Will a Truvativ Triple Crank (GXP) work with my SRAM Red GXP Bottom Bracket?
I have a several questions regarding bottom brackets and cranks. My bicycle is equipped with SRAM Red with GXP bottom bracket. I am planning on participating in a hillcimb event, and I'm definitely a spinner, so I know I want to equip with a triple for the event.
So here are my questions:
1. What is the difference between the GXP double and triple bottom bracket spacing? Is the difference in the bottom bracket or the cranks themselves?
2. If I switch to a triple Truvativ mountain bike crank, can I keep my current GXP bottom bracket?
3. If I switch to a triple Truvative mountain bike crank, do I need spacers to be able to use them with my SRAM Red GXP bottom bracket? Do the spacers need to go on both sides? Do the spacers go between the bottom bracket and the crank, or the bottom bracket and the frame?
4. Can I keep my left SRAM red crankarm and use it with a truvativ GXP right crankarm (to save a minute amount of weight)? Are the splines the same for the left crankarm?
5. If I get a triple mountain bike crank, and I don't care at all about using the outer chainring, can I remove it and use the two inner chainrings with my SRAM Red front derailleur (i.e. will the spacing allow my SRAM Red front derailleur shift between the inner and middle chainring of the triple)? I know I would need to lower my front derailleur to work with the 22/32 tooth arrangement.
The BBs should be compatible, no guarantees about the splines, double/triple chainline is fixed by the crank. For the MTB cranks, you may need to put spacers under the BB cups. The spacers go between the BB cups and the frame.