[-BB-]

At this point, I can do almost all of my own wrenching... the one thing that still drives me nuts (and to my local LBS) is general drivetrain tuning.

Can some of you gurus please tell me the process that is used to get your shifting into tip-top shape?

 

[-BB-]

cmon guys

 

[biggins]

i would like to know as well. i can do almost everything as well except drive train tuning. i guess no one wants to respond to this cause it is actually bike related.

 

[Westy]

I go for a 2-step approach.

with the bike in the stand I adjust the barrels until the mech visually lines up with the proper gear to get a baseline adjustment.

Then go for a ride and do a little trial and error. Try two clicks out see if things get better, if not go back to the baseline then try two clicks in. If that improves things try two more clicks until things get worse again.

A little practice and it gets easy. And remember after you get everything set up the only adjustment that is likely to be needed is turning the barrel out to compensate for cable stretch. But in general if things are upshifting slow turn the barrel in, if they are downshifting slow turn the barrel out. Unless you have rapidrise then you need to buy a SRAM drivetrain.

 

[Repack]

First, start by checking your cables. Dirty cables are a derrailleurs worst enemy. Shift onto the largest cig, stop the wheel, shift out all the cable slack while leaving the chain on the largest cog and you will be able to slip the housing out of the slotted guides. Slide the housing up and down the cable and feel for friction. Sometime you can see dirt and wipe it away. If it feels bad at all, I just replace it. For cable lube, I like Pedro's Ice Wax. It dries very lite and is durable.
To start the actual adjustment, the first thing I do is set the limit screws (H&L) H is the smallest cog as in high speed. Always makes sure that there is slack on the cable. Start by threading the barrel adjusters all the way in so you know you have some slack. The slack makes it easier to adjust the limit screws. I adjust the screw so the the upper jockey wheel line up ~50% to the outside of the laregest and smallest cog.
To start with the cable tension, I first make sure that the barrell adjuster(s) are screwed almost all the way in.
Then I pull the cable tight. I don't put too much pressure on it. Once the nut is tight, I use the barrell adjuster(s) to fine-tune the tension so that the cable is just barely tight when on the small cog.
Then I start actually shifting. REMEMBER:
When you are shifting into easier gears in the back (no rapid rise), the cable tension is physicly pulling the derr up. When you downshift, it is gravity and a weak spring pulling it down. It should shift to easier gears fastest. The chain should just pop right up without hesitating or going too far and then dropping back. The same is true for shifting into faster gears.
If you need to adjust the limit screws, take the pressure off the derr by pusing it towards the larger cogs. Just turning the screws can pit the stop plate and/or mushroom the tip of the screw, making adjustment more difficult.
Everytime I make a tension adjustment I quickly shift through the entire range of gears a few times to make sure that the cable has settled.
When installing a new cable/housing, leave the chain in the small gears and upshift without pedaling. Don't kill the shifter. This will seat the cable and housing. To relese pressure, just pedal. Using the shifter can damage it.
Wow. That just got long.

 

[Matt D]

To be honest, the whole system is very simple. You just have to understand what you're doing, and think about each adjustment you're making.

Increasing cable tension will move the der. up, decreasing will move it down. The amount the der.s can move is limited by the (believe it or not) limiting screws.

Problems happen when stuff is bent (der. hanger, derailleurs etc) or worn out (cables/housing, chain, der.s, shifters).

Sorry to be so vague, but I learned everything by just playing with it and seeing what happened.

 

[Kornphlake]

Honestly I never worry about the H/L stops unless I'm putting on a new derailur, I just shift to the smallest cog, loosen the cable locking nut, screw in the barrel adjuster on the derailur until there's about 2 threads showing then pull the cable through and tighten it down. Then I pedal the bike and shift up one gear, if it doesn't shift I turn out the barrel adjuster until it does if it shifts up two gears I screw the barrel adjuster in until it shifts down to the right cog although you shouldn't need to screw the barrel adjuster in if you tightened the cable locking nut carefully. At this point if everything else is working as it should all the gears should be pretty darn close, if one gear is a little whacked check to see it is a gear combination you'd actually use and if not shift the chain to a different chainring and 9 times out of 10 the problem dissapears.