Shimano 10-speed road to mountain conversion.

[hypnos]

As we head into winter, I am thinking about another "upgrade" for our tandem. Our current setup is Ultegra 6700 shifters and triple drivetrain, 52-39-30 chainrings and 11-32 cassette. The 52/11,12 gears are completely useless for us. Would like to replace both cassette and chainrings. I'm considering a SRAM 12-36 cassette and Specialites TA 48-38-28 chainrings. My questions are:

Will a Shimano RD-M786-SGS paired with a Wolf Tooth Tanpan 10 work with my Ultegra 6700 shifters? The Wolf Tooth website claims compatibility but I'm curious about real world experience.

Assuming proper height adjustment, will my FD-6603 derailleur likely shift this chainring combination?

Thank you in advance.

Jeff

[Mr.Appa]

I have real world experience using 10 speed road shifters with 9 speed mountain derailleurs over 10 speed cassettes - they use the same pull but with an extra 'click' and so no weird add-ons are required.

The deore M591 would be a great candidate and should still be pretty easy to find.

As for the FD it might have some funky shifting from the small ring to the middle ring (due to the smaller radius), but for reference I use a 600-series FD on a 42/22 double with friction and it works incredibly well...so long as the FD can be lowered enough.

Good luck!

[marciero]

We also have Ultegra 6700 set up (thats the 10 speed, correct), with a 50-39-30 triple up front. We currently have 11-42 in back with a Wolf Tooth Roadlink and it works well with the exception that sometimes it is a bit slow shifting to the smallest cog, and sometimes it sort of refuses. I had to do some grinding on the wolf link but that was due to the frame- I've not had to grind wolf tooth on other bikes.

I've not used the tanpan. But it looks like it is adapting the pull ratio. I would be wary of that because of the added friction. I've accepted on our 6700 tandem that it will often take two shifts to accomplish a single shift down, because of the long cable run and sharp corners. (our 7700 tandem shifts cleanly in both directions) Id think the tanpan would make things worse. If you dont have that problem then who knows.

I realize I've not answered your question...

[marciero]

Originally Posted by Mr.Appa

As for the FD it might have some funky shifting from the small ring to the middle ring (due to the smaller radius), but for reference I use a 600-series FD on a 42/22 double with friction and it works incredibly well...so long as the FD can be lowered enough.

IME Shifting between middle and big can be more of a potential issue because of the profiling of the outer cage. The different Shimano front road triple deraileurs actually have different minimum tooth difference requiremts. With our 50-39 the Shimano 6700 front der. rubbed ever so slightly in the big ring. I swapped that for a 105 and it is fine.

[MikeD]

I would definitely go with a mountain bike 9S rear derailleur. Not sure about the front. You might have to try and see. Have you considered going to bar end shifters? Then you could get a front derailleur that better fits the profile of the chainrings you want.

On my touring/gravel bike, I've got 10S 22x32x44 crank, 11x32 cassette with a Deore 9s derailleur, bar end shifters, v brakes, tektro v brake levers. I'm very happy with it.

[robt57]

i dont beleive you'll need the RD wolf/tanspam or anything.

That DR prob do a 40t top cog.. And capacity is 43. Your example is one tooth over capacity with chain rings you've sited.

[2metalhips]

I've been using a Tanpan with a 10s Ultegra shifter with an XT MTB rd, 11-36 XT cassette. It works fine. Had it installed by a mechanic.

[lorenbike]

I've used 10speed shimano brifters for years with a 9spd deore rear mech and 10spd 11-36t cassette. Shifts perfectly fine and no need for a longer b screw or wolftooth extender.

[MikeD]

Originally Posted by robt57

i dont beleive you'll need the RD wolf/tanspam or anything.

That DR prob do a 40t top cog.. And capacity is 43. Your example is one tooth over capacity with chain rings you've sited.

What rear derailleur are you referring to, the original triple or the 10s XT one that was referenced?

[NHAero]

I apologize if I misunderstand your question. I have used both 5703 triple shifters and 10 speed Dura Ace bar end shifters to shifter a Shimano RD-M952 SGS XTR rear derailleur without any intervening hardware or road links, etc. That's what is on my Bob Jackson now and has been for quite some time.

[dddd]

Originally Posted by marciero

IME Shifting between middle and big can be more of a potential issue because of the profiling of the outer cage. The different Shimano front road triple deraileurs actually have different minimum tooth difference requiremts. With our 50-39 the Shimano 6700 front der. rubbed ever so slightly in the big ring. I swapped that for a 105 and it is fine.

This is the exact issue.

You will need to use a road front derailer with your 6700 or any road-STI levers, because of the cable pull.
The 48t large ring should be fine with the 6700 FD.

The critical issue marciero addresses is that the tooth-count difference between the two bigger rings needs to stay the same with very little room for deviation.
The small-to-mid chanring size difference on the other hand can be quite a bit larger in my experience with little consequence as to shifting.

A 9s Shimano MTB rear derailer with SGS cage will work perfectly with your shifters and will likely handle your gearing range, especially if you can avoid use of the small-small sprocket combination.

[NHAero]

Originally Posted by dddd

This is the exact issue.

You will need to use a road front derailer with your 6700 or any road-STI levers, because of the cable pull.
The 48t large ring should be fine with the 6700 FD.

The critical issue marciero addresses is that the tooth-count difference between the two bigger rings needs to stay the same with very little room for deviation.
The small-to-mid chanring size difference on the other hand can be quite a bit larger in my experience with little consequence as to shifting.

A 9s Shimano MTB rear derailer with SGS cage will work perfectly with your shifters and will likely handle your gearing range, especially if you can avoid use of the small-small sprocket combination.

Indeed. I had to use a 5700 FD to work with the 5703 shifter. Chainrings are 48-36-24 so only one tooth difference from the 52-39 you have.