Carbon frame repair

Author
Discussion

esuuv

1,306 posts

204 months

Tuesday 18th October 2016
quotequote all
okgo said:
If you saw how slap and dash many of these frames are (especially the fake Colnago's like the above vs the Lugged ones) on the inside, you'd soon realise that the repair is likely better than the initial job.

I looked inside my S Works Frame and its a disgrace, sharp carbon bits poking out everywhere, looks like it took about 2 minutes to make.
I'd echo this - my Cervelo P5 really isn't pretty at all inside.

Composite Guru

2,205 posts

202 months

Tuesday 18th October 2016
quotequote all
esuuv said:
okgo said:
If you saw how slap and dash many of these frames are (especially the fake Colnago's like the above vs the Lugged ones) on the inside, you'd soon realise that the repair is likely better than the initial job.

I looked inside my S Works Frame and its a disgrace, sharp carbon bits poking out everywhere, looks like it took about 2 minutes to make.
I'd echo this - my Cervelo P5 really isn't pretty at all inside.
That's why would never waste my money on a carbon frame. If you could see them being made you would not pay the money. Most are wet laid in halves and then wrapped together afterwards.
Not a nice process and pretty slap dash IMO. biggrin

upsidedownmark

2,120 posts

134 months

Tuesday 18th October 2016
quotequote all
First up, why on earth would you waste time (and weight) putting a nice finish on the inside of the tubes?

Second, the 'normal' way of building carbon frames (at least decent ones), is to lay pre-preg over a former (EPS, bladder, whatever), stick that inside a mould and cook it while blowing it up from the inside. Then you take the mould apart, remove the former and presto - a frame. No wet layup, no glueing halves together.

Even the 'cheap chinese' frame I took apart was made up of tubes 'lugged' together, not two halves glued together.

battered

4,088 posts

146 months

Tuesday 18th October 2016
quotequote all
I thought the default position was to buy the Ribble one that's identical in every way to a DeRosa, in every regard except the paint job. Same factory, same moulds, same materials, so I'm told. The Ribble one's half the price.

okgo

37,861 posts

197 months

Tuesday 18th October 2016
quotequote all
upsidedownmark said:
First up, why on earth would you waste time (and weight) putting a nice finish on the inside of the tubes?

Second, the 'normal' way of building carbon frames (at least decent ones), is to lay pre-preg over a former (EPS, bladder, whatever), stick that inside a mould and cook it while blowing it up from the inside. Then you take the mould apart, remove the former and presto - a frame. No wet layup, no glueing halves together.

Even the 'cheap chinese' frame I took apart was made up of tubes 'lugged' together, not two halves glued together.
The point I was making is that they're hardly works of art, and that someone who knows what they are doing could easily match the quality with a repair.

outnumbered

4,067 posts

233 months

Friday 9th December 2016
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yellowjack said:
"The one in Dorking" is actually in Leatherhead, just outside the M25, if it's the one that was recommended to me. In the end I didn't go down the repair route, but several people, including local independent bike shop owners, have pointed me in their direction...

http://www.carbonbikerepair.co.uk/
I can also give a recommendation for these guys. They have a very professional operation, well organised and super-clean workshop, lots of kit, dedicated spray booths. It looks rather unprepossessing from the outside but very different when you go through the door.

They repaired the headtube on my Canyon SLX that I rode into a gate, and a snapped rear dropout on my C50. The respray work is excellent, even on the Canyon's matte finish, you'd never know it had been repaired. The repairs took 4-5 weeks to complete, and they seem pretty busy.


BenGismo

297 posts

167 months

Friday 9th December 2016
quotequote all
The 3 scott carbon frames I have are pretty smooth on the inside and look good in there. (even inside top tubes n downtubes)

Ok, Maybe not quite as aestheticly pleasing as the outside gloss finish but still very well put together and look professionally made.
https://www.bikerumor.com/2010/06/25/first-look-20...

https://www.youtube.com/watch?v=LJ46J3NQIVg

There's a good thread here with loads of cross section views of frames
http://weightweenies.starbike.com/forum/viewtopic....

And having got aluminium versions and carbon versions of similar frames....Id much rather have the carbon one in terms of feel and weight.

Repairs on carbon fibre are possible, but it will often not have the strength it did before hand unless extra layers are added on the inside or outside. Just adding resin across the crack and repainting is no where near as strong as the original frame. I personally wouldnt want to ride a repaired frame unless it was only a small repair which was done correctly by bridging any gaps with new carbon on the inside.

Edited by BenGismo on Friday 9th December 13:53

idiotgap

Original Poster:

2,112 posts

132 months

Friday 9th December 2016
quotequote all
Coincidentally, I got my frame back from LondonCarbonRepair today. I elected not to get it painted as I'm going to build the bike back up and see how I feel about it, so went for minimal outlay. I might get it painted at a later date if I decide I'm going to ride it a lot. I might still buy another bike/frameset and keep this one as a spare.



outnumbered

4,067 posts

233 months

Friday 9th December 2016
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Looks like they just stuck some electricians tape over it smile


Fluffsri

3,161 posts

195 months

Friday 9th December 2016
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If I did a repair like that at work it would have to be removed. We are taught to have rounded corners to prevent stress raisers.

idiotgap

Original Poster:

2,112 posts

132 months

Friday 9th December 2016
quotequote all
A bike frame would be subjected to a good deal less stress than components in an aeronautic application, I would imagine. Do you think this is a significant issue?

It looks quite similar to other repair images I've seen so I didn't find it so alarming.

Edited by idiotgap on Friday 9th December 16:57

Eddh

4,656 posts

191 months

Friday 9th December 2016
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Looks like they just stuck some duct tape over it, i'd have done that for £20!

idiotgap

Original Poster:

2,112 posts

132 months

Friday 9th December 2016
quotequote all
It's not come out very well in the photograph. It's not a patch of tape.

JustinF

6,795 posts

202 months

Saturday 10th December 2016
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This might be of interest to a few of you. Cutting open carbon frames.
https://www.youtube.com/watch?v=EZbg5hCRyvs&t=...

idiotgap

Original Poster:

2,112 posts

132 months

Saturday 10th December 2016
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JustinF said:
This might be of interest to a few of you. Cutting open carbon frames.
https://www.youtube.com/watch?v=EZbg5hCRyvs&t=...
Cheers J, I watched that the other week. It does demystify the carbon frame a little and illustrate the progression over time. Most surprising to me were the manufacturing defects and voids in the layups some of the frames and forks have from new.

AyBee

10,522 posts

201 months

Monday 12th December 2016
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Did the insurance pay out in the end?

idiotgap

Original Poster:

2,112 posts

132 months

Monday 12th December 2016
quotequote all
AyBee said:
Did the insurance pay out in the end?
Yeah they did. I don't strictly speaking need this frame, but it seemed a shame to bin it and I haven't bought anything else yet.
Sadly I don't see you in the bike park anymore, they fixed our building up so we have our own, plus my firm got bought so we're moving over to Liverpool st. next year.

AyBee

10,522 posts

201 months

Monday 12th December 2016
quotequote all
idiotgap said:
AyBee said:
Did the insurance pay out in the end?
Yeah they did. I don't strictly speaking need this frame, but it seemed a shame to bin it and I haven't bought anything else yet.
Sadly I don't see you in the bike park anymore, they fixed our building up so we have our own, plus my firm got bought so we're moving over to Liverpool st. next year.
Aah, fair enough. I guess if that's the case, you can see how it feels, and if it doesn't feel right, buy a replacement thumbup

scherzkeks

4,460 posts

133 months

Tuesday 13th December 2016
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idiotgap said:
My best bike got broken in a car accident. A large crack in the carbon fibre down tube.

I've been googling about and trying to find opinions on repaired carbon frames and I didn't see what I expected. I thought it would be a bit like with the generic Chinese frames, folk would be saying they'd never ride a repaired frame, but I'm not seeing much of that at all.

Would you ride a repaired frame? or get rid and buy a shiny new bike?

The seat tube on my Colnago Extreme-C was damaged by an airline in shipping and I had it repaired. Aesthetics aside, it is like new.

I would repair any decent quality frame. Fact is, in terms of durability, carbon is not an ideal material for the average joe, so unless you've got hordes of cash to toss away, buying new carbon frame is rather silly.

Or just ditch the carbon altogether for aluminum.

idiotgap

Original Poster:

2,112 posts

132 months

Wednesday 27th September 2017
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I like to see a thread through, for the benefit of anyone finding this through google or whatever later on.

The repaired frame rides beautifully and I'm still really enjoying it. I've just upgraded the groupset and always thinking about new wheels.