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Hello all, sad news to report. A crack has developed in the top tube on my much-loved Canyon Ultimate AL 9.0. The frameset is nearly 5 years old, but that seems young at my age  3 It's done about 1600km/year so that's probably about 7000km - mainly rough London streets on the commute, but also a bit of light touring, the DunRun, winter bike etc.

I noticed last night there was a slight bump in the top edge of the rear brake cable port, where there hadn't been before. I looked through a magnifying glass, and the crack is already 8mm long.

//imageshack.com/a/img922/4549/XasRGy.jpg)

//imageshack.com/a/img924/7840/L4sxiO.jpg)

1. What to do? I have no claim under guarantee, as I bought the frameset second hand, and I've used a rack etc, so the question is: ride it and see? Or attempt a repair? It looks too hard to weld - and likely to cause stress problems if it were to be welded.

2. What to replace it with? I've loved its efficiency and directness. Sharp steering and a rock solid bottom bracket area. A new Canyon frame is nearly £800, post Brexit! Ideas welcome.

 

31 comments

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matthewn5 [1201 posts] 1 year ago
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OK, so I've bought a Cinelli Experience 2016 frameset in the sales for £280. Exactly the same geometry within a few mm and only slightly heavier - so hopefully, a bit sturdier.

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barbarus [535 posts] 1 year ago
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I'd love to hear your opinions on the cinelli, Matthew, I've been umming and ahhing about one for a while now. Sorry to hear about your canyon!

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matthewn5 [1201 posts] 1 year ago
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barbarus wrote:

I'd love to hear your opinions on the cinelli, Matthew, I've been umming and ahhing about one for a while now. Sorry to hear about your canyon!

OK, I'll report back in due course.

Yes it's sad about the Canyon - in retrospect having such a large hole in the top tube near the seatpost looks like a design failure...

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dottigirl [819 posts] 1 year ago
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I don't know that frameset too well, but it looks like your brake cable is far, far too short. That could be placing extra stress on the frame. In fact, I wouldn't be surprised if that's caused the crack. 

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matthewn5 [1201 posts] 1 year ago
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dottigirl wrote:

I don't know that frameset too well, but it looks like your brake cable is far, far too short. That could be placing extra stress on the frame. In fact, I wouldn't be surprised if that's caused the crack. 

Probably a bit too short, but the cable outer simply goes through the frame so there's no stress from the brake cable on that point at all. You can move it freely with a finger. I think it's the flexy 'VCLS' seatpost that's putting stress on the thin top tube at that point.

The large hole so close to the junction is something I've seen cause cracking in other frames - e.g. the problem with some Whyte frames reported here last year.

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freebsd_frank [73 posts] 1 year ago
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matthewn5 wrote:

Yes it's sad about the Canyon - in retrospect having such a large hole in the top tube near the seatpost looks like a design failure...

If you put a hole in a stressed component, then the hole will act as what's called a "stress riser". ie. you will get increased stresses about that hole.

The magnitude of the stresses is difficult to model or quantify and thus are best avoided or you can end up with a frame like that pictured above where the material has failed.

If you want a frame that might last, then avoid frames that have had holes drilled in them.

 

 

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matthewn5 [1201 posts] 1 year ago
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freebsd_frank wrote:
matthewn5 wrote:

Yes it's sad about the Canyon - in retrospect having such a large hole in the top tube near the seatpost looks like a design failure...

If you put a hole in a stressed component, then the hole will act as what's called a "stress riser". ie. you will get increased stresses about that hole.

The magnitude of the stresses is difficult to model or quantify and thus are best avoided or you can end up with a frame like that pictured above where the material has failed.

If you want a frame that might last, then avoid frames that have had holes drilled in them.

Exactly, nothing wrong with external cables in my view! Last for ever.

At least that big hole should have had a stiffening lip - as the front cable 'hole' does have.

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madcarew [741 posts] 1 year ago
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A hole in itself is not a stress riser (in fact it's normally the opposite) but depending how the hole is made and finished it may contain stress risers. The best thing you can do is to drill a small (3-4mm hole right at the end of the crack. What this does is spread over a larger area whatever stress is causing the crack to creep . This should stop the damage getting any worse. Then filling the hole with a semi-flexible epoxy will fix cosmetic and water ingress. Clamping around the crack with a band (i.e. seat clamp) will almost certainly return the frame to virtually full strength. Or you could get a good frame builder to do a proper repair!! This certainly doesn't have to be the end of the frame.

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freebsd_frank [73 posts] 1 year ago
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madcarew wrote:

A hole in itself is not a stress riser (in fact it's normally the opposite) but depending how the hole is made and finished it may contain stress risers.

You're mistaken.

From:

https://en.wikipedia.org/wiki/Stress_concentration

Quote:

Geometric discontinuities cause an object to experience a local increase in the intensity of a stress field. Examples of shapes that cause these concentrations are cracks, sharp corners, holes, and changes in the cross-sectional area of the object. High local stresses can cause objects to fail more quickly, so engineers must design the geometry to minimize stress concentrations.

madcarew wrote:

The best thing you can do is to drill a small (3-4mm hole right at the end of the crack. What this does is spread over a larger area whatever stress is causing the crack to creep . This should stop the damage getting any worse. Then filling the hole with a semi-flexible epoxy will fix cosmetic and water ingress. Clamping around the crack with a band (i.e. seat clamp) will almost certainly return the frame to virtually full strength. Or you could get a good frame builder to do a proper repair!! This certainly doesn't have to be the end of the frame.

Drilling a hole at the end of the crack may stop that crack propagating but the stresses present are likely to result in either a new crack propagating from the new hole or another crack propagating from the original hole.

Whatever happens, the stresses will cause any crack to lengthen until it suddenly propagates across the entire tube when it reaches it's critical length. Let's hope he's not going too fast when that happens and subsequently faceplants.

My advice: chuck the frame and buy one made of a sensible material (not Al alloy) without any holes in it.

You could get it welded but where is the next crack going to show up? And more importantly, are you going to notice it before it fails?

With regards concealed cables:

OK on a time trial bike which is going to see few miles.

Anything else: avoid like the plague.

 

 

 

 

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freebsd_frank [73 posts] 1 year ago
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matthewn5 wrote:

Exactly, nothing wrong with external cables in my view! Last for ever.

At least that big hole should have had a stiffening lip - as the front cable 'hole' does have.

Agreed. If you're going to have holes in your frame, then at least beef them up with a bit of extra material about the hole.

But beefing up one but not the other? Makes zero sense to me. Completely half-cock.

The other problems with concealed cables are:

* increased difficulty running new cables.

* water ingress. You end up with a pool of water in which your bottom bracket sits. Nice.

The advantages are said to be:

* more aerodynamic. Doesn't matter a damn to those who don't tt.

* straighter run for cables. That's never caused me any problems with external cables.

 

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matthewn5 [1201 posts] 1 year ago
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Hi all,

So Canyon has responded, suggesting that if I install the missing frame cable guide, it will be fine:

Quote:

From you images it does appear that you are running this frame without one of the frame cable guides.

Please can you send me the serial number from the is bike? It should a 14 digit code, beginning with a letter, usually M or R, on a small sticker with a qr code.

Once I have this I could send you an exploded diagram of your bike and you could order the correct fitment for this cable to stop any unnecessary stress being applied to the frame.

 

As someone noted above, the fitting of the brake cable has nothing to do with the crack, since the cable run is made with a full outer and there's less than the usual compressive stress on the top tube from brake cable forces. I suppose the 'frame cable guide' might conceivably strengthen the opening, but if it's like the usual plastic fitting, I doubt it.

Comments?

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gunswick [131 posts] 1 year ago
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a plastic / rubber cable guide costing 50p to produce (or less) is not a stress supporting structure!

 

that guide is highly unlikely to reduce stress on the frame that could cause a crack.  prevention of paint peeling or visual marking yes, but I don't believe cable outers can crack frames.

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CXR94Di2 [2110 posts] 1 year ago
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Get someone to TIG weld it,  it will cost only a few quid.  In the London  area there must be loads of TIG welders.

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matthewn5 [1201 posts] 1 year ago
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CXR94Di2 wrote:

Get someone to TIG weld it,  it will cost only a few quid.  In the London  area there must be loads of TIG welders.

Anyone know a good TIG welder in London?

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matthewn5 [1201 posts] 1 year ago
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So Canyon have come back after a bit of to and fro, and said this:

Quote:

You appear to be missing part 19 (A1022937) from this diagram and this will be causing the issue you are experiencing.

Part 19 is the little plastic insert that takes the back end of the brake cable.

That is NOT going to a). stop the frame cracking any more, and b). heal up the existing crack. It's like Canyon are not even reading my messages.

//img2.brain3.photobox.com/906617745e6aabb45950599977cccd967b4363f1bb294e4c1c2f29c9f1daab20e0061bf5.jpg)

In my view, it's a design fail, the hole is just too big: 31mm long and 9mm wide.

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beezus fufoon [972 posts] 1 year ago
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matthewn5 wrote:
CXR94Di2 wrote:

Get someone to TIG weld it,  it will cost only a few quid.  In the London  area there must be loads of TIG welders.

Anyone know a good TIG welder in London?

bikefix in lamb's conduit street  020 7405 1218 

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matthewn5 [1201 posts] 1 year ago
1 like
beezus fufoon wrote:
matthewn5 wrote:
CXR94Di2 wrote:

Get someone to TIG weld it,  it will cost only a few quid.  In the London  area there must be loads of TIG welders.

Anyone know a good TIG welder in London?

bikefix in lamb's conduit street  020 7405 1218 

Cheers I'll give them a try!

 

superpython wrote:

'd be wanting a replacement or a proper repair done at their expense, get a quote for a repair and if they refuse just state you'll go to trading standards

Problem is I bought it second hand, so I have no consumer rights, according to that website...

 

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dottigirl [819 posts] 1 year ago
2 likes
SuperPython59 wrote:

It's BS, it was me that said the cable shouldn't be stressing the frame and for it to crack and that's absolutely accurate. To think that a plastic grommet/insert would have prevented that is delusional or just a plain lie.

Back to my original point. Without examining the frame in person, I respectfully disagree:

A brake cable is under tension. Even without much tension, a cable can rub substantially at a frame. Alloy is soft, but we've seen this with a couple of other brands where they didn't get their insertion angle or frame protection right (e.g. Mekk - the cables were actually eating through the frame). My first road bike (also alloy) had dips on the head tube and other areas where cables rubbed over the course of a couple of years. Some of these cables were relatively slack, but they still rubbed.

Look at the angle the cable enters the brake caliper. That's not good. The cable should sit square, and it doesn't. Even if there's no tension exerted when not in use (and there should be to keep the pads near the wheel), there will be force when the brake is used.

It's not possible to see the inside of the tube, but I'm betting the cable has rubbed away at the inside of the tube. This has created a weak point. The insert may well have prevented that, and guided the cable to a more desirable angle.

If second hand, buyer beware. He's bought a frame with an essential part missing, and there's not much comeback to that - Canyon could say the part was initially present.

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matthewn5 [1201 posts] 1 year ago
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dottigirl wrote:

It's not possible to see the inside of the tube, but I'm betting the cable has rubbed away at the inside of the tube. This has created a weak point. The insert may well have prevented that, and guided the cable to a more desirable angle.

If second hand, buyer beware. He's bought a frame with an essential part missing, and there's not much comeback to that - Canyon could say the part was initially present.

That's a good theory, and you're right about the cable being slightly short, but it doesn't appear to be the case here.

Here's some more photos:

//img2.brain4.photobox.com/99961667dcd9ae37817d240004cbba970c9ff8bf05ea7379a959e20e8cc03707c6d12fb1.jpg)

There's no visible reduction in thickness at the edge, and no sign of 'polishing' of the inner surface, looking at it under a bright light. There's a tiny amount of polishing of the edge of the hole, if anything.

//img2.brain4.photobox.com/25666975972695182db7f97c36d45b2826e170c72cc62d57a7317c3f9f000ec091546984.jpg)

This shows that the section resting against the cable has actually gone inwards... and the section forward has gone outwards. You can feel it.

So all in all, I think it's probably a design or manufacturing fault. With a straightedge you can see the top tube is slightly concave on the left and straight on the right. Probably always was stressed through the asymmetry.

BUT since I bought it second hand, and yes, ran it with a full outer instead of the plastic fitting, I don't think Canyon are under any obligation.

I'm going to take it to Bikefix, see what they can do.

 

 

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matthewn5 [1201 posts] 1 year ago
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OK, Bikefix say they can fix it, but it won't be pretty. I'll report back!

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matthewn5 [1201 posts] 1 year ago
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Right, Bikefix said they could fix it, preferably with carbon, but at quite a price, and they advised that it would probably crack again.

I've sold it to a chap who was looking for a cheap turbo trainer frame.

Thanks for all your help and advice!

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matthewn5 [1201 posts] 1 year ago
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barbarus wrote:

I'd love to hear your opinions on the cinelli, Matthew, I've been umming and ahhing about one for a while now.

It's brilliant value for the £279 I paid. So far it seems stiff enough, if not as 'immediately impressive' stiff as the Canyon. That's probably only because of the BSA threaded BB means not such a width for welding the downtube. As a result it is much more comfortable over rough London roads than the Canyon, admittedly with Canyon's brilliant VCLS seatpost moved over to the Cinelli. The steering is a delight, and the frame really comes alive over 20mph. There's no big holes in the frame to cause stress concentration. The front forks seem pretty comfy too despite the 1 1/2" tapered alloy steerer.  Lovely paintjob, too, in black with what looks like WW1 geometric 'dazzle' painting in white and silver.

The only annoyance so far is the dowtube cable adjusters. They're close to the head tube meaning the cable enters through a tight curve. That makes them a bit stiff to adjust. It's a minor problem as you don't really need to adjust them once it's all set up properly.

There's plenty of clearance for 25mm tyres and mudguards, and you could probably fit 28s in there without them. So to conclude, it seems perfect for a commuter/winter bike with a bit of character.

 

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matthewn5 [1201 posts] 1 year ago
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PS: The chap I sold the cracked Canyon frame to has only gone and sold it on Ebay without mention of the cracked frame! This is the frame that Bikefix said couldn't be repaired.

http://www.ebay.co.uk/itm/Canyon-Ultimate-9-0-AL-F8-Road-Bike-Shimano-58...

What a scammer. Looks nice though. Ho hum

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iandusud [67 posts] 1 year ago
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What a scumbag!

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tritecommentbot [2266 posts] 1 year ago
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Yeah, real scummy move that. Hope he gets chargebacked.

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racingcondor [239 posts] 1 year ago
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Replace it with a Cinelli Experience. Brilliant frame, especially for the price you can get them now.

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barbarus [535 posts] 1 year ago
1 like
matthewn5 wrote:
barbarus wrote:

I'd love to hear your opinions on the cinelli, Matthew, I've been umming and ahhing about one for a while now.

It's brilliant value for the £279 I paid. So far it seems stiff enough, if not as 'immediately impressive' stiff as the Canyon. That's probably only because of the BSA threaded BB means not such a width for welding the downtube. As a result it is much more comfortable over rough London roads than the Canyon, admittedly with Canyon's brilliant VCLS seatpost moved over to the Cinelli. The steering is a delight, and the frame really comes alive over 20mph. There's no big holes in the frame to cause stress concentration. The front forks seem pretty comfy too despite the 1 1/2" tapered alloy steerer.  Lovely paintjob, too, in black with what looks like WW1 geometric 'dazzle' painting in white and silver.

The only annoyance so far is the dowtube cable adjusters. They're close to the head tube meaning the cable enters through a tight curve. That makes them a bit stiff to adjust. It's a minor problem as you don't really need to adjust them once it's all set up properly.

There's plenty of clearance for 25mm tyres and mudguards, and you could probably fit 28s in there without them. So to conclude, it seems perfect for a commuter/winter bike with a bit of character.

 

Great stuff, sounds exactly like what I want. Although in fact for me this would be a summer bike for chaingangs and faster club runs. Next step, persuade other half that I need two bikes...

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MrGold [6 posts] 1 year ago
2 likes
matthewn5 wrote:

PS: The chap I sold the cracked Canyon frame to has only gone and sold it on Ebay without mention of the cracked frame! This is the frame that Bikefix said couldn't be repaired.

http://www.ebay.co.uk/itm/Canyon-Ultimate-9-0-AL-F8-Road-Bike-Shimano-58...

What a scammer. Looks nice though. Ho hum

You should report him to ebay. What he did was dangerous and he scammed someone out of their hard earned ££.

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matthewn5 [1201 posts] 1 year ago
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racingcondor wrote:

Replace it with a Cinelli Experience. Brilliant frame, especially for the price you can get them now.

That's what I did! And it is an excellent frame. Cheap too.

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matthewn5 [1201 posts] 1 year ago
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barbarus wrote:
matthewn5 wrote:

Great stuff, sounds exactly like what I want. Although in fact for me this would be a summer bike for chaingangs and faster club runs. Next step, persuade other half that I need two bikes...

Good luck with that! It's a great frame for a cheap build. My other half liked it too, phew  3

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