Originally Posted by
Bill Kapaun
It's unlikely your RDER is rated for 34T. You can usually fudge 2, but 4 gets more unlikely.
A rule of the thumb is you need 1/2 as many links as the increase in cog/ring size.
A 30>34 is 4T, so you'll need 2T more, or 1 link set.
IF your RDER is stretched to the max and still doesn't reach the big ring, I'd PROBABLY add 2", or 2 link sets.
I think the RDER is rated for 34t cassette
but not 39t ___ Crank (50-34) + cassette (34-11) = 39
I think it was rated for a 34 cog & 37t
But then again some say the total has some fudge factor
Edit: You're right
Saw somewhere rated for 34 cassette but now everything i find is 32
Read it was tested with a 50/34 & 11-32. hoping it works, just need a little wiggle room.
Shimano web site -> 32 max 41 total:
http://bike.shimano.com/content/sac-...d-3500-gs.html