Moderator: Moderator Team
SRAM Force shifter, a few years old.
Red FD, a few years old, matte grey, which I think means it is the Ti version.
Force crankset, 130 bcd.
46t SRAM ring, 39t SRAM ring.
I typically train and race in the big ring, but I do like having the inner because I sometimes put road wheels on the bike and road ride in bad/winter weather.
It was shifting well but when cleaning the drivetrain I realized that in smallest cog (11) and outer ring the FD outer cage rubbed the back of the crank arm. These are 2012 Force arms and have a big backwards curve. I tried to set it right but also had the LBS work on it. They set up the FD so it cleared, had to move the clamp up the ST just a bit.
Last night when remounting kicked the pedal, chain dropped to inner ring. While chasing back to the pack and trying to upshift I couldn't get it to shift up. Then the paddle shifted inwards, beyond the lever and got hung up there. I had to coax it back to behind the lever.
I've been told various things. The Ti Red FD sucks. The FD isn't happy with the 39-t ring and would prefer a 36-t. My cables need replacing. If I move the FD any higher the shifting will be worse.
I can get it to shift into the outer ring in the workstand however. But, I would like this to perform more smoothly and also not malfunction during a race and cause me to burn up the entrance fee.
I'm not sure what is the best solution. And, I'm wondering if this overshift of the paddle means my shifter is broken. I just bought this crankset so would rather not have to buy a compact. Some have suggested a Shimano CX70 FD.
Sorry for the length, trying to be clear. Thanks for any feedback.
- It sounds pretty strange that your crank arm is hitting the FD, I don't think I've heard of this problem before. Is there any spacer missing from the drive side crank or bb?
- I've run shifters from Apex (what I'm currently using on my cx bike) through Red and have only used Rival or Force FDs. When setup properly, I've never had an issue whether on road or cross. Those Ti Red front derailleurs have a terrible history of being too flexy which may be a reason why you're experiencing shifting issues under load (as opposed to just working in the stand)
- I've had my paddle get hung up before (only on my Apex levers though) and never thought much about it, mainly that it was just annoying. I need to play around with it but one reason may be that the return spring or whatever setting you have on the brake might not be high enough to keep the lever blade out of the way when shifting. I've never experienced this with Rival, Force, or Red so your guess is probably as good as mine. But, I wouldn't jump to the conclusion that your is broken just yet.
- I've heard things about 39s not being too happy with the 46 but have never tried and can't weight in with any experience. However, I'm not sure if it makes sense that there are issues since the gap between 39-46 is not that large (compared to normal 53-39 and 50-34 ranges) so that shouldn't be that much of problem
- Cables are potentially an issue, so I would make sure they aren't fraying anywhere or gunked up
In my opinion, I think the FD itself may be your best bet to fixing this issue (barring any other component issues that may not be obvious at this point). I haven't noticed a difference between a Rival or Force FD in terms of performance and the weight difference is so minimal that you might as well go for the cheaper one. Not sure if this solves anything, but hopefully it's helpful!
I didn't install the BB, as it is BB30 and I've never worked on that and the tutorial made it look kinda hard and I didn't have the proper tools. The mechanic is a pretty competent guy, but I could ask him to confirm/check it out. I think the spacing issue is due to it being a road standard crank and using such a small outer ring. I've had some say it's installed wrong, others say as long as it clears and doesn't rub, leave it be.
Cables aren't frayed but wouldn't hurt to replace it.
Ah, the flex under load/off the stand now makes more sense. Of course it isn't subjected to same forces in the stand.
Yep, I'm confused about the paddle overshift too.
I do think a new FD might be the best choice, though I've been tinkering on this bike a lot lately and was finally ready just to ride. This whole thing started when I noticed my pedals were loose. Turns out the pedal inserts (Al) on carbon FSA-made Cannondale Si cranks became unbonded. That lead to the Force crankset, deciding to replace a 3-year old BB...and all these associated headaches.
Thanks for the feedback.
I'm not entirely convinced that the chainring is too small for the 130BCD. Some manufacturers, such as Wolftooth, are making chainrings, although meant for singlespeed, down to 40t for a 130 crankset. Oh and another thing, the inside face of the Force BB30 crankset is rather bulbous. There's another thread where people had to sand down the pin on an FSA chainring to make it fit (I've done the same thing). I'm not sure this is part with your rubbing issue, but your FD shouldn't be tuned that far out to be able to rub the crankarm. I've also never had issues with a Force BB30 (110BCD) with a force FD running 46/36.
It shifts pretty good from small to big ring, plus the paddle overshift is gone.
But...now when it is all the way out...the FD cage rubs the crank arm at the back. I think moving the FD up will cause a diminished shifting performance. Gonna get some photos, but any ideas? I have to trim it one click/position and the rub stops, but I don't want to have any rubbing issue at all.
I guess move it up just 1-2 mm's?
Nope, never had chain drop issues, either side. I think I've dropped my chain on this bike/set-up exactly once in three years. (knock on wood).
Amazing how relatively simple things can be so complex. I put it in the stand and tried to fine tune everything and I've got the limits set front/back, moved the FD angle just a bit and am getting all the gears.
I still only have 2 mms of clearance at the back of the crank arm but it isn't rubbing. I'll leave well enough alone, ride it tonight, and if anything move the outer limit screw just a bit if that becomes an issue.
I also saw in the tech docs they suggest 6mm of clearance between cassette and jockey at the back. I had more like 3mms so I adjust my b-screw.
- Similar Topics
- Last post
- 0 Replies
- 299 Views
Last post by goldmine848
Sun Aug 20, 2017 6:26 pm
- 3 Replies
- 617 Views
Last post by jjde34
Thu Sep 28, 2017 7:48 am
- 6 Replies
- 640 Views
Last post by jekyll man
Thu Nov 02, 2017 11:10 am
- 5 Replies
- 746 Views
Last post by stormur
Wed Sep 27, 2017 6:15 pm
- 16 Replies
- 1444 Views
Last post by JBeauBikes2
Mon Jul 17, 2017 8:34 pm