cbfight

For starters, I am trying to find money for a nice compact double crankset

But until then I am trying to make do. I recently acquired a frame (Giant OCR2) with braze on FD mounts. Only problem is it came with triple cranks (truvativ touro 30-42-52).

I am trying to set this up with Shimano Sora 8 speed STI brifters, but I can't get the tension right. I'm using Performance Bike's Forte 10 speed FD, which supposedly works with triples according to one of the mechs there. Only problem is when I set it up to shift adequately between the rings, the tension is so high on the large outer chain ring that I have had to dismantle my brifter twice now due to jamming issues. To give an idea: my thumb actually hurts from trying to downshift from the large chain ring.

Is there any hope in this situation, or should I just stop trying and find a double crankset? (I want to go to a double anyway, this triple business is pointless in my flat city)

rogerstg

It sounds like a brifter issue - not a FD problem. But it could be as simple as having set the high limit screw a little to tight so that the final click of the shift happens when pushed up against the limit stop, causing excess tension on the shifter.

joejack951

First off, if you want to make a temporary double out of your triple, just remove the inner chainring, or set up the derailler such that the little ring is locked out. Problem solved cheaply.

Second, the only reason downshifting would ever get to the point of being that hard is if you had your high stop screw set too far in. You are hitting the mechanical stop which is why it's so hard to get the shift to complete. By forcing the shift to complete, you are risking breaking your shifter. How did you go about setting up your front derailler?

|3iker

Funny to see this post as I have just converted my triple to a double 2-days ago. Similar set up with Sora STI up front.
I have to adjust the H limit screw. Instead, I screwed down the L limit to lock out the FD from dropping the chain into the now absent granny ring. It took me 5 minutes. Shifts b/t the large and mid chain rings fine.
But at your current situation, it may be worthwhile to start from scratch. Bicycletutor.com has a good video on FD adjustments.

IIRC, to go with compact crankset, you would need to replace the BB as well. C I think the reason is the spindle is a bit longer to accommodate triple chainring. orrect me if I am mistaken here.

joejack951

That is usually true. However, most compacts being sold now are integrated spindle cranks which use external bearing bottom bracket. A new bottom bracket would be needed regardless (assuming current crank is not external bearing). If it is external bearing (doubtful given the chainrings), there is a good chance of finding a compact compatible with the existing bearings.