It seems at most of my events that I have done (IM AZ 08, OC Tr 08i, Cool Breeze Centruy 08, Bull Dogs Bike Race 09), I have dropped my chain on both my tri bike (QR Lucero) and my road bike (Cervelo Soloist). Always going from the big gear to the smaller gear up front. During training rides I don’t think I have ever dropped a chain.
Am I doing something to contribute to this or is this a FD adjustment issue on both bikes (tri- Shimano Dura Ace, road- Campy Chorus).
About a 1/4" turn on the limit screw may prevent this from happening. If you are racing and therefore shifting “quicker” the normal, you could be dropping the chain to the inside. The 1/4 turn should stop the “quick” shifting drop. Then again, it may also prevent the chain from shifting to the small chainring if you shift it slowly. You may be shifting so quickly while racing that the chain is jumping past the small chainring. Make sense?
Thanks, I will try that.
In my experience, dumping the chain occurs when two circumstances come together. The first thing that occurs, is that I am severely cross chained ( i.e. 53 - 25 combo on a 12-25 cassette), and then I shift under power which causes the chain to be pulled right over the top of the small ring.
The way to prevent this, is to anticipate the need to shift earlier and shift up to a 21 or even a 19 gear in the back, then shift to the small ring in the front. I’ve had the best luck with this method, but I suppose that it might work if you simply soft pedal and switch to the small ring in the front, which would eliminate the “shift under power” problem. I can’t say that I remember trying that.
BTW, with practice, you can exercise the afore mentioned shift almost in one motion, but definitely leading with the rear derailleur shift first, while almost simultaneously shifting the front derailleur.
FWIW, you can get the chain back on the front chain ring by shifting back to the big ring, and soft pedaling until the chain is picked back up by the chain ring. This of course requires you to have enough momentum to keep rolling while you perform the soft pedal. And as you know, momentum is sometimes considered a luxury…
If I were you I’d give your front derailleur systems a self ‘tune-up’. It is extremely easy, no special tools required, and step-by-step instructions are located here:
http://www.parktool.com/repair/readhowto.asp?id=75
As zipp mentioned it’s probably one of your screws being out of the optimum range. The process at the link above will fix this.
Hey,
Check the limit screws and the angle and height of the front derailleur, they can all be factors.
If you are lazy or under qualified, pay somebody who does it for a living set it up for you, they will charge $10-$15
Martin