San Andreas Bottom Bracket Question
Hello Mountain Cycle experts,
I'm helping a friend upgrade his MC San Andreas DHS. He tried to install a TruVativ Stylo 2.2 GXP crankset but the outboard bottom bracket pushed the chainline well outside of the usable range. The chain is at such an acute angle that the lowest cassette gears are not usable in the middle ring and the chain constantly falls inboard.
TruVativ cranksets require no BB spacers with a 73mm shell so there is no opportunity to move it inboard by rearranging spacers. Shimano and RF outboard (X-type) bottom brackets specify one spacer on the drive side for 73mm BB shells so we are wondering if they might work if this spacer is installed on the non-drive side instead.
Has anyone successfully used an outboard bearing RF or Shimano crankset on a San Andreas? Will any outboard or X-type BB work with this frame or do we need to find an ISIS solution?
Thanks for your help!
It's not the San An that's for sure.
Any standard crankset should fit. I have a LX Hollowtech II and it works fine with one spacer on the drive side.
I prefer Shimano cranks, if for no other reasons than they seem to shift best. Shimano cranks also offer an outside bearing system that can be reset as the bearings wear. IE you can reset the bearing preload, just like a standard free bearing hub, as things wear.
Some of the outside bearing systems use an ISIS style spindle with crush washers (Truvative is one of those) and they can't be reset easily to maintain the bearing's preload.
You also need a crank puller to work on those unlike other cranksets.
In any case, you shouldn't have any problems mounting a crank to a San Andreas Classic DHS. There is something else wrong with the install, or the crankset itself.
Communist Party Member Since 1917.
Thanks for your response. I am very familiar with the different types of outboard bearing bottom bracket systems. The TruVativ is clearly not compatible with the San Andreas DHS that we have here. It results in an unusable chainline. Normally, the best chainline for the middle ring is achieved in the 4th or 5th cog of the cassette. With the TruVativ, the middle ring is aligned with the 7th cog on the cassette and the chain will not even stay on the middle ring when shifted to the lowest gear on the cassette. It wants to drop down to the granny gear. Apparently the Shimano outboard bearing crankset worked for you and does not push the cranks as far outboard.
Has anyone had success with a RF X-type crankset on a San Andreas DHS?
I have Saints installed on My San An without any issue with the chain line. I did though put a Truvativ chain device on it and that was a huge PIA. Basically I had to strip the whole thing down and re-arrange the way it went together to make it work with the Shimano BB.
I think it's a Truvativ.... errr...SRAM... issue that's causing it.
Design Guy [SanAndreas 2.0, Zen II]