My son’s mountain bike hasn’t been shifting properly, and it was time to take it to an expert. My girlfriend’s brother-in-law likes to work on bikes, and I thought it would be a good idea to ask him for some help. It turns out he has a website, works on his friends bikes, and actually tunes skis and snowboards in the winter too! If your interested, here’s the link: http://garyskiandbiketuneups.com/
ratchet system in shifter messed up by the extra long screw I used
Anyhow, when he looked at it, he found two things that were causing problems with the shifting. First, the internals in the front shifter were completely messed up. The main ratchet system was bent, and the screw the cap was secured with was threaded into a plastic part, not the metal threaded part, and it was locking up the shifter so that it would not even engage. After hearing about this, I remembered the silly shifter cap falling off a couple years ago, and rummaging around on the work bench, I found a screw, and put it back on. Maybe I should have been a little more careful to use a screw that wasn’t five times longer than the the depth of the shifter. I held my tongue initially, but came clean when I went to pick up the bike. I just couldn’t shoulder the guilt.
He was able to take apart another shimano shifter he had, and replaced the parts in ours. There is a picture on the right showing the bent screw, and one on the left of the damaged parts.
The other shifting issue was the derailleur hanger. There was too much movement in the derailleur when he was adjusting it, so he took it off, and noticed that the hanger was almost completely severed. He thinks this is from either laying the bike down on the derailleur side, or the derailleur shifting all the way into the spokes at some point. Apparently, the derailleur hanger is designed to fail in the event something happens, in order to protect the frame. I guess I should be thankful that I’m not replacing my frame. I am thankful he was able to modify a spare derailleur he pulled off another bike to use on mine
After all that work, the bike shifts great, and all the gears work except for the top two rear cassette rings, which we don’t really need anyway. I guess the rear shifter is wearing out, so it just doesn’t get up to those top two gears; however, it’s not worth replacing the whole shifter just for those, when there are plenty of other perfectly good gears. He also did a full tune up, which is a bunch of stuff including tightening up the breaks, taking all the cables off, out of their casings, and lubricating them, and de-gunking and re-lubricating the chain.
I highly recommending finding someone who likes to tinker on bikes, as opposed to a big business to work on your bike. Get someone who’s hobby is working on bikes, someone who isn’t influenced by profiteering, or required to support the overhead of a commercial space and stuff. If your in the Chicago Suburbs, click on the link above and see if he has time for your bike.