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Shimano Crank Chainline changes

2K views 6 replies 5 participants last post by  crisillo 
#1 ·
I have a 2005 Shimano Saint crankset.

It has a default of a 50mm chainline, has anyone switched one of the spacers to create a chainline (47.5mm)?

I'm using the bash guard version and probably only use the six rings on the rear, thus having a smaller chainline will create a much more straight chain line.

Any experiences?
 
#3 ·
I've seen this done as well but I must worn you that the left cup does not have enought thread to securely hold it in the bike. if you take both cups and hold them against each other you will see that the LH cup threads are not as long as the RH cup. the RH cup is designed to be able to accomadate for 2 spacers but the left hand cup is not. I think this would work better with 73mm BB shells but I dont think 47.5mm Cl is needed for 73mm BB shells.
 
#4 ·
Dover said:
I've seen this done as well but I must worn you that the left cup does not have enought thread to securely hold it in the bike. if you take both cups and hold them against each other you will see that the LH cup threads are not as long as the RH cup. the RH cup is designed to be able to accomadate for 2 spacers but the left hand cup is not. I think this would work better with 73mm BB shells but I dont think 47.5mm Cl is needed for 73mm BB shells.
But on 68mm BBs, you need to use one spacer on the NDS, so, as you say, at least on 73mm BBs it can be done....even so I have read posts where pelople used the 2 spacers on the NDS on 68mm BBs........ it is good to pay attention to the threads though...
 
#5 ·
If your BB shell width is 68mm and you don't like the 50mm chainline, try 3.5mm of spacers (2.5mm + 1mm) on each side. You'll have to find two 1mm spacers from somewhere to go with the supplied 2.5mm's. The result should give a chainline of 48.5mm with a very slight offset to the non-drive side. This setup has worked well for me.
 
#6 ·
On that note, do the x-type shimano cranks with...

this wider chainline require the use of a newer front derailer? I just put on some XTm760 cranks (in place of some ISIS stylos) and the chainline/front der. were off significantly. I've made some adjustments to the derailer (XT 751 series), but it still seems a bit off. Have the newer XT760 derailers been been designed to have the new chainline as the "sweet spot"? Or do I just need to tinker a little more? Can my 751 work perfectly with the newer cranks?

thanks for any help
 
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