Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.Bridlemile
08-05-07, 07:50 PM
Also posted in the bicycle mechanics forum
BACKGROUND: I have a 57cm scandium Coppi frame with carbon seat stays that is a few years old. A few months ago the 5x0.8 mm fastener that connects the left chain stay and left seat stay loosened up but didn't completely retract. I cleaned the screw and fastener of dirt&grease and used permanent Locktite to secure the fastener. I watched it carefully and probably rode 2k miles with not issues.
This last weekend at mile 80 during a century with many miles on chipseal I kept hearing noise from the frame but had assumed it was my headset which wasn't quite right. I stoped the bike, got off and wasn't able to move the rear wheel and then saw that the left side fastener was missing and that the rear tire was rubbing against the frame.
I took it to a mechanic who fixes Ti and Steel frames. Initially he was going to use 2part epoxy to fix it but after seeing that the frame was misaligned in it's relaxed stated he decided that the frame was compromised and didn't want to incur any liablity.
QUESTIONS:
1) Has anybody had a similar circumstance? Either the same Coppi frame or trying to repair a scandium/carbon frame.
2) I've never seen any other frames that have had the stays secured with a machine screw. Is this a common method for higher end frames? Was Coppi trying to save money or is there some other reason for the assembly method?
3) The mechanic's comment about the relaxed state does seem valid. Any thoughts? The right side has cracks in the paint along the joint lines betweent the chain and rear seat stay.
4) I purchased JB-Weld and stainless machine screws in preperation to make the repair. I'm going to use a Dremel to remove any excess Loctite prior to bonding. Any concerns that this is not the appropriate method to folllow?
5) Assuming go forward on the JB-Weld repair method, what are the throughts on the structural integrity of the frame? Again noting the non-aligned relaxed state, any repair will put the frame into a stressed state but again it's likely been that way for the 5k miles that I've ridden over the last 1.5 years.
I have photos but but am getting upload errors today. Photos and same thread are on http://forums.roadbikereview.com/sho...d.php?t=103351
BACKGROUND: I have a 57cm scandium Coppi frame with carbon seat stays that is a few years old. A few months ago the 5x0.8 mm fastener that connects the left chain stay and left seat stay loosened up but didn't completely retract. I cleaned the screw and fastener of dirt&grease and used permanent Locktite to secure the fastener. I watched it carefully and probably rode 2k miles with not issues.
This last weekend at mile 80 during a century with many miles on chipseal I kept hearing noise from the frame but had assumed it was my headset which wasn't quite right. I stoped the bike, got off and wasn't able to move the rear wheel and then saw that the left side fastener was missing and that the rear tire was rubbing against the frame.
I took it to a mechanic who fixes Ti and Steel frames. Initially he was going to use 2part epoxy to fix it but after seeing that the frame was misaligned in it's relaxed stated he decided that the frame was compromised and didn't want to incur any liablity.
QUESTIONS:
1) Has anybody had a similar circumstance? Either the same Coppi frame or trying to repair a scandium/carbon frame.
2) I've never seen any other frames that have had the stays secured with a machine screw. Is this a common method for higher end frames? Was Coppi trying to save money or is there some other reason for the assembly method?
3) The mechanic's comment about the relaxed state does seem valid. Any thoughts? The right side has cracks in the paint along the joint lines betweent the chain and rear seat stay.
4) I purchased JB-Weld and stainless machine screws in preperation to make the repair. I'm going to use a Dremel to remove any excess Loctite prior to bonding. Any concerns that this is not the appropriate method to folllow?
5) Assuming go forward on the JB-Weld repair method, what are the throughts on the structural integrity of the frame? Again noting the non-aligned relaxed state, any repair will put the frame into a stressed state but again it's likely been that way for the 5k miles that I've ridden over the last 1.5 years.
I have photos but but am getting upload errors today. Photos and same thread are on http://forums.roadbikereview.com/sho...d.php?t=103351