Should be fine on trainer.

Near seat post on down tube? Pics?

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If it only going to be used on a trainer then you could get a pretty crude repair done and it won't matter. You could just take the cheapest quote you can get or there must be some sort of patch you can buy and glue on. Maybe someone here has some experience? But I'd be tempted to look for something I can slap over it.

At the very least mark the ends of the crack with a sharpie and that way you can see if it is getting worse.

Even on a trainer, you should still consider the distance between your head and the ground, and you should note whether the ground is carpet or hard concrete. Bikes can still fail on the trainer, sometimes catastrophically.

That said, depending on exactly where the crack is and how exactly the crack is oriented, you might be able to do a half-assed trainer-ONLY repair with a few monster zip ties, the stronger and the wider the better:

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Anybody have that thread where the guy posted massive blood loss all over the floor after his bike broke on the trainer? Didn't he shear off his seat tube and it went into the artery on his leg or something?

I'd use it on the trainer for sure after you've patched it some, just not standing to pedal.

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Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

Unless there's another thread, that was from a computrainer flywheel explosion: http://forum.slowtwitch.com/..._latest_reply;so=ASC

I fix carbon fibre frames for myself and for friends. I never charge and therefore never have to worry about guarantees. I explain the situation to the bike owner and they ride the bike after it's fixed, but they all take care to monitor the repair.

I suggest that before you retire it, you get it fixed. From your description, it sounds like it you removed the bottom bracket, you could probably have access to the inside of the frame, with fingers or suitable home made tools. I have a BMC frame I will be fixing shortly and it's cracked on the top of the top tube about 2" in front of the seat tube.

I will do the following

1. Cut out the damaged section of top tube (about golf ball size)
2. Insert a deflated inner tube (folded over) down the seat tube and into the top tube, going about 2" past the hole (towards the head tube)
3. Insert a piece of glad wrap over the inner tube (so the inner tube can be removed later without sticking to the bike frame.
4. Cut a number of chunks of carbon cloth in increasingly large sizes (about 1/3" larger each time). Make 3 or 4 patches.
5. Soak the largest patch with epoxy and stuff it in the hole. making sure it spreads out and is flat, inside the tube. do the same with the other smaller 2-3 patches of carbon cloth.
6. Slowly, ever so slowly, pump up the inner tube until the layers of patch are evenly pressed against the inside of the frame tube and bulge through the hole by about a millimetre or less.
7. Let the epoxy go off (set). (I recommend West System epoxy from the boat store. Then remove the inner tube.
8. Sand the slightly bulging epoxy/carbon cloth carefully, so it is at the same level as the original frame tube. A file works well for this if you've let the epoxy set properly.
9. Fill any small holes (around the edges of the hole in the frame) and sand again as necessary.
10. Paint as best you can.

I've used this method twice so far and it works great. No failures and my buddies love that they can use their bike again on the trainer or as a winter hack. It adds very little weight and works really well. I actually saw a doco on carbon fibre last year and they used a similar technique to fix the damaged carbon rocker panel part of a chassis of a Lamborghini. I wasn't impressed with the guys material or workmanship (he didn't even use the same carbon weave as original and didn't even line up the weave with the original weave. a bit rough to be honest) , but it was the same technique I'd already figured out on my own so I was happy about that.

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TriDork

"Happiness is a myth. All you can hope for is to get laid once in a while, drunk once in a while and to eat chocolate every day"

What does Specialized say? Not a potential warranty fix / replacement?

That's the one! The craziest part was the OP put up all those pics and then disappeared for what seemed like eons. People were wondering if he died. lol. It was one of the top 10 threads from ST I've ever seen.

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Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

The bike is potentially under more/different stress on the trainer than it usually is on the road.
I would be reticent about using a frame I didn't trust on the trainer. While my biggest fear would be a catastrophic mechanical failure on a fast decent, I can imagine someone hurting themselves as badly, or even worse, off a trainer as on a moderate speed road ride. Do you have hard surfaces, and hard, sharp objects around your bike that you could fall onto or hit your head on?
Even worse, if the frame were to collapse under you, there's the potential for you to fall onto the broken frame and that could be very serious if you were unlucky.
Obviously this is worst case scenario, but the point is that a trainer isn't necessarily safe.