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-   -   Shimano 105 5800 front shifter and derailleur issues (https://www.bikeforums.net/bicycle-mechanics/1137274-shimano-105-5800-front-shifter-derailleur-issues.html)

General Geoff 03-03-18 12:36 AM

Shimano 105 5800 front shifter and derailleur issues
 
So, I just received my new 2018 Lynskey Cooper CX that I opted to have pre-built and shipped. Got it on Wednesday. This bike is equipped with a 2x11 Shimano 105 5800 groupset, but with a Gossamer Pro 386EVO ABS Crankset (50/34T).

I've been trying to get used to the STI shifters (first drop bar bike I've had), and couldn't seem to get the hang of the front shifter. Always seemed to require shifting twice just to switch from small to large cog (and vice versa). Then when examining what exactly the shifter was doing to the front derailleur, I noticed that there is a very distinct click or index halfway in between the large ring position and small ring position. I'm thinking they installed a triple front derailleur and shifter instead of a double. :o

My question is, are the front derailleur and shifter specific to double- and triple spec? i.e. will I need to replace both of these components to get everything working correctly? I'd rather avoid having to ship the bike back to them so I'll probably install these components myself when I get replacement(s). Thanks :)

cpach 03-03-18 12:47 AM

There's a trim position to each ring--a partial shift up from the small ring for crosschaining on the small cog, and a partial shift down for crosschaining on the big ring and big cog.

Your derailleur is correctly adjusted when:
-The derailleur cage clears by 1-3mm above the tallest teeth on the large chainring.
-The derailleur cage is parallel to the chainrings.
-When shifted in the small-big, there is 1-0mm of distance between the cage plate and the chain. It should ideally not rub in this position.
-When shifted into the big-small, there should be 1mm of clearance to the chain cage.
-You should ideally have no chain rub when in the trimmed, cross chained positions.
-If your bike has a braze on derailleur tab, the support bolt should be in contact with the frame.

You do not have a set up for a triple because 5800 (and all of the 11 speed Shimano road groupsets) does not come in a version for a triple.

General Geoff 03-03-18 12:50 AM

OK, so clicking the smaller inner shifter should result in a halfway shift? I know I can pull the big shifter fully over to achieve two "clicks" at once, but I have to click the inner shifter twice to get completely down on the small ring.

Thank you for clearing up my ignorance on the double/triple thing!

I did make some very minor adjustments following a few youtube Shimano derailleur adjustment procedures, and if I utilize the middle index position on the front derailleur, I can crosschain to any combination with no rubbing.

cpach 03-03-18 01:13 AM

A confident pull of the brake/shift lever should shift all the way into the highest tension setting of the front derailleur, and a confident, full click of the inner shift lever should shift you down to the small ring in the lowest tension setting. The trim positions are accessed by gentle, partial presses of the levers; many riders are actually unaware that they exist. (You don't really need them if you don't cross chain at all, although at least I cross chain slightly pretty often on a compact crank).

The main thing to be aware of is that those 11 speed "long arm" front derailleurs are extremely sensitive to cable tension adjustments. Once adjusted however they do shift really, really well.

General Geoff 03-03-18 01:16 AM

Yes, I noticed that just a single 1/4 turn of the tensioner can make a BIG difference in positioning and rub. I'll have to practice with the inner shift lever to see if I can get it to do a "full" click instead of a half click.

General Geoff 03-03-18 01:29 AM

I took a (crappy) video of the shift indexing. It's actually THREE clicks going down and three clicks going up. The last part of the video is me pushing all the way on the inner shifter, it only shifts two clicks. Still need to release and push again to get it to drop all the way down.



edit; I found a video that specifically addresses the 105/5800 and trim indexes. Thanks again for your help in understanding!


dsbrantjr 03-03-18 07:08 AM


Originally Posted by General Geoff (Post 20202121)
Yes, I noticed that just a single 1/4 turn of the tensioner can make a BIG difference in positioning and rub. I'll have to practice with the inner shift lever to see if I can get it to do a "full" click instead of a half click.

I find that 1/4 turn is often too large an adjustment. I tend to adjust in 1/8 turn or less increments, which can be enough to go from perfect to poor shifting. If you make too-coarse adjustment you may miss the sweet spot.

General Geoff 03-07-18 12:54 AM

Thanks again for your help, guys. I have it dialed in just about perfectly now, no rubbing, even in both full crosschain combinations. Smooth running and smooth shifting!


I also read up on Shimano's mid generation "upgrade" for the Front Derailleur mechanism, the 5801. It appears I have the original 5800 FD, not the 5801. I'll continue running it as-is since it works just fine, and trying to maintain the "latest and greatest" in components is an exercise in futility and frivolous spending. :)


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