OldandSurly

I’ve got a Surly LHT 60cm frame and have a Shimano Deore FC-T6010,10 speed, 48/36/26, 175mm crankset and a Deore RD-T6000-SGS, 10 Speed, 63/66 drop angle, duel pull rear derailleur. The cassette is 11- 34t, and this stuff has a 50 mm chain line. I’m looking for a compatible front derailleur (bottom pull based on Surly specs and probably down swing) e.g., Shimano FD-T6000-H3; -T8000-3; -T781-3; -T671-3; -T611-3 or something else that will work. Hopefully, from the US since I’m tired of paying an arm and a leg for shipping from Asia. I haven’t found any US suppliers online.

Not having done this before, I don’t know the compatibility of similar Shimano MTB components (seems like max cogs are too small and chain stay angle is off i.e, 66/69) or Shimano road bike components e.g., Tiagra 4703 has 45mm chain line.

Any suggestions? (I don’t want to start over with the crankset, RD, and cassette)

shelbyfv

What shifters are you using?

70sSanO

Your specs are for Shimano Touring componenets which were never available in the US. My brother had to go to a steeper road chanistay FD and I think he had to go overseas to get one. I think he is running a 42t or 44t so he was pretty much stuck.

I am far from anyone knowledgeable on chainstay angles and have spent my life being oblivious to them as I have used older MTB FD on road bikes over the years.

That said, you need to see if a 63-66 MTB FD will work, since you are also looking for a 50mm chainline. Because you are running a larger chainring, 48t, the curvature of a MTB FD cage might be more of an issue than chainstay angle; running it that high probably won't come close the hitting it.

I don't know what shifters you are running, but since you have mentioned both road and mountain FD's, I'm assuming the front is friction. If that is the case, maybe an older FD from the 90's/2000's might work. I'm running an M-900 on my road bike that is compatible with 46t/48t. I think an FD-M761 has a 48t max.

The other alternative is to continue to buy a Shimano Touring FD from overseas and keep riding, maybe buy 2 since I think they have been discontinued. Considering there was a time when you couldn't get non-US parts, high price for something you can't easily get is not really that high.

John

OldandSurly

I was thinking about a friction set up but hadn’t picked anything yet since my understanding those are pretty flexible.

OldandSurly

Thanks John. I’ll check out your FD-M761 suggestion.

shelbyfv

If you go friction for the shifter you should be able to find something. I had one of the Trekking compact triples and used a 9 speed road triple FD, maybe 105 or Ultegra, with 9 speed bar ends. I didn't consider chainline so it may have been all wrong. IIRC, it worked fine.

HillRider

Drop bars or flat bars? If drop bars then bar end shifters or, better yet, Gevenalle brake lever mounted shifters, offer indexed rear shifting and friction front shifting making your choice of front derailleur far less critical.

OldandSurly

Drop bars is what I have now so I’ll check out the Gevenalle option. I know friction has advantages especially in out of the way places but, I doubt I’ll be spending much time outside North America. Thanks for the suggestion!!

shelbyfv

It looks like for drop bars the Gevenalle GX is about your only choice. You'll have friction for the front, with many FD options, and 10 speed MTB for the rear. I think that's what the RD T6000 needs but best to confirm. I don't think there is any other drop bar set up that will give you both. There are some pulley kludges for road brifters and MTB rears but you would still have the front to worry about.

HillRider

Friction front shifting has its advantages right here in North America too. As noted, the choice of a front derailleurs becomes far less critical and you can trim the FD in any possible gear, including fully cross chained. It's very versatile and shifting is just as accurate and fast as indexed front shifting and that's particularly true with a double crankset.

cpach

Maybe try Altus FD-M371 . It's 9 speed, but for front derailleurs the difference is extremely minimal, and it is designed around a 48t chainring and 50mm chainline. You would have to friction shift this.

For indexing, the best bet is an IRD Alpina-d, which is also designed around a 48t large chainring.