[Colin]

Hi,

Does anyone know why the newer ('03 & '04) Shimano LX and XT cranks have different spindle width recommendations? For XT Shimano recommends 113/118mm, but for LX they recommend 121/126mm. I've used LX Hollowtech cranks in the past, but always with either a 113 or 118mm spindle.

Why the switch to the wider bottom brackets? And just for LX? I thought the cranks were the same, with XT getting better chainrings. Reason I ask, Shimano now makes an LX crank with 48-36-26t gearing -- which, minus the granny, would be perfect for a 'cross bike.

I'd really appreciate any info or insight. Thanks!

 

[Repack]

Could it be b/c of Hollowtech II? The outboard bearing dealie?

 

[NastySid]

I suspect the offset on the newer LX is a bit deeper..

The deeper the offset the longer the bb axle has to be.

But.. As the BB is a ware 'n tare product you could just get a new one.

The old BB can you use as a lure if you decide to sell the old crank.

 

[JoeRay]

Shimano changed the width of the bb's for the '03 LT and XT cranks when they went from the old stright edge style to that teardropish shape. The reason at the time I was told was that the '03 and later cranks had a greater offset toward the frame of the bike and needed a slightly longer BB.

Its also something to keep in mind if you need to tweak chain line. '02 cranks on an '03 BB length gives a pretty wide chain line at the front.

The '04 XT is hollotech two and as such doesn't need a bb, think new XTR. But yes it does have a 'touring' option with the bigger rings. not sure about '04 LX need to check my shimano manual.