being too high once the wheel is built.

As far as I'm concerned, failures like this after a few thousand Km simply cannot be from "overtensioning". There's a fundamental flaw in the hubs.....

Post Reply