Drivetrain Help (Please Help me...)
I figure a bunch of you toy around with builds and mix and match componentry so you might be able to help me out. Thanks in advance.
Background:
I worked my ass off to get together the money for a build I just finished. It's an 84 trek 760 and it has a mixed drivetrain. The front der is the original suntour superbe, the rd is a veloce, the shifters and cranks are campy centaur (compact crank), and the chain and cassette are shimano 105. I know it's a real crazy mix of components, but I put it all together about 2 weeks ago and it all worked really well. The LBS was amazed that the shimano spacing could be made to work and I was just thrilled that it all worked well enough to ride.
I raced the bike this past weekend and it didn't mis shift and let me down at all. It was a blast to ride and I was glad to be able to leave my cannondale at home since the weather was going to be nasty and I didn't want to end up crashing the bike (it was my first race).
I went out for a 25 mile ride on the bike yesterday and everything was working fine.
The Problem:
The problems started today, I set the bike up on the trainer and was spinning pretty easily. I was in the middle of the cassette and I decided to shift down to the smaller chainring. All of a sudden, there's no tension in the chain anymore. The chain is just gliding on top of the small chainring and it refuses to go onto the small chainring. If I shift up and down a few times from the big ring to the small ring, it'll eventually fall into place, but it was NEVER like this before. It just 'glides' or 'skates' over the small chainring and refuses to drop onto the small chainring...
While trying to do this, the chain not only dropped onto the bb off the small chainring, it also fell off the big ring and scratched the crap outta the finish of my cranks... I understand that I can drop my chain if I'm really badly crosschained and I shift in the front, but I have no idea how to fix this problem.
I'm really distraught about this and I honestly can't figure out what's going on.
Please help me out?
Thanks in advance.