Shifting issues

[Spartan]

Hi everyone,

I recently changed the dérailleurs on my bike. After attaching the cables and putting the chain on, I tested it and discovered a couple problems:

-The rear dérailleur shifts up, but does not shift back down.
-The front dérailleur doesn't shift at all because the grip shift can't turn.

What have I done wrong here?

Parts I'm using:
Front Dérailleur/Shifter = Shimano Deore LX, SRAM Centera
Read Dérailleur/Shifter = SRAM X.7, SRAM 7.0

Thanks!

[GeorgeET]

Look at the tutorials on this site. On my computer they are right on top of this thread.

Undo your cables set high and low screws on both so they are around 1/8 inch inside and 1/8 inch outside the chain (set chain on inside sprockets and than outside for this)than adjust as indicated. Screw in barrels to get longest cable and attach with a bit of slack, just a touch in the inboard position. Than tune with the screw barrel as you turn the crank. If you do not have a stand try this upside down or hang bike with ropes.

Usually if the dérailleur does not shift down its because the cable is too tight.

Grip shifts are problematic, make sure all is clean and lubricated.

[Spartan]

(08-18-2010, 02:53 PM)GeorgeET Wrote:  Look at the tutorials on this site. On my computer they are right on top of this thread.

Undo your cables set high and low screws on both so they are around 1/8 inch inside and 1/8 inch outside the chain (set chain on inside sprockets and than outside for this)than adjust as indicated. Screw in barrels to get longest cable and attach with a bit of slack, just a touch in the inboard position. Than tune with the screw barrel as you turn the crank. If you do not have a stand try this upside down or hang bike with ropes.

Usually if the dérailleur does not shift down its because the cable is too tight.

Grip shifts are problematic, make sure all is clean and lubricated.

Thanks for the response.
I've watched related videos on this site and countless others on Youtube up till this morning. Set the screws, undid/redid the cables, adjusted the barrels etc. as you (and the videos) suggested and it's still not shifting back down. On top of that the upper pulley is griding against the cassette and adjusting the b screw is doing nothing to stop that.

The grips-shifts are all clean as they are brand new.

Don't even know what the heck is going on anymore. Just a hair away from putting this bike craigslist and buying a new one...

[GeorgeET]

Don't give up. Take it to a LBS for tune up. No big deal.

[Finelineco]

Hi , I'm new and not sure if I'm asking my question in the right place but here goes. I have a 12 Year old Giant ATX 780 with Shimano Deore XT Rapid Fire Shifter . Left shifter has lost it's locking ability. Should I brave the dismantling as per Alex's video, or is this shifter broken?
Thanks. ( Great site by the way)

[GeorgeET]

Well if its broken you got nothing to loose. Try spraying some cleaner in there and when dry some lubricant.

If that does not fix it replace it.

Make sure the problem is the shifter first.

[Finelineco]

(08-20-2010, 10:38 PM)GeorgeET Wrote:  Well if its broken you got nothing to loose. Try spraying some cleaner in there and when dry some lubricant.

If that does not fix it replace it.

Make sure the problem is the shifter first.

Thanks, I think I will take a stab at it! There's no clicking or locking so that's why I assumed the problem is with the shifter.