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Note: Wrong parts were listed originally as Alivio FD-M4000-DS6. Apologies. The broken derailleur was not replaced with the crankset a few years back.

I haven't found great information on how to replace this old part, and I need to figure out what'll be compatible. I can't find the part itself in the US, and I don't want to buy it used, evidently they tended to fail the same way, with a little metal tab holding the spring that snaps off.

  • Crankset: FC-M4000 (40-30-22T)
  • Shifters: Dura-Ace bar end (friction shifting is fine in front)
  • Drivetrain: 3x9
  • Mounting: clamp-mount, 28.6mm
  • Action: downswing, bottom-pull

Budget: I want to get this ~2009 Raleigh Sojourn rolling again, and probably get a decent bike in a year or two. I like to do unsupported centuries, so I don't want to cheap-out too hard.

I found conflicting reports that the R3030 might work. Help would be appreciated!

2 Answers 2

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The specs for the derailleur you need are:

  • Chainstay angle: 66-69 degrees (specified as DS6 in the model code)
  • Big ring size: approximately 40 teeth (maybe 42 or 44 might work but derailleurs intended for 48-teeth rings or bigger rings work badly)
  • Chainline: MTB triple, which means 47.5 mm
  • Pull ratio: any, road or mountain, will work due to friction shifting
  • Approximately 9 speeds (maybe plus or minus 1 speeds work, 11-speed might be already too narrow) -- however, since you are using friction shifter maybe you could in a pinch use too narrow derailleur, it requires just more trimming, but that is easy with friction shifter
  • Mount: 28.6mm clamp or a larger clamp with a reducer ring
  • Pull: bottom-pull or dual-pull
  • Type: for triple cranksets (if you use a double front derailleur, it will work extremely badly)

FD-R3030 appears to be available as 63-66 degree chainstay angle version (not sure if you can find the needed 66-69 degree version, probably not as FD-R3030 is roadish and 66-69 degree angle is MTB-ish), for 50-teeth chainrings (way too large for your configuration) and for 45mm chainline (road triple). Any of these mismatches in the specifications can cause problems.

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  • Sorry, correction. I just double checked my parts ... a few years back my LBS replaced my crankset with the FC-M4000, but left my old derailleur on, FD-4503, which I thought they said was incompatible. My mistake. It never shifted great, but it was acceptable. So, key differences appear to be: chainstay angle of 63-66, chainline 45mm, top gear teeth: too many. Based on your research, then FD-R3030 may match, yes?
    – drfloob
    Commented Dec 11, 2021 at 19:26
  • (glad I kept my broken derailleur)
    – drfloob
    Commented Dec 11, 2021 at 19:29
  • Looks like the 50-tooth chainring max is a deal-breaker regardless. Thank you for the research here.
    – drfloob
    Commented Dec 11, 2021 at 19:46
  • Since I butchered the details in the question, I created a new one so folks don't get confused. Apologies. bicycles.stackexchange.com/questions/82066/…
    – drfloob
    Commented Dec 11, 2021 at 20:40
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You need basically any 9-speed bottom-pull or dual-pull mountain triple FD. Don't get a road derailleur.

There are many past derailleurs that would work. FD-M4000-DS6 is still in production and is the one that's made to pair with that crank, so it would work well and is cheap. Any other FD that meets the above criteria would be fine - the ones that would be a little less fine are the ones that are contoured for a 44t, but even that difference is marginal.

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  • Is the 50mm chainline going to be a problem if my setup is closer to 45?
    – drfloob
    Commented Dec 11, 2021 at 20:20
  • Since I butchered the details in the question, I created a new one so folks don't get confused. Apologies. bicycles.stackexchange.com/questions/82066/…
    – drfloob
    Commented Dec 11, 2021 at 20:40
  • There won't be a chainline issue unless potentially the shop put the fc-m4000 on a shorter spindle than the 118 spec'd one. If they did do that, yes there could be a chainline issue, although even then I doubt it. If that does come up, just get a 118 spindle at that point. Commented Dec 12, 2021 at 0:26
  • Also you can easily see whether that's going to be a problem by just measuring the chainline of the cranks. Commented Dec 12, 2021 at 6:01

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