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Discussion Starter · #1 ·
Hello, I'm new to the forum and was hoping for some help. My current frame is all XT except for my crankset, brakes, and shifters. This weekend I managed to break one shifter, bend a crankarm, and ruin one chainring... pretty much everything that I haven't already upgraded! Anyway, the problem is that my current setup is 8 speed and I really don't want to pay to upgrade everything over to 9 speed. Is it possible to use a newer XT or XTR crankset with my older 8 speed components? FWIW shimano customer service says no but my local bikestore says yes.

My current crankset is shimano STX/RC (22,32,44) and bottom bracket is a 73x110 shimano LP-26. I'd like to replace the whole thing. Trying to find old 8 spead XT/XTR is not easy, and not much cheaper than the newer hollowtech. Also, I'd go with raceface too, I just want to get this thing riding again. Any recommendations on crankset and bottom bracket would be greatly appreciated. Thanks in advance for any help and suggestions.
 

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I'm using the latest M760 XT crankset on my otherwise 8 speed drivetrain with no troubles. I did move the bb spacer to the nondriveside to maintain chainline, contrary to the instructions. I'm not sure how much you want to spend but I didn't have as much luck with the original 1999 LX 9 speed cranks. The shift pins would catch the chain in some gear combos. I haven't had this trouble with the newer cranks though.

I'm not sure how much you wanted to spend but I would highly recommend the newer integrated bb cranksets. It would be a quantum leap and drastic improvement from your STX-RC. Check eBay for the deals.
 

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Discussion Starter · #5 ·
Homebrew said:
I'm using the latest M760 XT crankset on my otherwise 8 speed drivetrain with no troubles. I did move the bb spacer to the nondriveside to maintain chainline, contrary to the instructions. I'm not sure how much you want to spend but I didn't have as much luck with the original 1999 LX 9 speed cranks. The shift pins would catch the chain in some gear combos. I haven't had this trouble with the newer cranks though.

I'm not sure how much you wanted to spend but I would highly recommend the newer integrated bb cranksets. It would be a quantum leap and drastic improvement from your STX-RC. Check eBay for the deals.
Thanks for the info. I'm curious what chain you are using, and I'm assuming you're still using an 8speed cassette? From what I can gather, the main issue with running 9speed chainrings in combo with 8speed components is that the wider 8speed chain can be sloppy due to the narrower size of the 9speed rings. I may not be fully understanding the issue here, but that is how shimano customer service desribed it to me, and also one local bike shop.

Also, I was incorrect in my first post - my current chainrings are 22,32,42 (not 44). The newer XT/XTR is all 44. Will this present a problem for my XT front derallieur or can is just be moved up slightly? Thanks again.
 

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igere said:
Thanks for the info. I'm curious what chain you are using, and I'm assuming you're still using an 8speed cassette? From what I can gather, the main issue with running 9speed chainrings in combo with 8speed components is that the wider 8speed chain can be sloppy due to the narrower size of the 9speed rings.
Lots of people run 9sp rings with 8sp drive train with no problem. I do and never noticed slop.
 

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tlg said:
Lots of people run 9sp rings with 8sp drive train with no problem. I do and never noticed slop.
Ditto. I'm using SRAM 8 speed chains (currently PC91). I've never had a problem with slop. I did burn through a Race Face middle ring in about 2 months. I just ordered a Salsa so we'll see if that lasts longer. I prefer a 34T so I haven't used the Shimano middle ring but for one ride. As for the front derailleur, you won't think you'll have any trouble with the 44T. As you said, you'll just have to slide it up a bit to clear the big ring. Other than that, you'll be fine.
 
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