Technique in shifting down on the chain rings?

Bobbinogs
Bobbinogs Posts: 4,841
edited September 2011 in Road beginners
Folks,

Twice on recent rides on my Mercian (Strada) I have dropped the chain going from big to small chain ring in prep for a hill. The drivechain all seems to be fine (it is a 9 speed with Veloce, Record and Chorus components, on a standard double) and I figure that there isn't anything drastically wrong given that I have only dropped the chain twice in about 400 miles.

I recall when Schleck and Contrador had their moment last year a few folks wrote that it was "Schleck's bad technique" that caused the problem. So, is this what I need to improve or is it a case of tinkering with the low stop or fitting a dog fang (I don't want to do either of the latter if they are just painting over the cracks of poor technique)?

I shift carefully, keeping the pedals spinning, just slow the cadence a bit and use firm/positive shifting using the 9 sp Record shifters (which are absolutely lovely to use...and the ability to roll down the block with the right thumb is a joy coming from clinical 105, anyway I digress).

Any thoughts?

Thanks

Comments

  • Erudin
    Erudin Posts: 136
    Had that problem with a Veloce triple chainset when running a 12-28 cassette have not had any chain unshipping since using a 12-26 and shorter chain.

    Have a look at this thread:

    http://forum.ctc.org.uk/viewtopic.php?f=5&t=54836&start=15
  • Bobbinogs
    Bobbinogs Posts: 4,841
    Interesting stuff, thanks Erudin. I think that will take a couple of reads to go through in depth but my setup is a real mix and I did recently add an extra link too (to factor in a bigger cassette).
  • rafletcher
    rafletcher Posts: 1,235
    Erudin wrote:
    Had that problem with a Veloce triple chainset when running a 12-28 cassette have not had any chain unshipping since using a 12-26 and shorter chain.

    Have a look at this thread:

    http://forum.ctc.org.uk/viewtopic.php?f=5&t=54836&start=15

    And I've never had any problem with a Veloce triple and 12-28.

    If you're unshipping the chain going to the inner then try adjusting the lower stop screw out 1/4 turn at a time.

    It could also be a result os a small mis-alignment of the cage with the "tail" being rotated slightly inwards towards the frame.
  • Ron Stuart
    Ron Stuart Posts: 1,242
    This has become more common since the use of compact chainsets and large cassettes, this results in a slack chain chain dropping a greater distance. This is made doubly bad with bumpy road surfaces, it has been quite common in the past on mountain bikes for the same reasons.
    Answer is a chain catcher, there are many types and of course prices but with your more traditional frame all you need is a plastic dog fang chain catcher just make sure you get the right diametre although you can pack them out. Picture here... http://www.cyclechat.net/topic/41592-de ... n-watcher/

    Ribble do them here.... http://www.ribblecycles.co.uk/sp/triath ... EDACHAJ200

    Locate when chain is on little chain ring and largest cassette ring just above chain ring and just missing chain ring.

    Also check out top left pick out of this bunch....
    http://www.google.co.uk/search?q=CHAIN+ ... d=0CEgQsAQ :wink:
  • ddraver
    ddraver Posts: 26,697
    Before you bother with all that I'd just check everything is still set up properly. The cable might have stretched a bit or the mech taken a bit of a knockette or the limit screws moved... Could just be the case of turning the cable barrel out half a turn but I'd loosen everything off and start form scratch, it will only take you 5-10 mins.
    We're in danger of confusing passion with incompetence
    - @ddraver
  • Ron Stuart
    Ron Stuart Posts: 1,242
    ddraver wrote:
    Before you bother with all that I'd just check everything is still set up properly. The cable might have stretched a bit or the mech taken a bit of a knockette or the limit screws moved... Could just be the case of turning the cable barrel out half a turn but I'd loosen everything off and start form scratch, it will only take you 5-10 mins.

    Why rely only on everything being set-up just right, surely for a few bob and grammes its worth having some insurance against it happening and sods law it will be when you need it least of all. Bradley Wiggins shipped a chain during a world champs TT and David Millar took off the front mech before a high profile prologue and lost the chain about 100m from the finish. :oops: You will find these catchers come as standard on a lot of brand new bikes as my Scott Addict R2 did.
  • Bobbinogs
    Bobbinogs Posts: 4,841
    Chaps, thanks for the ideas. I double checked the setup and still couldn't find anything wrong...so bought and fitted a Deda dog fang. Job done :)

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