Hairy Posted August 8, 2019 Posted August 8, 2019 "warranty" only means that the product will last for that amount of time... so 6 months means after 6months and 1 day the BB will explode leaving carbon pieces stuck in your legs and @$$#Naturally ... did you not know that all carbon bikes explode at midnight of the day following the end of their warranty period!?!?! Let us also not forget that Bogus designed and build his own carbon bike, which I understand has not exploded yet. Jewbacca, Quagga and BigDL 3
Jewbacca Posted August 8, 2019 Posted August 8, 2019 #Naturally ... did you not know that all carbon bikes explode at midnight of the day following the end of their warranty period!?!?! Let us also not forget that Bogus designed and build his own carbon bike, which I understand has not exploded yet.It won't either.... He gave it a lifetime warranty...... bullet77, AdamA and Hairy 3
MudLark Posted August 8, 2019 Posted August 8, 2019 Oh well. At least there's one happy lawyer out there.
Hairy Posted August 8, 2019 Posted August 8, 2019 Oh well. At least there's one happy lawyer out there.probably planning his new S-Works build right now too Wayne pudding Mol, MDJ, AdamA and 1 other 4
Veebee Posted August 8, 2019 Posted August 8, 2019 probably planning his new S-Works build right now too but he plays golf...
Hairy Posted August 8, 2019 Posted August 8, 2019 but he plays golf...golf in the week, MTB on the weekend! Wayne pudding Mol and MDJ 2
DieselnDust Posted August 8, 2019 Posted August 8, 2019 (edited) A bb shell is typically made from the highest modulus carbon fabric in the bike. To repair it properly requires extensive removal of carbon material to reform/reshape the broken area to the required tolerance (remember a bearing cup has to go back in there. A precision machines mandrel matching the bb specs needs to be machined.In order to create the best bond of the carbon cloth to the old material the repair shop needs an external mould and a high pressure system to ensure good adhesion and penetration of the resin.Does the repair shop know what resin was used?The engineering required to repair the bb area is not the same as a down tube or seat stay or chain stay. It’s the most precisely engineered part in the whole bike. It can’t be recreated without incurring more cost than the frame is worth.Repair at your own risk. Advising someone else to risk their safety on such a repair is more than a little irresponsible even for pre weekend fun Edited August 8, 2019 by DieselnDust Capricorn, ChrisF, Hairy and 4 others 7
EmptyB Posted August 8, 2019 Posted August 8, 2019 golf in the week, MTB on the weekend!MTB after midnight.... Hairy 1
Hairy Posted August 8, 2019 Posted August 8, 2019 A bb shell is typically made from the highest modulus carbon fabric in the bike. To repair it properly requires extensive removal of carbon material to reform/reshape the broken area to the required tolerance (remember a bearing cup has to go back in there. A precision machines mandrel matching the bb specs needs to be machined.In order to create the best bond of the carbon cloth to the old material the repair shop needs an external mould and a high pressure system to ensure good adhesion and penetration of the resin.Does the repair shop know what resin was used?The engineering required to repair the bb area is not the same as a down tube or seat stay or chain stay. It’s the most precisely engineered part in the whole bike. It can’t be recreated without incurring more cost than the frame is worth.Repair at your own risk. Advising someone else to risk their safety on such a repair is more than a little irresponsible even for pre weekend funbut are "we" not just filling the void of the ovalisation vs building a new BB shell?
Veebee Posted August 8, 2019 Posted August 8, 2019 but are "we" not just filling the void of the ovalisation vs building a new BB shell? do you have shares in CD, why always trying to cover up their wrong doing ? Yeah, let me just fill up the groves on my BB shell and go bashing through the mountains waiting for something to go wrong.
DieselnDust Posted August 8, 2019 Posted August 8, 2019 but are "we" not just filling the void of the ovalisation vs building a new BB shell? filling in a "void" in a highstress high pressure (press fit) area is a not a permanent repair. When the frame is new the fix is too bond in the cups so that they don't move or damage the shell to bbcup interface. The pressure on the cups is evenly distributed around the shell. With a filler option like you suggest that area will take all the strain and its not adequately bonded to ensure longevity or reliability.Once that's compromised gluing in the cups gets you nothing but more trouble. Its a temporary fix to delay the inevitable. The only proper fix is to cut out the bb shell and bond in a new one or remould the entire area. This a not a repair job. The only fix is a new frame. Skubarra 1
i24 Posted August 8, 2019 Posted August 8, 2019 filling in a "void" in a highstress high pressure (press fit) area is a not a permanent repair. When the frame is new the fix is too bond in the cups so that they don't move or damage the shell to bbcup interface. The pressure on the cups is evenly distributed around the shell. With a filler option like you suggest that area will take all the strain and its not adequately bonded to ensure longevity or reliability.Once that's compromised gluing in the cups gets you nothing but more trouble. Its a temporary fix to delay the inevitable. The only proper fix is to cut out the bb shell and bond in a new one or remould the entire area. This a not a repair job. The only fix is a new frame. We have not seen the damage but ... The "void" should have been filled with epoxy when the bike shop fitted the BB. They didn't and the void has "grown". Now it probably needs to be filled with something like an epoxy/cotton flox mixture and carefully ground (machined?) back to size. Then the new BB can be epoxy'd into place. If any of the carbon layers have been damaged, then you may need to put in a layer of carbon, then grind it back to original size. That would be a lot of work. If enough material had been removed to weaken it the frame, then you may have to put an extra layer of carbon on outside of the BB to restore the strength. That would be a labour of love, as you would have to respray the frame when you were finished. But I doubt this happened as it would take a very Special rider to carry on riding a bike while the BB was destroying the frame to this extent. But Bonus has seen the damage and he is prepared to fix it.... Hairy 1
DieselnDust Posted August 8, 2019 Posted August 8, 2019 We have not seen the damage but ... The "void" should have been filled with epoxy when the bike shop fitted the BB. They didn't and the void has "grown". Now it probably needs to be filled with something like an epoxy/cotton flox mixture and carefully ground (machined?) back to size. Then the new BB can be epoxy'd into place. If any of the carbon layers have been damaged, then you may need to put in a layer of carbon, then grind it back to original size. That would be a lot of work. If enough material had been removed to weaken it the frame, then you may have to put an extra layer of carbon on outside of the BB to restore the strength. That would be a labour of love, as you would have to respray the frame when you were finished. But I doubt this happened as it would take a very Special rider to carry on riding a bike while the BB was destroying the frame to this extent. But Bonus has seen the damage and he is prepared to fix it....We have not seen the damage but ... The "void" should have been filled with epoxy when the bike shop fitted the BB. They didn't and the void has "grown". Now it probably needs to be filled with something like an epoxy/cotton flox mixture and carefully ground (machined?) back to size. Then the new BB can be epoxy'd into place. If any of the carbon layers have been damaged, then you may need to put in a layer of carbon, then grind it back to original size. That would be a lot of work. If enough material had been removed to weaken it the frame, then you may have to put an extra layer of carbon on outside of the BB to restore the strength. That would be a labour of love, as you would have to respray the frame when you were finished. But I doubt this happened as it would take a very Special rider to carry on riding a bike while the BB was destroying the frame to this extent. But Bonus has seen the damage and he is prepared to fix it....Just the methods you're mentioning are reinforcing my belief that this frame shouldn't be repaired. Grinding?! Cotton wool as filler....I trust bonus to know what he's doing but these methods rely to much on the assembly staying in place and if that bike has the speaz Crank I'd be nervous as heck.good luck to all involved
Me rida my bicycle Posted August 9, 2019 Posted August 9, 2019 A bb shell is typically made from the highest modulus carbon fabric in the bike. To repair it properly requires extensive removal of carbon material to reform/reshape the broken area to the required tolerance (remember a bearing cup has to go back in there. A precision machines mandrel matching the bb specs needs to be machined.In order to create the best bond of the carbon cloth to the old material the repair shop needs an external mould and a high pressure system to ensure good adhesion and penetration of the resin.Does the repair shop know what resin was used?The engineering required to repair the bb area is not the same as a down tube or seat stay or chain stay. It’s the most precisely engineered part in the whole bike. It can’t be recreated without incurring more cost than the frame is worth.Repair at your own risk. Advising someone else to risk their safety on such a repair is more than a little irresponsible even for pre weekend funtotally agree, I have seen a bb shell fail that was probably 1 if the worst crashes I have seen. The forces going through your crank on a MTB are so much with jumps, drop offs, rough trails and you want to take it on with a "plaster" in that area?!Would like to see how these guys who recommend the repair jump up and down if their frame with 2 years warranty left just get patched to fix something a bike shop f...ed up. MudLark and BigDL 2
i24 Posted August 9, 2019 Posted August 9, 2019 Just the methods you're mentioning are reinforcing my belief that this frame shouldn't be repaired. Grinding?! Cotton wool as filler....I trust bonus to know what he's doing but these methods rely to much on the assembly staying in place and if that bike has the speaz Crank I'd be nervous as heck.good luck to all involved Cotton flox, as used for building and repairing composite aircraft:https://www.aircraftspruce.com/catalog/cmpages/flockedcotton.php FUD: https://en.wikipedia.org/wiki/Fear,_uncertainty,_and_doubt DieselnDust and Jewbacca 2
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now