So are you suggesting that common sense (we'll maybe come back to that interesting concept later) is to just carry on regardless, and not have this damage checked?
Ride or Replace?
- Thread starter KneesUp
- Start date
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So are you suggesting that common sense (we'll maybe come back to that interesting concept later) is to just carry on regardless, and not have this damage checked?
davidphilips
Phil Pip
- Location
- Onabike
The damage was caused by rubbing and not an impact so as Yellowsaddle said It's just superficial. Ride on and let the bike wear its scars with pride.
I would have to agree with all the posts concerning replacing or at least getting it checked by a carbon repair specialist if it where not for the fact that you know what caused the damage and its only surface rubbing.
I would have to agree with all the posts concerning replacing or at least getting it checked by a carbon repair specialist if it where not for the fact that you know what caused the damage and its only surface rubbing.
If we knew what "surface rubbing" meant, and what the depth of the carbon fibre was at that point, then I'd agree with you. Say the CF is 2mm thick there, and a half millimetre has been rubbed away. I mean, half a mill.........who'd be bothered by that? Who'd even know?
davidphilips
Phil Pip
- Location
- Onabike
Mike surface rubbing is when the rubbing is on the surface only and not into the structure of the item and in this case looks very like its only the paint that is rubbed away but if there was a big grove worn in the forks then yes get it checked/repaired or better replaced.
Thing about carbon (did you ever try and cut it with a metal blade in a hacksaw) is its very wear resistant its even used on chain wheels so chances are theres very little wear on it if any and i can not see any in the photos, now if it had been impact damage then i would say replace it asap as you would have no way to know if there was a crack..
Yellow Saddle
Guru
- Location
- Loch side.
Yes.
I know. But how do we know that the OP's assessment of the damage as only being surface rubbing is correct? That's my point. For the sake of 5 minutes in a bike shop, I can't see why so many are resistant to the idea of getting a crucial part of the structure looked at.
Which is why the definition of common sense is such an interesting topic.
Yellow Saddle
Guru
- Location
- Loch side.
Start a thread for it and see if anyone bites.
Yellow Saddle
Guru
- Location
- Loch side.
It seems to me that the OP is pretty sure how it happened.
And what will 5 minutes in a bike shop help? Have you got any idea what goes into checking the structural integrity of carbon composites?
It'll probably help a bit more than uninformed comments from random people on the internet whose only evidence of the structural integrity of a critical part of a bike is "it's only on the surface" from a non-expert.
Yes thanks. You'd start with a visual assessment. If it is just the paint that's been removed, and the OP's opinion is therefore backed-up, then there'd be no need to go any further. Until then, we've just got that to be going on.
I like Skol
A Minging Manc...
- Location
- Sunny Ashton-under-Lyne
5 minutes in a bike shop? That will consist of 15 seconds of them looking at the fork and agreeing that there is 'some' damage and then 4min 45s of them telling you that there is no certainty that the forks integrity hasn't been compromised and the sensible option is to replace the damaged item for safety's sake. They cannot tell you anything else!
Please tell me what the next step would be if it was suspected that there might be more than just paint damage. I am genuinely interested because I have three bikes with carbon forks in Skol Towers.
Johnno260
Guru
- Location
- East Sussex
My bikes got carbon forks and seat post, if this was mine I would be miffed about the paint but not concerned about the structure, but I'm no expert.
A fully carbon bike terrified me hence the reason I didn't go full carbon.
A fully carbon bike terrified me hence the reason I didn't go full carbon.
GuyBoden
Guru
- Location
- Warrington
Sell it cheap in the "For Sale" section.
OP
OP
KneesUp
Guru
Thanks for all the replies so far.
I am certain that it's from rubbing on something, but I don't know exactly what - it was fine near Inverness, where it put it on the back of the car as the last bike on a 4 bike rack and drove back to Yorkshire, unloaded the bikes and went to bed. I rode it to work the next morning and it spent the day in the corner of my office (I only get to keep it in the office when I'm the only one here, so I know nothing happened at work) On turning it around to come home I noticed the damage - so I've concluded that it was rubbing on some part of the next bike on the rack for some proportion on the 450 mile or so return from Schotland.
I'm pretty sure some carbon has gone - it'd be extremely unlikely to just take the paint off, surely? If I rub my thumb on it I get a bit of black dust, but then it could just be mucky. The 'step' down to the damage doesn't seem very much thicker than the paint, though, and my guess was that forks are built with a fair degree of tolerance in them.
The reason I asked is because, as has been pointed out, fork failure is generally pretty catastrophic because you lose steering, most of the braking, support and balance all at the same time. That is pretty grim pootling along a quiet back road minding your own business, but doesn't bear thinking about when you're commuting alongside buses and lorries.
I rode it again this morning.
I am certain that it's from rubbing on something, but I don't know exactly what - it was fine near Inverness, where it put it on the back of the car as the last bike on a 4 bike rack and drove back to Yorkshire, unloaded the bikes and went to bed. I rode it to work the next morning and it spent the day in the corner of my office (I only get to keep it in the office when I'm the only one here, so I know nothing happened at work) On turning it around to come home I noticed the damage - so I've concluded that it was rubbing on some part of the next bike on the rack for some proportion on the 450 mile or so return from Schotland.
I'm pretty sure some carbon has gone - it'd be extremely unlikely to just take the paint off, surely? If I rub my thumb on it I get a bit of black dust, but then it could just be mucky. The 'step' down to the damage doesn't seem very much thicker than the paint, though, and my guess was that forks are built with a fair degree of tolerance in them.
The reason I asked is because, as has been pointed out, fork failure is generally pretty catastrophic because you lose steering, most of the braking, support and balance all at the same time. That is pretty grim pootling along a quiet back road minding your own business, but doesn't bear thinking about when you're commuting alongside buses and lorries.
I rode it again this morning.
Globalti
Legendary Member
The paint on modern frames is thick and glossy but not very strong. Look at the pic below of the quite similar damage TNT did to a bike I sold by driving a sharp object through the carton in transit. Sadly the buyer's wife allowed the courier to pressure her into signing for the package "in good condition" making my battle for recompense very difficult but in the end I managed to shame TNT into paying for most of the respray.
Back to your forks - the paint has gone full depth and there may have been some abrasion to the actual resin, in which the carbon fibres are encapsulated like the steel reinforcing rods in structural concrete. If the abrasion is over a wide area and is smooth, just get it resprayed. If there was a sharp cut or gouge I'd be a little more worried as that could form a stress riser and start a crack in the same way as when you tear open a plastic package by nipping the edge with your teeth. Even then I wouldn't worry too much; I would fill the damaged area with resin, re-finish smoothly so as to transfer stresses evenly, re-paint and carry on riding. You would spot a propagating crack long before the forks collapsed because the other leg is also massively strong. Deep damage to the reinforcing carbon fibres would be more worrying.
Back to your forks - the paint has gone full depth and there may have been some abrasion to the actual resin, in which the carbon fibres are encapsulated like the steel reinforcing rods in structural concrete. If the abrasion is over a wide area and is smooth, just get it resprayed. If there was a sharp cut or gouge I'd be a little more worried as that could form a stress riser and start a crack in the same way as when you tear open a plastic package by nipping the edge with your teeth. Even then I wouldn't worry too much; I would fill the damaged area with resin, re-finish smoothly so as to transfer stresses evenly, re-paint and carry on riding. You would spot a propagating crack long before the forks collapsed because the other leg is also massively strong. Deep damage to the reinforcing carbon fibres would be more worrying.
