do I ned a new chain?

kayakerchris
kayakerchris Posts: 361
edited December 2009 in Road beginners
Hi I have done about 1500 miles on my Boardman. Today the chain jumped on me 3 times.

I was going up a small hill and I was in top gear powering up when all of a sudden the chain seemed to miss a sprocket and then jumped off the front chain ring. Fortunatelt no traffic around and I stopped and put the chain back on.

Second time was after coming to a standstill again in top gear and really loading on the power to get moving again.

Third time was again going uphill same as first.

Similar thing happened over the summer on my touring bike when I had a damaged chain.
I have ust looked at the chain and it seems fine. Not twisted or buckled.

Changing gear is perfect and the settings are all fine.

The only thing I can think of is that the chain is worn and under maximum tension it is jumping a tooth.

I am about to buy a new chain as it sounds something good to have in but does anybody have any other ideas?

Chris

Comments

  • redddraggon
    redddraggon Posts: 10,862
    I was going up a small hill and I was in top gear powering up

    Why were you in top gear powering up a hill? Grinding at <40rpm is just not sensible. Probably part of the reason why you suffered a bit of skipping.
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  • pianoman
    pianoman Posts: 706
    Find a mate who's got a chain checker tool like I have and see whether the second metal bit with "1.0" fits in the slot. If it does, then the chain is worn and needs replacing.

    If you change it when it's needed, you'll get away without needing to replace the cassette.
  • Why were you in top gear powering up a hill? Grinding at <40rpm is just not sensible.
    It wasn't a real hill and I try to do this incline in top gear and keep the cadence well above 40 standing up as part of my power work on my evening commute. So I was really transferring a load of power. It could be the chain is stiff and catching coming round the rear derailleur as I havent cleaned it for a few weeks!

    Chris
  • pianoman
    pianoman Posts: 706
    Why were you in top gear powering up a hill? Grinding at <40rpm is just not sensible.

    Correct. As I've said in other posts, I've never listened to those who try to force you to ride over 90rpm all the time, I end up getting gassed in no time and only end up going slower, but 40rpm is probably even more ridiculous. Also, try sitting down in the seat and sit further back to get the big levers - also known as legs - moving to their full potential. Stand up if you want to sprint or are dragging yourself up in your lowest gear, but NOT for every pedal stroke as soon as the road goes uphill.
  • redddraggon
    redddraggon Posts: 10,862
    Why were you in top gear powering up a hill? Grinding at <40rpm is just not sensible.
    It wasn't a real hill and I try to do this incline in top gear and keep the cadence well above 40 standing up as part of my power work on my evening commute. So I was really transferring a load of power. It could be the chain is stiff and catching coming round the rear derailleur as I havent cleaned it for a few weeks!

    Chris

    Even so Top gear is a 35+mph gear. If you've been doing it a lot, it's no wonder you've worn out the 11 or 12 sprocket, and I'd say that's probably the issue rather than a worn chain.

    Unless you training for Track sprinting over gearing like that is far more damaging to equipment and knees than what benefit you'd gain.
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  • Consider that your gears need re-indexing; after 1500miles you may have some cable stretch. Do you have any ghost shifting or noise from your cassette / rear derailleur?
  • Wappygixer
    Wappygixer Posts: 1,396
    If you have been putting huge strain through your hears you could have a damaged tooth on you alloy chain rings.
    It doesn't take much to mash one up.
    Also as you've said about maintenance or rather the lack of then this too will not help and will probably have worn both chain rings and cassette.
  • balthazar
    balthazar Posts: 1,565
    It is very probably not chain wear. To be sure, you can find out whether your chain is worn or not by measuring a length of it with a ruler. When new, each (half)link of a chain is precisely 1 inch long. Measure 12 links along the bottom run of chain, and if they are longer than 12 inches by a small amount (a sixteenth of an inch, or a couple of mm), then your chain is worn to the extent that it is damaging the rear sprockets, and should be replaced.

    The "chain checker" tools are imprecise. Use a ruler (any kind) or steel tape measure.

    I expect that the problem is much more likely to be caused by a stiff chain link, or out of whack indexing, or a damaged sprocket or chainring tooth.