Cracked frame - Seeking advice

[OzJustin]

Hi everyone,

Long story short, I've been using my current Avanti Kona road bike (7005 kenesis aluminium double butted frame and carbon forks) for the last 3 years. Put it in for a service with my LBS last week and they discovered a hairline crack in the headtube where it joins the top tube. It is only about 3-4mm long. See image below.



Needless to say I was quite surprised and saddened by the news.

My next question is can the frame be repaired (and economically)? I have a family friend in the welding business. I wonder whether it could be welded up given the location.

I'm also curious how long it would last until failure. My mechanic suggested the crack could expand down my head tube over time and my headset would become loose. This makes sense but I'm just wondering whether this would happen over 1 month or 1 year of continued use.

[funnybike]

3 years. Warranty?

[Nobody]

3. what this warranty covers and term of this warranty

3.1. This Warranty only covers bicycles that have a wheelbase exceeding 640mm or have a wheel size of 16” (40cm) and larger.

3.2. This Warranty covers:

(a) standard steel, alloy and carbon frames and framesets, for as long as the Purchaser owns the Bicycle (but note that the fork is not a part of the frame or frameset);

(b) suspension frames and framesets (including but not limited to, all suspension attachment points, bushings, pivots, fasteners, stays and shock units) for two years;

(c) all other standard components and accessories forming part of the Bicycle, including standard forks, wheels, suspension forks, rear shock absorbers, drive train, brakes, seat post, handlebar and stem, paint, decals and finish for one year.

3.3. A lifetime warranty on your frame or frameset does not guarantee that the Bicycle will last forever. The length of the life of the Bicycle will vary depending on the type of the Bicycle, riding conditions and care the Bicycle receives.

http://www.avantibikes.com/nz/warranty/

The three things I get from this are:

If you haven't crashed it, it the frame should be under warranty.

The fork only has a one year warranty. (Unusual)

3.3 seems to be a weasel-out clause to me. If it was old enough they could just say that was it's life. Read about this being done by Cannondale with a 15 year old Al frame. See below.
http://www.bicycles.net.au/forums/viewtopic.php?t=11641

[find_bruce]

I have a 1993 Avanti Kona from 1993 & guess what, that is eaxactly the same problem I had. In my case I had a matching crack in the seatpost.

First step should be to check your warranty documentation. Avanti advertise their bikes as having a lifetime warranty for the original owner & while that excludes "normal wear and tear including the results of fatigue", 3 years is a fair way short of what you might expect as a lifetime.

The distributors of Avanti in Australia will, in my experience, look to avoid any warranty claim, and any repair will be gratefully siezed upon as a basis to refuse your claim.

So if you are the original owner I would be taking it to the nearest avanti dealer & saying you want it repaired or replaced under warranty.

If you are not the original owner or Avanti stay true to form and weasel out of the lifetime warranty they promise but don't deliver then it is possible to have the crack repaired. There are a few difficulties with this.

First the bad news

[1] Aluminum bike frames need to be heat treated after welding, basically for stress relief. An excellent TIG welder should be able to minimise the heat & therefore the stress.
[2] Having your frame put into a furnace for heat treatment as a one off will cost more than replacing the frame.
[3] After welding, in the absence of stress relief, the weld will be harder than the surrounding aluminium. The next crack will inevitably be down the edge of the weld.

The good news is that having found it fairly early, the weld will be small & heat issues much less. At least in my case it was fairly cheap to have welded up & the repair lasted reasonably well, at least at the headset.

[twizzle]

[1] Aluminum bike frames need to be heat treated after welding, basically for stress relief. An excellent TIG welder should be able to minimise the heat & therefore the stress.

Depends on the alloy. 6-series need heat treatment, 7-series don't (which is why most of the manufacturers switched to them).

[OzJustin]

Sorry I should have clarified that I am not the original owner (I'm the 3rd) so I understand Avanti aren't obliged to honour the lifetime frame warranty.

Thanks for the clarification Bruce. Hmm the need to heat treat the frame has me a little concerned welding it alone may be a bandaid fix. That said, I could have been riding it like this for months unknowingly (I have never crashed it during my ownership). Do you know roughly how much a basic weld repair like this would cost? I'll have to weigh this up with replacing the frame ($600ish For something similar?)

[Nobody]

Ask Gripsport. They specialize in this stuff.

[find_bruce]

[1] Aluminum bike frames need to be heat treated after welding, basically for stress relief. An excellent TIG welder should be able to minimise the heat & therefore the stress.

Depends on the alloy. 6-series need heat treatment, 7-series don't (which is why most of the manufacturers switched to them).

Sorry Twizzle, but that is twaddle.

7005 does not need to be precipitation hardened, see for example http://en.wikipedia.org/wiki/7005_aluminium_alloy, but it still needs heat treatment. Some good discussion at http://www.satincesena.net/bicycle-fram ... s-al-7005/ if you are interested.

Long story short, 6061 at 180° then rapidly cooled in liquid, 7005 lower temps 90°C & 140°C for longer & then air cooled. I have seen considerable variations on the length of times recommended for heat treating 7005 but almost no variation in the temperatures & I have not seen anyone saying it does not need to be heat treated.

Sorry I should have clarified that I am not the original owner (I'm the 3rd) so I understand Avanti aren't obliged to honour the lifetime frame warranty.

Thanks for the clarification Bruce. Hmm the need to heat treat the frame has me a little concerned welding it alone may be a bandaid fix. That said, I could have been riding it like this for months unknowingly (I have never crashed it during my ownership). Do you know roughly how much a basic weld repair like this would cost? I'll have to weigh this up with replacing the frame ($600ish For something similar?)

Don't let me trouble you - SWMBO is a metalurgist & I regularly get lectures on the topic.

Welding aluminium is a temporary fix, but all aluminium will crack, its just a case of when. How long it lasts will depend on the quality of the job. Plenty of people here from Brisbane way who will be able to point you to a good frame repairer locally.

But as the gripsport website shows, there are alternatives

Even got me thinking I might get my beloved old frame repaired properly this time.

[twizzle]

Depends on the alloy. 6-series need heat treatment, 7-series don't (which is why most of the manufacturers switched to them).

Sorry Twizzle, but that is twaddle.

7005 does not need to be precipitation hardened, see for example http://en.wikipedia.org/wiki/7005_aluminium_alloy, but it still needs heat treatment. Some good discussion at http://www.satincesena.net/bicycle-fram ... s-al-7005/ if you are interested.

I stand corrected. However... I suspect that 7005 frames are made heavier so they can skip the heat treatment.

Comments from various bike building sites, forums etc. etc.

"7005 does not require expensive heat treatment to be strong "
"And although 7005 alloys, like the Easton Varilite, don't need to be heat treated ..."
"from 7005, which gains it strength from the alloy, and not heat treat. So you can weld 7005 all you want, and it doesn't adversely affect the tensile strength."
"7005 series doesn't require heat treatment "
"7005 bikes don't require the heat treatment"

I would be interested in finding which manufacturers do the heat treatment on their 7-series 'cheap' frames.

[queequeg]

3. what this warranty covers and term of this warranty

3.1. This Warranty only covers bicycles that have a wheelbase exceeding 640mm or have a wheel size of 16” (40cm) and larger.

3.2. This Warranty covers:

(a) standard steel, alloy and carbon frames and framesets, for as long as the Purchaser owns the Bicycle (but note that the fork is not a part of the frame or frameset);

(b) suspension frames and framesets (including but not limited to, all suspension attachment points, bushings, pivots, fasteners, stays and shock units) for two years;

(c) all other standard components and accessories forming part of the Bicycle, including standard forks, wheels, suspension forks, rear shock absorbers, drive train, brakes, seat post, handlebar and stem, paint, decals and finish for one year.

3.3. A lifetime warranty on your frame or frameset does not guarantee that the Bicycle will last forever. The length of the life of the Bicycle will vary depending on the type of the Bicycle, riding conditions and care the Bicycle receives.

http://www.avantibikes.com/nz/warranty/

The three things I get from this are:

If you haven't crashed it, it the frame should be under warranty.

The fork only has a one year warranty. (Unusual)

3.3 seems to be a weasel-out clause to me. If it was old enough they could just say that was it's life. Read about this being done by Cannondale with a 15 year old Al frame. See below.
http://www.bicycles.net.au/forums/viewtopic.php?t=11641

It does say that the warranty is for the lifetime that the original owner has the bike. Same as Trek, who replaced my Alu frame hybrid twice in 3 years due to cracked/broken frame.

[JustJames]

For now, mark the end of the crack.

If the crack spreads, drill a small hole at the base of the crack which will at least prevent the crack spreading further.

[find_bruce]

JustJames, are you sure that either of your suggestions are a good idea for a crack in an aluminium headtube ? Ever seen what happens to an aluminium can when you put a small tear in an aluminium can

[OzJustin]

My first preference is certainly to repair the frame if economical. The bike has been fantastic to me and had I not been made aware of the tiny crack I'd still be riding it for years to come.

Any Brisbane veterans with recommendations on repairers and likely cost (if my family friend cannot tig weld it)?

Worst case scenario, can anyone recommend a replacement frame for me (assuming I keep all my other existing gear)? Lifetime warranty preferred.

[grantw]

I'd be stripping the parts off and finding another frame. Not an easy repair.

[JustJames]

JustJames, are you sure that either of your suggestions are a good idea for a crack in an aluminium headtube ? Ever seen what happens to an aluminium can when you put a small tear in an aluminium can

The drilled hole should stop the crack spreading.

Are you saying that it won't?

[twizzle]

Ribble frame & fork, delivered to your door, for under $330. Heavy, but bomb proof.


Sent from my iThingy...

[Nobody]

Ribble frame & fork, delivered to your door, for under $330. Heavy, but bomb proof.

How long have you been trying to break yours for? I think TLL has been trying to break his for years.

Cheap and strong. A hard combination to ignore unless you have weight-weenyism. Which is probably closely related to ungradeitis.

[gabrielle260]

Wasn't really paying attention to this thread but got on my commuter to ride home and found it totally separated at the chain stay/seat stay junction.
Can't complain - a 12 yr old Evolution built by Ken Evans or his son that was my number 1 bike until a redundancy package 4 yrs ago.
However, I must admit I am sad - it was a great bike!

[OzJustin]

Ribble frame & fork, delivered to your door, for under $330. Heavy, but bomb proof.


Sent from my iThingy...

Is it the Ribble 7046 Sportive Curved Frame (aluminium) you're referring to? I found that one on ribblecycles.co.uk for roughly $280 (plus postage) with a 20% off sale at present.

[twizzle]

Nope - the Audax/Winter frame, or the horizontal/sloping road frame. Include the fork & headset, they fit the headset and pack it into a box... with a DA chain in the package as well, it was ~$340 delivered to my post office box. I bought one after having my 'good' steel frame break, this was the only reasonable option to get me back on the road without selling a kidney.

[find_bruce]

JustJames, are you sure that either of your suggestions are a good idea for a crack in an aluminium headtube ? Ever seen what happens to an aluminium can when you put a small tear in an aluminium can

The drilled hole should stop the crack spreading.

Are you saying that it won't?

I am saying that I wouldn't drill a hole in a headtube ever, and especially not in relation to a edge crack that has extended half way through the significantly beefed up ring at the top and bottom of the head tube.

The reason that beefed up section is there (& wasn't in aluminium bikes of the 80s and 90s) is that Aluminium has a tendency to tear and fatigue crack at precisely those points. Similarly why modern aluminium bikes have a collar at the seatpost instead of welded lugs per steel bikes.

As I understand it an unfilled hole in aluminium does not prevent the propogation of a crack and instead in many cases can be the source of the crack. What you are suggesting is sometimes done by aircraft maintenance engineers to temporarily retard the propagation of a fatigue crack until a more permanent repair can be made. When where & how it is done are all of critical importance. It does not restore the structural integrity of the part & what caused the crack has not been addressed. If you feel like some reading on the ineffectiveness of stop drill holes in aluminium, have a read of the NTSB's investigation into the crash of a Grumman Turbo Mallard, caused by plane's right wing falling off during flight The investigation found multple-site fatigue damage inboard of the stop-drilled crack.

[OzJustin]

Quick update on my frame. After speaking with AvantiPlus it looks as if I'll be sourcing a new frame now. I've been put in touch with someone selling a Fuji aluminium road frame for a good price so will go and inspect (the Fuji sounds like it will be a better fit for me as my Kona frame was too small). If that falls through then I'm back to looking at the Ribble frames.

Some options I'm considering:

http://www.ribblecycles.co.uk/sp/road-t ... ibbfrat600

http://www.ribblecycles.co.uk/sp/road-t ... ibbfrar230

http://www.ribblecycles.co.uk/sp/road-t ... ibbfrar269 ($276)

The last option seems the most enticing to me. I would then have to purchase matching Ribble forks and a headset then too? Could I reuse my existing Avanti carbon forks?

[twizzle]

"This frame is only supplied when you also order Ribble 7046 Sportive Carbon Road Forks"

Besides which, unless it's a full carbon fork you should replace them every few years anyway. Fatigue in the steerer tube is not pretty when it fails.

Any why are you considering a TT frame?

[OzJustin]

"This frame is only supplied when you also order Ribble 7046 Sportive Carbon Road Forks"

Besides which, unless it's a full carbon fork you should replace them every few years anyway. Fatigue in the steerer tube is not pretty when it fails.

Any why are you considering a TT frame?

The TT frame was physically appealing, a good price and didn't require purchasing forks like the other two. Would I notice the frame geometry being that much more aggressive than my current Avanti? It's just an option I was throwing out there. Happy to be referred to other more suitable frames.

[twizzle]

TT geometry is very different from road geometry.