Sram Force FD impossible to index!

CRAIGO5000
Posts: 697
I recently uninstalled the shifter cable from my Ribble Stealth which runs Sram Force due to poor initial set-up which left the gearing impossible to index correctly. I fixed the RD by re-installing the original cable and choosing the inner cable path from the shifter body aswell as lubing up the cable housings. Sweet!
The problem I now have is that the FD is still impossible to tune/index. I've managed to fray the existing cable so bought a new one, lubed it and the housings, chose the inner cable path like the RD and followed the Sram online instructions 100% and it's just impossible to tune/index.
Here is the scenario;
1. Install FD, get height and position correct as per instructions and also use the top threaded hole for compact chainrings.
2. Set lower limit and wind the cable adjuster all the way in (less one full rotation)
3. install cable OVER the lobe and ensure cable follows the little line in the clamp.
4. Shift up to big chainring and set the upper limit to within 1mm of outer plate and chain clearance.
5. Adjust barrel until FD has enough load to just touch the high limit screw.
6. Check shifting in all combos.
Here is what I get. A set-up that requires SO MUCH force that I feel like the shifter is going to snap. It clangs very loudly, won't change into the large chainring unless im in the smallest rear cog. There is so much force required that I lose the trim function. If I take the tension out, I get trim in the largest chainring back, but then lose the power to actually shift the chain up to the large ring. It's a complete vicious circle and I've spent 8 hours over the last two nights trying to remedy it!
The only issue I can think of is that the cable run could be off, but that's a limitation of the Ribble Stealth that I can't overcome. The cable runs down through a barrel adjuster mounted on the frame near the head tube as per usual and then under the BB through a cable guide. Coming out that guide it then runs internally through a 90 degree angle THROUGH the body of the frame and pops up behind the seat-tube through a tube appearing at the FD cable clamp.
My Dolan takes the same path BUT where it runs under the BB cable guide, it then arcs up around the BB and back of the seat tube which I think offers a more gradual curve.
What to do? It came delivered with rock hard shifting from Ribble, I've played with it to no avail and so if I take it to my LBS, there is no guarantee it can be sorted? :?
The problem I now have is that the FD is still impossible to tune/index. I've managed to fray the existing cable so bought a new one, lubed it and the housings, chose the inner cable path like the RD and followed the Sram online instructions 100% and it's just impossible to tune/index.
Here is the scenario;
1. Install FD, get height and position correct as per instructions and also use the top threaded hole for compact chainrings.
2. Set lower limit and wind the cable adjuster all the way in (less one full rotation)
3. install cable OVER the lobe and ensure cable follows the little line in the clamp.
4. Shift up to big chainring and set the upper limit to within 1mm of outer plate and chain clearance.
5. Adjust barrel until FD has enough load to just touch the high limit screw.
6. Check shifting in all combos.
Here is what I get. A set-up that requires SO MUCH force that I feel like the shifter is going to snap. It clangs very loudly, won't change into the large chainring unless im in the smallest rear cog. There is so much force required that I lose the trim function. If I take the tension out, I get trim in the largest chainring back, but then lose the power to actually shift the chain up to the large ring. It's a complete vicious circle and I've spent 8 hours over the last two nights trying to remedy it!
The only issue I can think of is that the cable run could be off, but that's a limitation of the Ribble Stealth that I can't overcome. The cable runs down through a barrel adjuster mounted on the frame near the head tube as per usual and then under the BB through a cable guide. Coming out that guide it then runs internally through a 90 degree angle THROUGH the body of the frame and pops up behind the seat-tube through a tube appearing at the FD cable clamp.
My Dolan takes the same path BUT where it runs under the BB cable guide, it then arcs up around the BB and back of the seat tube which I think offers a more gradual curve.
What to do? It came delivered with rock hard shifting from Ribble, I've played with it to no avail and so if I take it to my LBS, there is no guarantee it can be sorted? :?
Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 3
2007 Specialized Allez (Double) FCN - 3
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Comments
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0.5 when installing FD make sure it is running parallel with the chainring
1. Install FD, get height and position correct as per instructions and also use the top threaded hole for compact chainrings.
1.25 shimano needs about 3mm clearance from derailleur to tooth, when new there is a guide but once it is used you have to do it by eye. I think SRAM is on the same principle
1.5 set shifter to small ring setting
2. Set lower limit and wind the cable adjuster all the way in (less one full rotation)
3. install cable OVER the lobe and ensure cable follows the little line in the clamp.
4. Shift up to big chainring and set the upper limit to within 1mm of outer plate and chain clearance.
5. Adjust barrel until FD has enough load to just touch the high limit screw.
6. Check shifting in all combos.
I haven't done the SRAM setup yet (my build is waiting for me) but on the Shimano there is trim function which is also available on the SRAM shifters.
On shimano when you shift up (ie. small to large chainring) the smallest on the rear should be engaged to check for derailleur clearance - adjust high screw. then click down once - trim and shift to largest at the back and adjust barrel for chain to just about touching derailleur then you are done.
this should be fine. from you described, i suspect your shifter was left in the large tooth shift position as I also made that mistake the first time.Road - Cannondale CAAD 8 - 7.8kg
Road - Chinese Carbon Diablo - 6.4kg0 -
I was in the small rear cog when setting H limit screw. Setting of the L limit is done without cable attached and whilst in the largest rear cog.
It's goofy. I've spoken to Ribble and they said it's probably just a limitation of the frame with it's internal cable routing through the BB that is causing the harshness and inability to shift correctly. Possibly, but it's still not acceptable as it's not doing the job it is supposed to do.
I have a thin clear plastic cable strip that is attached to the exit of the BB where the cable comes through to connect to the FD clamp bolt. I've read online that some people have added some of this to the routing where the cable enters the BB so I may try that if I can find any!? That all sounds a little bodged to me though.
Oh well. Another 4 hours of fiddling looms trying to get this FD and bike to agree with each other.Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 30 -
With everything undone and the chain in small front/large rear wind the H limit screw all the way in and then set the L screw so the FD cage is where it should be.
Then attach the cable (Cable needs to be tight) and shift into large front/small rear and attack the H screw to get it where it needs to be.
If that does not work there is something amiss with cable routing or FD itself.Yellow is the new Black.0 -
Unclamp the cable, remove the chain if possible and see how the derailleur feels when you move it by hand. Should be smooth and low friction.- - - - - - - - - -
On Strava.{/url}0 -
Its sounds like you know what you''re doing, but make sure you have clamped cable in the mech in the correct way. Have a look on google images.
If you have, then:
Throw your force mech in the bin and buy a shimano one (5600 or 6600). They're shite and you'll be wasting your time otherwise.0 -
Quick point: if the mech is a clamp on, then make sure it is correctly aligned in terms of hight, and also rotation around the frame.0
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smidsy wrote:With everything undone and the chain in small front/large rear wind the H limit screw all the way in and then set the L screw so the FD cage is where it should be.
Then attach the cable (Cable needs to be tight) and shift into large front/small rear and attack the H screw to get it where it needs to be.
If that does not work there is something amiss with cable routing or FD itself.
this is the right way, also what i think i was trying to cut into your procedureRoad - Cannondale CAAD 8 - 7.8kg
Road - Chinese Carbon Diablo - 6.4kg0 -
NapoleonD wrote:Have you pulled the cable too tight?
That's what it sounds like to me. The procedure for low limit seems right but I'm not sure after that - having to push too hard on the lever sounds like you're having to overcome the tension to get to the index position.
I've found that starting at the beginning is the best solution to that. Work through it methodically and it should work.
I keep reassuring myself that a FD is a simple thing!I'm left handed, if that matters.0 -
When I first installed Force I had the front Der alignment slightly off (heel in) and as a rersult ended up with a very high cable tension.
2 minutes with the mechanic at Sigma (loosed off the cable, lowered and rotated the clamp and reattached the cable) and the whole thing started working perfectly. Cable tension is now almost completely slack when in the small ring.
Although the frame may make it harder to get working well there must be enough Ribble Stealth's out there that we'd have heard if this was a frame issue.0 -
Does the cable run free? You could try undoing the cable from the FD clamp and operating the shifter while pulling on the cable lightly to give it some tension, that way you can see if the cable runs smooth and eliminate the FD alignment from the equation. If the cable isn't running freely then even a perfectly set up FD is going to be hard to use.
I have SRAM Force and it works fine, but the FD is quite loud on the shifts.______________________________________
Alive at both ends, but a little dead in the middle.0 -
Turns out the cable routing is nice and slick under the BB having inspected it further, the cable liner running through the BB of the frame is present at the entrance and exit of the cable route. I can operate the shifter with the cable un-hooked and it moves very freely at the derailleur end.
I've managed to get somewhere with it now. It will drop off the large chain ring to the lower but will only change up to the large if I'm in the smallest rear cog. I don't need loads of tension either and get to keep the trim function too (not that my set-up needs it)
Still, It's not right so I'm taking it to my LBS and will see if they can shed any light.Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 30 -
Chain length??Yellow is the new Black.0
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I don't know? It was built by Ribble but i'll check that out.Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 30 -
CRAIGO5000 wrote:I don't know? It was built by Ribble but i'll check that out.
I meant to ask about that as you said in the OP that you were doing all this due to bad original set up.
What was bad? Was is that it simply did not select properly or was it just that it seemed noisy/stiff/etc?
I only ask as it may have been absolutely set up properly but just run that way because thats all it can do (if you see what I mean).
Anyway you are taking it to your LBS now so they will tell you what's what.
Be sure to come back and let us know.Yellow is the new Black.0 -
I've already told you the problem. YOu have a SRAM front mech, they're crap. USe a shimano one as I stated above0
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smidsy wrote:CRAIGO5000 wrote:I don't know? It was built by Ribble but i'll check that out.
I meant to ask about that as you said in the OP that you were doing all this due to bad original set up.
What was bad? Was is that it simply did not select properly or was it just that it seemed noisy/stiff/etc?
I only ask as it may have been absolutely set up properly but just run that way because thats all it can do (if you see what I mean).
Anyway you are taking it to your LBS now so they will tell you what's what.
Be sure to come back and let us know.
All of the shifting was very stiff and poorly indexed, it would chatter and skip about. I thought the feel was just the way of Sram as I knew no different but from the start I noticed that my RD B-screw was about an inch from the cassette so I knew it had been poorly built at that point! Sram specs state a min of 6mm gap. I then bought a Dolan with Apex and it's so much lighter and accurate to shift. I then stripped back my Ribble and have managed to get the same exact feel by re-routing the RD cable properly to gain a lighter shifter action and thus proper control over the indexing. I'm now struggling with the FD hence this post.
I may well end with a Shimano FD on it if the problem isn't resolved.Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 30 -
styxd wrote:I've already told you the problem. YOu have a SRAM front mech, they're crap. USe a shimano one as I stated above
Nothing wrong with my SRAM front mech, it's not crap, works just fine!______________________________________
Alive at both ends, but a little dead in the middle.0 -
orderodonata wrote:Nothing wrong with my SRAM front mech, it's not crap, works just fine!
Maybe we're the only 2 people in the world though whose Sram mechs work ok.0 -
Just you wait.0
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mate, the sram and shimano front mech work in almost identical ways. I can't see how your sweeping statement come from. I have read people have issues with the red FD - the titanium ones as it was too flexible. Never heard any other sram ones having issues.
to OP take the bike to the local bike shop and get them to index it for u. it will take them 3 minutesRoad - Cannondale CAAD 8 - 7.8kg
Road - Chinese Carbon Diablo - 6.4kg0 -
Quote from one of my club riders.
The media were complicit with understating the problems there were with SRAM front shifting on their road systems until this year. I've set up a few groupsets with these and the best way is to make sure the cable tension is absolutely tight at the fully released point.
If the shift is still rubbish take more drastic steps. Take the pliers and bed the forward most part of the inner side of the cage inward a couple of degrees. its an old and crude technique but it works.
The original problem is made worse as the rider tries to force the shift by holding the lever trying to get the chain to move. this forces the cage against the chain and ring and progressively wears and bends the cage making it get worse.
It's all fixed thanks for that little tip that led me to compare internal measurements between my problematic Force FD to my newer Apex FD. They are close to identical in terms of shape, inner derailleur lobes and size. I'd imagine the Force FD is a shade lighter but that's probably it in terms of difference.
Anyway, after taking a metal ruler to both components, I found that my Apex FD had an internal measurement at the front of 10mm wide compared to my Force which was 14mm! The inside rear of the Apex tail measured 11mm and my Force had widened to 13mm. Probably, due to the fact the rear of both derailleurs is boxed together by a screw and thus stronger at the tail (less tolerant to deflection and warping) than the open, unsupported end at the front of the derailleur. So it appears that over time, my Force FD has opened up and widened.
I removed the Force FD and took a set of pliers to it. Drastic sounding but care was taken with a rag to prevent scratching. A bit of careful manipulation later and voila - one Force derailleur back in spec.
It literally took me 5 mins to set it up and index from scratch after the modifications and now it runs like a champ in all gear combos with the lightest of cable tension. I also have my trim back even though It's not required on my set-up.
Thanks again for all the input guys, especially Peter from Manchester Wheelers who put me on to grabbing the pliers
Here are some gratuitous reference pics.
Inner plates of my new Apex FD. Measurement of 10mm
Inner plates of rear tail Apex FD. Measurement of 11mm
The Force FD bent back into original spec. Note how the diagonal sloping edge ends at the OUTSIDE of the inner plate. It used to end at the INSIDE of the inner plate thus was too wide to shift accurately.Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 30 -
Mine worked fine. Although I 'downgraded' eventually from red to force as the red front mech was too flexy. Much better. Still sounds to me like the cable is too tight...Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
if it was too tight you could have raised the FD by a little bit then you have scope for the chain to smoothly run over the chianset. the fact it took so much force to shift up suggests you might not have had enough clearance to the chainset.
anyway you seems to have fixed it.Road - Cannondale CAAD 8 - 7.8kg
Road - Chinese Carbon Diablo - 6.4kg0 -
NapoleonD wrote:Mine worked fine. Although I 'downgraded' eventually from red to force as the red front mech was too flexy. Much better. Still sounds to me like the cable is too tight...
I think it depends on the year of your Groupset too. Old Red FD's look exactly like 2012 Force FD's. Only now Red has this yaw feature and some look alot smoother in design with the large sweeping Sram logo across the facia.
Mine operates as slick as this guys now: http://www.youtube.com/watch?v=qyUdzW5dkko
It also has that slight clang noise when dropping to the small chainring. I think the carbon frames exaggerate the noise too.
Regarding the raising of the FD comment, I tried this originally and it made no difference. The fact my internal plates were 4mm wider than they should was the reason I couldn't shift up while in the larger rear cogs but could just about change up when in the small rear cog. It's all fine now though and installed as per Sram install instructions (parrellel to chainrings and ~2mm height gap from the large chainring teeth.Ribble Stealth/SRAM Force
2007 Specialized Allez (Double) FCN - 30