Small to Big ring...no matter what I do, seems like I can't get it to work well

[Wayne77]

Looking for some help with a problem that has me completely flummoxed. I've built many bikes but I've run into an issue with the front derailleur shift from small to big ring on a new build for a friend. I've taken it to the shop, checked and re-checked my setup, called the crank manufacturer and I'm just stumped.

Here's what's happening (see full setup details below): It seems to shift fine on the stand, but when riding it on the road with any normal riding pressure on the crank whatsoever the chain sounds like its catching a pin repeatedly, but it just slides up and back down the inside of the big ring...it just won't "grab" any of the ramps and pins and move over to the big cog. It gets worse progressively from small to big cog. I do understand that shifting from a 34T to a 50T cog isn't always that great (definitely not as good as my DA9000 50/34 setup!), but my last road bike had a 50/34 with a Yaw der and it was fine. I even put older generation Sram Force rings on it and it still had the same issue. Here's another thing: In my desperation of just trying all possibilities I threw on an old 6800 Ultegra der, which of course isn't going to work with shifters designed for a Yaw der, and due to the much narrower cage it shifted much better. But of course I had horrible chain rub since there is no trim with these shifters.

- This is a gravel bike build I'm putting together for a friend of mine...someone who got a little more serious last year and now wants to try some gravel and maybe cx this fall. All parts below are brand new.

-Frame: 53cm 2017 Norco Threshold (she wanted this particular frame)

-Crank: Praxis Zayante M30 crankset. 165mm crank arms, 50/34 compact gearing, PF30 BB. I called Praxis and spoke to Ross. He has been extremely nice and even sent me another big ring on the off chance it could be some type of machining issue with the pins and ramps. This has not helped. I also checked the BB setup with the correct spacers used & correct tightening of the cups per his recommendation. I mentioned to Ross that the chain is behaving like the chain rings are too far apart, but he explained that the width of the tabs that the rings bolt onto is universal and they were within spec. I have not measure very accurately but if I recall I think they were something like 3mm. My lady friend is rather petite and 165mm arms seem to be the right size for her. I assume it couldn't have anything to do with that though.

- Chain is an Ultegra 11 speed chain

- Sram Force22 Road hydraulic shifters/brakes/calipers (not sure if they are different than the CX1/Force1 shifters...they look identical)

- Sram Force22 Yaw front der

- Sram Force22 long cage rear der

- Sram Force 11-32 cassette

- I've checked and re-checked the Yaw front der setup, experimented with a few different heights, and even borrowed a friend's Sram Yaw der to rule out it being a front mech issue. It is setup exactly according to Sram spec...lined up correctly with the hash marks, etc

-Chain stay length is 42.5cm

-Chain length: I've used both the equation method as well as wrapping around big-big to validate chain length. The equation gives me 55 inches which is exactly where it's at.

I must be missing something really obvious... Any help would be sincerely appreciated!

[carpediemracing]

I have zero experience with pretty much all the components you list (I use other size Praxis rings). I had to Google the front derailleur because I don't know what it looks like.

Based on that minimal information I'd try three things.

First. I'd use some channel locks to "narrow-ize" the front of the front derailleur cage. You mentioned that the narrower Shimano cage shifted better. Try to replicate that in the Yaw derailleur. For me it's such a good hack that I do it to every metal caged derailleur I've owned. (Note: if the cage is aluminum then probably not a good idea to bend it).

Second. It may be the chain is a bit too flexible/smooth? With longer stays the chain can flex more, resisting shifting a bit. Can you try a different chain? If you use a Missing Link to install it then you can use the chain on a different bike if it doesn't work on the problematic bike.

Third. I usually position my front derailleur such that it barely clears the big ring. It's a couple mm lower than spec but it makes shifting a bit more precise. I usually go a bit low at the beginning, causing the derailleur to hit the chainring when cable tension flexes the derailleur before moving it, but I raise it just a touch and then it's good.

Final thought - on the stand there is very little pressure on the chain, with virtually no resistance. If the rider is not easing up on the pedals on the upshift the chain will not move as readily. It may not be sexy to have to ease a touch when shifting to the big ring but the reality is that it works better that way. On my trainer I have to build some momentum/speed in the small ring so that I can shift into the big ring with virtually no pressure on the pedals. If I pushed hard at low rpm the chain would literally never get onto the big ring.

[Gummee]

I'll second the motion of 'ease up on the shift' and then add 'shift it like you mean it' to the above.

M

[AngryScientist]

i know you said you triple checked the setup, but sounds to me like a clear case of improper FD set-up to me, but of course i'm sitting about 3500 miles from the problem.

in line with the above, i'd get the FD as close as you possibly can to the large ring, and set the outboard limit screw looser to allow the inner plate of the fd to push outward more.

like cdr above, i have zero experience with the components you list, other than the praxis rings - and every praxis ring i've used has been an excellent shifting ring.

not second guessing your skills Wayne, but that's my gut feeling based on what you've descibed.

[jtakeda]

Is it possible that there is friction in the B.B. guide for the cable?

Or did you clamp the cable on the FD on the correct side of the bolt?

[Wayne77]

Great responses guys. I’ll try lowering the front der, along with some of the other suggestions. I will say that “easing up” is definitely something I do, and in this case I’m easing up as well...definitely not trying to shift with tons of pressure on the pedals. The only way I can get it to upshift is by coasting faster than I’m spinning - basically freewheeling.

I’ll try narrowing the cage as well...my worry there is that doing so might negate the so called yaw benefits where you don’t get chain rub when in the other big-big/small-small combos. A non-issue normally, but with shifters with no trim it is an issue. Needless to say I am NOT a fan of the Sram Yaw design...works fine when it works but you have to use Sram shifters and it negated an easy solution here: just use the Ultegta der I already have.

[Wayne77]

Is it possible that there is friction in the B.B. guide for the cable?

Or did you clamp the cable on the FD on the correct side of the bolt?

Yeah, I verified the cable is clamped correctly and last I checked I’m not detecting friction with the cable routing...something I will double check though. Maybe there could be some issue near the lever end...

[dave thompson]

There’s something odd going on. I’ve got the very same Praxis crank/BB combo that you do and my experience with the Praxis is that it offers the most positive and firm shifts, even better than Dura Ace.

Are you sure that you’re using the correct 2MM (NOT 5MM) drive side spacer? If you’ve inadvertently installed the 5MM spacer, it will situate the crank 3MM too far outboard and give you the symptoms that you’re now experiencing.

Another thought; if you pull on the front der cable, does it swing the derailleur far enough outboard to effectively shift to the big ring? If so, I’d then suspect the equipment: (I don’t know SRAM at all) does the front der have limit screws?

[bitpuddle]

Just $.02: I’ve worked on a bike that had a compact praxis crank. Shifting was not great. Switching to some FSA chainrings I had sitting around improved things quite a bit. I suspect that Shimano chainrings would have been even better.

The Praxis rings seemed to have much less aggressive pins than the FSA.

[Wayne77]

There’s something odd going on. I’ve got the very same Praxis crank/BB combo that you do and my experience with the Praxis is that it offers the most positive and firm shifts, even better than Dura Ace.

Are you sure that you’re using the correct 2MM (NOT 5MM) drive side spacer? If you’ve inadvertently installed the 5MM spacer, it will situate the crank 3MM too far outboard and give you the symptoms that you’re now experiencing.

Yeah, I agree there is something going on. All the reviews I’ve read have been very positive, especially in terms of shifting quality. So I’m sure it has nothing to do with bad design. I’m actually using the 1mm spacer that is recommended for their direct mount crank design (per the directions). It came with a 2mm spacer, but not a 5mm spacer.

[exapkib]

There’s something odd going on. I’ve got the very same Praxis crank/BB combo that you do and my experience with the Praxis is that it offers the most positive and firm shifts, even better than Dura Ace.

Are you sure that you’re using the correct 2MM (NOT 5MM) drive side spacer? If you’ve inadvertently installed the 5MM spacer, it will situate the crank 3MM too far outboard and give you the symptoms that you’re now experiencing.

I second the call to double check the spacers--I was certain I had them installed correctly, but eventually came to see that I was in error.

[Russity]

Just a thought....but remember Shimano higher end chains are directional. Both Ultegra and Dura Ace need to have the chain markings on the outside. The blank side of the chain needs to be facing in.

Now I’m not saying this will solve your problem, but maybe just check you have the chain on correctly.

And if you can find the correct chain line measurement, maybe check that too.

[oldpotatoe]

but when riding it on the road with any normal riding pressure on the crank whatsoever the chain sounds like its catching a pin repeatedly, but it just slides up and back down the inside of the big ring...it just won't "grab" any of the ramps and pins and move over to the big cog.

Look at the part of the front dear on the inner cage that is responsible for pulling chain to big ring...fder may be too high. Also a little more tail out might help, makes the fder more 'aggressive'...

Also above tells me fder isn't moving out far enough...limit screw?

'Might' look at trying a 6700 front dear too...I've had great success that way.

[skouri1]

I am sure there's are videos online . I know the yaw derailleur has a specific set up due to its different design...may honestly be worth bringing in a shop where the mechanic rides sram .

I had a lot of trouble with my dura ace 7900 derailleur recently. Turn si out that the Outer cage USB bowed a bit.
So I go to a line of sight from back by the cassettes and noted that the inner cage was not parallel with te chainrings .
Realigned then readjusted the limits and now I have excellent front shifting and the fd doesn't scrape the crank arm .
And angry said , a very small adjustment of The outer limit can make a world of difference. But if your derailleur isn't aligned to begin with vertically and rotationally, you're Not going to get good shifts

[ghammer]

I had a similar problem a few years ago. I run a mix of sram cassette + red/force parts and was using campy chain. the bike was smooth and quiet, rear der worked well but for some bizarre reason the front shifting was garbage. couldn't get it to work, it dropped frequently, and i didn't know what to do.

At the time the campy chains were quieter and i knew from having been a long time campy user that campy chains were quiet and lasted a long time - until one day when I was practicing sprints, the chain fell off, i tried to shift while pedaling, forced it a bit too much, gouged the stays and bent the chain. i was flummoxed, livid that something that used to work *perfectly* prior to swapping chains was such a complete mechanic failure.

so i walked the 3km home on my socks, cursing to high heavens. At home i ordered the cheapest 10spd chain i could find, which was a reg sram chain ($18 on amazon). IT BLEW MY MIND that as soon as i replaced the chain, the drivetrain, *specifically* the front derailleur resumed working on its full mechanical glory. Then I realized that my period of mix and matching parts was over and a half. Never again. Now it's all sram and no dropped anything anymore, not even miss shifting.

One other reason to consider is if your bike has internal routing. A friend ran sram red 11 on his Ritte. The bends on the handlebars plus the various bends inside the frame turned his shifting into "do the sign of the cross, say a prayer and hope for the best" front shifting. That disappeared once he got eTap.

For the record, my bike was external gear routing and that has never been an issue - fewer turns for quicker, more precise shifting.

dump your chain, get a matching chain and your bike will improve its transmission performance.

Good luck,

G

[berserk87]

I hate front derailluer issues.

My solution would be to throw the bike in the trash and get a new one.

[bobswire]

How To Adjust SRAM Yaw Front Derailleurs
https://www.youtube.com/watch?v=jKzA-QVyBWo

[dddd]

Good suggestions, you can always do worse than keeping an original gruppo intact, and yes, SRAM front derailers can be sensitive to the outer cage plate angle with the big ring.

Is the OP checking the FD cage height with the outer cage plate in-plane with the big ring? Often the height setting comes up different if the cage plate is hanging a bit inward or outward of the big ring itself.

I usually recommend using Shimano chain for these kinds of chainring-grabbing problems, but since this is a complete SRAM gruppo I am withholding that recommendation for now. Shimano chains have shown themselves to shift dramatically better than SRAM chains on many, many Shimano 10s bikes I've worked on, which I would tend to state as fact.

Backwards chain has been an issue on more than one Shimano chain-equipped bike I've worked on as well, in case the OP is using a Shimano chain(?).

I've tweaked quite a few outer cage plates (inner plate is not something I would bend), but I save any cage modification for my very last-ditch effort with any flummoxing FD issue. I would hate to see a pro mechanic starting by replacing the derailer that an owner deliberately bent!

I very occasionally get a bike in where the owner's bike has no FD cable adjuster, and I let them know that the FD will likely never work as well as it should without one. The last such bike was all-SRAM btw.

[NHAero]

Great group of suggestions. If it were in front of me I'd throw a different chain on first, to see if that changed things.

[Ralph]

Is cable tight enough....so when you move your hand the FD also moves as far as it's set to go?

[benb]

SRAM Components + Compact crankset + 3rd party rings + Shimano chain.. that's a quadruple dose of challenge.

Good luck, this is why SRAM pushes 1X all over the place.

The in line front derailleur cable adjuster got mentioned.. if you don't have that forget it, put one on. My Trek Domane came without one since the frame doesn't have a stop for the normal downtime style adjusters (shop build) and I refused delivery until they put it on.

[Joxster]

Is it a band on or braze on front mech? If it's braze on check that it's tight (if hex bolts) or the rivets aren't bongo'd

[Wayne77]

Just a thought....but remember Shimano higher end chains are directional. Both Ultegra and Dura Ace need to have the chain markings on the outside. The blank side of the chain needs to be facing in.

Now I’m not saying this will solve your problem, but maybe just check you have the chain on correctly.

And if you can find the correct chain line measurement, maybe check that too.

Thanks. The logos are facing out. If I remember the Praxis recommend chain line was something like 43.5mm, and I remember measuring it was pretty close. It probably wasn’t the most accurate way to measure...I eyeballed the center of the downtube and measured from there to the midway point between the large and small ring. Perhaps there is a more accurate way to measure chainline...

[Wayne77]

Great group of suggestions. If it were in front of me I'd throw a different chain on first, to see if that changed things.

Thanks. I’ve tried a Sram Force 11 chain, Campy 11 chain, KMC 11 chain, (all these had about a year of use), currently running a new Ultegra 11 sp chain.

[Wayne77]

Is cable tight enough....so when you move your hand the FD also moves as far as it's set to go?

Yes...I’ve played around with various chain tensions...from just enough to move the der the right distance, to much higher tension

[Wayne77]

SRAM Components + Compact crankset + 3rd party rings + Shimano chain.. that's a quadruple dose of challenge.

Good luck, this is why SRAM pushes 1X all over the place.

The in line front derailleur cable adjuster got mentioned.. if you don't have that forget it, put one on. My Trek Domane came without one since the frame doesn't have a stop for the normal downtime style adjusters (shop build) and I refused delivery until they put it on.

Keep in mind I started with the stock Sram chain. Then tried several others. LBS highly recommended an Ultegra chain so that’s what’s on there now. So really the wild card is the Praxis crank. Most reviews mention the shifting is great with Sram and Shimano setups. I do agree that compact cranks don’t provide the same performance as a std crank does. Anyway, totally agree with the overall gist of your thoughts though. I do have an in-line adjuster installed.

[Wayne77]

Is it a band on or braze on front mech? If it's braze on check that it's tight (if hex bolts) or the rivets aren't bongo'd

It’s a braze on mech that is bolted to the Sram band adapter. Could that be an issue? It is snugged up very tight...

[jtbadge]

I think running the Force 22 crank is going to help you out, the chainring spacing is probably an issue with the weird movement of the Yaw front derailleur.

I ran full Force 22, but with a cheaper SRAM 11s chain (1130), and didn't run into this issue.

[Kontact]

Could this be a chainline issue? I noticed that the Praxis BB has a variety of spacers depending on the crank use. Could you have the crank too far outboard?

https://praxiscycles.com/wp-content/uploads/M30_Rubber_Collet.pdf

[marciero]

I have zero experience with pretty much all the components you list (I use other size Praxis rings). I had to Google the front derailleur because I don't know what it looks like.

Based on that minimal information I'd try three things.

First. I'd use some channel locks to "narrow-ize" the front of the front derailleur cage. You mentioned that the narrower Shimano cage shifted better. Try to replicate that in the Yaw derailleur. For me it's such a good hack that I do it to every metal caged derailleur I've owned. (Note: if the cage is aluminum then probably not a good idea to bend it).

Second. It may be the chain is a bit too flexible/smooth? With longer stays the chain can flex more, resisting shifting a bit. Can you try a different chain? If you use a Missing Link to install it then you can use the chain on a different bike if it doesn't work on the problematic bike.

Third. I usually position my front derailleur such that it barely clears the big ring. It's a couple mm lower than spec but it makes shifting a bit more precise. I usually go a bit low at the beginning, causing the derailleur to hit the chainring when cable tension flexes the derailleur before moving it, but I raise it just a touch and then it's good.

Final thought - on the stand there is very little pressure on the chain, with virtually no resistance. If the rider is not easing up on the pedals on the upshift the chain will not move as readily. It may not be sexy to have to ease a touch when shifting to the big ring but the reality is that it works better that way. On my trainer I have to build some momentum/speed in the small ring so that I can shift into the big ring with virtually no pressure on the pedals. If I pushed hard at low rpm the chain would literally never get onto the big ring.

I've used all these to great effect. I've used 1 to fine tune the shifting on my tandem triples. Regarding 4, is second nature to me to let up slightly, almost imperceptibly, for a split second on shifts. I probably started doing this when I started using non-standard gearing on all my bikes (hence, ramps and pins are not in the right place relative to the chain)
Aside from that, you might try angling the derailleur. For the longest time it was my practice to position the outer plate ever so slightly past parallel.

[oldpotatoe]

Is it a band on or braze on front mech? If it's braze on check that it's tight (if hex bolts) or the rivets aren't bongo'd

Good point, if braze-on and carbon frame, it might be flexy, why EPS and Di2 have ways to stiffen it...grab the front dear...easy to move around?

[Gummee]

Look at the part of the front dear on the inner cage that is responsible for pulling chain to big ring...fder may be too high. Also a little more tail out might help, makes the fder more 'aggressive'...

Also above tells me fder isn't moving out far enough...limit screw?

'Might' look at trying a 6700 front dear too...I've had great success that way.

I had 5 SRAM Red bikes set up before I went Shimano 11sp. ALL of them had Shimano front derailleurs on them. IME SRAM can't make a front derailleur that shifts to save their lives.

...that's why they want everyone to run 1x

M