Would a double chainset with a triple shifter work?
I have a nice retro shimano 600 double chinset I would like to use with a triple shifter on a flatbar set up.
If I adjused the stop screws on the front derailleur I cant think of a reason why it wouldnt work, but maybe I am forgetting something obvious As always, thanks in advance.
Remember, a triple is only a triple by the addition of an inner ring. If you never used the inner, you'd only be using a double!
The problem might happen if your double was close ratio. I think the triple changers have a different geometry to double changers - the cage drops further as it goes inwards on a triple. I think I'm right in saying that.
The indexing is the potential issue - a triple lever has 3 settings - you only need, obviously, to use 2 of them BUT the "travel" may be slightly different.
Of course, if you can put the shifter in friction mode there's no problem (I have 3 or 4 bikes with friction bar-end levers combined with a mish-mash of doubles/triples in incompaible brands of mechs and chainsets - all works fine, you just tune the lever movement)
The indexing is different between road and MTB. You need to ensure that the mech and the levers are both the same, which is possible with flat bars. Don't worry about the rear, road and MTB rear ends have the same indexing for the same number of sprockets.
Thanks for the advice.
All the gear controls are mtb so should all work together, famous last words I know What is the best front deraileur to use, a double or a triple?
If the front shifter is MTB then you need an MTB front mech. The road one won't index properly though you might be able to bodge it using the limiter screws.
Mick has the idea. For although PW is right that road and MTB front indexing is very different, our questioner only wishes to run a double so the fact that the MTB shifter pulls and releases more cable than the road mech needs, doesn't matter at all.
You set the cable tension so that when the shifter says middle, the mech is correctly aligned with the outer ring, snug against the "high" stop screw but not pressing against it too hard. Then, when you click down the shifter to inner, the cable goes slack as the mech returns to the position set by the "low" stop screw. There will be more slack than Mr Shimano intended, but that doesn't matter at all.
The only snag is that the MTB shifter doesn't have any mech alignment trim positions. Neither do some, cheaper, road STIs, so you'll do better to choose a Sora or Tiagra front mech rather than anything fancier. Actually you're also limited to those models by the number of speeds in back, since MTBs don't do 10-speed, so your chain will necessarily be 8 or 9-speed width.
Re-reading the OP though, I see you're probably using the existing front mech. But you don't specify if this is a MTB/hybrid/trekking or a flat-bar-road style of bike, i.e. exactly what kind of front mech that is, and what size the rings are on this double chainset. It could make a difference. If it's of the MTB family: this mech won't sit nicely over an outer chainring bigger than 48T, but might nevertheless work (probably with an increased tendency of the chain to overshift into the crank arm) and will need the next ring down from that to be at least 12T smaller - than whatever size that outer ring actually is. Apart from those considerations, it'll also do a double just fine.
Chris Juden One lady owner, never raced or jumped.
/monkey.jpg)
