rotor 3df drive side issues

[TomColnago]

Just been cleaning my bike and noticed that the crank arms in two positions are slightly pushing the chain off the chainring. i am wondering if anyone else has had this issue?

as seen in the pictures the chain isn't sitting on the chainring correctly

[mike]

Are the cups installed in a chased bb?

[TomColnago]

thanks for the reply mike i meant to put crank spider... doh best edit my post

[mattr]

What BCD is the crank and what size chainrings?
If its 38 tooth and 130 or 34 (?) and 110 it might just be that the spider is very very slightly oversize, in exactly the wrong place, so it lifts the chain slightly.

[TomColnago]

What BCD is the crank and what size chainrings?
If its 38 tooth and 130 or 34 (?) and 110 it might just be that the spider is very very slightly oversize, in exactly the wrong place, so it lifts the chain slightly.

the crank is 130bcd and im running 53/39 q rings, i think thats whats happening. maybe a dremel will sort it?

[mattr]

Ah, Q-Ring, yes, thats it then. The low points on the ring coincide with the high points on the spider arms.
Just touching the end of the spider with a dremel will sort the clearance issue, i'd recommend a polish afterwards to take any machining/dremelling marks out. From what i can remember, there is plenty of material on those cranks so it's unlikely to make any noticeable difference.

Isn't the "standard" 130 BCD Q-Ring pairing 40/53? Most of the guys i know running them are on 40 or 42 IIRC.

[TomColnago]

Ah, Q-Ring, yes, thats it then. The low points on the ring coincide with the high points on the spider arms.
Just touching the end of the spider with a dremel will sort the clearance issue, i'd recommend a polish afterwards to take any machining/dremelling marks out. From what i can remember, there is plenty of material on those cranks so it's unlikely to make any noticeable difference.

Isn't the "standard" 130 BCD Q-Ring pairing 40/53? Most of the guys i know running them are on 40 or 42 IIRC.

with my old campy crank i was running 53/40 but when i upgraded to a rotor crank they recommended 53/39 maybe its the new standard?

i'll take the dremel to it later and hopefully solve the issue. thanks for the advice