Bicycle Mechanics - Changing Gears

I'm a newbie to a bike with gears. Been riding a single speed. I now have a Giant Sedona (Comfort Mtn) which has Grip Shift Twist Shifters. Thougt I understood that when I have the left in 2, I shold be able to shift to 4-6 on the right grip However, it is smooth only on 4 -- when I shift up to 5 it grinds a little, when I go to 6, it grinds still more. Does this need an adjustment. Thanks.

Forgive me for not knowing the correct lingo yet. :confused:

There should be a few clicks of "trim" in your left shifter. That is, between shifts, you can make small adjustments up or down to stop the chain from rubbing on the front derailleur.

I'm not sure if that was clear, so let me try it one more way.

When the chain rubs on your front derailleur, turn the left shifter one click up or down. This will move the derailleur enough to stop the chain from rubbing, but will not cause the gears to shift. Whether you move it up or down will depend on which side of the derailleur the chain is rubbing against. Turn it whichever way works. Try both to figure it out.

Thanks RegularGuy -- I have a lot to learn. :)

Welcome to Bikeforums, Bett.

Cool digital paintings on your website! :)

also if the bikes new you may want to call the shop. sometimes new bikes need some adjustments especially if you put a few hours on them.

It might need to be adjusted and it might not. The left shifter shifts the gears on at the crank (on the front). When you shift with the right shifter (rear gears) the chain will sometimes rub on the front derailleur. What you need to try is to trim the front derailleur. What I mean by that is sometimes when you change the rear gears you will need to adjust the front gears. When you go to larger (higher numbered) gears in the rear you should try to move the front (left shifter) a little towards the 3 without actually shifting into 3rd. Then when you start shifting down (lower numbers on the right) you might have to slightly click towards 1 on the left shifter, again without actually shifting into 1. This is called trimming the gears. Some people call it feathering the gears. They are wrong of course. If the gears can’t be trimmed while riding then you may have to adjust them.

What RG said about trimming the front derailleur (left shifter). Also, while standing next to or straddling the bike, look down at the derailleur while clicking the shifter one click at a time. Note which way it moves. When you shift the rear (right) shifter to smaller numbers, the chain moves inward (onto bigger cogs). And vice-versa.

This movement changes the angle at which the chain moves through the front derailleur. By understanding which direction the front derailleur moves (inward, outward) when you turn the left shifter, you can understand which direction it needs to be trimmed if it's rubbing after a shift of the rear.

Also, you should take your new bike in for its 30-day tuneup. As new cables seat themselves and settle in during the break-in period, they can seem to "stretch" and require adjustment. Have the shop show you how to do this for yourself, too.

As you gain more experience, you'll focus less and less on the index numbers on the shifters until you find you never look at them at all. You'll shift by feel, and you'll tim the FD without even thinking about it.

RichC

Thanks for all the replys. I'm learning.

MsVickie, I'm glad you enjoyed my digital paintings. One of my many, many hobbies. :)

Welcome to Bikeforums, Bett. You may find it useful to have a friend hold your bike with the rear wheel off the ground, while you turn the crank forward and operate the grip shifters. Observe the action of the derailleurs and the sounds the chain makes. Learn to distinguish front derailleur noises (e.g. the chain scraping on the cage) from rear derailleur noises (e.g. cog teeth rattling against the chain). It is much easier to watch, listen, and learn than to try to read about it here.

There is a misconception about the left gripshift shifter. On some bikes the shifter is indexed, 1,2,3 is in fact 1,2,3. However on most bikes, like the Sedona, the shifter is not indexed, but has many little clicks, so for the new person, who sees that number and arrow and lines it up(Which makes sense) the der might not be inline with the number and in some cases the correct position is quite a ways from the gear number.