Friday, March 16, 2012

Broken Bike

As I shifted to the big chain ring while riding my Cervelo R3 on the Tuesday night group ride the chain became wedged between the outer chain ring and the derailleur. This didn't seem to be too much of a problem. I gently back pedalled to get it un-stuck and them soft pedalled forward to finish the shift. It still did not go so I shifted to the small chain ring and softly pedalled again. This time the chain went back to the inner chain-ring but there was an awfully loud rubbing noise. So I decided it was time to pull over and take a look. The two guys behind stopped with me but Chad, who was in front of me, did not here us yell so he pedalled on.

Curiously, I dismounted to asses the problem when I noticed that the front derailleur was sitting directly on top of the outer chain-ring causing the noise I was hearing. My assumption was the bolt that holds the derailleur to the hanger bracket had come loose and the entire assembly had shifted down. No problem I got out my handy multi-tool and loosened the bolt. Strangely the bolt was still pretty tight. The cable tension would not let me raise the derailleur so after loosening the cable I was able to lift the derailleur back out of the way. Upon a closer inspection I notice that the hanger bracket, that is attached to the seat tube, was loose. I never payed attention to how this bracket was attached to the frame but it looked like it was riveted on the top but nothing on the bottom. Then I noticed that the rivet was missing from the bottom. Big problem I thought.

Like any good rider, on a 30 degree above average temperature day, nothing was going to stop me from riding. I put the derailleur in the outer ring position and rode on making sure I did not shift out of the big chain-ring. Luckily it was a pancake flat ride.

Once I go home and was able to asses the damage closer. I noticed the bracket was bent as well as the rivet missing. My mind was racing as to how I was going to get this fixed. I had bought the bike used so there was no warranty and our local bike shop does not deal with Cervelo. There is a bike shop in Bettendorf that sells Cervelo maybe they could help. Then I kept thinking how long was it going to take to get the frame fixed, would they have to send it to the factory, and what was I going to ride while it was being fixed? When I bought this bike last year I stripped down my old Trek project one and used the parts to upgrade my wife's bike so all that was on the old bike was the seat post and handle bars. My only option would be riding my cross bike with some road tires. I have done that before and since I needed to get used to that bike before Trans Iowa that wouldn't be so bad. All these thoughts and more kept racing through my mind as I tried to sleep.

On my lunch hour the next day at work, I tried to search for repair hints on line to see if any other riders had solved this same dilemma. I was not having any luck. The closest I could find was a forum about a rider that wanted to remove the hanger and have it anodized when he repainted his frame. The suggestion was drilling out the rivets and then replacing them. It mentioned the rivets were 3mm. That still did not solve the bent hanger problem. After work I decided to see if I could gently bend the bracket back it to place. I was able to use a pair of vice grips with a board against the down tube and very carefully squeeze the vise grips until the bracket was back in place. It was pretty easy to do and I was able to see when the holes in the bracket and frame were in line. First step completed and I was feeling optimistic.

A quick trip to the hardware store to pickup a box of 3mm rivets and I was off to the bike shop to borrow a rivet gun. The rivet fit perfectly and the operation went off without a hitch. I assume they bond the hanger to the frame and install the rivets but there was no way to bond it back on so hopefully the rivets will hold. If I do break another rivet I still have 24 more in the box that cost me $3. It looks like my R3 will live to ride another day.

No comments: