Originally Posted by
cyccommute
True.
The problems with the derailer happens In theory, perhaps. In practice it isn’t an issue. I’ve been running a mountain crank with a road derailer for 15 to 20 years without any kind of shifting issues. The cable has to be kept tight because the road derailer is at the end of travel and the crank has to be moved inboard by 2 to 2.5mm for the road front derailer to get the range needed but it’s fairly easy to set up. The one caveat that I would include is that the less expensive Shimano road derailers work better for this application than the higher end ones. 105 and higher have much more sculpting of the plates and are narrower than Tiagra and below. 105 and higher can be made to work but it is very fiddly to set up. Cheaper Shimano derailers are more forgiving.
I’m not familiar with
Tourney STI shifters (didn’t even know they made them until now) but the bike that Bjorneas is using is already set up with the proper front derailer to fit the Tourney crank which, as far as I can tell, is a mountain bike crank to begin with. He’s only changing out the crank which should be just a straight up change.
Yes, it would.
the thing to remember is that not all people possess endless patience with mechanical things, time to fiddle with balky shifting, or our lifetimes of accumulated mechanical skills and related knowledge..
tourney groups/parts are available in mostly MTB style,.... but also in road style.. rare, but still out there.
oldbobcat mentioned the road group.
i run up against the "cage tail" issue frequently in my shop... add a badly worn out chain, and low to mid shifts may not happen at all.
chains sometimes drag on the tail bridge too.... smaller tooth counts equal more diameter change on the MTB 42-32-22 sets, per step....
seat post and chain stay angle differences between Road frames and MTB frames can also cause issues, when swapping FDs. the bb sets lower in relation to the axles, tire clearance requirements are different..... and the axle is farther away from the BB on a 700c road frame, compared to a 26" mtb.... usually.