Road Bike, Cycling Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter · #1 ·
I went from a 52/42/30 to a 53/39 (new bb and crankset)... what are the proper steps for adjusting the front derailleur/shifter for it to work correctly? 9 speed Tiagra set-up. Tell me please I don't need a new shifter/brifter. Thanks!
 

·
Registered
Joined
·
5,234 Posts
I haven't done this myself, so take it as such...

You should really only need to set the limits on the derailleur for the new crank. Set up the cable tension so that when the shifter is at its lowest tension, the derailleur is sitting on its low limit stop. Basically what you're doing is setting things up so the shifter operates as though you were using only your small and middle ring on the triple setup. The high limit screw should prevent you from being able to shift the third time.

Triple derailleurs are supposed to be problematic at times on double cranks. Luckily, they're a lot cheaper than the whole shifter. Or it could be fine. Since you went one tooth larger, there's also a possibility that you'll need to move your derailleur up your seat tube a hair, but it's such a small difference that it seems unlikely to me.

I'm curious to hear how this goes.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #3 ·
This is what I've done so far:

1. Loosened the derailleur cable from the derailleur, and loosened the clamp and moved it up the seat tube about 1mm or so.

2. Set the low limit screw to be in a good lower ring position.

3. Tightened up the derailleur cable and tightened the bolt. Now the shifter in its lowest position is centered on the lower chainring and works great for the lower climbing gears. It rubs a little if I try to go into the faster gear combinations in the lower chainring. No trimming possible because...

4. One click shifts to the upper chainring, there's no room to trim. I tried to set the upper limit screw but all of a sudden it's really really hard to turn and I don't want to strip it. When I can get in the upper chainring, again, I can't trim at all, and anything but the fastest gears wants to rub.

I am not opposed to starting from scratch if that's what it takes. Anyone done this successfully?
 

·
Registered
Joined
·
21,540 Posts
Park Tool

baldmanrunning said:
I went from a 52/42/30 to a 53/39 (new bb and crankset)... what are the proper steps for adjusting the front derailleur/shifter for it to work correctly? 9 speed Tiagra set-up. Tell me please I don't need a new shifter/brifter. Thanks!
The Park Tools web site has a whole bunch of step by step instructions. Go there, read up, and you should have no problems. It's quite a simple procedure at least on the first pass. Sometimes there are little tweaks required, but you need to do the normal setup first.
 

·
Registered
Joined
·
281 Posts
This thread is dead, but for anyone interested I just thought I'd add a comment because I went through the process myself today. I went from an Ultegra 6603 to Ultegra 6700 crank.

First lesson.

It turns out the triple front derailleur wasn't even close to functioning properly on a double crank. The triple derailleur itself is very large and there is no way to raise it high enough without it rubbing on the both of the cranks. Normally the triple derailleur sits above the 30cog, but with a double crank, it had to sit right above the 39. Not even close.

In order to install the double derailleur, the chain had to be cut. However, once installed everything worked fine. Surprisingly the brifters did not need a whole lot of adjusting. It takes two swipes with the left hand to shift up and and two swipes to shift down. But its otherwise perfect, with no compromise in smoothness or range.

Bottom line...the double front derailleur is a necessity, the brifters are not.

But keep in mind, you'll need to replace the chain.
 

·
Registered
Joined
·
83 Posts
M-theory said:
This thread is dead, but for anyone interested I just thought I'd add a comment because I went through the process myself today. I went from an Ultegra 6603 to Ultegra 6700 crank.

First lesson.

It turns out the triple front derailleur wasn't even close to functioning properly on a double crank. The triple derailleur itself is very large and there is no way to raise it high enough without it rubbing on the both of the cranks. Normally the triple derailleur sits above the 30cog, but with a double crank, it had to sit right above the 39. Not even close.

In order to install the double derailleur, the chain had to be cut.
I didn't have to cut the chain when I replaced my 105 front derailer. There's a screw I took out and slipped the chain though the derailer. Replaced and tightened the screw and all is good.
 

·
Cycling induced anoesis
Joined
·
13,006 Posts
baldmanrunning said:
This is what I've done so far:

1. Loosened the derailleur cable from the derailleur, and loosened the clamp and moved it up the seat tube about 1mm or so.

2. Set the low limit screw to be in a good lower ring position.

3. Tightened up the derailleur cable and tightened the bolt. Now the shifter in its lowest position is centered on the lower chainring and works great for the lower climbing gears. It rubs a little if I try to go into the faster gear combinations in the lower chainring. No trimming possible because...

4. One click shifts to the upper chainring, there's no room to trim. I tried to set the upper limit screw but all of a sudden it's really really hard to turn and I don't want to strip it. When I can get in the upper chainring, again, I can't trim at all, and anything but the fastest gears wants to rub.

I am not opposed to starting from scratch if that's what it takes. Anyone done this successfully?
I think where you may have gone a little wrong is in step #1 when you loosened the cable to relocate the FD. If one click now shifts from inner to outer ring with no trim, you may not have had the left shifter 'parked' in its lowest position prior to tensioning the cable. When in the inner ring and the shifter is parked, you should need to click once for trim and again to execute a shift to the outer ring. There's a trim setting there as well.
 

·
Registered
Joined
·
281 Posts
wobblyRider said:
I didn't have to cut the chain when I replaced my 105 front derailer. There's a screw I took out and slipped the chain though the derailer. Replaced and tightened the screw and all is good.

Yeah, the Ultegra 6603 derailleur had the screw of which you speak, but the new 6700 series has a rivet with no threads.
 
1 - 8 of 8 Posts
Top