Front Derailleur for Riv Silver 34/24 cranks?

[Justin Wyne]

As much as I love the looks of this crankset, I feel like it should come with a disclaimer of "good luck finding a front derailleur that'll work". Does anyone else have this crankset, if so what front derailleur are you using? The previous 2 I've tried can't get low enough to the big ring to call it a safe distance before hitting the cage on the chainstay. Most recent failure being the Shimano fdm618 low that although can be mounted low enough, just cant seem to get properly adjusted enough to allow even a millimeter of quiet non chain rub which requires constant trimming. I'm running 2x7.

[dougP]

Rivendell must have an answer.  I recall hearing that the ideal gap from the outer cage plate to the big ring should be 2 mm (1/8") but that may be an ideal, not a hard'n'fast requirement. 

On my Atlantis, I have a 24/34/44 triple & 11-36 9 speed with a Shimano Deore (no other ID on it; nothing special) FD.  With the FD clearing the chainstay by a whisker, there's a good 1/4" gap from the outer cage to the 44 ring.  So on the 34, the outer cage plate has to have a huge gap to the 34 chainring.  I rarely use the 44, so it's pretty much 34 for 99% of the time & I can get all 9 cogs without fussing.  On the rare occasion I need the 24, everything seems to work fine; no dropped chains or overshifting on the upshift. All flat rings, no ramps'n'pins.

dougP

[Joe Bernard]

Yes, what Doug is saying. I think you're trying too hard to get the fd down close to what your eyes say is the big ring, but the ring is in the middle position on that crank. I have a 36/24 crank with a bigger chainguard in the outer position, and a Deore XT double similar to your fd resting above that big guard. It works fine this way, I think your derailer needs to slide up to meet an imaginary big ring or guard. 

[Joe Bernard]

Oh, I missed an important  data point. I'm using a 10-speed fd with a 9-speed chain, which is as much as you can fudge that. A 7/8-speed chain would be way too wide. 

[Garth]

   Yes to what DougP has stated. Relax the FD gap !   I have a seeming large gap also on my Bombadil 24/36/44 crank with a road FD, whose radius doesn't really match at all.  On top of that the flat regular 44t ring is reversed, as 44t rings are designed for middle/small use. So in "theory" it's just all messed up, but reality isn't a theory. I use a little more finesse to shift to the big ring, and it just works. That's the beauty of all this manual shifting stuff, it's very fluid and adaptable and friendly. 

[brendonoid]

I currently have a FD-CX70 (that riv used to sell) running indexed with a 3x LX trigger shifter from the 90s. Works great but like others said you have to have a big gap. Align it with an imaginary 3rd ring in the crank and you'll be fine. If you aren't trying to index just about any old derailleur can be made to work.

Love this crank for its Hillibiking competence. and the steel chainrings are super strong to boot.

[Lyman Labry]

Riv set up a Homer for me this spring using a FD-CX70 with the Silver 34-24 x 9spd and non-indexed shifters. Works fine.

Lyman in Austin

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[Jason Fuller]

I am really hoping Grant is working on a Silver FD to solve exactly this issue - it would be a godsend to have a simple & classy looking front derdeder optimized for low range doubles (ie max 42T).  I would buy several.   

[Joel]

Since it is basically a triple with the large ring not there and a guard in it’s place wouldn’t a triple FD work? 

[Joe Bernard]

"Since it is basically a triple with the large ring not there and a guard in it’s place wouldn’t a triple FD work?"

Yes, it just looks odd because it sits so high over a guard barely bigger than the "middle" ring. This "problem" started with Grant's original plan to have these cranks run without front derailers, we were supposed to kick the chain over or use a stick. That idea never made it to new complete Rivs nor did it catch on with any of us, so now we have small-ring doubles with a small outer guard and big gaps to derailer cages. Whoops!

Joe Bernard 

[Garth]

  Jason there was a photo of a Microshift FD in an email or blahg that they bought to try for small rings. Looking at their catalog there are 2 such FD's . The "s" after the model denotes the "shorter chainstay" models which have a shorter cage. Note the 36-50t "top gear" ring. I could only find these for sale overseas as I'm not privy to business sources to get them. Who knows if they will start selling them.

https://www.microshift.com/en/product/fd-r74s-bf/

https://www.microshift.com/en/product/fd-r52s-bf/

[Nick Payne]

I use MTB 2x FDs for this purpose. Here's a XT 2x10 M786 front derailleur that I used on a bike setup with 32-22 chainrings. The FD clears the chainstay.

Nick

[Nathan F]

I had the same issue when setting up my girlfriend's Cheviot last year. She runs the Silver 34/24 crank set up with a 9 speed drivetrain, set up with trigger shifters. At first I tried a cheap triple, which didn't work as well as I'd have hoped (would've been fine if run friction). Then a Sora double, which didn't work at all (unique pull ratio, again would've been fine if run friction). 

Eventually I settled on a 10-speed Deore XT FD-M785. It works perfectly, and I found the "low clamp" much easier to set up than other styles, as the clamp is below the small chainring. Yes it's not an elegantly forged piece of art, but hey it's got a silver cage and the uglier bits are hidden behind the crankset.

[Jim M.]

I'm using a Deore XT front derailer, but I'm not sure which model. What helped me with the setup was using the Microshift thumb shifters that Riv sells.

https://www.rivbike.com/collections/shifting/products/microshift-thumb-shifters-9-speed-sl-t09?variant=41310793549

Works really well for me. I'll see if I can find the model number in the daylight.

jim m

wc, ca

[lconley]

IRD sells a front derailleur specifically for sub-compact double cranksets called the Sub-C. It is all silver - the back in the picture below is the sold-separately clamp.

Laing

Delray Beach FL

 

[Greg Murphy]

Shimano Deore mountain double derailleur. Something similar to this:

https://www.modernbike.com/shimano-deore-fd-m6025-l-10-speed-double-top-swing-bottom-pull-low-clamp-front-derailleur

On Sat, Sep 12, 2020, 8:56 PM Justin Wyne <illum...@gmail.com> wrote:

As much as I love the looks of this crankset, I feel like it should come with a disclaimer of "good luck finding a front derailleur that'll work". Does anyone else have this crankset, if so what front derailleur are you using? The previous 2 I've tried can't get low enough to the big ring to call it a safe distance before hitting the cage on the chainstay. Most recent failure being the Shimano fdm618 low that although can be mounted low enough, just cant seem to get properly adjusted enough to allow even a millimeter of quiet non chain rub which requires constant trimming. I'm running 2x7.

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