Home

Hi everyone,

I follow the road.cc for quite some time, but registered just now, since I experienced a shocking revelation yesterday while inspecting my FD.

 

On the very second ride with my new TCR Advanced I dropped the chain on a slight incline. It's my first carbon bike and I did not give it a secong thought at that point. I also always ease on the pedals when switching into the small ring, since I want to avoid exactly that. However, it seems to have left a pretty nasty damage on the chainstay. 

It looks (at leas I hope) like mostly paint damage, except for the lower part. I'd like to hear your more experienced opinions, before I decide what to do next.

//i.imgur.com/hBZDpRI.jpg)

//i.imgur.com/4HEuwvH.jpg)

//i.imgur.com/Sw94Hez.jpg)

//i.imgur.com/m8aBUBE.jpg)

 

Thanks everyone,

Cheers!

 

23 comments

Avatar
peted76 [1637 posts] 4 days ago
0 likes

Wow that's a bit of a knightmare, that's a hell of a crunch. You should check your chain and try and find out why you experienced chain suck. I don't think that I can remember ever experiencing it.

I reckon there'll be no structural damage done there, it's a very tough part of the frame, best you can do is put some clear coat over it. 

 

 

 

Avatar
Dingaling [134 posts] 4 days ago
0 likes

Chain suck is something I have experienced several times over many years and it was usually associated with a mountain bike triple drive train.  I think it is more likely when a chain is worn and doesn't drop off the bottom of the chain ring and gets carried up and "crunch". One recommended way of treating damage to a carbon surface is put super glue on it. After that I would put a few layers of reinforced tape on the chain stay to protect it against the next time it happens.

Avatar
theraPi [6 posts] 4 days ago
0 likes
peted76 wrote:

Wow that's a bit of a knightmare, that's a hell of a crunch. You should check your chain and try and find out why you experienced chain suck. I don't think that I can remember ever experiencing it.

I reckon there'll be no structural damage done there, it's a very tough part of the frame, best you can do is put some clear coat over it. 

 

 

 

 

Hi, thanks for the reply.

It happened on a slight uphill section, when I switched into the smaller ring. The chain dropped, and I assume got caught by the ring in the process...

 

I'm a bit relieved to hear that it is "probably" fine. However, I'm tempted to take it somwhere for inspection.

Avatar
The _Kaner [1220 posts] 4 days ago
0 likes

I'd get it expertly checked.
2nd ride and a shipped chain.
Might want to ask the bike shop, I'm presuming it was from a bike shop, to check the set up and see why the chain was able to come off the chain wheel.
Looks like the indexing/ front derrailleur may be out a tad.

Avatar
Judge dreadful [444 posts] 4 days ago
1 like

I think that's just paint damage, personally. If the CF is damaged, you normally see loose threads sicking out. But it's better to be safe than sorry, and a scan of the frame might put fears at rest.

Avatar
Bobbinogs [351 posts] 4 days ago
0 likes

yeah, I am not convinced that is chain suck, probably more a case of either the setup not being right or just bad luck (hitting a bump in the road mid-shift). 

As above, get the damage checked out (there are quite a few good CF repairers out there now) although it does look cosmetic.  Might also be worth getting a chain catcher fitted as part of the front shifter check/setup afterwards (the Token ones work well and cost as little as a tenner).

Avatar
AfterPeak [164 posts] 4 days ago
0 likes

Looking at the width (top to bottom) that looks too long to be a chain but there are two/three strips  down that look about chain link width apart. Almost looks like the damage has been done upwards not downwards. No chance it was your shoe/heel from a missed clip in or something else more random?

 

Also agree with others that it doesnt look like any damage to the carbon. You get chips that deep from inside the chainstay where wheels might rub or under the bridge of the seatstay from stuck stones but as you are not sure how the damage was done best ask the shop at the very least.

Avatar
theraPi [6 posts] 4 days ago
0 likes
Bobbinogs wrote:

yeah, I am not convinced that is chain suck, probably more a case of either the setup not being right or just bad luck (hitting a bump in the road mid-shift). 

As above, get the damage checked out (there are quite a few good CF repairers out there now) although it does look cosmetic.  Might also be worth getting a chain catcher fitted as part of the front shifter check/setup afterwards (the Token ones work well and cost as little as a tenner).

 

Well, what qualifies as chain suck?

I definitelly dropped the chain first, and by the inertia made approximately half a turn on the cranks. It was 90rpm or so... I assume the small ring teeth picked the dropped chain and  puled it upwards. I dropped the chain on my other alloy bike couple of times, but te chain never got pulled up like that.

Avatar
alotronic [646 posts] 3 days ago
0 likes
theraPi wrote:
Bobbinogs wrote:

yeah, I am not convinced that is chain suck, probably more a case of either the setup not being right or just bad luck (hitting a bump in the road mid-shift). 

As above, get the damage checked out (there are quite a few good CF repairers out there now) although it does look cosmetic.  Might also be worth getting a chain catcher fitted as part of the front shifter check/setup afterwards (the Token ones work well and cost as little as a tenner).

 

Well, what qualifies as chain suck?

I definitelly dropped the chain first, and by the inertia made approximately half a turn on the cranks. It was 90rpm or so... I assume the small ring teeth picked the dropped chain and  puled it upwards. I dropped the chain on my other alloy bike couple of times, but te chain never got pulled up like that.

 

There's more vertical material on deep section carbon chainstay than on aluminium, so there will be more visible damage = more area to damage. FWIW less worried about damage in this part of the frame than say, headtube, because you are less likely to hurt yourself if a chainstay breaks! A bit of wear and tear in this area is unvoidable though I can see how doing it so early on a new frame will be a blow!

Avatar
Mybike [83 posts] 3 days ago
0 likes

You should always use a chain catcher

Avatar
Jimmy Walnuts [105 posts] 3 days ago
0 likes

As folk have previously posted, that’s just superficial damage and it doesn’t need to be looked at for structural integrity problems. You have a few aesthetic repair options - buy some wet and dry sandpaper from Halfords and sand the area down so there are no more flakes of paint, then get some clear nail varnish and give it a few coats to seal it in. You could also just buy a matte black chainstay protector, cut a section of it and stick it over the offending area after sanding off the flakes (don’t pick at the flakes).

Avatar
longassballs [158 posts] 3 days ago
0 likes

I don't care what anyone else says - I'd be taking it back to the shop for replacement or refund. For that to happen on a second ride is unacceptable and the fault of whoever set the bike up

Avatar
theraPi [6 posts] 2 days ago
0 likes
longassballs wrote:

I don't care what anyone else says - I'd be taking it back to the shop for replacement or refund. For that to happen on a second ride is unacceptable and the fault of whoever set the bike up

Well the whoever person would be me actually, since I re-adjusted it before the first ride.  1 And I'm actually confident doing this, having built up my earlier bikes. Just have to learn proper shifting, apparently  2

Avatar
NickJP [14 posts] 2 days ago
0 likes
AfterPeak wrote:

Looking at the width (top to bottom) that looks too long to be a chain but there are two/three strips  down that look about chain link width apart. Almost looks like the damage has been done upwards not downwards.

Chain suck is upwards - the lower run of the chain sticks on the bottom of the chainring, usually as it is midway through changing onto the small ring, and gets carried upwards as the chainring rotates until it jams between the chainstay and chainring. Changing down at the same time as hitting a bump in the road is what can cause it. In the 1990s I had a Lemond OCLV, and it actually had a small curved piece of aluminium sheet bonded onto the chainstay with double-sided tape at that point so that if chainsuck happened, the carbon fibre stay was protected by the aluminium. But I can't recall that it ever got called into action.

I have had chainsuck on a steel touring bike when shifting onto the granny chainring - the chain got quite firmly jammed and scraped some of the metal away on the chainstay, and I scraped a bit more away freeing the chain from where it was jammed so I could continue riding. When I got home I patched the paint up, and that bike is still in use many years later.

Avatar
Mungecrundle [1647 posts] 2 days ago
0 likes

Presumably, new bike, new chain?

Been a little while since I opened a new chain but I sort of recall that they are shipped with a grease which might be a little sticky, especially in the cold. I usually give them a good wipe down and a few squirts of ACF 50.

Avatar
theraPi [6 posts] 2 days ago
0 likes
Mungecrundle wrote:

Presumably, new bike, new chain?

Been a little while since I opened a new chain but I sort of recall that they are shipped with a grease which might be a little sticky, especially in the cold. I usually give them a good wipe down and a few squirts of ACF 50.

 

You're right about that.

This chain is EXTREMELY tacky. I'm tempted to really soak it in WD40 and then lube it properly

Avatar
Rick_Rude [483 posts] 2 days ago
0 likes

Just lacquer it. Got similar damage in a few places on mine after stuff like my father in law using my propped up bike as a sawhorse. In some ways there's a nice release in having a damaged bike, a bit like if you've got a car with a few scrapes and you no longer care if someone scratches it.

Avatar
longassballs [158 posts] 2 days ago
0 likes
theraPi wrote:
longassballs wrote:

I don't care what anyone else says - I'd be taking it back to the shop for replacement or refund. For that to happen on a second ride is unacceptable and the fault of whoever set the bike up

Well the whoever person would be me actually, since I re-adjusted it before the first ride.  1 And I'm actually confident doing this, having built up my earlier bikes. Just have to learn proper shifting, apparently  2

Oh, man! That really does suck. At least it's not terminal. Some good advice on here then fixing it

Avatar
arckuk [113 posts] 2 days ago
0 likes

Below is the chain stay of my Canyon Ultimate after a chain drop while Zwifting earlier this year. The edge of the metal plate that was double-sided-sticky-taped on to protect the frame got caught by the chain and was ripped off, causing damage to the paint (which looks like the case in the original pic  in this thread), and at least one layer of carbon fibre. Not sure if it was the top of the chain being pulled downwards, or the bottom pulled up by chain suck. I sent it off to the fantastic Rob Hayles at https://carbon-concepts.co.uk/ who did a great job at repairing and re-painting it so it now looks at least as good as new.

Avatar
Ruklaw [4 posts] 1 day ago
0 likes

Funnily enough this story sounds very familiar.

 

My TCR Advanced had chain suck when it was just a month or two old, took a lump of paint off the chain stay and I was very upset with it, but mostly myself as the rings were a little bit dirty which could have contributed (and I think I had also changed the cassette from 12-30 to 11-28 without shortening the chain, although that shouldn't really matter).

 

Anyhow, put a bit of white insulating tape over the damaged areas (as luck would have it the paint was white....) and I'm still riding the bike now perhaps 5 years (and about five thousand miles) later without any issue, and I've killed a few other frames in the intervening period.

 

So yeah, I suspect the frame is completely fine, but in view of how new the bike is it might be worth reporting the damage to the bike shop and perhaps trying to get something in writing to confirm that this won't effect the warranty/guarantee as there is no question of poor setup/maintenance (by yourself) being responsible at this early stage - you don't want it to fail in a year or two and for them to try and blame you for letting the chain suck happen due to poor maintenance/whatever.

 

As above there are also numerous carbon repair shops that can fix the frame should it come to it.

 

Best of luck!

Avatar
Ruklaw [4 posts] 1 day ago
0 likes

Just to add, I did have a chainstay fail on a trek 5000 (carbon frame) and it was quite bizarre really - I tried to pull away at the lights and the back wheel wouldn't turn round.

 

When I got off the bike, the wheel spinned - took me a good while to work out what was going on! As soon as load was applied to the chain the wheel pulled forward and wedged against the other stay.

 

So yeah, exceedingly unlikely you'll come to any harm should the frame fail in this area.

Avatar
LastBoyScout [663 posts] 1 day ago
0 likes

Trickier to do with carbon frames than metal ones, but my bikes, where possible, have several thin zip ties around the chainstay to avoid exactly this.

Pretty sure I've seen self-adhesive stainless patches for this, too.

Avatar
philhubbard [208 posts] 1 day ago
0 likes

Bit of sanding with wet and dry and steal some clear nail varnish from the better half will sort the cosmetics as it doesn't look structural. 

Pop some of this over any areas where you could get stone chips, cable rub and around the chainstay; https://www.amazon.co.uk/d/DIY-Home-Improvement-Tools/Protection-8671HS-...

 

If you want to do it on the cheap, as you have a black bike use an old inner tube with a thin black/clear zip tie round it and as other people have mentioned by a chain catcher!