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Re: P3 BRAKE BOSS FAILURE [Avago] [ In reply to ]
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Agreed.

However, second owner, so no warranty. I'm just trying to help Larry keep a classic (and fast!) Cervelo racin'.

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
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Re: P3 BRAKE BOSS FAILURE [damon_rinard] [ In reply to ]
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Damon,
The second repair attempt was successful!

What I did different; I confirmed that preparation is key!

1. AL boss plate
a. I wore gloves the entire time once I started prepping the plate, oil from my hands may have contributed to first failed repair attempt.
b. To ensure the plate was adequately etched, I submerged the plate in the etching solutions vice just coating it, otherwise, I followed the instructions exactly. After removing the plate from the etching solution part B, the plate had the part B yellow/orange tint, this was not the case the first time around. Inadequate etching may also have contributed to the first failed repair attempt.
c. I did not use wax this time, the wax may have contaminated the joint and contribute to the failure. I just roughed out the holes with a drill once the epoxy cured and then used an X Acto blade to fine tune the holes. I also used the X Acto blade to remove excess cured epoxy from the frame.

2. CF recess
a. I used acetone on both attempts to prep the CF; however, I believe I may not have allowed the acetone to adequately evaporate/dry prior to making the joint. There was no epoxy residue in the CF recess when I removed the AL plate after the repair failure, so I believe residual acetone in the CF recess dissolved the epoxy when I made the joint - likely the most important mistake.
b. I used compressed air to evaporate/dry the CF recess on round two. This was a little risky in that there is some moisture and compressor oil in compressed air. The risk paid off, the joint is solid on this attempt.

I believe this tread, as a whole, captures what is required to adhere AL to CF.

Thank you for all you help!

Larry
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Re: P3 BRAKE BOSS FAILURE [lollice] [ In reply to ]
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Looks like you got it to go, hopefully this time will do the trick!

Some other points for others:
1. Be careful when seleting fingernail polish removers. Some contain oil or other conditioners for fingernails (go figure!) This may affect the final cleaning of CF parts. You can get pure acetone at auto parts supply places (in Canada, Canadian Tire; in the US, probably Pep Boys or NAPA).
2. Wax will definitely prevent the proper curing of *some* epoxies but not all. If you can avoid it, then don't use wax. As Damon notes, it's easy to chase the threads with a M6 tap.
3. Surface roughness of both parts is key to getting the epoxy to bond. On the aluminum side you can use 80 or 100 grit paper; on the CF that's difficult since it's in a recess, but whatever you can do in there to break up the existing surface is going to help the epoxy bond the two parts together.

Less is more.
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Re: P3 BRAKE BOSS FAILURE [Avago] [ In reply to ]
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Avago wrote:
if in 2017 the brake boss plate of your 2014 Mercedes / Toyota or whatever was coming out, I'm just taking a guess that you'd be straight to your dealer to get it fixed.... under warranty even and if the Senior Technologist for that company said " Bummer the plate's coming out ", then you'd be pretty annoyed
so if in 2017 the brake boss plate of my 2014 Cervelo P3 was coming out, I'm just taking a guess that I'd be straight to my dealer to get it fixed.... under warranty even and if the Senior Cyclist Technologist for that company said " Bummer the plate's coming out ", then I'd be pretty annoyed
Well, we'll soon see. My new P3 rear brake bridge is loose as the insert in the frame has come loose. The bike is a few months old and ridden a handful of times.

I've contacted Cervélo. Given the bike is a few months old only, I'm not going to be particularly impressed if all I get is advice on epoxying the insert back in the frame.
Last edited by: JerseyBigfoot: Sep 18, 14 21:47
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Re: P3 BRAKE BOSS FAILURE [JimMoss] [ In reply to ]
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JimMoss wrote:
Yeah, but he used "vigilante" when he meant to use "vigilant" in his most recent post below. So close...

Vigilante? I LOVE Vigilantes!



Twenty-five years and my life is still
Trying to get up that great big hill
of hope
For a destination
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Re: P3 BRAKE BOSS FAILURE [JerseyBigfoot] [ In reply to ]
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Right, so a quick update…

Cervélo UK now say they can't help. The bike is four months old, been ridden outside about ten times and probably around another twenty times on the turbo trainer as I do most of my interval work on the road bike. All in all, it's not seen much use. The "Lifetime Warranty" looks about as much worth as the paper it was written on.

I'll post up photos when I'm back from this trip, and any further response from Cervélo.
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