Adjusting the front derailleur

[twozeronine]

I decided to give my FD a bit of a tweak at the weekend, as the chain was rubbing on the outer cage when on the large ring/small rear sprockets. One thing that had me confused is how to adjust the high limit screw. I expected it to behave like the lower limit screw, ie. making the FD move in and out as you turn it, but it doesn't seem to affect the position of the FD. I looked at some tutorials, and they suggested that it should be exactly the same as adjusting the low limit.

So what's the correct procedure for adjusting it?

By the way, I fiddled with the height/angle of the FD and the tension of the cable, which has alleviated a lot of chain rub (mostly luck really), but I was still left scratching my head regarding the high limit adjustment.

 

[martint235]

I decided to give my FD a bit of a tweak at the weekend, as the chain was rubbing on the outer cage when on the large ring/small rear sprockets. One thing that had me confused is how to adjust the high limit screw. I expected it to behave like the lower limit screw, ie. making the FD move in and out as you turn it, but it doesn't seem to affect the position of the FD. I looked at some tutorials, and they suggested that it should be exactly the same as adjusting the low limit.

So what's the correct procedure for adjusting it?

By the way, I fiddled with the height/angle of the FD and the tension of the cable, which has alleviated a lot of chain rub (mostly luck really), but I was still left scratching my head regarding the high limit adjustment.

On my Shimano 105 one, if you turn the screw clockwise it moves the cage towards the frame. On the lower limit, clockwise moves the cage away from the frame. When my front cable went, I had both screws tight in so that the chain ran on the big chainring without touching the cage at all.

 

[photography27]

i did mine last week, and it was a nightmare to get right, from my own experience, i would turn the high limit screw only quarter turns at a time, and change gears to test if the chain rubs, i would go through the gears after every quarter of a turn, it is a fiddley job to get right, it took me nearly 3 to 4 hours to get my gearing spot on, but it is worth it now

 

[MontyVeda]

if the FD doesn't move when you adjust it, the FD isn't butted up against it... just keep turning it till you see it's affect on the FD... and make sure you're in the right gear.

 

[HLaB]

The High limit screw doesnt adjust the derailleur position it just defines the limit the gear cable can pull the derailleur to. If the set up was fine x months ago, the cable probably just needed tightening. Loosen the limit screw too much would just mean that the cable could pull the deraileur further and possibly result in the chain coming off.

 

[twozeronine]

Right, ok. So do you need to shift to the small ring, adjust it, then shift up to see it's effect, or...?

 

[twozeronine]

OK - thanks lee. I'll give that a go and see how I get on.

(apologies for deleting the post you quoted)

 

[HLaB]

Right, ok. So do you need to shift to the small ring, adjust it, then shift up to see it's effect, or...?

You probably won't need to bother about the first minute of this video but after 1:16 Bicycle Tutor explains it well. If the cables good you might not even have to bother shifting to the small ring and tightening, a shift of the barrel adjuster may suffice.

 

[zacklaws]

[QUOTE 1343514"]

Now manually put the chain onto the largest chainring, it maybe a bit tough but it can be done. With the chain on the largest chainring and with your non dominant hand position the front mech exactly where you want it, hold it in place and adjust the H screw turning it clockwise. You should feel the mech move in your hand after a couple of turns of the screw. Stop when you are happy with the position of the mech and there is no chain rub against the side of the cage.

Re attach the inner gear cable, the less slack the better. NOT touching the front mech gear shifter use the barrel adjuster on the downtube or gear shifter to get rid of any remaining slack.


[/quote]

But should you not move the chain back onto the small chainring and large sprocket before tightening the cable. Every thing that I have read indicates that's the correct procedure. If its a triple, then the cable would be far too loose to move from the inner and onto the middle?

 

[twozeronine]

Thanks.