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General Category >> Technical >> Carbent Seat Mount Failure
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Message started by jayg on Apr 17^th, 2013, 7:24pm

Title: Carbent Seat Mount Failure
Post by jayg on Apr 17^th, 2013, 7:24pm

As I was transporting my Carbent high racer to the Lancaster Country Ride, last Saturday, I heard a cracking sound as I turned a corner and the rear of the bike slid about 15". I had the fork installed in a fork mount on the floor of my van and the front of the bike secured with a tie-down to keep the bike in an upright position. Inspected the bike at Lancaster and couldn't see any damage, so I went ahead and rode it 42 miles. Last Tuesday, I started riding it at WRL and noticed the seat was moving back and forth as I pedaled. Inspection revealed the carbon fiber seat mount was not attached to the carbon tube frame member. It's a glued joint (aircraft grade epoxy). After conferring with the manufacturer, Bent Up Cycles, determined that the carbon frame tube had delaminated. The bike is 6 months out of warranty, so I'm up the creek. I'm not going to spend hundreds of dollars to send it to the manufacturer for a repair attempt and certainly not thousands for a new frame. Going to attempt to repair it myself with the epoxy the manufacturer originally used to attach the seat mount to the frame (Costs about $90) and hope the tube does not delaminate further. Guess I should have purchased a CA 2.0. :(

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00126_zps69d7ef6e.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00126_zps69d7ef6e.jpg.html)

W-shaped seat mount detached from frame tube.

Title: Re: Carbent Seat Mount Failure
Post by dd5339 on Apr 17^th, 2013, 7:46pm

Ouch! That stinks.

Semper Fi

Title: Re: Carbent Seat Mount Failure
Post by rmillay on Apr 17^th, 2013, 7:48pm

You might consider reinforcing the glue joint with a metal strap screwed to the seat frame. Titanium would be neat! But aluminum should work. [smiley=chinscratch.gif]

Title: Re: Carbent Seat Mount Failure
Post by LightningPilot on Apr 17^th, 2013, 7:49pm

jayg wrote:

Bummer, hate that it happened to you [smiley=undecided.gif]

Title: Re: Carbent Seat Mount Failure
Post by Ric_Clark on Apr 17^th, 2013, 7:52pm

jayg wrote:

My money is on Jay completing the repairs better than new...... [smiley=stirthepot.gif] [smiley=stirthepot.gif] [smiley=stirthepot.gif]

[smiley=dancer.gif]

Title: Re: Carbent Seat Mount Failure
Post by TonyWard on Apr 17^th, 2013, 9:54pm

I think you should cut it up and send it back to you know who. Then tell them to keep it - you'd rather ride a Musashi anyway. Then I'd cross post on BROL.

6 months out of warranty is bs. I'm sure your bike has a lot fewer miles on it then others riding the same bike with a lot more weight and produce a lot more power. Heck you have so many bikes there is no way you could wear one out.

Title: Re: Carbent Seat Mount Failure
Post by aikigreg on Apr 17^th, 2013, 11:09pm

Seriously, Dana won't fix it?

Title: Re: Carbent Seat Mount Failure
Post by Andy on Apr 18^th, 2013, 8:13am

If you can't fix it contact Franz of Pterovelo in Oklahoma City. he fixes carbon frames for people all the time around here and does amazing work reasonably. holler if you need contact info.
Andy. :)

Title: Re: Carbent Seat Mount Failure
Post by TonyWard on Apr 18^th, 2013, 9:51am

Well look at the bright side. You may need a new high racer. I hear the M5 is pretty nice. [smiley=laugh.gif]

Title: Re: Carbent Seat Mount Failure
Post by aikigreg on Apr 18^th, 2013, 2:17pm

Oh, it is. But it's really more of a lowracer - you just get the benefit of the bigger front wheel.

Jay, did you talk to Dana directly? I mean, mine is rock solid at 250 pounds and 4 years of solid use. It's been on cross country trips, two different hill country races over texas chipseal, the race across Oregon, 2 or 3 tejas time trial races, and countless brevets. No way a featherweight like you who doesn't ride it exclusively damaged that bike.

TonyWard wrote:

Well look at the bright side. You may need a new high racer. I hear the M5 is pretty nice. [smiley=laugh.gif]

Title: Re: Carbent Seat Mount Failure
Post by jayg on Apr 18^th, 2013, 4:04pm

aikigreg wrote:

[/quote]

Yes, I have talked to him personally and been in contact with him via E-mail. When I first talked to him, thought the problem was defective glue bond. Told him I wanted to repair it myself, because I have worked with epoxy, and I wanted to ride the bike at Muenster, week after next. He sent me info on the glue and some instructions. I looked at the mount this morning and confirmed that the frame tube had delaminated, rather than the mount glue bond failing. As a matter of fact, there is a loose layer of carbon fiber on the tube that is not embedded in the epoxy matrix. Because of my 145 pound weight, Dana still thinks the bike will be safe to ride, if I repair it myself. The other options are to ship the bike to California and have my frame repaired or have a new frame frame built, using salvageable components from the damaged frame. Dana would discount the prices. I don't want to spend big bucks, so will probably attempt to repair it myself. Think I'll beef up the mount-to-tube joint by applying aircraft grade epoxy and fiberglass on each side of the mount and run it down onto the tube. This type of seat mount failure has been reported on only one other Carbent.

Speaking of high racers, my 2008 Corsa was a great bike. Should have kept it, instead of entering the carbon bike world.

Title: Re: Carbent Seat Mount Failure
Post by jcsadowski on Apr 18^th, 2013, 4:24pm

Quote:

Speaking of high racers, my 2008 Corsa was a great bike. Should have kept it, instead of entering the carbon bike world.

As I recall, You didn't like that bike either.

Title: Re: Carbent Seat Mount Failure
Post by aikigreg on Apr 18^th, 2013, 4:27pm

I'm VERY surprised that Dana isn't just straight-up taking care of it. That's not very like him at all. I had a similar experience when my carbon aero 1.0 exploded after I dropped the front wheel into the great, except the frame was completely toast. That frame had serious defects from the start which were kept very hush hush by Bacchetta. I'm very thankful for homeowner's insurance.

Title: Re: Carbent Seat Mount Failure
Post by jayg on Apr 18^th, 2013, 4:41pm

aikigreg wrote:

He's considering it a "crashed" bike. Last Saturday, I transported the bike to Lancaster with the fork secured to a fork mount on the floor of my van and the front of the bike tied down to prevent tipping. When I turned a corner the bike's rear tire shifted to the side about 15", followed by a cracking sound. Apparently, that's when the majority of the failure occurred. After that, the seat mount must have been bonded to the tube on its perimeter, because I rode 42 miles at Lancaster with no indication of a problem (Glad it didn't give way on the one 37 mph downhill run I made). The mount totally failed when I started riding at WRL, last Tuesday.

Title: Re: Carbent Seat Mount Failure
Post by jayg on Apr 18^th, 2013, 4:53pm

jcsadowski wrote:

Quote:

Speaking of high racers, my 2008 Corsa was a great bike. Should have kept it, instead of entering the carbon bike world.

As I recall, You didn't like that bike either.

I didn't like the Euromesh seat, it killed my butt. It was a great bike after I replaced the Euromesh with a carbon seat. However, did have to stay away from mud, sand, and gravel, because it would go down in a flash.

Title: Re: Carbent Seat Mount Failure
Post by jayg on Apr 19^th, 2013, 10:24am

Thanks everybody for the comments and suggestions. Last night, I ordered $90 worth of aircraft grade epoxy adhesive to use in accomplishing the repair work.

Title: Re: Carbent Seat Mount Failure
Post by jcsadowski on Apr 19^th, 2013, 11:22am

Quote:

Last night, I ordered $90 worth of aircraft grade epoxy adhesive to use in accomplishing the repair work.

Jay,
Good Luck.
John

Title: Re: Carbent Seat Mount Failure
Post by jayg on Apr 19^th, 2013, 11:51am

jcsadowski wrote:

Quote:

Last night, I ordered $90 worth of aircraft grade epoxy adhesive to use in accomplishing the repair work.

Jay,
Good Luck.
John

Thanks, John.

Title: Re: Carbent Seat Mount Failure
Post by jayg on May 5^th, 2013, 9:08pm

Due to the great expense of having the factory fix my Carbent's failed seat-to-frame attachment, decided to attempt the repair myself. I've been putting it off, because it's a one- shot deal. If I screw it up, the bike is ruined. Everything seemed to go OK. I followed the bike manufacturer's prep and adhesive application instructions, strapped the seat to the frame, then aligned the seat and struts. In 5 days, after the epoxy adhesive fully cures, I'll find out whether or not the repair attempt has been successful. Hope to ride the bike this Saturday at the Cedar Hill "Head for the Hills" ride.

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00154_zpsad1579bc.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00154_zpsad1579bc.jpg.html)

Prepped frame and seat mount.

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00162_zps7f692a22.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00162_zps7f692a22.jpg.html)

900 grams of aircraft grade epoxy adhesive. I used only 24.6 grams. Cost me $90. Smallest quantity I could buy.

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00158_zpsc5d3df89.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00158_zpsc5d3df89.jpg.html)

Applying adhesive.

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00160_zps22f8d73d.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00160_zps22f8d73d.jpg.html)

Strapped seat to frame with ratcheting load strap.

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00159_zpscd85b93b.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00159_zpscd85b93b.jpg.html)

http://i1021.photobucket.com/albums/af339/jayg_2010/DSC00147_zps0738ca9e.jpg (http://s1021.photobucket.com/user/jayg_2010/media/DSC00147_zps0738ca9e.jpg.html)

The squirrels keep coming in the garage and bugging me, so I have to go out and feed them. :)

Title: Re: Carbent Seat Mount Failure
Post by Action Lad on May 6^th, 2013, 6:16am

"900 grams of aircraft grade epoxy adhesive. I used only 24.6 grams. Cost me $90. Smallest quantity I could buy."

Perhaps with the rousing success of the repair you could offer the same job to other unfortunates...depending on how risk averse you are.

.....................................................................................................................................................

"The squirrels keep coming in the garage and bugging me, so I have to go out and feed them. :) "

Aww! Reminds me of Dr. Doolittle: "If I could talk to the animals..."
(gee, I wish this site could accept alt codes)

Title: Re: Carbent Seat Mount Failure
Post by obent on May 6^th, 2013, 6:52am

A few years ago, while at RBM talking with Jack, one of the bike repair techs, came by to say hello (Dana). As he turned around, and started to walk away, I noticed the back of his jacket was moving. I asked what is going on with your back. He pulled out a baby squirrel. It turned out it had fell out of a nest, and he had raised it back to health. Dana released it back to nature, a few weeks later.

Title: Re: Carbent Seat Mount Failure
Post by jayg on May 6^th, 2013, 10:11am

Action Lad wrote:

Perhaps with the rousing success of the repair you could offer the same job to other unfortunates...depending on how risk averse you are.

I think the best service I could provide would be to give the following advice to people contemplating shelling out big bucks for a CF high racer: Don't buy a low production bike glued together like a model airplane. Buy a CA 2.0.

Checked the bike this morning. The epoxy set hard overnight, so everything is looking good, so far.

Title: Re: Carbent Seat Mount Failure
Post by jayg on May 6^th, 2013, 10:19am

obent wrote:

I'm worried about baby squirrels. I'm surrounded by healthy, fat squirrels when I go outside, right now. When their babies start showing up there's going to be a herd of them waiting for me to come outside. :D

Title: Re: Carbent Seat Mount Failure
Post by jayg on May 10^th, 2013, 7:17pm

Let the epoxy adhesive cure for 5 days, then took the bike for a 6.4 mile round trip to WRL this afternoon. Ran it over a rough plank bridge twice at speed and hit some bumps with it. The seat remained solidly attached to the frame tube, so the repair is apparently successful. Bill, John, and Corsa Ken, look for me on the bike at "Head for the Hills", tomorrow morning.