's Forum Archives - Cyclo-Cross

Archive Home >> Cyclo-Cross(1 2 3 )

Off Topic - Cracked Frame?(4 posts)

Off Topic - Cracked Frame?Jakob
Aug 29, 2002 10:51 AM
I posted this question on mtbr the other day and got few responses. I thought you guys might be able to help.

My friend has an aluminum Trek 6700 mountain bike frame that creaks and I am wondering if it's cracked or if the creak could be caused by something else.

We stripped all the parts off the frame and could still make it creak. I put the frame on a carpeted floor with dropouts/chainstays/bb touching the ground. I put one foot on the chainstays near the bb to stabilize the frame, both hands on the top tube near the seat tube, and then I put as much weight as I could on the top tube. It creaks a little from the pressure and even more when I release the pressure.

When built up, the frame creaks when you sit down, hit the brakes, or mash big gears while seated. I figure that it creaks louder when build because I can't put as much pressure on it from just my body weight.

I kinda think it's cracked but I can't find any visible cracks and he's started to get the run around from a local Trek dealer.

re: Off Topic - Cracked Frame?ferrul
Aug 29, 2002 11:20 AM
Contact Trek directly. They have a lifetime Warranty on all their bikes.
re: Off Topic - Cracked Frame?OffRoadTourer
Aug 30, 2002 6:10 PM
Yes but warranties only cover faulty workmanship. They don't cover things wearing out or being damaged in accidents or through misuse. All metals will eventually crack, aluminium generally cracks earlier than steel. I would be very surprised if this was a warranty issue because it sounds like there was nothing wrong with the original manufacture of the frame, it has just worn out or been damaged. Throw it in the bin and get another frame.
re: Off Topic - Cracked Frame?atpjunkie
Aug 30, 2002 10:34 PM
If there is no visible signs of damage then I think the misuse/damage/accidents point is moot. Those things usually show like a bent headtube etc...If this is a new (sub 5 year) bike I think it still may be warranty (possible) A hi grade Aluminum frame shouldn't 'wear out' in 4 years even if you are riding it 4 days a week. I'm not totally sold on the cracks yet, strip it, turn off the lights and shine a bright light (NiteRider or something) down the tubes and look for light leaks. Check the stays carefully especially at the bb joint. If assembled stand and pedal, sit and pedal, coast etc... try to isolate if it's from pedaling, sitting, etc.... and never throw it in the bin, leave it out, some kid will take it and be happy.