Sti's and mountain cranks
08-02-15, 12:38 PM
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Sti's and mountain cranks
Rebuilding my Fargo and I would like to ditch the bar ends at least for now as I have no extended tours on the horizon for awhile.
The current setup is 3x9 XT all around (the cranks, m770, are 44 32 22) with dura ace bar ends on Paul thimbles. I have a set of tiagra 3x9 shifters laying around and I'd like to find a way to make them jive with my cranks.
In my searches I came across the IRD alpina d front dérailleur, but from what I can tell it's designed for a min 46tooth chainring. Will it work with my 44? Or alternately can I replace my big chainring witha 46 to make it work? I could also swap the middle if nec. But I'd like to keep my 22on the low end. Any help would be greatly appreciated.
The current setup is 3x9 XT all around (the cranks, m770, are 44 32 22) with dura ace bar ends on Paul thimbles. I have a set of tiagra 3x9 shifters laying around and I'd like to find a way to make them jive with my cranks.
In my searches I came across the IRD alpina d front dérailleur, but from what I can tell it's designed for a min 46tooth chainring. Will it work with my 44? Or alternately can I replace my big chainring witha 46 to make it work? I could also swap the middle if nec. But I'd like to keep my 22on the low end. Any help would be greatly appreciated.
08-02-15, 02:25 PM
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Most front derailleurs will work with a big chainring tooth count a fair bit off from the manufacturer's spec, particularly in the lower direction. For example, Shimano's road front derailleurs designed for a 52T big ring also worked well with a 46T big ring RSX crank. So, the IRD should work fine with your 44T chainring, particularly if you can lower it to have the proper clearance.
08-02-15, 10:21 PM
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Many times a road STI front control is paired with a ATB der and or crank the resulting cage throws are not correct for the ring c-c spacing. We've tried a number of combos with varying results from almost spot on to a no question no go. This is why many touring bikes with ATB drive trains have bar end speced by the manufacturers. Andy
08-02-15, 11:06 PM
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Many times a road STI front control is paired with a ATB der and or crank the resulting cage throws are not correct for the ring c-c spacing. We've tried a number of combos with varying results from almost spot on to a no question no go. This is why many touring bikes with ATB drive trains have bar end speced by the manufacturers. Andy
08-03-15, 07:29 AM
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Many used to run "standard" MTB derailleurs when chainrings went "compact" with no issues. This is exactly the same case as yours (44t chainrings, 46t cage.) Your usage of a friction front shifter will make this easier
08-03-15, 07:57 AM
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Only 2 teeth off wouldn't even blip my radar.
My Rocket recumbent with a 20" rear wheel has a 60 tooth chainring with an XTR front derailleur. I was concerned about making everything work but I've had no issues whatsoever. I am using a friction shifter on the front, however.
My Rocket recumbent with a 20" rear wheel has a 60 tooth chainring with an XTR front derailleur. I was concerned about making everything work but I've had no issues whatsoever. I am using a friction shifter on the front, however.
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08-03-15, 08:04 AM
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I've converted touring bikes which come stock with bar end to STI, and the two biggest issues were FD and brakes. A road triple FD solves the shifting issue; swapping from V to canti brakes or using Travel Agents solved the brake issue.
The conversions I did involved a touring crank, though, 30, 4x, 50 rings -- no experience trying to mate road triple derailleur with offroad gearing chainring sizes. I'd give it a shot, though, and expect decent performance. Maybe add a shark tooth or other chain catcher to prevent chain drop on the inside just for extra peace of mind.
The conversions I did involved a touring crank, though, 30, 4x, 50 rings -- no experience trying to mate road triple derailleur with offroad gearing chainring sizes. I'd give it a shot, though, and expect decent performance. Maybe add a shark tooth or other chain catcher to prevent chain drop on the inside just for extra peace of mind.
