Chain Rubbing Rivet on Big Ring
 

Okay - so I'll probably butcher this explanation for this call for help but here goes. I have a Litespeed Teramo and just installed a new FSA SLK Light crank with a new Dura Ace chain. However, I now have an issue where one of the rivets on the big ring is actually catching the chain. It occurs when the rear is on the smallest cog (12 tooth) and front is on the smallest ring (34 tooth). I clearly can't ride in this gear now, but what can I do to fix it? Can I shave the rivet down, remove the rivet (not sure what the purpose of it is), or is there another solution?

Thanks in advance for the help and please let me know if you have any questions. I tried taking a couple of pics of the rivet catching the chain.

You should not ride in the small chainring and small cassette cog combination. Cross-chaining is less efficient due to extra friction. Cross chaining will also cause components to wear faster.
If the chain rubs the side of the big chainring when on the small chainring and next to smallest cog you can correct this by shifting the crankset slightly to the right with a 2 mm bottom bracket spacer. These work very well if your bottom bracket is the conventional type, not the out board type.

Edit: Deleted as Al1943 beat me to it! :D

In addition to the cross chain issue remember that there is enough overlap between gear ratios on the different chainrings that the large chainring will likely have a gear very close to that same ratio, especially in these days of closely spaced freewheels.

Thanks - I do realize this is not recommended for various reasons. However, I've never had an issue getting this to work on any bike I've had or even with this bike but with a different crank. While I don't use this combo often, I do use it in certain situations.

Al1943 - thanks for the spacer recommendation. I never thought of that. I may take it to my LBS as well for a recommendation since I've got to go there for a spacer anyhow.

Just went to FSAs on our tandem - same problem. Can't use either of the smallest cogs in the middle ring. Moving crank probably not best option. Moves chainline, which is probably where it's supposed to be. I just relearned my shift pattern and now spend much more time in the big ring. Less chain tension that way, too, so longer chain life.

Moving the crankset 2 mm would not hurt a thing. A BB spacer is an easy installation and can be done without removing the chain.

I have a similar issue: THere are two televisions in my house...
one automatically turns the volume down when there is no signal, but the other one gives me the full noise of the 'snow.' I sometimes leave the television turned to watch 'snow', but the noise is annoying. Can I modify my television to fix this problem?

To the OP:
My advice is to avoid cross-chaining.
While I am not sure because I never wanted to try it, will adding a spacer to one side of the bb not make the space between the crank and the frame different on either side? (Q- factor is different on either side). Is this change ever perceptable or annoying to anyone?

I have ridden with chainrings with rivets as shifting aids, and chainrings with little machined notches as shifting aids. The rivets tend to catch the chain when you cross-chain, the notches do not.

Also, the rivets actually seem to help the shifting, the notches do not.

All you have to do is find a similar ratio with the large chainwheel. 34/12 is 2.83. Just divide your large chainwheel teeth by 2.83 and that will tell you what rear cog gives you the same ratio. Absolute worst case is that it will be off by 3% or 1/2 of a 1 tooth jump.

Which brand of crankset did the FSA replace?

The major brands(Shimano, Campy, SRAM, FSA) do have different width outboard bearings. SRAM has the widest by far. Minor shimming may work on the Shimano/FSA style.

common problem with compact cranks, dont cross chain. chainline for double cranks remain the same across many manufacturers, sram measures theirs differently for some reason.

I replaced a Truvativ Rouleur. I actually really liked that crank, I just developed a wobble in the big ring, plus I found a screamin' deal on this one.

It's only one rivet that causes the problem - the others pass just fine. Which is why I was thinking of potentially shaving that one rivet down (assuming the spacer idea does not work).

Thanks for recommendations everyone!!

I'd be careful adding that spacer. FSA cranks rely on having a specific distance between the bearings in order to get the proper preload (Shimano does not). you may find that after you tighten the cranks down that they no longer spin smoothly, or at all. I would advise simply avoiding that gear combo. It shouldn't be hard given that it's only the smallest cog. Shaving down that rivet will make upshifting to the big ring slower as that rivet is designed to pick up the chain.

One more thought, if you are currently using an 8 or 9 speed chain, switching to a narrower chain would yield a little more clearance to the big ring.

JJ951 - thanks. Now that I know the rivet has a purpose, I won't mess with it. I had no idea, I learn something new every time I come here!

I currently use a DA 10speed chain. Is there any chain narrower than that?

Campy's 11 speed chains are more narrow but that would be a harsh solution to this "problem." Do you need your current lowest gear? Swapping the 34 tooth chainring for a 36T would improve the situation and probably shift a little better too.

Yes, I actually do use my 34x27 combo quite a bit. I do a fair bit of climbing and tend to drop into it more often than I'd like.