help with FD tuning please (on hybrid)

MB Lacey

I'm cycling a triple hybrid.
In the last few weeks the chain has stopped moving down from the middle to the smallest cog at the front (strong headwinds and cycling up Crumlin rd hill make this option vital at times).

I have watched this Evans youtube video

and successfully tuned my gearing on the cassette (felt quite pleased with myself), I twisted the gear barrel at the front (I can't remember which way) and the chain slipped down to the small cog - great, I was the best.
I went through all the gears, did a few more adjustments to beautify the chain movement along the cassette, then for whatever fkn reason, I started to tighten and loosen the two screws on the FD - and now everything has broken.
No amount of turning the gear barrel at the front will get the chain to shift down to the smallest cog from the middle cog.
Any advice?
Here's a photo of the screws and the type of front gear barrel, in case that makes any difference to advice.
Thanks

Coronal

Those screws are called the limit screws, as they set the limit for the derailleur movement. If you turn the 'low' limit screw when the shifter is set for the lowest gear you should see the derailleur cage move in or out. Just turn the screw until the chain will sit over the small ring. Do the same for the big ring and you're good to go

In theory.

MB Lacey

Thanks Coronal, in theory is correct, I turned them both but couldn't easily detect any FD movement at all.
However, the chain slipped down to the small chain ring and is now working fine.

:rolleyes:

Type 17

Yes, the cage-positioning versus the chainwheels, the limit screws and the cable tension are three separate adjustments, although they can interfere with each other if badly out of adjustment.

The best way to set up a FD is to do things in a particular order:

Firstly check the height and angle of the cage, moving the whole FD on the frame if required. The outer side of the cage should be parallel with the chainwheels, and this same edge of the cage should be no more than 3mm above the largest chainwheel at its closest point, when it's directly above it. This is particular adjustment is crucial for quick and accurate shifting.
Next, put the RD on the largest sprocket and the chain on the smallest chainwheel, then adjust the FD's L screw so the inner side of the FD cage (the side closest to the wheel) is as close to the chain as possible without touching it.
Then use the FD's shifter to put the chain on the big chainwheel and put the RD on the smallest rear sprocket - don't worry about the cable tension just yet.
With the chain in this gear, set the FD's H screw so that the outer side of its cage is as close to the chain as possible without touching it.
Now that the screws are set, you can set the cable tension - basically, you want the three 'clicks' in the shifter to match the three chainwheels, so use the barrel adjuster on the FD shifter to do it. If you run out of travel on the adjuster, turn it back, and move the cable in the pinch bolt and then use the adjuster again.
From experience, I've found that, on most hybrids, the FD cable tension will be right when the chain rubs lightly on the outside side of the FD cage when the chain is on the middle chainwheel & smallest sprocket, but yours might differ a bit.

Hope that helps.

Coronal

MB Lacey wrote: »

Thanks Coronal, in theory is correct, I turned them both but couldn't easily detect any FD movement at all.
However, the chain slipped down to the small chain ring and is now working fine.

:rolleyes:

Always the same, ask for advice/show it to somebody and it just starts working...

smacl

Agree with Type17. My experience, and many wasted hours, on adjusting FDs is it is that it is quicker, easier and more reliable to start from scratch with cables disconnected than adjusting from your current position with cables attached. I've a campag triple on my road bike, and found the campag FD adjustment manual excellent as a step by step, which works as well for the Deore triple on my hybrid. Also worth taking the FD off to check if there's any grit on the sprung section, and checking the cables are running smoothly when not under tension. Note, if you're nervous about doing this, take a few photos of your current set-up that clearly show how everything is currently placed. I've a couple of discreet pen markings on the frame and limit screws for my optimum settings.

joxerjohn

Good explanation from Type 17 !

On adjusting the cable tension I see in the picture of your barrell adjuster that it is fully tightened. You can tell because the metal holder for the cable appears to be all the way out. So as suggested you need to back off the cable tension by turning the barell adjuster clockwise and then re-adjust the the cable tension at the pinch bolt (with the chain on the smallest chain ring).

Also one the liimt screws (H) seems to be screwed out more than I would expect to see. The limit screws can sometimes be difficult to turn and if this is the case removing them and cleaning out any grit and old grease and then refitting them will make adjustments easier, remember to adjust by a quarter of a turn at a time.