(Originally posted this to E-Bike Technical, but realized this is probably a better spot for it)
I'm trying my first build of a Gravity Deadeye Monster with a BBSHD and am having some trouble determining if a 100mm BBSHD will fit on the frame. I'm based in the US and buying from em3ev, so returns aren't really feasible, so I want to make sure I get this right the first time.
Despite bikesdirect stating that the 2018 Gravity Deadeye Monster has a 102.5mm BB, I measured it to be 100mm: pic
(the caliper is upside-down- that's a 99, not a 66
). My only worry is that the chainstay might get in the way of the motor. Recommended by this article
, I measured 2.75in from the middle of the bottom bracket to get the width of the motor (side view
, top-down view
), and saw that I think I need about 5mm of space on the drive side to fit the motor next to the chainstay. From this article
, Karl mentions that you can fit a bottom bracket that is 5mm smaller than the space needed, but that's right on the edge for my setup, so I'm a little nervous about pulling the trigger.
If nothing else, if I got the 100mm BBSHD and it was a little too short, I could probably grind away a little of the BB from the non-drive side and squeeze it on. I've never used one before though, so I'd really rather avoid that if possible. I've also read from spinningmagnets and elsewhere that a 120mm BBSHD works fine on a 100mm BB, so 120mm is probably the safer play if I wanted to be risk-averse. I just don't want to add BB spacers if I don't need to. Does anyone have any insight here?