dreamy

I hope what I am trying to ask here make sense

My Fuji touring bike has 52/42/30 crank, Tiagra shifter + Tiagra front derailer

Today I..
1.Replaced crank with 44/32/22
2.Moved derailer further down tube
3.Tightened cable

However, now i find that the range of movement of the derailer does not go far out enough, ie I can't shift onto the large chainring, even with the adjusting screws at their far limit, but I can adjust to well inside the inner chainring. Is there some other way of adjusting this to get the derailer further out (other then pulling the crank further onto the spindle which I dont really want to do)
Should I be trying to pull the cable tighter, or is there some other adjustment on the derailer that I am missing???

Thanks

sydney

Did you replace the BB with one matched with respect to spindle length spec for the new crank? There is nothing you can do with respect to making the FD travel further. You may also find that the original road FD doesn't work well with the much smaller mtb rings.

thomson

I think Sydney is right but it is possible that your cable is so slack that the lever cannot take up the slack and shift to the larger ring. Simple test, pull the cable directly (from under the down tube) and see if it will get to the large ring. If so, your cable is too slack.

Rich vSB

I just did a similar gearing change on my bike. I have a Windsor Tourist which I think is similar to the Fuji. I used my Truvativ Touro crank and put 24-38-48 TA Specialites chainrings on in place of the stock 30-42-52. The STI Tiagra front derailleur then needed some significant adjustment. I pulled up the instructions from the Shimano web site for the Tiagra derailleur (FD4403 Technical Service Instructions).

1. I set the height for a 2mm gap to the large chainring.
2. The outer cage should be parallel to the large chainring where it contacts the chain.
3. I did the low adjustment by adjusting the low travel screw to barely clear the inside of the cage when in the small front and large rear gears. This must barely clear to get the travel I needed.
4. I attached and tensioned the cable.
5. I did the top adjustment with the chain on the large front and small rear gears.

That procedure worked well for me. Shifts fine.

You may run into issues if the change of crank altered the distance of the chainrings or because you are running a significantly smaller large ring (44 vs 52).

sydney

You run into bigger issues if the spindle is longer or shorter than what's speced for the new crank. If the spindle is so long the dreailer can't reach the big ring,no amount of fiddling or adjusting will cure it.

dreamy

Thansk for the replies. I took the crank off anmd compared it to the old one and discovered the problem. On the old crank the rings are offset much closer to the inside ie the outer chainring ia a good 1cm further out on the MTB crack than on the road crack, so there is no way the derailer will ever reach. Oh well, back to the drawing board. The only good thign is that I didn't shell out $$$ for the new crack

sydney

Get the correct spindle length for the crank you are trying to use.