Carbon swingarm vs alloy

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Carbon swingarm vs alloy

Postby Spoonman » Tue Jul 17, 2018 3:10 pm

I recently purchased a 2017 Scott Spark Premium 700. I had the bike for about 3 weeks when somehow while out on a big ride managed to get my foot stuck (whilst clipped in) in the carbon swing arm. Heard a crack and stopped to inspect. Broken swingarm.

Was about 50 kms from home which wasn’t ideal but gave me time to ponder why this had happened. Couple of reasons:

-Boost hubs (frame really wide coming off the hubs and easily clipped especially if your riding style is slightly duck footed)

-Frame Design (noticed on my Kona hardtail that the rear triangle actually had some curves on the diagonal which are in exactly the position your foot could get caught. Apparently they are also to allow some flex in the frame)

After this unfortunate incident on a high end bike (RRP $9199) I was told by LBS would not be covered under warranty and that it would be $3000 to repair or $1700 to replace. Large amount of money to spend so soon after spending a large amount of money.

Would like to know if anybody else has had a similar issue with a carbon swingarm and whether I might be better off with an alloy swingarm? Or maybe alloy mainframe as well because I have no faith in carbon anymore. :(

cooperplace
Posts: 389
Joined: Sat Sep 12, 2009 11:42 pm
Location: Adelaide

Re: Carbon swingarm vs alloy

Postby cooperplace » Tue Jul 17, 2018 5:24 pm

I think everyone I know with a carbon frame has had a crack, they're all on their 2nd/3rd/4th frames. I share your lack of faith.
Please be nice to me, I'm not very bright.

eeksll
Posts: 2468
Joined: Tue Oct 20, 2009 10:36 pm

Re: Carbon swingarm vs alloy

Postby eeksll » Tue Jul 17, 2018 10:01 pm

that doesn't sound right to me. I'd be googling like crazy and definitely be seeking second/third/fourth opinions.

mikgit
Posts: 753
Joined: Fri Jul 27, 2012 8:26 pm
Location: Launceston

Re: Carbon swingarm vs alloy

Postby mikgit » Tue Jul 17, 2018 10:06 pm

My mate had an Aluminium Specialised, he went through...I don't even know how many chainstay/swing arms on that, I think it was 4. he also had 2 replacement Cannondale aluminium HT frames.
Another friend broke an aluminium GT Zaskar...and apparently they are unbreakable
My aluminium FS frame was so full of cracks there were more cracks than frame...

On the other hand another mate has a carbon Trek HT, bought it 2nd hand in like 2000, rode/raced it hard for years and it's still going strong, similar for his carbon Scott FS bike

Carbon, aluminium, doesn't matter you can still break them in the stupidest ways
Look 675 Pro Team, Cervelo R3, GT Xizang, GT Zaskar, Scott Spark 710, Yeti ARC, DiamondBack Apex

User avatar
Duck!
Expert
Posts: 6975
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Carbon swingarm vs alloy

Postby Duck! » Tue Jul 17, 2018 10:20 pm

That repair price sounds excessive. While it's true that carbon repairs are not particularly cheap, due to the high manual work component, unless it's a major break a repair should compare favourably against replacement. Additionally, I'm tipping the damage is moderate at worst.... The forces necessary to cause a major fracture from sticking your foot in it would cause a similar degree of damage to said foot.

Contact Paint My Bike, Luescher Teknik or a similar carbon repair firm for a proper estimate of repair cost.
I had a thought, but it got run over as it crossed my mind.

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Re: Carbon swingarm vs alloy

Postby Spoonman » Wed Jul 18, 2018 8:57 am

Duck! wrote:That repair price sounds excessive. While it's true that carbon repairs are not particularly cheap, due to the high manual work component, unless it's a major break a repair should compare favourably against replacement. Additionally, I'm tipping the damage is moderate at worst.... The forces necessary to cause a major fracture from sticking your foot in it would cause a similar degree of damage to said foot.

Contact Paint My Bike, Luescher Teknik or a similar carbon repair firm for a proper estimate of repair cost.


Thanks Duck! I have started chasing this up off my own bat. Scott have come back and said they would supply new swingarm at a “goodwill” price of $850. (Inclusive of freight charges) Paint my bike came back with a quote of $795 for the repair. Six of one...

I was hoping for some goodwill from the bike shop where the bike was purchased. Seeing that this happened 3 weeks after purchasing the bike. Is it unreasonable to expect them not to charge for labour involved removing and refitting the swing arm?

User avatar
Duck!
Expert
Posts: 6975
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Carbon swingarm vs alloy

Postby Duck! » Wed Jul 18, 2018 9:09 am

Given crash damage is not covered by warranty, it is a little unreasonable to expect the shop to supply free labour.
I had a thought, but it got run over as it crossed my mind.

User avatar
MichaelB
Posts: 9107
Joined: Tue Feb 20, 2007 9:29 am
Location: Adelaide, South Australia

Re: Carbon swingarm vs alloy

Postby MichaelB » Wed Jul 18, 2018 3:24 pm

Duck! wrote:Given crash damage is not covered by warranty, it is a little unreasonable to expect the shop to supply free labour.


Agree with that.

And I'd go with a new part for $50 extra and have the other one as a spare that can be repaired. Quicker turn around too probably.

User avatar
ValleyForge
Posts: 1681
Joined: Tue Jan 27, 2009 5:37 pm
Location: Brisbane

Re: Carbon swingarm vs alloy

Postby ValleyForge » Wed Jul 18, 2018 7:59 pm

As an aside, we have four duallies in the house, two with alloy rears and two with carbon. 1 x Cube, 2 x Focus and 1 x LaPierre.

Certainly no issues with cracking - some have taken a pounding. And some are poodled about.
Ha ha ha! Cookies on dowels.

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Re: Carbon swingarm vs alloy

Postby Spoonman » Tue Aug 14, 2018 10:46 pm

I have finally received the replacement swingarm! It only cost $850! Was fantastic for five days and 2 rides. I was Washing the bike when I noticed a crack on the chai stay just under the spot my foot cracked the other one. Not another one!

I am not at all impressed. By definition this bike is not fit for purpose. I bought the bike to compete in a multiple day stage race at the end of the year in the southern alps of NZ. It’s clearly not going to be able to do that. It’s not like I’m doing backflips either.

Is this the bit where I demand a full refund?!

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Re: Carbon swingarm vs alloy

Postby Spoonman » Wed Aug 15, 2018 6:19 pm

It also makes me wonder whether the initial break was a warranty issue also? The Carbon is obviously pathetic. Why did I fork out $850 for something that clearly has its issues?

chriso_29er
Posts: 229
Joined: Fri Jul 31, 2015 9:00 pm

Re: Carbon swingarm vs alloy

Postby chriso_29er » Wed Aug 15, 2018 7:10 pm

Perhaps something you should be discussing with Scott. Does seem very strange that you managed to do this twice.
Do you have photos of the two breaks you can show us?
Image

User avatar
Comedian
Posts: 5479
Joined: Mon Aug 09, 2010 7:35 pm
Location: Brisbane

Re: Carbon swingarm vs alloy

Postby Comedian » Thu Aug 16, 2018 10:53 am

cooperplace wrote:I think everyone I know with a carbon frame has had a crack, they're all on their 2nd/3rd/4th frames. I share your lack of faith.

Shhhh! You'll be branded a heretic like me if you aren't careful. :mrgreen:

On topic I've noted a number of brands used alloy rears on CF frame bikes. Clearly- this is another less than stellar application for CF.

User avatar
Duck!
Expert
Posts: 6975
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Carbon swingarm vs alloy

Postby Duck! » Thu Aug 16, 2018 11:08 am

They do it because it's cheaper; they use the same swingarm on both aluminium and carbon models in the series.

As alluded to in another post above, it's more to do with the manufacturer than the material; truckloads of aluminium bits have broken over the years too.
I had a thought, but it got run over as it crossed my mind.

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Re: Carbon swingarm vs alloy

Postby Spoonman » Sat Aug 18, 2018 12:50 pm

I would like to post some photos to hear some opinions out there. How do I do that?

User avatar
find_bruce
Moderator
Moderator
Posts: 7809
Joined: Mon May 09, 2011 8:42 pm
Location: Sydney

Re: Carbon swingarm vs alloy

Postby find_bruce » Sat Aug 18, 2018 1:31 pm

Spoonman wrote:I would like to post some photos to hear some opinions out there. How do I do that?

Here you go: How to post images on the Australian Cycling Forums

User avatar
trailgumby
Posts: 13170
Joined: Sat Jan 03, 2009 5:30 pm
Location: Northern Beaches, Sydney
Contact:

Re: Carbon swingarm vs alloy

Postby trailgumby » Sat Aug 18, 2018 1:40 pm

The mistake you made was buying a Scott. The Australian distributor has a terrible reputation for supporting its product. And I would be asking for my money back under the Australian Consumer Guarantee. It may be carbon, but it's a mountain bike and crashes and a hard life are to be expected, and should be engineered for. It looks like that hasn't happened here. Merida is another brand on my black list, for the same reason.

Cannondale had a similar reputation, and their distributor here was changed by Cannondale as bike shops were dropping the brand as a result of their treatment. Monza seem to be much more professional.

On the upside I have a 5 year old carbon Cannondale Scalpel 29er. It's taken some massive hits from babyhead rocks flying up off the front wheel, and a few stacks in races. I made sure I took copies of all their web pages saying their flex stay technology had a near-infinite life. I haven't needed them yet.

Giant, and anything imported by Paul Rowney would be on my white list. Great customer support from what I hear.

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Re: Carbon swingarm vs alloy

Postby Spoonman » Sun Aug 19, 2018 5:46 pm

Not sure if this will work. Fingers crossed!

Image
Image
Image
Image
Image
Image

User avatar
find_bruce
Moderator
Moderator
Posts: 7809
Joined: Mon May 09, 2011 8:42 pm
Location: Sydney

Re: Carbon swingarm vs alloy

Postby find_bruce » Sun Aug 19, 2018 6:18 pm

Spoonman wrote:Not sure if this will work. Fingers crossed!

Image
Image
Image
Image
Image
Image

Not quite - go to the first url you posted, right click on the image, copy the image url, gives you
Image

User avatar
Comedian
Posts: 5479
Joined: Mon Aug 09, 2010 7:35 pm
Location: Brisbane

Re: Carbon swingarm vs alloy

Postby Comedian » Mon Aug 20, 2018 2:26 pm

find_bruce wrote:
Spoonman wrote:Not sure if this will work. Fingers crossed!

Image
Image
Image
Image
Image
Image

Not quite - go to the first url you posted, right click on the image, copy the image url, gives you
Image


Cripes.. that will buff right out. :shock:

A friend just had her carbon bike crack in the same spot on a roadbike (after only 2k) and they just replaced it. If you are going to make bikes out of a material that is prone to this type of failure you've got to be prepared to pony up with replacements. Or you don't have to - but then people will stop buying 5k bikes than only cost you a tenth of that to make in Asia...

Spoonman
Posts: 7
Joined: Tue Jul 17, 2018 2:48 pm

Re: Carbon swingarm vs alloy

Postby Spoonman » Mon Aug 20, 2018 10:06 pm

Hi All,

Images 2,3 and five show the initial break on the seat stay and near the rear axle. The other ones show the more recent crack on the chain stay. I have no idea how this one happened but i can tell you it is annoying. I spent $7850 less than three months ago, and don't have a bike to ride! :(

Image
Image
Image
Image
Image
Image
Image
sulfate aluminium

User avatar
ValleyForge
Posts: 1681
Joined: Tue Jan 27, 2009 5:37 pm
Location: Brisbane

Re: Carbon swingarm vs alloy

Postby ValleyForge » Tue Aug 21, 2018 2:22 pm

That's impressive. But not in a good way.
Ha ha ha! Cookies on dowels.

Who is online

Users browsing this forum: No registered users