Chain rub on a triple - to be expected?

[RoseC]

Sara,

I'd definitely ask your LBS about trim. I'm still getting the hang of it myself... I posted a thread here a few weeks back because I thought my front derailler was out of whack since I got chain rub up front when I was in the smaller cogs (higher speeds) in the back.

Turned out I wasn't using trim properly. On my bike, when I'm in those gears in back, my shifter for the front has a sort of half shift thing it can do - I push the inside lever a little bit (not allll the way across - just about halfway), there's a sort of pop, and the rub stops. I'm still not real clear on how it works - seems like that adjustment just magically becomes available when I need it.

I need to read up on it. And probably ask the bike shop folks for another tutorial.

[BleeckerSt_Girl]

Sounds pretty normal to me. You can't use ALL gear combinations, because you'll be cross chaining. Once you get chain rub that can't be fixed by trimming the front, it's a sign that you should change to the next front ring.

[mimitabby]

yes, yes.
don't go farther than the 5th gear in the lower chain ring.

however, you should be able to reach ALL of them in the middle chain ring.
if you can't you need an adjustment.

[spokewench]

Ditto to Mimi: Whether you have a double or a triple, you can't use all the gears are your rear cog in all of your combinations up front. You want to avoid as they say above, cross-chaining. That means you don't want to be in your little ring up front and your little gears (harder gears) in the back. Just switch to your next chain ring, i.e. when you start getting chain rub in the back, gear up in the front to your middle chain ring. Mimi is right, you should just about be able to use everything in the back from the middle. Occasionally, this won't work dependent on how big your cog differences are in the back, so you might not be able to use your last cogs in back on the small side and big side from your middle chain ring.

spoke

[RolliePollie]

Cool! So I'm gonna head to the LBS for some possible adjustments, and then try to avoid certain gear combinations. Now that I can actually switch chain rings without dropping the chain every sinlge time, maybe I'll change rings a bit more often. I have Sora shifters so I'm not sure I have those half-click adjustments. Seems like if I mess around with the left-hand shifter, it tries to change rings on me. Perhaps when I go to the LBS, a little lesson will be in order too!

The great advice here just continues to amaze me! Thanks to everyone

[ridebikeme]

It's great that you are wanting to learn more about your bike and how it works!!! I only wish that more people in general would take that stance!

As for your bike, it indeed you have Sora shifters, then you're right you do NOt have trim with your front derailleur... that starts with the nine speed drivetrains. But learning not to cross chain is always a good thing, and there are many areas where there are duplicate gear(gear inches) without having to cross chain.... I'm sure tthat your bike shop will be glad to show and explain that to you.

[RolliePollie]

It's great that you are wanting to learn more about your bike and how it works!!! I only wish that more people in general would take that stance!

As for your bike, it indeed you have Sora shifters, then you're right you do NOt have trim with your front derailleur... that starts with the nine speed drivetrains. But learning not to cross chain is always a good thing, and there are many areas where there are duplicate gear(gear inches) without having to cross chain.... I'm sure tthat your bike shop will be glad to show and explain that to you.

Ahhh, so another thing to add to my list when I upgrade my bike in a year or two...better shifters! No trim with Sora...bummer! As I find more things about my bike that I'm somewhat dissapointed in, I'm thinking it will be more like only one year until I ugrade. But you have to start somewhere. This bike is getting me around just fine and I can beat the poor thing up a little bit and not feel too bad about it.

I still think a trip to the LBS may be in order. But I think working out better gear combos to avoid cross chaining is going to help. What would really help is if my legs were stronger so I didn't need those granny gears so much. But I know they're getting stronger, so it's probably just a matter of time.