Bicycle Mechanics - Removing granny gear

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View Full Version : Removing granny gear


mzeffex
10-17-09, 09:50 PM
I decided to convert my triple FSA gossamer crank to a double tonight. Removed the granny, put the crank back on, all went well. Now I adjusted the limit screw so it won't go down too far, but it just won't go to the big ring. I don't know why. Any ideas? It has a 105 triple front derailleur, could this be it? Thanks.


DannoXYZ
10-17-09, 09:54 PM
Did you turn the correct limit-screw? Did you re-adjust the cable?

Is this a new FSA crank? Did you clean off the splines on both the crank and spindle? I've found little slivers of metal less than 1mm in size will keep the crank from sliding onto the spindle correclty.

Measure your chainline; that'll tell you if everything went back on correctly.

mzeffex
10-17-09, 10:03 PM
Do I need to readjust the cable? I didn't think of that. It is in all the way. So by readjust I assume you mean loosen the bolt on the derailleur and tighten the cable?


Jeff Wills
10-17-09, 11:00 PM
Did you turn the correct limit-screw? Did you re-adjust the cable?

Is this a new FSA crank? Did you clean off the splines on both the crank and spindle? I've found little slivers of metal less than 1mm in size will keep the crank from sliding onto the spindle correclty.

Measure your chainline; that'll tell you if everything went back on correctly.

I'd ditto this. If you didn't touch the outer limit screw, something has changed with the spacing from the center of the bike to the outer chainring.

Does the chain drop in to where the inner chainring used to be? Then you adjusted the wrong screw- it happens to the best of us (except Operator, maybe).

Bianchigirll
10-18-09, 09:15 AM
if the inner limit scew was adjusted without the cable being removed, the shifter 'thinks' it is shifting from the granny to the middle ring. yes?

mzeffex
10-18-09, 09:16 AM
After another hour of frustration I'm putting the granny back on. Forget being less of a fred.

Retro Grouch
10-18-09, 09:19 AM
if the inner limit scew was adjusted without the cable being removed, the shifter 'thinks' it is shifting from the granny to the middle ring. yes?

Maybe. It depends on what position the shifter is in.

My question is: "What has the OP gained by doing this?"

mzeffex
10-18-09, 11:20 AM
What was my intention? To have a double. The granny gear has literally not been used once.

nahh
10-18-09, 11:25 AM
What was my intention? To have a double. The granny gear has literally not been used once.

put it back on, ride more/steeper!

HillRider
10-18-09, 11:28 AM
What was my intention? To have a double. The granny gear has literally not been used once.

To repeat what the others have posted, if the bike shifted to the big ring before you removed the granny, it should do so now without it. Either you adjusted the wrong limit screw, didn't seat the crank completely or didn't have the shifter in the proper setting when you adjusted the limit screw.

First, be sure the crank is installed properly. What type of bb does it have? If it's an ISIS, did you align and seat the splines properly. It's easy to have the splines butt against each other rather than interlace and that will leave the crank much too far out and, damage the splines if it's ridden that way.

If the crank has been installed properly, disconnect the cable and see if the front derailleur will move over the big ring when moved by hand. Adjust the outer limit screw until it does. Do the same with the now small ring and adjust the inner limit screw to align the fd correctly. Then shift the brifter to the smallest ring position and attach the cable pulling out all slack. Fine tune the barrel adjuster to get it to shift cleanly.

Garthr
10-18-09, 11:34 AM
I decided to convert my triple FSA gossamer crank to a double tonight. Removed the granny, put the crank back on, all went well. Now I adjusted the limit screw so it won't go down too far, but it just won't go to the big ring. I don't know why. Any ideas? It has a 105 triple front derailleur, could this be it? Thanks.

It sounds like you adjusted the wrong screw. Since there's only 2, try the other one. Try it even with your granny installed. You can adjust the FD so it won't shift into the granny..... no need to take it off.

DannoXYZ
10-18-09, 02:38 PM
if the inner limit scew was adjusted without the cable being removed, the shifter 'thinks' it is shifting from the granny to the middle ring. yes?Yes, if the cable wasn't adjusted, then the shifter still moves from middle ring to big-ring on the 2nd click (ignoring trim half-clicks). The shifter still thinks it's moving from middle to big-ring as the FD moves from the new inner to big-ring.

If he shifts down in the reverse direction into the granny, he gets a dead click between #2 & #1. The shifter moves, the cable relaxes, but nothing happens because the inner limit-screw prevents the FD from moving into the granny position. Then if he starts shifting up, he'll get one dead click that takes up the cable-slack. Then the 2nd click moves the ring from middle to big, same as before.

The way to get around the dead-click is to shift the lever into the granny-gear position. Set inner-limit screw to center over middle ring (new inner). Loose cable-clamp bolt, pull cable through to take up slack. Tighten clamp-bolt. Now it'll work like it should with no dead-clicks into phantom positions. There IS a phantom position on the outside now, but the outer limit-screw prevents the FD from moving that far and the shifter can't pull enough cable to click into that position.

DannoXYZ
10-18-09, 02:42 PM
After another hour of frustration I'm putting the granny back on. Forget being less of a fred.Don't know about that. Admitting defeat and going back to triple may actually make you more fred than before. I'd stick with it until you figure it out.

Al1943
10-18-09, 03:37 PM
First be sure the crankset is properly seated with enough torque.
With the chain on the inner chainring and largest cassette cog, set the low limit screw for the inner ring.

You must disconnect the front shift cable, flip the smaller shift lever several times while pulling the free end of the cable. This is to make sure all of the cable has been released from the shifter. Make sure the end of the cable in the shifter is properly seated.

Re-connect the cable with all slack removed.

It will now shift to the big ring. The way you set it up would cause slack in the cable after downshifting.

Al

mzeffex
10-18-09, 05:12 PM
I don't know what the deal was. I put it back on, turned the limit screw out and in (respectively) and it shifts fine. It actually shifted to the big ring before I did any adjustments..

I am a mechanic at a shop (in training) so I definitely was doing the right screws. I've adjusted probably hundreds of front derailleurs in the 9 months I've been doing this. Never had to remove a granny and not put a new one on, though. Who knows. Maybe I'll try again sometime when I don't want to go for a ride.