A Bizarre Mechanical Problem

Cycling up Kirkstone Pass Last Sunday, I felt a loud clunking of the gears. Involuntarily I found the only gear to work to be the lowest – the 28 sprocket, but it was much noiser than usual.


My Shimano Dura Ace – I will be starting bike maintenance classes soon – just $99 a month with $300 joining fee. Sign up before places go…

Thankfully, I didn’t mind being in the 28 sprocket, if it had been any other gear, I might have had to look at it. But, with stuck in the 28, I resorted to my first rule of bike maintenance

#1 – If the bike is still going forward just ignore the loud noise and you’ve solved 50% of your bike problems. (Confessions of an amateur bike mechanic)

I cycled the last 7 miles back to the end of the ride, with the gears making more noise than usual. – So much for Shimano Dura Ace and their expensive price tag. My Shimano Sora are quieter than this.

After the epic ride on Sunday, I went for a recovery ride on Monday. Before setting off I was bemused to find the bike looking like this. I’m sure it wasn’t like that for the whole Sunday ride.  Even with my rudimentary bike skills, I know you don’t put on a chain like that.

The chain must have somehow come out of the rear derailleur and over the top during the ride. This explained why it was making a lot of noise and why the gear indexing wasn’t working properly.

It is possible to pull the rear part of the gear mech apart, but, I couldn’t manually push the chain back through the gap. I had to get out the chain tool, break the chain and put it back together.

I’m really not sure how this chain managed to come out of its usual line. But, despite my luck in finishing the ride, it is a reminder to always have a chain tool on long rides. If you puncture, you can fill your tyre with grass and cycle home. If you chain fails, it’s a long walk to the nearest railway station.

3 Responses to A Bizarre Mechanical Problem

  1. Alex August 14, 2012 at 9:30 pm #

    Dura-Ace is only rated for a 27 rear sprocket. It is not designed to take a 28.

    What you have discovered is the safety mechanism that prevents you ripping the rear mech hanger off the bike, trashing the frame, or destroying the rear mech. I suspect you have too much tension on your chain, kicked hard whilst cross-chained in 50/28 or 53/28, and that’s what happened. I’ve done it when I put two too few links in a new chain and did as above.

    Also, make sure your B-Tension screw is set properly.

    • tejvan August 16, 2012 at 8:11 am #

      thanks Alex. that sounds to make sense.

  2. Tom August 14, 2012 at 10:41 am #

    I always carry 4 split links with me too. I’ve never had to use them but have found myself donating some to people walking their bikes home before now.

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