# High limit adjustment on Red FD



## qatarbhoy (Aug 17, 2009)

Okaaaay... I'm still having trouble adjusting my Red FD (search my previous posts and threads all over RBR).

I'll skip the details as to why I needed to reinstall my front derailleur. I've got the front derailleur to shift, and pretty promptly too (yay!) _but_ when in the big chainring and smallest cog, the chain is barely clear of the cage and under riding conditions I can hear the horrible sshh-shssh of chain rub. Man, I hate chain rub. 

It should be easy to use the high limit screw to get the required 0.5-1mm of clearance. The problem is, the limit screw doesn't do anything to back the cage further away from the chain - it just backs out leaving a space to the rest stop. If I turn the screw the other way, i.e. pushing harder against the rest stop, the cage moves right onto the chain.

Sooo, what do I need to adjust to get rid of the chain rub and have the limit screw resting on its stop as it should?  Please explain in simple words and possibly with diagrams (but not SRAM's, as they only explain what to do when everything falls magically into place).

I suck at being my own mechanic.


----------



## cxwrench (Nov 9, 2004)

this sounds more like a 'your crank isn't installed properly' issue than a derailleur adjustment issue. can't remember the last time i saw a derailleur that couldn't be adjusted properly for the high limit. sometimes on mtb's w/ shimano topswing frt derailleurs you can't get them to move far enough to clear the chain on the low gear, but that's completely different.


----------



## AppleCyclingComputer (Aug 3, 2005)

Is this the new 2012 Sram Red or the previous version?


----------



## qatarbhoy (Aug 17, 2009)

It's old Red with a Ti cage.



cxwrench said:


> this sounds more like a 'your crank isn't installed properly' issue than a derailleur adjustment issue. can't remember the last time i saw a derailleur that couldn't be adjusted properly for the high limit.


You're underestimating my uselessness at anything mechanical. :blush2:  I'm glad to say the cranks are fine. I think I just need to take up some more slack in the cable to get the cage to move further out (does that sound right?), but I welcome input from those who know what they're doing.


----------



## Kristatos (Jan 10, 2008)

qatarbhoy said:


> I think I just need to take up some more slack in the cable to get the cage to move further out (does that sound right?)


this is what I was thinking. You then probably will want to start over and adjust the lower limit, hook up and tension the cable, then adjust the upper limit. At least that's what I'd do first and see if it fixes the issue.

I would also set that upper limit screw back where you can still adjust it once you re-tension the cable, so it isn't already at the end of it's range. I'd do that first, before tensioning the cable. You may not need to re-do the lower limit, it may work just to pull that cable and then reset the upper limit.


----------



## cxwrench (Nov 9, 2004)

i took for granted that cable tension wasn't a problem here, but that does sound like the most likely issue. as stated by others, always start in the small ring/large cog combo and set the low limit. then attach the cable and set the high limit in bigring/small cog. then shift it a bunch and re-adjust cable tension.


----------



## qatarbhoy (Aug 17, 2009)

Hello again... 

I didn't want to start over as I was nearly there. I took in more cable slack which finally got the cage clear of the chain in the big ring, and then set the high limit. So far so good.

Having double-checked which way to turn the barrel adjuster... ahem... I can now get it to shift up _most_ of the time, but it's still not as reliable as it has been in the past; sometimes the chain doesn't make it to the big ring but scrapes against it. 

Downshifting is no problem, so it seems like I should simply increase the cable tension some more, but so far I've found that increasing the cable tension beyond its current point simply causes upshifting problems to occur on different cogs. I used to be able to just turn the barrel adjuster until I had snappy and reliable upshifts every single time and in all circumstances. Now it is being very fussy and I also find that shifting from the hoods is more likely to work than from the drops as it seems to need a more forceful lever push.

The bike has also developed an annoying tick/ping/creak noise when I'm making an effort (e.g. when shifting to the big ring to stand on the pedals for a short climb). I've been going through the low-hanging fruit in the list of things to lube/grease/adjust/reinstall and today's test ride was rather quieter than yesterday's. Hopefully the other items I've tackled today may also help in that regard. 

What with the shifting and the noise I am a sad puppy right now. More fiddling tomorrow.


----------



## Seagoon (Nov 22, 2009)

Is your chain long enough?


----------



## cxwrench (Nov 9, 2004)

qatarbhoy said:


> Hello again...
> 
> I didn't want to start over as I was nearly there. I took in more cable slack which finally got the cage clear of the chain in the big ring, and then set the high limit. So far so good.
> 
> ...


this really shouldn't be too hard. granted you have a red ti front derailleur, and if you are using a compact crank that can have a negative effect as well. do you have normal/externally routed cables? if so, set your low limit...small ring/large cog. attach front derailleur cable. shift down to small cog. pull cable away from down tube w/ your hand, and check the shifting, and make sure your high limit is set correctly. if you the chain goes up to the big ring easily when you're pulling the cable by hand, but doesn't when you use the shifter...your only problem is lack of cable tension. that should be easy to fix. 
if you're using a compact, you probably have a huge gap between the tail of the derailleur cage and the large ring. the shape of the red cage is weird, and they don't seem to match up to most normal seat tube angles very well. this is such a problem that SRAM has a tapered shim to help fix the problem. 
if you have internally routed cables, it's not much harder. move the paddle to shift up to the big ring...watch the derailleur carefully. when you move the paddle does the derailleur move immediately or is there some lag between shifter movement and derailleur movement? if there is, cable tension is low.
of course, all of this advice is useless if you don't have the derailleur mounted on the bike correctly. i'm trusting that you have this part done already...1-2mm above the big ring, parallel to the chainrings, maybe very slightly tail out.


----------



## qatarbhoy (Aug 17, 2009)

Chain is the correct length: the FD was working perfectly when first set up, and the chain length hasn't changed.



cxwrench said:


> this really shouldn't be too hard. granted you have a red ti front derailleur, and if you are using a compact crank that can have a negative effect as well. do you have normal/externally routed cables? if so, set your low limit...small ring/large cog. attach front derailleur cable. shift down to small cog. pull cable away from down tube w/ your hand, and check the shifting, and make sure your high limit is set correctly. if you the chain goes up to the big ring easily when you're pulling the cable by hand, but doesn't when you use the shifter...your only problem is lack of cable tension. that should be easy to fix.
> 
> ...watch the derailleur carefully. when you move the paddle does the derailleur move immediately or is there some lag between shifter movement and derailleur movement? if there is, cable tension is low.
> of course, all of this advice is useless if you don't have the derailleur mounted on the bike correctly. i'm trusting that you have this part done already...1-2mm above the big ring, parallel to the chainrings, maybe very slightly tail out.


Standard chainrings and external cables, correct gap, tail slightly outwards... so those aren't the problem. I understand the theory but actually getting the FD set in practice is what troubles me... I must be simply the most inept mechanic ever. 

There appears to still be some slack in the cable so I think I may be better off starting afresh after all as I suspect the barrel adjuster is at its limit and that that's why turning it further doesn't help. I have a race tomorrow so I want to get it right and not worry about missed shifts. Best get started now as I've a busy day ahead. :thumbsup:


----------



## cxwrench (Nov 9, 2004)

qatarbhoy said:


> Chain is the correct length: the FD was working perfectly when first set up, and the chain length hasn't changed.
> 
> 
> 
> ...


always start w/ the barrel adjuster turned all the way in. it sounds like your only issue is tension...this should take maybe 30 seconds to fix. undo the cable, turn in the adjuster all the way, re-attach the cable. dial up the tension 'til it works. done. 
what i meant when i was telling you to pull the cable by hand was this...if you can get the shift to happen when pulling the cable away from the downtube w/ your hand, and it doesn't work when you use the shifter, it's a tension issue. you need more tension. pulling the cable by hand just confirms that your high limit and derailleur position are correct.


----------



## qatarbhoy (Aug 17, 2009)

cxwrench said:


> always start w/ the barrel adjuster turned all the way in.


Will that be by turning it clockwise or counter-clockwise, when looking from the handlebars towards the rear wheel? (My barrel adjuster is in the middle of the cable, not flush with the ferrule.) I assume clockwise tightens the adjuster 'into' the frame which actually reduces cable tension. Let me know if that's wrong.

My latest tinkering with the cable and adjuster has improved matters but it still doesn't seem quite as good/snappy/reliable as it has been. Perfectionism married to ineptitude is a really poor combination...


----------



## cxwrench (Nov 9, 2004)

qatarbhoy said:


> Will that be by turning it clockwise or counter-clockwise, when looking from the handlebars towards the rear wheel? (My barrel adjuster is in the middle of the cable, not flush with the ferrule.)* I assume clockwise tightens the adjuster 'into' the frame which actually reduces cable tension*. Let me know if that's wrong.
> 
> My latest tinkering with the cable and adjuster has improved matters but it still doesn't seem quite as good/snappy/reliable as it has been. Perfectionism married to ineptitude is a really poor combination...


you're exactly right w/ that. you can easily tell what's going on w/ cable tension by just turning the thing a bunch and pulling on the cable. if you find it's hard to get enough tension even w/ the barrel adjuster, you can try this trick...
undo the cable from the derailleur, and turn the adjuster all the way 'in' (loose).
turn the low limit screw 1/4 or 1/2 turn 'in' (the the cage would rub the chain)
re-attach the cable
back the limit screw out the same amount you turned it in. 
this will 'preload' some tension on the cable before you tighten it w/ the adjuster.


----------



## qatarbhoy (Aug 17, 2009)

cxwrench said:


> you're exactly right w/ that. you can easily tell what's going on w/ cable tension by just turning the thing a bunch and pulling on the cable. if you find it's hard to get enough tension even w/ the barrel adjuster, you can try this trick...
> undo the cable from the derailleur, and turn the adjuster all the way 'in' (loose).
> turn the low limit screw 1/4 or 1/2 turn 'in' (the the cage would rub the chain)
> re-attach the cable
> ...


Thanks cxwrench for your patience and good advice. I will try the preload trick. 

Yesterday's 'race' (the ride part of a duathlon, no running for me thank you very much) went well: I was happy with my time. I had only one missed upshift in the race (and one later on a recovery ride), although admittedly not much front shifting was required. A nanosecond of attention was needed to ensure I moved the lever enough to upshift, especially when in the drops. Hopefully the preloading will eliminate that nanosecond.

If all else fails, I see Ultegra FDs are going for a paltry 20-odd quid these days  but when the Red Ti works, I really love it, and you can't beat the weight. It looks cool too. I mean, _titanium_. MMmm.


----------



## qatarbhoy (Aug 17, 2009)

*Okay, I am done...*

with my Sram Red Ti FD. 

I don't mean done as in "I have finished adjusting it and it works perfectly". I mean done as in "I have ordered an Ultegra 6700 FD".

After another hour or so of getting greasy, sweaty and increasingly irritated, I still can't get this thing to shift reliably. It might shift on the workstand, but once out on the road, it's not interested. Maybe if I really shove the lever, it'll think about it. Or perhaps it wants a gentle tickle on the shifter instead. There's often no response except the incessant whisper of chain rubbing hopelessly against chainring. I have adjusted the cable tension here, there and everywhere... still not shifting reliably.

I tried all the tricks given here, with optimism in my heart, and a few others mentioned elsewhere: still not shifting reliably. I have tried 1, 2 and 3mm off the chainring: still not shifting reliably. I have tried tail out and tail in. I have tried pulling the cable finger-tight and using pliers: still not shifting reliably, or at all.

I recognise that I am useless at mechanical stuff. Even basics take me longer than anyone else. But I managed to refit my Tiagra FD and it has never needed looking at since. It has sat outside in sand, wind, sunshine and rain and gets zero TLC. It still shifts perfectly. The Red Ti looks the part but might as well be made of wet tissue paper for all the use it is at shifting up. 

So... tomorrow I will head for the LBS and get their guy to adjust it for me again. That way I can ride this bike until the the Red FD goes out of adjustment again, when it will be promptly replaced. At 59g it won't even make a decent paperweight.

Thanks again to cxwrench and everyone else who tried to wake me from this first-world-problem nightmare. It seems hard to believe the same people who brought us Double-Tap shifting and the Red rear derailleur also brought us this ill-thought-out wrong-material-for-the-application was-it-even-road-tested POS. When it worked, it was bliss; but so was my first marriage, and I am done with that as well.


----------

