Road Cycling - good or bad shift?

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View Full Version : good or bad shift?


leefunk33
08-17-04, 02:56 AM
I was practicing at Infineon Raceway two weeks ago and constantly working my shifters. My Dura Ace derailer had a particular tough time shifting in this scenario: After coming of of a hill, in which I'm in the smaller gear up front and the farthest left gear in the back, I try to shift from the granny to the bigger gear up front. This was particularly painful (for my components) as the chain kept on going around and around without upshifting. It took about 10 seconds every time. However, when I'm on the middle spot of the rear cog, it's easy to upshift up front. Is this normal? Are we not supposed to try to upshift when the rear gear is on the far left side? Also, when we shift gears, are you supposed to be pedaling while you're doing so or not?
Manny


khuon
08-17-04, 03:04 AM
Anytime the big-big combo is involved, your drivetrain will suffer. If you're really applying a lot of power, the chain is under a lot of tension. Attempting to force it onto the big ring while you're in your big cog in the rear means it has to enter a lot of deflection while under a lot of tension. This will undoubtedly result in very poor shifting. The basic rule of thumb is that the straighter your chainline is, the happier your drivetrain is. You want to avoid large chainline deflection. So before entering the big ring, upshift the rear a few cogs to straighten out the chainline first. Likewise, if you find yourself in a big-big combo while attempting to climb the hill, you have a very good chance of throwing the chain if you try to dump to the inner ring. This is because there will be so much tension that when you release the chain off the big ring, it can slingshot right past your small ring. As painful as it may seem, it's better to upshift the rear a few cogs to straighten the chainline before dumping the front ring to the inner ring. Envisionng and managing the chainline is the key to smooth shifting.

leefunk33
08-17-04, 04:15 AM
Khuon,
You're the man...Thanks for the info..