Originally Posted by
Leisesturm
Considering changing our FSA triple rings from the 55/42/32 to a 53/39/30 or 28 to have a better climbing range and increase the cadence. Bike has ultegra brifters, ultegra front derailleur and current cassette is an XT 11-34 9 speed. Rear derailleur is a long cage XTR.
52/42/30 was the stock triple on our road tandem. 11-27 9-speed cassette. Since I was going through the hassle of changing rings I figured I may as well make it count. Why bother go from 30 to 28 or even 26? I went to 24T for the granny and have not regretted it. Granted with a 34T its less of a must have, but you might take the opportunity to tighten up the cassette spacing for smaller steps.
I can find 10 speed rings (albeit double crank type) much easier and cheaper than 9 speeds. First, will 10 speed rings for a double crank work and should I run a 9 speed chain or 10 with the 9 speed cassette?
Crank bolt circle spacing determines what will or will not work. I think the bolt circles on our Truvativ triple were 110mm for the two big rings and 74mm for the granny. Double cranks only have the one bolt circle and it may, or may not, be compatible with what you want to accomplish.
Does the middle need to be ramped and pinned? 90% of our riding is either in the middle or large ring so if it takes a bit to get it from the little to the middle, I'm not too worried, unless it just won't work.
Ramps and pins are the status quo these days. I am not sure you can even find middle and big rings without ramps and pins.
If you're using double rings for the big and middle, the middle is not ramped and pinned for the up shift from the small.
Our Co-Motion is set up this way with Praxis 53-39 double rings and a Salsa 26 for the small.
The shift from the small to middle ring can be slow, but we rarely use the small ring. The trade off for the better shifting from middle to big with the Praxis rings is worth the poor shifting from small to
Middle in our case