I am new to bike maintainance. I recently tuned up my Trek 800 mountain bike. I went to the Park Tools website and read their reference notes on adjusting the derailleurs. My bike derailleurs now seem a lot more responsive. However, when I did a test run, I noticed one problem. The front derailleur has difficulty downshifting from the large chainring to a smaller chainring if I am riding up a steep hill (with lots of torque on the crankshaft). When I am riding on a flat surface, I do not have any problems shifting with the front derailleur.
Is this a problem due to overtension in the front derailleur gear shift cable? Or is this a problem due to the adjustment of the front derailleur stop screws? How do I address this problem?
You need to "soft pedal" when shifting. In other words, the problem you're experiencing is most likely caused by "lots of torque on the crankshaft" as you say. When shifting, ease up on the torque, even though you keep the pedals moving............and as I believe Ned Overend once said: the front derailleur is the weak link on a bicycle, use it as seldom as possible.......Or something like that........I'll add that, since you've already utilized the excellent instructions on the Park Tool site, if you've got a barrel adjuster for the front derailleur you might try turning it clockwise just a bit to loosen the cable tension a little. That will make downshifting with the front derailleur a little more responsive. But mostly, "soft pedal" when shifting-
well biked - thanks for the advice. i adjusted the cable tesnions using the barrel adjuster (decreased the tension a little) and it is much more responsive now downshifting.
My bike feels like it's brand new. It's 12 years old, and I haven't had it serviced in a long time. I decided to buy a repair stand and now have been doing all of my own repairs/maintenance. Having a good quality repair stand has really made it much easier to work on my bike.