Rear derailleur CAAD3

[IdahoBrett]

I replaced my RD on my R400 with a 105 to match the FD. I can not get the L limit screw in adjustment. I’ve watched the Park Tool video multiple times.

I do believe I’ve discovered the issue. The first step in the video is to make sure the derailleur hangar is straight. It looked straight enough to me in the beginning. After struggling for a few days I had another look and eyeball compared it with my other bikes. It is not straight. Looking at a picture with wheel removed it is obvious now. And the frame almost looks bent.

 

[IdahoBrett]

Nope. Optical illusion with all the curves. Nothing is bent. I carefully measured and compared to my CAAD4 frame. If there are differences it’s less than half a mm. It’s a bicycle not an airplane.

I just don’t know how to dial in a RD apparently….

 

[black lightning 1987]

I set the limit screws with the cable disconnected. Turn the crank with one hand and run the derailleur with the other. You want to adjust it so that it will shift to all cogs but prevent the cage from contacting the spokes.

 

[JohnnyD]

I set the limit screws with the cable disconnected. Turn the crank with one hand and run the derailleur with the other. You want to adjust it so that it will shift to all cogs but prevent the cage from contacting the spokes.

This is how I do it as well. Although I "ball park" the L screw by eye without the chain installed before. This way I am typically only about a 1/4 to 1/2 turn off on having it perfected. Of course this varies when I installed the wide range 12 speed, but thankfully SRAM has made B gap adjustment needed before the L screw for those almost idiot proof IMHO. Actually, now that I think about it, I've never had to adjust the H screw on any of my 12 speeds, and only the L screw by about 1/4 turn right out of the box and they worked perfectly.

 

[IdahoBrett]

It's weird. I can get it shifting like a Swiss watch through the first 7 cogs. But the biggest rear cog (8th) eludes me...

I shall try it with the cable disconnected.

Any chance that it could be a chain issue? It isn't worn to the 50% level yet as checked with the Park Tool chain checker.

 

[JohnnyD]

I know this might sound crazy, but have you double checked that the shifter was in the correct gear when installing the cable? Granted I use indexed trigger shifters on my MTB's , but I have mistakenly thought that I had the shifter in the highest gear when connecting the cable to the derailleur before. Left me scratching my head as to why I couldn't get it to go into the lowest gear for a while. Easy to check and eliminate as a possible cause.

 

[IdahoBrett]

I did not even think of that @JohnnyD

Thanks!

 

[JohnnyD]

Just like when you trouble shoot aircraft systems. Look at the simplest things first.. If I hadn't made that mistake a couple of time over the years I wouldn't have thought to check it either. I've even done it with my old Deore LX friction shifters that came with the M700.

 

[IdahoBrett]

When you don’t know where to start, go back to the beginning.

It was the shifter. I put the original Sora brifter back on and voila, all 8 cogs are accessible.

Turns out my ignorance has cost me once again. The Shimano 105 Flight Deck ST-5500 is absolutely in fact a 3X”9” brifter. And is NOT compatible with an 8 speed cassette. Regardless of what the ebayer advertised it as. It was advertised as 3x8.

I did find a compatibility chart from Shimano for 2004-2005. They don’t have one older that I could find. The chart was not perfectly clear to my interpretation. But clear enough that I oughta swap back and see if was my problem. It was. And thanks to the anonymity of internet forums I only have to hide my face in shame here on VC.

Thanks all.

 

[JohnnyD]

When you don’t know where to start, go back to the beginning.

It was the shifter. I put the original Sora brifter back on and voila, all 8 cogs are accessible.

Turns out my ignorance has cost me once again. The Shimano 105 Flight Deck ST-5500 is absolutely in fact a 3X”9” brifter. And is NOT compatible with an 8 speed cassette. Regardless of what the ebayer advertised it as. It was advertised as 3x8.

I did find a compatibility chart from Shimano for 2004-2005. They don’t have one older that I could find. The chart was not perfectly clear to my interpretation. But clear enough that I oughta swap back and see if was my problem. It was. And thanks to the anonymity of internet forums I only have to hide my face in shame here on VC.

Thanks all.

No shame to be had. Anyone who claims they never make mistakes, or has things go perfectly 100% of the time is lying to themselves. Besides, your problems taught somebody else somewhere. That is always a good thing.

 

[black lightning 1987]

When you don’t know where to start, go back to the beginning.

It was the shifter. I put the original Sora brifter back on and voila, all 8 cogs are accessible.

Turns out my ignorance has cost me once again. The Shimano 105 Flight Deck ST-5500 is absolutely in fact a 3X”9” brifter. And is NOT compatible with an 8 speed cassette. Regardless of what the ebayer advertised it as. It was advertised as 3x8.

I did find a compatibility chart from Shimano for 2004-2005. They don’t have one older that I could find. The chart was not perfectly clear to my interpretation. But clear enough that I oughta swap back and see if was my problem. It was. And thanks to the anonymity of internet forums I only have to hide my face in shame here on VC.

Thanks all.

People sometimes forget that 8 clicks mean 9 gears, not 8.

 

[IdahoBrett]

Absolutely. First thing I did when I opened the shipping package was count the clicks. I got 8. My brain said “great! It’s an 8 speed!” Duh!

 

[black lightning 1987]

Maybe install a 9 speed cassette.

 

[IdahoBrett]

Maybe.....

 

[black lightning 1987]

I have several NOS black 5501 short cage RDs if you want everything matching.

 

[IdahoBrett]

I have several NOS black 5501 short cage RDs if you want everything matching.

That would be a great look for the bike. But I'm happy with it for now. Thanks!